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Epson MFJ-1278B User's Manual

1. PART MODE PART MODE H L PART MODE H L CALSET FREQ CALSET FREQ CALSET DEMODULATOR MODULATOR R113 HP R106 HPL R77 VPH CALSET 32 2125 247 2200 240 R114 VB R122 VBL R105 HPH CALSET 32 2125 247 2295 229 ROM R78 VPL R119 VBH 8 1200 438 2975 177 RUS CW R138 SSTVH R129 MCW NO CALSET SEE NOTE BELOW 1500 350 700 751 SEE NOTE NOTE Separate procedure required to do alignment of CW demodulator center frequency NOTE MCW modulator tone is also used for SSTV transmission However CW receive through a narrow filter for HF CW operation will require the CW demodulator center MFJ 1278B MULTI MODE OPERATIONAL COMMANDS RVFALWAY ON OFF Mode Mailbox Default ON Parameters ON Initiates forwards and reverse forwards of all forwardable messages OFF Mailbox ignores Forward and NODEforw commands The setting of RVFALWAY s controls whether the TNC will initiate forward events via the FORWARD and NODEFORW commands in the absence of forwardable messages If OFF the TNC will ignore FORWARD and NODEFORW commands entered in the absence of forwardable messages When ON the TNC runs the event for the sole purpose of eliciting reverse forwardable messages from the remote BBS RXINVERT ON OFF Mode RTTY ASCII Default OFF Setting the RXINVERT command to ON causes the MFJ 1278B to change it s decoding scheme for Baudot RTTY and ASCII signals The MFJ 1278B changes the d
2. gt l than n than n than n Connect callsign Mode Pactor Immediate Command Parameter callsign where callsign is the amateur callsign of the person you want to connect with CONNECT is an immediate command It initiates a connect request to the MFJ 1278B with CALL using regular timing The CONNECT command should be used when initiating Sak The ds Ne ee eS MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CONPERM ON OFF Mode Packet Default OFF Parameters ON The current connection on the current stream will not be allowed to enter the disconnected state OFF Thecurrent stream may be connected to and disconnected from other stations This command when switched ON forces the MFJ 1278B to always maintain the current connection even when frames to the other station exceed RETRY attempts to get an acknowledgment RESTART and power off on cycling will not affect this connected state This command only takes effect when a connection is established It functions on a stream by stream basis when multiple connections are allowed It is useful for certain networking applications meteor scatter and other noisy less reliable links while still allowing connections on other streams to operate normally automatic disconnect based on RETRY etc MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CMSG ON OFF Mode Packet Default OFF Parameters ON A text message is sent as the first packet after a connection i
3. R GEN 106 Printer Connection 12 tete eit cetero tee eei eerte necs 106 Receiving SSTV Pictures 107 SSTV Printing to the Printer eene eene neon beer 107 Printing SSTV Pictures to the 110 Saving SSTV Pictures to Disk essseeeeeeeeee nennen 111 Terminating SSTV Printing essere eene 111 Transmitting SST V Pictures cse eet pete iere ig 111 Creating SSTV Pictures for Transmitting essere 112 ADVANCED PACKET nennen rennen ens 114 SPECIAL CHARACTERS uh Sonia ie ek a ede eid Bolg otal 114 PACKET OPERATING MODES cinese Date torii tiens 115 Command Mode eet eet dete oer de eee 115 Entering Data Transfer Modes sse eene 116 Converse ee e eec er Uere IHRER 117 Transp rent Mode enero tee pe eret iret eri r 118 FLOW CONTROLE nU URDU n IE I 119 XON XOFF Flow nenne trennen 120 Hardware Flow Control eese nennen nennen nennen 121 Type in Flow Control 5n nee poete cbe p RE Re trate 121 DETAILED VHF PACKET OPERATION eene eene eene 121 Ctatian Tdantifinntian 191 MFJ 1278B MULTI MODE TABLE OF CONTENTS Packet Timing iei ette o eee eiie evt enden 125 Radio Baud R te ceo te EREMO 126 Special Protocol Timing 00 eee ee cee
4. 149 What to Expect tec Herd D PU DEED eripere atte 149 Packet Picture Transfer s oir pti beo d eut 151 Printing Packet Pictures thru Built in Printer Port sess 151 Using PKTPIX ae REIS 151 Packet Picture transfer to the computer screen sseeeeene 151 DETAILED HF PACKET OPERATION esee nennen 152 Radio Setup for HF Packet Operation essere 152 Operating HF Packet ete eene ee esee erts 155 MFJ 1278B KISS MODE TNC 2 MODE HOST MODE eee 161 KISS INTEREACE POR TCP IP tette RR UR Une RD S 161 COMMAND PREFACE e nete tte DEI eire eode 163 ENTERING COMMANDS eese nennen nennen R nne ener trennen 163 Command list n eo ETT 164 COMMAND NAME 37 eed pope ec pre e edi efie eee need 164 Mafanlta MFJ 1278B MULTI MODE TABLE OF CONTENTS Link St tus Messages ere eee tiii cte ds 302 MFJ 1278B SPECIFICATIONS eese roe een rennen eene enne nene 305 GENERAL DESCRIPTION 306 DETAILED CIRCUIT DESCRIPTION sneri iiss isre ar i ir ees nene 307 E E e ate 307 Dividers and Baud rate Generator esssseseeeeeeeeeeee nennen 307 CPU Complex tese ee i uper tme 308 Serial Interface otn pe oet ete re RERO EE 308 Watch dog DImer 44 cod iere rider eite ente 309 Mod emi d
5. 12 COMPUTER BAUD RATE netter Ru 13 Autobaud Ive eMe eM ID 13 Changing Terminal Baud Rate cece nennen eene 14 VERIFYING SERIAL PORT OPERATION essere 15 PARALLEL PRINTER epi reete dp eene t eee ete des 16 Printer Port tet teret erro eU I ete pere ede 16 Printer Consideration oe eee een eni S H etn 17 Printer Port Test ce teme ridet te hero eE EE Renten ipee ore estes 17 RADIOINTEREACING ono note tte ton RE beak sa oop ena eet eee 18 MFJ 1278B Radio Ports essent entren 18 RADIO PORTS CONNECTION ea nren eene enne 19 HANDHELD RADIO CONNECTION rennen ee 20 RADIO INTERFACING METHODS eee enne nre 21 Method 1 Direct Connection to Microphone and 21 Transmit Audio Level Adjustment for Method I Interface 21 Setting the Receiver Audio Input Level eese 22 MFJ 1278B MULTI MODE TABLE OF CONTENTS FSK CONNECTION er bet e tee e dete ee 29 GETTING STARTED ipe e PER ERE RETI guid onions e ORE 30 First Steps ue eed eeu RU 30 Basic Commands PEPPER EE rE T 30 SERIAL PORT CONFIGURATION airne e eaaa E een nen ren eene 31 Parity and Word Length orestis ieioea ie ener 32 eek te radi ee eee e 32 New Line
6. zu MFJ 1278B MULTI MODE APPENDIX JUMPER FUNCTIONS Table G 1 Jumper Function Cont JMPF ON default Disable Low Tone RTTY Demod Enable Low Tone RTTY Demod JMPG ON default Disable Low Tone RTTY Mod Enable Low Tone RTTY Mod JMPH ON default Disable Low Tone RTTY Mod Enable Low Tone RTTY Mod JMPJ TX audio has flat response OFF default TX audio 6db oct pre emphasized JMPK TX audio loopback to PTT OFF default for Radio Port 2 JMPL TX audio loopback to PTT OFF default for Radio Port 1 esl zu Z Z Z JMPR ON Analog audio loopback JMPZ When JMP23 is shorted it will RESET the MFJ 1278B This means that all parameters will be reset to the default values This is the same as removing the bbRAM battery except it is much quicker DO NOT SHORT THIS JUMPER MORE THAN A COUPLE OF SECONDS OTHERWISE BATTERY DAMAGE COULD RESULT g3 MFJ offers an optional Real time clock module MFJ 43 that can be installed on the MFJ 1278B mother board This clock keep the MFJ 1278B clock running all the time You will not have to reset the clock everytime you turn the MFJ 1278B on When these jumpers JMP E JMP F JMP JMP are removed the MFJ 1278B will operate RTTY using the European tone standard when the VB modem is selected four jumpers must be removed in order to operate RTT using the European tone standard MFJ 1278B MULTI MODE APP
7. NOTE Separate procedure required to do alignment of CW demodulator center frequency NOTE CW receive through a narrow filter for HF CW oneration will reauire the CW MFJ 1278B MULTI MODE APPENDIX B MODEM CALIBRATION Calset Values for Various Modulator Tone Frequencies CALSET Modem Remarks 2125 R106 HF Packet amp RTTY O Fe 2200 Hz 2295 R105 170 Hz shift 1300 404 R78 Packet 1700 Hz 800 Hz shift CCITT V 23 std preferable for HF 1200 baud works well on VHF FM too 2100 R 1200 438 78 Packet 1000 Hz shift standard Too wide to fit comfortably through SSB filters for linear mode 1200 baud use 2200 240 2125 R122 VHFRTTY Fe 2550 Hz 2975 R119 50 Hz shift R139 R139 R139 R139 751 R139 CW 55 ips alallala oJ lon 750 715 800 825 700 HF RTTY ASCI AMTOR 2220 Hz 850 Hz shift gt N N o Ax Au aS SJN t Low Tone RTTY European Standard 170Hz shift Fc 1360Hz es ER MFJ 1278B MULTI MODE APPENDIX B MODEM CALIBRATION CW MODEM TUNE UP PROCEDURE The CW modem in the MFJ 1278B is fundamentally different from the other modems It is NOT an AFSK modem It sends and receives only tone For this reason it requires a different alignment procedure than the others NOTE If the Modulator and Demodulator are not EXACTLY on the same frequency for BOTH stations involved in FM MCW operations
8. 86 88 88 89 9 9 MFJ 1278B MULTI MODE APPENDIX COMMAND SUMMARY PACTIME Packet Determines the 6 92 length of time between transmit and receive PARITY Packet Sets the parity mode for terminal or computer data transfer h Selects the ASCH character used for the pass input editing character T modes received with invalid CRC fields FAX SSTV pictures Packet Allows the MFJ 1278B to print packet 6 97 pictures to the built in printer port PRINTGRA ONIOFF on FAX SSTV Determines whether the MFJ 1278B will 6 98 print the graphics to the printer or the terminal screen parallel printer port PROFMARS 1 RTTY ASCII Invokes pre set commands for MARS operation PTOver I command Pactor Designates the Pactor changeover character Pactor Same as issuing the U1 unproto 6 100 command oT fe ELE AMTOR Used to break a link in AMTOR 6 100 AMTOR Is the equivalent to QRT 6 100 1 Allows the user to select the radio port on 6 100 the MFJ 1278 I PTS QR PRINTTES TSe DOMCW ONIOFF Allows the used of the random code 6 101 generator Sux 0 RTTY ASCII you are currently connected a station editing character functions remotely stored parameters RESET T a Resets all parameters to their default values and reinitiates the unit RESPTIME n Packet Sets a minimum delay that is imposed on 6 103 MFJ 1278B MULTI MODE APPENDI
9. sees 325 Symptom The MFJ 1278B appears to be signing on but only gibberish is printed eene ens 326 Symptom The MFJ 1278B signs on OK but won t accept commands 326 Symptom The MFJ 1278B appears to have lock up i e not responding to any Commands sedente tolo eoe 326 EXPLANATION OF PROTOCOL eese nennen nenne ennt rennen 327 Physical Eayer idee aeger eed p tbe bee 327 Data Link Layer sss iiie tetto eec eunhept een 327 HDEC FRAMBS 2 onere b eere tefie e e terres 328 AVY AKTIT CVET TWA 2520 MFJ 1278B MULTI MODE TABLE OF CONTENTS Comprehensive Alignment Procedure sse een 340 Set Modulator Tones Using Built in Calibration Software 340 Demodulator Center Frequency Alignment eee 341 Tuning Indicator Alignment eese enne nenne 342 CW MODEM TUNE UP PROCEDURE eere 346 Detailed CW Demodulator Alignment Procedure sees 347 AUDIO OUTPUT CALIBRATION eese rene eene eerte nenne 350 Audio Output Level Adjustment Procedure sse 350 RADIO ALIGNMENT ae ntt et teret dne ede eo er ederet 352 FIRST METHOD NOISE AVERAGE FREQUENCY eee 352 SECOND METHOD FILTER SKIRT AVERAGE FREQUENCY
10. b Messages can also be read individually by the slot number This is good for reading other messages like bulletins or messages addressed to ALL In order do an individual read type R ENTER Where is the slot number of the message that you wish to read c The Mailbox will respond with the message from the slot specified messages read will be in the following format Slot tm To From Subject This is an example of a message from the Mailbox Where Sloti column 15 the number of the slot which the messages in The lower case t is the Type Flag block The lower case m is the Message Flag block The To column will MFJ 1278B MULTI MODE BASIC OPERATION is proper Pactor etiquette If you access your Mailbox via the SYsop command then you must issue a CTRL C to exit the Mailbox and return to command mode The SYSOP mode is accessed through the Packet mailbox as mentioned earlier in this section The command prompt will indicate the stream you are on The command prompt may look like this lAcmd where indicates that you are on packet stream To re enter the Pactor mailbox you would type the following from the cmd prompt PACTOR ENTER This is the only way the remote users can access your Mailbox Mailbox Messages You have new mail Upon accessing the mailbox this message will appear if there are any new messages are addressed following the last time you logged into the mailbox You have mail
11. HISCALL YOURCALL HISCALL YOURCALL HISCALL For as many CR s as you typed Your friend will have little trouble finding you and tuning you in for the QSO amp Aftar tha 1079D finichac can ding tha ctrina anf COV naclata liotan far K ta MFJ 1278B MULTI MODE ADVANCED OPERATION The above method of calling CQ is NOT appropriate for use on one of the crowded calling frequencies There everyone is already tuned more or less to the same frequency To call CQ on one of the calling frequencies do the following Find the center of the channel by tuning the radio so that the tuning indicator is centered on most of the signals 2 sure your UNProto field is set to CQ 3 Enter converse mode 4 Occasionally strike a CR 2 a minute or so if DCD lets your packets clear the channel that fast and wait for the MFJ 1278B to get an opportunity to squeeze the packet into the activity on the channel Allow some time after your packet has been sent for someone to attempt a connect with you and then send another CQ packet by typing a CR 5 If when someone connects immediately negotiate a QSY to a clear channel Then call him on the new frequency as outlined above in the clear channel CQ procedure for a scheduled contact Please use care in selecting the QSO frequency so as to avoid unnecessary interference to other amateur services As in all amateur communication modes it is polite to listen
12. If you are using one of the MFJ Starter Packs you should use the cable provided to connect the MFJ 1278B to your computer Follow the instruction manual provided with the Starter Pack to operate the terminal program and to connect the MFJ 1278B to your computer When finished with installation of the MFJ 1278B proceed to the Computer Baud Rate for further information about TNC installation The Computer Baud Rate section in this chapter will continue to explain installation of the MFJ 1278B Computer Interface without MFJ Starter Pack If you are not using an MFJ Starter Pack you should follow the instructions in this chapter for computer interfacing SERIAL PORT SIGNALS The serial port connector is on the rear panel your MFJ 1278B There are several signals available at this connector labeled RS 232 SERIAL You will not need all of these serial port signals for normal operation For some special applications such as binary file transfers or some Bulletin Board operations you may want to use more of them In that case see MFJ 1278B Serial Port Pin Functions in this chapter In Table 2 1 the user will see a list of the serial port pins that must be used between the MFJ 1278B and the computer The pins listed are required by the MFJ 1278B for normal operation Note that the MFJ 1278B connects to a computer exactly as if the MFJ 1278B were a standard RS 232C modem If you have successfully used your computer with a telephone modem
13. Mailbox Ready nn free n Mailbox B E H elp J K L M R S T NOTE The nn free indicates the amount of RAM space available for messages in the Mailbox to which the remote user is connected to The nn will be no higher than 65K if a 512K or a 128K Mailbox is in operation If the Mailbox is 32K then nn will be 32K NOTE The n indicates the memory bank being used for the Mailbox Please refer to the explanation of the M command for the Mailbox in this section Now at this point all of the Mailbox are available to you The remote user may then type M to switch the memory bank of the Mailbox K to kill a message L to list all messages R to read the messages S to send a message B to logout and disconnect from the Mailbox or H for the HELP menu 3 To send a message the S or the SP commands must be used It must be used in conjunction with a callsign as in the examples below S KB5JNZ lt CR gt this will send an ordinary message to the callsign KB5JNZ SP KB5JNZ lt gt this will send a private message to the callsign KB5JNZ The Mailbox will respond with Title The remote user will enter the message subject or title at cursor prompt then press the MFJ 1278B MULTI MODE ADVANCED OPERATION The Mailbox will respond with Send msg Control Z or EX to end The remote user will then enter the message at the cursor prompt If you are using a 512K or 128K Mailbox then users can upload disk files int
14. Other Computers with Nonstandard Serial Ports Computers with non standard serial ports must meet the following conditions First the signal levels should be RS 232C compatible The MFJ 1278B requires that the voltage levels sent from the computer be greater than about 3 volts in one state and less than about 1 volt in the other state Second the polarity of the signals must conform to the RS 232C standard This means that the low voltage state must correspond to a logical 1 and the high voltage state to a logical 0 Third the computer must be able to correctly receive signal that meets RS 232C specification The MFJ 1278B supplies signals that meet this specification Make or buy a cable that provides the following connections The common pin on the computer s RS 232C serial port must be connected to pin 7 on the MFJ 1278B serial port Connect the line that sends data from the computer to pin 2 on the MFJ 1278B RS 232C port Connect the line that your computer receives data on to pin 3 on the MFJ 1278B RS 232C port MFJ 1278B MULTI MODE COMPUTER INTERFACING TERMINAL SOFTWARE REQUIREMENTS Any software package that enables your computer to act as an ASCII terminal with an ordinary telephone modem should work with your MFJ 1278B If you have a program that you have used successfully with a telephone modem and that you are familiar with use that program to communicate with your MFJ 1278B If you are using a terminal pr
15. PRINT ON ENTER to activate the built in printer port Ensure that the printer is turned on and is ON LINE Now all AMTOR received will go to the printer port until a PRINT OFF command is issued or you exit back to the main cmd line Summary of AMTOR Contact Sequence 1 At cmd command prompt type MODE AM this will take you to AMTOR mode B FEC mode Indicated by the cmd command prompt 2 LISTEN or LI allows you to monitor mode ARQ and switches from mode B 3 Issuing an R will switch from mode A to mode B from the a cmd prompt 4 ARQ xxxx connects you with a station heard calling cq 5 Ror QRT in ARQ mode removes the link between stations 6 keys the transmitter and broadcasts a mode B message 7 CRTL C from the converse mode will return you to the a cmd prompt and twice will exit back to the main cmd prompt MFJ 1278B MULTI MODE BASIC OPERATION NAVTEX OPERATION Navtex is a new direct printing service operating on 518 KHz NAVTEX stands for Navigational Telex Navtex broadcasts urgent weather navigational and other information that is intended for ships Navtex Stations and Frequencies Navtex Stations currently cover most coastal areas of Europe and the Eastern United States West Coast Stations for the United States are in various phases of planning or construction and will begin transmitting within a few years Currently operational Navtex stations in the United States
16. Ground FSK Figure 3 9 FSK Cable Note The factory setting of the FSK signal polarity is normal on the MFJ 1278B If your radio requires you to provide a reverse FSK signal you will need to relocate the shorting jumper to position 2 amp 3 of the JMP 14 header on the MFJ 1278B mother board MFJ 1278B MULTI MODE BASIC OPERATION GETTING STARTED This chapter will guide you through the basic operation on all the modes that the MFJ 1278B is capable of performing It contains the basic information required to operate PACKET PACTOR RTTY ASCII CW AMTOR NAVTEX FAX SSTV and CW Memory Keyer Note In this section you will see this symbolism lt ENTER gt This means to press the Carriage Return or Enter key on your keyboard First Steps 1 sure that your computer is connected to the RS 232C port or the TTL port on the MFJ 1278B according to Chapter 2 2 Make sure that your radios are connected to the MFJ 1278B according to Chapter 3 3 Turn on your computer Load and run the terminal program 4 Turn on the MFJ 1278B The MFJ 1278B will sign on with cmd prompt sign If the MFJ 1278B fails to sign on press the return key on your computer a few times in succession the MFJ 1278B will sign on as as follow xJ bbRAM LOADED WITH DEFAULTS ENTERPRISES INC MODEL MFJ 1278B AX 25 Level 2 Version 2 0 Release XXXXX date XX K RAM Checksum XXX cmd Note
17. MFJ 1278B MULTI MODE OPERATIONAL COMMANDS When the MAILBOX is ON the System Operator can access the mailbox by typing the immediate command SYSOP commands are available to the SYSOP When the SYSOP has completed operating the MAILBOX he must return to command mode with Control C or the current COMMAND character to allow the remote users access to the MAILBOX TIMEDCMD text string Mode Mailbox Default Parameters string max 119 chars This string in the TIMEDCMD parameter is executed as a TNC command whenever the minutes register in the time of day clock equals the value in the TIMEDMIN parameter The string is executed when seconds equals one execution is deferred while the user is entering a command TIMEDMIN n Mode Mailbox Default 60 Parameters n 0 60 specifying 1 minute intervals The TIMEDMIN parameter is compared against the minutes register of the real time clock to determine when the TIMEDCMD string is sent to the command interpreter Setting this parameter to 60 disables the feature Combined with the TIMEDCMD string the user may configure his TNC to perform hourly automatic forwards and reverse forwards TINV ON OFF Mode AMTOR Default OFF Parameters ON Transmit signal is inverted from standard low tone MARK to high tone MARK OFF Transmit signal is standard low tone MARK TINV controls whether the MFJ 1278B inverts the transmitted AMTOR signals It is similar to TXINVERT in RTTY ASCII modes MFJ 12
18. Missed frames are detected by receiving a frame number different from that expected DM Sent in response to any frame received other than a connect request SABM when the TNC is disconnected Sent in response to an SABM whenever the TNC is on the air but can t connect to the requesting user e g if the TNC is already connected to someone else or if CONOK is OFF SABM Set Asynchronous Balanced Mode initiates a connect DISC Initiates a packet disconnect sequence UA Sent to acknowledge receipt of an SABM or DISC FRMR Sent when an abnormal condition occurs i e the control byte received is undefined or not proper protocol at the time received UI An I frame without a frame number It is not acknowledged MFJ 1278B MULTI MODE PACKET RADIO PROTOCOL CHANNEL USE AND TIMING FUNCTIONS The following discussions mention timing parameters which are set by various commands These timing functions are also discussed in Chapter 5 An important part of any packet radio protocol is the means by which many stations make efficient use of an RF channel achieving maximum throughput with minimum interference The basis for this time domain multiplexing is Carrier Sensed Multiple Access CSMA with collision detection and collision avoidance CSMA means simply that as every Amateur knows no station will transmit if the frequency is in use The MFJ 1278B continually monitors for the presence of an audio data carrier on frequency and
19. a 100 sync 1550 wits 1600 MFJ 1278B MULTI MODE OPERATIONAL COMMANDS PKTPIX ON OFF Mode Packet Immediate Command PKTPIX is an immediate command that provides a method for the MFJ 1278B to print packet pictures and other graphics format data transmitted by another station in the VHF packet mode The user must be connected to another station with a printer connected to the built in printer port Once connected you must go back to command mode with a CTRL C and obtain the cmd prompt When the characters PK are typed the MFJ 1278B will display the following message Entering transparent mode for packet pix reception The MFJ 1278B is now ready to print packet graphics Packet pictures data transmitted from the connecting packet station are received and data is sent directly to the printer attached to the MFJ 1278 without any intervening modification Therefore all data MUST use the same printer control codes that your printer uses Typically EPSON format codes will be used Packet picture printing to the MFJ 1278B printer port requires you to first establish a packet connection with the station who is going to send the picture Note that you won t be able to call up PKTPIX until the connection is made You must have the printer powered and selected before MFJ 1278B will let you use the PKTPIX command Once these conditions are met all data received over the packet link are sent directly to the printer Exit PKTPIX by using t
20. ccce specifying a character string of up to 15 characters in length The MEND parameter which may also be up to 15 characters long is effective when MATCH is ON and a Mode B signal has set off the matching function The MFJ 1278B will print all of a Mode B transmission received after text matching MBegin is received until text matching the MEND string is received or the transmission physically ends n1 n2 n3 n4 Mode Packet Default none Parameters n 0 7F specifying an ASCII character code Up to 4 characters may be specified This command allows you to specify characters to be filtered or eliminated from monitored packets The parameters nl n2 etc are the ASCII codes for the characters you want to filter You can enter the code in either hex or decimal For example if a lt CTRL L gt character causes your screen to be cleared and you don t want thina ta hannan cn nan o MEOIN TOD 127 T v alan wrant ta aliminata TDT Tr MFJ 1278B MULTI MODE OPERATIONAL COMMANDS MHCLEAR Mode Packet Immediate Command MHCLEAR is an immediate command It causes the list of stations heard to be cleared You can use this command in conjunction with MHEARD to keep track of the stations on the air over a given period of time such as an evening or a week Clear the list of stations heard when you first begin to monitor the packet activity MHEARD Mode Packet Immediate Command MHEARD is an immediate command The MHE
21. 1 ARQ ASENDCHA AUTOBAUD AUTOLF f f n f n 4 n 4 n n n AUTOTRAC AWLEN AX25L2V2 AXDELAY Packet Function Page Enables transmission of 8 bit data in converse mode Enables MFJ 1278B to operate 8 gray levels in FAX and SSTV modes Set MFJ 1278B to transmit and to receive 16 gray levels FAX and SSTV ALTCALL command in mode A ARQ the Mailbox link Permits an acknowledging TNC to trans mit without regard to slotting delay D qoe n P Controls a delaythat occurs whenever any packets thathavebeen received are not addressed to that unit Character used to force the MFJ 1278B to match its transmit speed to that of the incoming signal Sets an alternate SELCALL that the MFJ 1278B responds to in AMTOR mode A Enables the MFJ 1278B sresponse to a Who Are You Set MFJ 1278B to polls all TNCs within range Specifies the character used to ASCII return to receive after transmitting Initiates mode A ARQ connection Invokes MFJ 1278B to analyze incoming signals Specifies the transmit character Sets a reasonable aspect ratiobetween the Hor Ver representation of the FAX picture Enables the autobaud function which matches MFJ 1278B terminal baud rate to terminal program baud rate Determines the way the lt CR gt characters are displayed Automatically locks onto the incoming cw signal and displays the speed 1278B s RS 232 port 2 or Ver 1 Protocol Sets the voice reneater kev
22. 1 Terminal 9600 Mode Modulated CW 20 cmd Operation of MCW is the same as in standard CW Please refer to CW OPERATION for further details MFJ 1278B MULTI MODE BASIC OPERATION BAUDOT RTTY amp ASCII OPERATION The user can configure the MFJ 1278B RTTY ASCII modems to copy several shifts including 170 425 and 850 Hz shifts The user can use the MODE command to configure the RTTY ASCII modems for the different shifts The MFJ 1278B will transmit and receive RTTY and ASCII at speeds of 45 50 57 75 100 110 150 200 and 300 baud The MFJ 1278B transmit and receive WIDE and NARROW shift RTTY or ASCII Wide shift RTTY ASCII operates on standard tone pairs of 2125 Hz for MARK and 2975 Hz for SPACE The frequency shift for WIDE shift RTTY ASCII is 850 Hz Narrow shift RTTY ASCII operates on standard tone pairs of 2125 Hz for MARK and 2295 Hz for SPACE The frequency shift for NARROW shift RTTY ASCII is 170 Hz In the RTTY mode the MFJ 1278B will receive and transmit both the American Western Union and the internationally recognized CCITT character set In ASCII mode MFJ 1278B will transmit and receive 7 bit ASCII code Note that the MFJ 1278B provides you with the option to select Low Tone RTTY ASCII Low Tone RTTY ASCII uses standard tones of 1275 Hz for MARK and 1445 Hz for SPACE The frequency shift for Low Tone RTTY ASCII is 170 Hz You can select Low Tone RTTY ASCII through the V modem The Low Tone pairs are the stan
23. 10ms 5ms Similar to AMTOR s DELAY and packet s TXDELAY The actual delay yielded is equal to 1015 TXDELAY 5ms If the combined TXDELAYs of both stations involved in the link exceeds about 180ms then shortpath connections may not work particularly at longer distances If difficulty is experienced try using the Longpath Connect LC command to connect TXDELAYC nnn Mode Packet Default 2 Parameter nnn Othru 255 in 1 ms step The time delay between when the MFJ 1278B depresses the PTT and when it starts sending packets is specified in terms of how long it takes to send TXDELAYC characters at the current radio baud rate TXDELAYC controls a new timer that runs after the regular TXDELAY time has expired see TXDELAY High speed radio users will find this command useful because they can select transmit delays much smaller than the 10 ms grains in TXDELAY For high speed use set TXDELAY to 0 and set TXDELAYC according to the formula below TXDELAYC Radio PTT delay time Time per character The time per character as related to the radio baud rate is as follows Time per character 9600 2400 1200 26 00 ms Examples 1l 200 ms 2 meter HT at 1200 baud TXDELAYC is MFJ 1278B MULTI MODE OPERATIONAL COMMANDS TXDIDDLE ON OFF Mode Packet Default OFF Parameters ON The MFJ 1278B uses the efficent square wave TXDIDLE routine OFF The MFJ 1278B uses flags during TXDELAY period TXDIDDLE determines
24. 231 Commands FORWARD 231 Commands FRACK 231 Commands FULLDUP 52 232 Camman dao CR ADUTI E 929 MFJ 1278B MULTI MODE Commands ID 234 235 Commands Id 234 Commands IDTIME 235 Commands K Converse 235 Commands KILONFWD 235 Commands KISS 236 Commands LC 237 Commands LCALLS 194 237 Commands LCSTREAM 238 Commands LEDmode 239 Commands LFADD 239 Commands LFadd 239 Commands LFADDALT 239 Commands LFIGNORE 240 Commands LISTEN 240 Commands MAILBOX 241 290 Commands MAILbox 240 Commands MAILLED 242 Commands MALL 243 Commands MARSMODE 244 Commands MATCH 245 Commands MAXDown 245 Commands MAXFRAME 245 Commands MAXSum 246 Commands MAXUp 246 Commands MBEGIN 246 Commands MCOM 247 commands MCON 46 Commands MCTEXT 248 Commands MEND 248 Commands MHCLEAR 249 Commands MHEARD 249 Commands MNONAX25 250 Commands MNONPRIN 250 Commands MONITOR 194 251 Commands MONitor 250 commands MONITOR 45 Commands MRPT 233 252 commands MRPT 46 Commands MSPEED 252 Commands MSTAMP 216 233 253 Camman da NATTINAROWIT 282 MANUAL INDEX MFJ 1278B MULTI MODE Commands MYcall 255 Commands MYDLCNUM 255 Commands MYHIERAD 256 Commands MYMCALL 256 Commands MYSELCAL 256 Commands NAVMSG 258 Commands NAVSTN 257 Commands NAVTEX 257 Commands NEWMODE 207 259 Commands NODEFORW 260 Commands NODEPATH 261 Commands NOMODE 261 Commands NUCR 2
25. 39 memory buffers transmitting of 39 Memory Keyer 71 Memory space decoder 317 318 Messages error 310 Messages link status 312 Messages sign on 308 MHCLEAR 46 MHEARD 46 Microprocessor 315 MODE command 37 Modem 316 319 modem components sets of 35 modem program 4 Modem demodulator modification 319 Modem external 135 315 328 Modem J4 disconnect 328 Modem modulator modification 319 Modem negative power supply 320 Modem radio 135 Modem telephone 9 11 Modem troubleshooting 334 Modulator 315 Monitoring 45 Monitoring On the Air 49 Monitoring callsign list 237 Manitaring character filtering 249 MANUAL INDEX MFJ 1278B MULTI MODE Monitoring selected stations 137 Monitoring time stamping 253 Monitoring while connected 46 247 MSPeed 73 Multiple packets for 1200 baud 134 N NEC 8201 serial port interfacing 9 NEC 8201 terminal program 13 New lines 35 Noise cause of retransmissions 45 NORMAL CW 75 NRZ to NRZI encoder 318 NRZ to NRZI encoder clock 318 NRZI encoding 339 Null modem cable 321 Operating modes 316 Operation Packet VHF 127 OSCAR operation 328 OSCAR operation full duplex 232 Oscillator 317 Oscillator troubleshooting 333 Outstanding packets 245 P packet mode VHF 42 Packet reception troubleshooting 335 Packet transmission troubleshooting 335 Packet maximum length 130 263 Packet protocol 131 Pa
26. AALT command ANSBSTR cccc Mode AMTOR Default blank ANSBSTR will enable the MFJ 1278B to respond to a Who Are You WRU Mode A AMTOR signal The text may be up to 15 characters When the MFJ 1278B hears a WRU request it will respond with the text in the ANSBSTR string MFJ 1278B MULTI MODE OPERATIONAL COMMANDS ANSWRQRA ON OFF Mode Packet Default ON Parameter ON MFJ 1278B responds to non digipeated UI frames addressed to QRA within 1 to 16 seconds with an empty ID packet OFF Disables MFJ 1278B s ping response function Who are you pinging is supported by the MFJ 1278B A ping polls all of the TNCS within range random number of seconds later each TNC that heard the ping will transmit its identification packet The purpose of this feature is to reveal to the packeteer particularly the transient one the names of all reachable TNCs and digipeaters In order to send a QRA ping 1 unprotocol callsign to cmd UNPROTO QRA lt CR gt The MFJ 1278B will respond with whatever the UNPROTO command was set to previously 2 Manually send an unconnected packet cmd CONVERSE lt CR gt lt CR gt C cmd This sequence will send an unconnected packet Once the local TNCs have responded with ID packets then the user can press a CRTL C The MFJ 1278B will respond with the cmd prompt ARCVCHAR nn Mode RTTY ASCII Default 12 Parameter nn 0 to 127 decimal or 00 to
27. Commands TVBREAKS 295 Commands TVHSYNC 296 Commands TVMODE 296 Commands TVX 297 Commands TXDELAY 52 Commands TXDelay 298 Commands TXDELAYC 298 Commands TXDIDDLE 299 Commands TXFLOW 300 Commands TXINVERT 300 Camman de TYTNO ANN MFJ 1278B MULTI MODE Commands UNPROTO 190 Commands UNSHIFT 302 Commands URepeats 302 Commands USERS 302 Commands VISBREAK 303 Commands VISTICKS 303 Commands VISTONES 303 Commands WAitdisc 304 Commands WDMODE 304 Commands WEIGHT 304 Commands WRU 305 Commands XFLOW 305 Commands XMITOK 305 Commands XOff 306 Commands XON 306 Commands XOn 306 Commands MODE 249 Commodore 64 or VIC 20 terminal program 12 Computer interfacing Apple Macintosh 6 Computer interfacing computers with 25 pin RS 232C ports 9 Computer interfacing IBM PCjr 8 Computer interfacing NEC 8201 9 Computer interfacing non standard serial ports 10 Computer interfacing Radio Shack Model 100 9 computer or terminal 4 CONNECT 44 Connect acknowledged by UA frames 342 Connect automatic 128 Connect automatic message transmission 128 Connect errors 208 312 Connect in progress 312 Connect initiated by SABM frames 342 Connect message 313 Connect request message 313 Connect starting a QSO 47 Connect timeout 201 Connect unsuccessful 45 CONTROL HDLC field 338 Converse Mode lt NULL gt transmission 262 Converse Mode 8 bit
28. ENTER where xx is the CW transmit speed The MFJ 1278B will respond with the mode status lines and end with the command prompt Note that if the user does not select a transmit speed the MFJ 1278B selects the default speed of 20 WPM The 1278 is now in CW mode of operation To receive CW you go into CONVERSE mode Enter CONVERSE mode by typing K ENTER The MFJ 1278B is now ready to receive Morse code The Tuning Indicator and the DCD led on the front panel assist the user in tuning in CW signals Tune your receiver to approximately center the tuning indicator when there is a CW audio tone actually present Note that between code elements dots and dashes the tuning indicator will indicate randomly Once the CW signal has been coarsely tuned in by using the tuning indicator further CAREFUL tuning should reveal a spot where the DCD LED flashes in synchronism with the incoming code If the DCD LED does not light then you must rotate the THRESHOLD control on the MFJ 1278B clockwise until the DCD LED flashes with the CW signal If the DCD LED is lit but does not flash with the CW signal then rotate the THESHOLD control counter clockwise until the DCD LED does flash with the CW signal The demodulator is an extremely narrow filter It is much narrower than the 500 Hz CW filter in your radio if you have such a filter in the radio This means that very careful tuning will be required for proper CW demodulation You shou
29. Follow the computer manufacturer s recommendations for connecting the serial port to a modem You may also find the technical information in this section useful Your MFJ 1278B is configured as Data Communications Equipment DCE the technical term for an RS 232C modem Most computers are configured as Data Terminal Equipment DTE If this is the case for your computer you may be able to wire pin 2 of the MFJ 1278B connector to pin 2 of your computer s RS 232C port Then wire pin 3 to pin 3 and pin 7 to pin 7 on the computer s RS 232C port You can provide these connections with a standard 3 wire male to female or male to male RS 232C extension cable depending on whether your computer has a DB25S or DB25P connector MFJ 1278B MULTI MODE COMPUTER INTERFACING If your computer is configured as DCE you will have to wire pin 2 of your MFJ 1278B to pin 3 of the computer RS 232C connector Then wire pin 2 of the computer s RS 232C connector to pin 3 of your MFJ 1278B Please note that pin 7 of the computers RS 232C connector will still connect to pin 7 of your MFJ 1278B serial port Some computers may require that pin 5 of the computer serial port connector be connected Others may require connections for pin 8 and pin 20 You can use the computer s output signals on pins 4 and 6 as shown in Fig 2 3 1278 RS 232C Computer RS 232C 2 2 3 3 7 4 5 6 8 20 Fig 2 3 Serial port wiring with jumpers for auxiliary signals
30. Otherwise the received byte contains actual display information as described above The color level of each pixel contain in the data byte is given below 000 001 110 111 white lightest grey darkest grey black NOTE If the data byte is NOT a sync byte you must remove the 30H bias BEFORE extracting the pixel information For example if an ASCII 9 is received then the following steps should be taken 1 Remove bias 39H 30H 9H 2 Extract pixel information aaa 001 bbb 001 3 Display two pixels of lighest grey level If an ASCII q or r is received then process the byte as a sync tone Information can be requested on the raw data format for 16 gray level fax from MFJ Enterprises Inc Transmitting FAX The MFJ 1278B is capable of transmitting 2 level or multi gray level pictures in the FAX mode To transmit FAX picture you must use a special terminal program capable of FAX operation Two Level FAX Transmitting In this section we will cover procedures for transmitting 2 level FAX images with the MFJ 1278B The 2 level FAX images that are transmitted by the MFJ 1278B are stored on disk in the format required by the MFJ 1278B You recall the stored FAX images from disk depending on the terminal program being used You will need to refer to the terminal program instructions to learn how to recall the FAX images from disk The 2 level FAX mode in the MFJ 1278B requires that the use of a monochrome graphics system w
31. Pseudo random CW is sent when in CW mode and RANDOMCW is turned ON To terminate sending random CW type CTL C and set RANDOMCW to OFF again The random CW is sent at the speed specified by the MSPEED command MFJ 1278B MULTI MODE OPERATIONAL COMMANDS RBITMASK xx Mode RTTY ASCII Default 0 Parameters xx 0 7F specifying the bit inversion during receiving The RBITMASK command controls the bit inversion process applied to the received ASCII and RTTY characters Bit inversion is a simple means of encryption RBITMASK should be selected to match the inversion pattern of the station you are receiving RECONNECT VIA call2 call3 call9 Mode Packet Parameters Callsign of TNC to be reconnected to call2 Optional callsign s of TNCs to be digipeated through As many as eight digipeat addresses can be specified RECONNECT is an immediate command It may be used to change the path through which you are currently connected to a station It may only be used when your MFJ 1278B is connected on the current stream to the station you wish to RECONNECT to Integrity of frames in flight between your station and the RECONNECTed station at the time of RECONNECT is not assured MFJ 1278B MULTI MODE OPERATIONAL COMMANDS REDISPLA n Mode Default 12 Parameters n 0 7F specifying an ASCII character code This command is used to change the redisplay line input editing character The parameter n is the ASCI
32. The IA may display as a vertical bar and any capital letter from A through J The first five lines are the sign on message which you will normally see only when you power up the MEJ 1278B The Command Mode prompt cmd will appear when the MFJ 1278B is in Command Mode The cmd prompt indicates that he MFJ 1278B is now ready to accept your instructions Upon sign on the MFJ 1278B is in the VHF packet mode Before the MFJ 1278B can be fully operational some of the basic parameters must be set Basic Commands With the MFJ 1278B signed on and in the VHF packet mode you are ready to start setting up the basic commands you will use The commands in the MFJ 1278B are set to their defanlte Same of thece defanlte mav he enfficient far the wav van wich the MET 127 amp 8BR ta MFJ 1278B MULTI MODE BASIC OPERATION followed by a carriage return Now let s try entering your callsign using one of the basic commands MYCALL by typing from the cmd command prompt MYCALL K5FLU followed by a carriage return The MFJ 1278B will respond with MYCALL was NOCALL cmd followed by the the system command mode prompt cmd Of course you should substitute your own call sign for KSFLU Do not forget the ENTER at the end of the line Your callsign will be used by the MFJ 1278B as its address The MFJ 1278B responds by telling you the previous value of the MYCALL parameter and gives you a new Command Mode prompt Note that commands a
33. Upon access to a mailbox this message will appear if there are messages addressed to you EH This message occurs when a command issued is not understood by the mailbox This could be out of range slot number missing slot number where one is required or bad command Cannot not yours This message occurs when a remote user attempts to kill a message which is not his or he tries to read personal message by or for someone else Mailbox full This message occurs when either all of the available slots are full or the actual message space is full Messages must be killed to recover from this error Not found This message occurs when one attempts to read or kill a non existent message from an empty slot None found A parameterless Kill or Read command did not find any messages addressed to the user No mail MFJ 1278B MULTI MODE BASIC OPERATION CW OPERATION The MFJ 1278B provides many unique features in the CW mode that are not found in other multi mode controllers The MFJ 1278B can key your CW transceiver in the CW mode of operation The MFJ 1278B can accommodate either positive direct or negative grid block keying voltages The MFJ 1278B also has a code practice mode built in that can be used with VHF FM radios in the Modulated CW MCW mode This mode holds the radio PTT line down and feeds keyed audio into the microphone input The CW mode in the MFJ 1278B is very easy and versatile Take for instance the
34. Use lower side band LSB unless you have an RTTY position on your rig Tune your radio until the 10th or 11th segments on the tuning indicator light during receive Ensure that the yellow DCD led is illuminated also during receive It is possible to tune to the center of the bar graph and not have the DCD led lit If the DCD led does not light then check the setting of the Threshold control on the front panel The DCD led needs to be lit for reception Some bouncing of the LED is normal since any audio other than the signal ORM QRN will also affect how it responds From the converse mode you should now see text being printed on the screen as it is heard Contacts usually take place on a one way at a time basis So one side will transmit and the other will receive and then the sides are reversed To allow the MFJ 1278B to transmit RTTY or ASCII type CTRL T while in converse mode to key the PTT on the radio The green PTT light should light and you should see power on your wattmeter All keystrokes are now sent out over the air Alpha numeric numbers and upper lowercase letters characters are the only kind of keystrokes accepted Some punctuation is allowed When the transmission standards were set up only mechanical typewriters tele type were used and these were the only keys in use Most other characters such as Greek and graphics are usually translated wrong and you ll see the other guy s mistakes when he types one of the characters T
35. keyed in RTTY ASCII Allows your station to be used as a digipeater Used to disconnect a connected station in 6 Used to list all the commands the MFJ 1278B acknowledges Used to list all the commands used in AMTOR Used to avoid collisions with digipeating Echos pactor transmitted data upon reciept of remote s acknowledgement Enables real time echoing of out going 6 53 CW RTTY and ASCII text Detrermines echoing of transmitted amtor data as you send it Allows the MFJ 1278B to transmit back to you everything that you type in all mode of operation command Determines if you are using an EPSON IBM or C ITOH printer Designates the character displayed when an unconnected packet is monitored Inserts an underscore if the MFJ 1278B 46 47 48 48 49 52 detects an error while receiving AMTOR Specifies the character which will be output when an lt escape gt character is to be sent Determines if exact callsign matching mode is used or not Enables the MFJ 1278B to transmit CW in Farnsworth method 53 54 54 54 55 55 55 56 56 56 Determines if the user will have to terminate the end of a FAX picture6 57 Sets the FAX formats in FAX mode Causes the receiving FAX picture to print 6 57 MFJ 1278B MULTI MODE APPENDIX COMMAND SUMMARY r FEC I command AMTOR Initiates the broadcasting of Mode B 6 58 forward error correcting mode FIRMRNR ONIOFF Packet Controls the handling of
36. radios allow operation of RTTY and ASCII at full power You should consult the owner s manual of your radio to see what is the acceptable power level at which your radio should operate BAUDOT RTTY OPERATION HINTS In this section we will cover a few of operative hints for the RTTY and ASCII modes To set the MFJ 1278B to RTTY mode type MODE HB ENTER for HF operation This sets the MFJ 1278B to the standard RTTY mode that most amateurs use On HF this is 45 baud or 60 wpm As mentioned earlier if you do not designate a speed after the two letter the MFJ 1278B selects the default of 45 baud Some RTTY bulletin boards use 75 baud or 100 wpm in which case you should type MODE HB 75 The number after the HB sets the character transmission and receive speeds in baud Some operators will refer to the speed as words per minute However the normal terminology is to refer to the speed in BAUD RATE Although speeds up to 300 baud are available only 45 MFJ 1278B MULTI MODE BASIC OPERATION To enter the converse mode type K This will take the MFJ 1278B out of the command mode and into converse mode When the MFJ 1278B enters converse mode the STA will illuminate Also after entry into converse mode the MFJ 1278B is in receive mode You can enter transmit mode by typing CONTROL T To re enter receive mode type a CONTROL R The command CONTROL C will return you to the command mode where you will get the cmd prompt on your screen
37. the MFJ 1278B responds to connect packets that match all the letters in your callsign and no more When OFF the looser buggy Pactor specification comes into play and your MFJ 1278B responds to any connect packet containing at a minimum the contents of MYCALL EXACTCAL matching will not always work to filter out improper callsigns when the offending unit is the pacomm Pactor version 1 0 unit because of its use of regular ascii 0x55 U characters to fill and terminate callsigns MFJ uses ascii OxOf as specified in Pactor documents instead of 0x55 to fill and thus fixes the bug MFJ 1278B MULTI MODE OPERATIONAL COMMANDS FARNSWOR ON OFF Mode CW Default ON Parameters ON Enables the FARNSWORTH special spacing OFF Disables the FARNSWORTH special spacing Many find training for CW tests with FARNSWORTH method of code generation more valuable because it teaches letter recognition at a speed fast enough to avoid the common learning plateau Some people have trouble passing this plateau as they increase their code speed When FARNSWOR is ON the MFJ 1278B transmits CW characters from keyboard or the Memory Keyer using 15 WPM equivalent letters and elements Setting FARNSWOR to OFF causes CW text to be sent at normal timing at the selected speed FAXEOP ON OFF Mode FAX Default ON When FAXEOP is ON the MFJ 1278B detects the end of picture for received FAX by looking for a long period of idle tone Setting it OFF disables all FAX
38. you will type TVMODE 1 The default SSTV mode for MFJ 1278B is TVMODE 1 8 5 seconds format After tuning to the desired SSTV frequency observe the TUNING INDICATOR of the MFJ 1278B while fine tuning the radio You will notice that with each scan the tuning indicator will move toward the center Tune the radio so that the 10th LED segment from left is lit at the end of each SSTV line scan Once you achieve this the SSTV signal is tuned in The DCD LED should light If DCD LED on the MFJ 1278B is not lit rotate the THRESHOLD control until it is lit SSTV Printing to the Printer At this point you will want to ensure that your printer is properly set Make sure that your printer to set to EPSON GRAPHICS or IBM GRAPHICS mode This is usually selected by DIP switches on the printer IBM GRAPHICS mode is not the same as EPSON GRAPHICS mode If you are using an EPSON graphics printer you should turn the IBM GRAPHICS mode off and set your printer to EPSON GRAPHICS mode Although most commands of the MFJ 1278B that affect SSTV printing are defaulted to allow successful printing you should check these commands before printing any SSTV picture You should insure that the commands EPSON and PRINTGRA are ON The default values of these commands are ON SSTV printing to the printer will not function unless these commandis are turned on Note that PRINTGRA honld he turned ON onlv if van are nrintino nictures thronoh the MFJ 1278B MULTI
39. 2 MFJ 1278B MULTI MODE APPENDIX E CONVERTING TO TNC 2 3 Construct Header U28 by connecting pins 2 5 6 12 15 and 19 to ground pin 10 Connect pins 9 and 16 to 5 Volts at pin 20 See Figure E 2 below 1 20 2 19 3 18 4 17 3 16 6 15 7 14 amp 13 9 12 10 11 Fig E 2 Header 028 4 Remove U27 on the MFJ 1278B PC board and replace it with Header U27 5 Remove U28 on the MFJ 1278B PC board and replace it with Header U28 6 Set the terminal program parameters as specified by the NET ROM documentation Upon power on the MFJ 1278B should signed on like a TNC 2 and it is ready to operate NET ROM or other TNC 2 firmwares MFJ 1278B MULTI MODE APPENDIX F 2400 BPS PACKET 1278 2400 BPS PACKET If your MFJ 1278B does not have the 2400 bps packet capability then the user can easily install the proper hardware The user can purchase the optional MFJ 2400 BPS modem and is easily installed Installation is simple because your MFJ 1278B is equipped with all the appropriate connectors necessary to make this installation quick and easy without modifications or soldering If you have the MFJ 1278BT the 2400 modem is already installed inside the unit With the MFJ 2400 modem installed your MFJ 1278B is capable of operating 300 1200 or 2400 baud packet With the MFJ 2400 BPS modem has no effect on the 300 and 1200 baud packet mode operations The addition of the 2400 modem feature will in no way require any internal modi
40. 353 CONVERTING THE MFJ 1278B TO LIKE TNC 2 354 MEJ 1278B 2400 BPS PACKPBET iicet tete RE ime dee 356 2400 BPS PACKET SETUP eed ai Sai es AR oa ES 356 2400 BPS Receive Audio Setting essere 357 2400 BPS Transmit Audio Setting eee ee ceeeceseesse cess caeeceeeeeeseeeeeeenereesensees 357 JUMPER FUNCTIONS AND LOCATIONS eerte 358 COMMAND SUMMARY oE EEE ER EEEn 362 MFJ 1278B 1278BT PARTS LIST ens ue enne e nenne 373 MFJ 1278B MULTI MODE TABLE OF CONTENTS MFJ 1278B MULTI MODE INTRODUCTION INTRODUCTION Welcome to the exciting world of Amateur Digital Communications By choosing the MFJ 1278B you have chosen the most versatile and powerful Multi mode Data Controller manufactured for the Amateur Radio Service The MFJ 1278B interfaces your radio with any personal computer that has an RS 232 or TTL level Serial Port and a terminal program While most communications programs will work MFJ recommends the use of MFJ Starter Pack for those who have IBM or compatible Macintosh Amiga or Commodore C64 128 computers With an IBM or compatible computer the MFJ Multicom terminal program gives you some added features that a standard terminal program just can not offer Features such as color SSTV color FAX 16 gray level FAX and color VGA packet picture transfer just to mention a few Multicom is men
41. 51 53 55 57 59 5B 5D 5F 61 63 65 67 69 6B MFJ 1278B MULTI MODE OPERATIONAL COMMANDS RXCAL Mode Immediate Command RXCAL is an immediate command When invoked the MFJ 1278B generates test signals based on CALSET see below that are used by the internal tuning software to align the demodulator components To use the RXCAL feature 1 Align the modulator components as described in the owners manual 2 Use the MODE command to select the demodulator to be tuned Make sure JMP8 JMP7 and JMP 4 are installed 3 From the cmd prompt type the command CALSET n Use the n value from the CALSET Adjustment amp Location Map on the next page 4 From the cmd prompt type the RXCAL command 5 Tune the appropriate trimpot R79 R113 R114 or R115 until the DCD light is lit fully 6 Continue tuning this trimpot until the CON and STA LEDs flash either alternately every half second and or both light up 7 Return to step 2 until all the demodulators are tuned NOTE RXCAL is not effective for alignment of the CW demodulator MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CALSET Adjustment amp Location Map This is a map of the physical locations of the adjustment potentiometers on the MFJ 1278B circuit board They are shown as they appear when looking down on top of the board with the board oriented so that the rear panel connectors are to the left Information in the boxes is organized as shown below
42. 7F hexadecimal The ARCVCHAR command specifies the character used in RTTY ASCII CW modes to return to the receive mode after transmitting MFJ 1278B MULTI MODE OPERATIONAL COMMANDS The ARQ command initiates a Mode A ARQ link ssss is the SELCAL of the station you wish to link with When ARQ is first issued the MFJ 1278B begins to key the transmitter in attempt to establish the link to the specified SELCALL Both the CON and STA LEDs immediately light to indicate the phasing condition If the remote station answers the link is established The STA LED extinguishes and the CON LED remains lit An IDLE ready state is indicated by this combination The MFJ 1278B is now ready to accept text for transmission Type K or CONV to get into text transmit mode CTRL C to exit ASA Mode Packet ASCI RTTY Immediate Command ASA is an immediate command When invoked the MFJ 1278B will analyze incoming signals such as RTTY ASCII AMTOR and HF packet It will display the result for speed data bits and whether or not the signal is inverted When invoked and the MFJ 1278B is told to analyze the incoming signal A message will be generated in the following format Speed Confidence Factor gt Data Bit lt RXInvert On Off gt The ASA command is used in conjunction with the OK command Once the user accepts the results given by ASA the MFJ 1278B will select the appropriate modem match the data rate set the RXInvert and will be r
43. ABOVE ORDER If they are not all done at the same time or in the correct order the modem may not be receiving and transmitting on the same frequency and the tuning indicator may give false indications The third step alignment of the tuning indicator should only be used in conjunction with alignment of the 300 baud 200 Hz shift demodulator The other AFSK modems available in the MFJ 1278B can be aligned using exactly the same steps presented here but substituting the appropriate part numbers for the adjustments However do NOT align the tuning indicator to anything but the 300 baud 200 Hz shift HF packet modem MFJ 1278B MULTI MODE APPENDIX B MODEM CALIBRATION Comprehensive Alignment Procedure It is important that the tuning indicator alignment be optimized for the 300 baud 200 Hz shift HF packet modem It will indicate correctly for all other modes when aligned for the HF packet modem As described elsewhere in this manual the exact configuration of your radio s filters and whether it has IF shift or not will determine the exact required center frequency for the modem Once the required center frequency has been determined the modem calibration can be carried out NOTE It is essential that the modulator tones be properly aligned FIRST as they will be used to align the demodulator center frequency Set the modulator tones to Fc MINUS 1 2 of the shift for the low tone and Fc PLUS 1 2 of the shift for the high tone For the 170
44. CARRIAGE RETURN or other control character is sent To have more control over when pending transmit characters are sent enter it as the new CWSEndch value For example setting CWSEndch to 02 will cause the MFJ 1278B to buffer CW characters for transmission until a CTRL B or CTRL R that always transmits the buffer character is typed To enable immediate transmission enter CWSEndch 255 or FF The immediate transmission mode enables the full break in feature in the CW mode The full break in CW feature is defeated if the CWSENDCH character is set to a value other than FF This tells the MFJ 1278B to send everything right away without delaying for a space or CARRIAGE RETURN like CWSEndch 000 would CWSPEEDM ON OFF Mode CW Default OFF Parameters ON Enables the transmit speed synchronization with the received speed OFF Disables transmit speed synchronization with the received speed When the CWSPEEDM command is ON the MFJ 1278B will adopt the CW speed that was last locked in through the CW Lock command as its transmit speed When CWSPEEDM is OFF the MFJ 1278B transmit speed will be the speed set by the user with the MSPEED command The default value of CWSPEEDM is OFF MFJ 1278B MULTI MODE OPERATIONAL COMMANDS DAYTIME date amp time Mode Packet No default Parameters date amp time Current date and time to set This command allows you to set the current date and time for the MEJ 1278B The format for entering the da
45. Call Callsign of BBS to enable Reverse forwards n 0 15 an optionally specified sub station ID SSID When this parameter is empty the mailbox reverse forwards all of its messages eligible for forwarding to the first SID compatible BBS to elicit a reverse forward with F gt Since this permissive technique is vulnerable to a malevolent operator who might attempt to connect and force your mailbox to forward to him the REVFLIM parameter is provided to limit your mailbox s response to other s reverse forward requests Simply place the callsign of the BBS you wish to enable reverse forwarding to in this parameter to limit remotely initiated reverse forwarding to only that callsign MFJ 1278B MULTI MODE OPERATIONAL COMMANDS RFE ON OFF Mode AMTOR Default OFF Parameters ON Continous retries mode enabled OFF Continous retries mode disables RFE is the Retry ForEver parameter When the RFE command is ON a Mode A call will continue until either a successful link is established or the QRT or R command is issued RINV ON OFF Mode AMTOR Default OFF Parameters ON Inverting of incoming Amtor data results OFF Incoming Amtor data is not inverted The RINV command controls whether the incoming received signal is inverted before detection processing It is similar to RXINVERT in RTTY ASCII mode MFJ 1278B MULTI MODE OPERATIONAL COMMANDS RXBLOCK ON OFF Mode Packet Default OFF Parameters ON The MFJ 1278B will send data t
46. Centronics male connector for the printer end should be used You may use a standard IBM parallel printer cable instead of trying to wire your own A Printer cable for connection from the MFJ 1278B printer port to a Centronics compatible printer is available from Enterprises Inc Model No is MFJ 5412 If you are using a terminal program that supports graphic printing from the computer to the printer then you should connect the printer to the computer printer port and not to the MFJ 1278B printer port The MFJ 1278B printer port is available for printing graphics This feature can be used whether your terminal program supports graphics printing to the computer screen or not It can be used to print graphics such as Packet SSTV or FAX pictures If you want to print graphics then you should connect the printer to the MFJ 1278B printer port In this case the printer must be either EPSON or IBM graphic compatible in order to insure successful graphic receiving to the printer The MFJ 1278B printer port configuration is shown in Table 2 5 MFJ 1278B DB 25 Name Primer Port Pina _ 2 Jj DatmBit E 3 2 4 Date Bits 5 ata Bits 6 ata Bits 12 thru 17 18 thru 25 MFJ 1278B MULTI MODE COMPUTER INTERFACING Printer Consideration The MFJ 1278B printer port will work with any printer that is compatible with EPSON or IBM graphics Printers that are not EPSON or IBM graphics compatible can not be used to
47. Hz shift 300 baud modem used for HF packet this would be Fc 100 Hz for the high tone and Fc 100 Hz for the low tone Set Modulator Tones Using Built in Calibration Software 1 sure that the modem and TNC are both configured for 170 Hz shift 300 baud operation This is done by typing MODE HP lt gt from the cmd command prompt on the MFJ 1278B 2 Place a push on jumper at JMP 4 3 Place a push on jumper at JMP 9 pins 1 and 2 This connects the modulator square wave output to the SIO chip so that the CPU can measure the tone frequency for you Also install a push on jumper at Pins 1 amp 2 and 3 amp 4 of JMP 16 The two jumpers when installed properly will be positioned vertically This would be if the leds on the MFJ 1278B are facing you 4 CALSET n lt CR gt Where n is a number determined by n INT 525000 F low 1 This tells the CPU what tone frequency you are trying to achieve A table of CALSET numbers to use for the various standard modem tone frequencies will be included at the end of this procedure 5 Command the MFJ 1278B into calibrate mode by typing CALI followed by a lt CR gt 10 11 12 13 14 15 MFJ 1278B MULTI MODE APPENDIX B MODEM CALIBRATION Adjust R106 carefully until both the CON and STA LEDs on the front panel of the TNC are lit One of the leds may filcker slightly This is normal This exits the MFJ 1278B from calibrate
48. JMPR JMP1 JMP9 JMP14 JMP18 JMP19 2 JMP22 JMP24 J14 J15 14 J2 J9 MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MFJ P N Descrpition Component ID 601 6021 2 0 MM PIN COAXIAL JACK P1 PC MOUNT MALE 601 5003 3 5 MM MINIATURE PC P2 P3 P11 MOUNT JACK STEREO 600 0011 PHONO JACK RIGHT Jil ANGLE PCB MOUNT 612 4001 2 POSITIONS PUSH ON JUMPER 5 8 JMP 9 2 MOLEX 15 38 1024 OR EQUAL JMP13 JMP14 1 PUSH ON JUMPER TO BE JMP 16 2 JMP18 1 INSTALLED ON JMP19 32K JMP22 JMP24 JMP26 JMP A JMP E JMP F JMP G JMP H JMP J J4 4 MISCELLANEOUS 402 1100 10 UH 20 MOLDED INDUCTOR L1 NYTRONICS RFS 10 OR EQUAL 401 0102 10 UH 20 MOLDED INDUCTOR L2 14 DALE IM 4 OR EQUAL 405 0090 4 9152 MHZ HC 18 U CRYSTAL Y1 504 0022 DPDT ON OFF SWITCH SWI ITT SHADOW F 2UEE OR EQUAL 760 2140 RED CAP FOR SW1 ROUND 760 0030 KNOB FOR R131 730 1305 3 VOLTS LITHIUM BATTERY BATT 1 COIN TYPE CR2430 OR EQUAL 730 2293 COIN BATTERY HOLDER BATT 1 740 108 RAP GRADU DICPI AV EIT TER PRN MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MFJ P N 715 8082 700 3063 705 1617 710 4017 701 7163 705 1403 701 2236 700 2221 862 1278 1 50 1274 2 50 1278 3 800 0210 1278 Descrpition Component ID 6 32 x 5 Hex or round Aluminum spacer threaded with 6 32 threaded on both ends To be installed on mother board Use mounting hole next to C201 and C203 6 3
49. K L M R S T Thus the 0 indicates the memory bank has been switched to bank 1 MFJ 1278B MULTI MODE ADVANCED OPERATION This command lets you read messages addressed to you When you list the messages in the mailbox you notice an N flag next to the messages which you have not read Once you read those messages the N flag will change to a Y flag This is an indicator to both you and the SYSOP that the messages have been read From there you can perform a global kill on all of your messages or the SYSOP can kill them individually NOTE The only way an N flag can get changed to Y flag during a read is that the person RiHE S call SP call who the message is addressed to needs to read it The flag will not change for any other person who reads the message Allows you to read the message in slot nn Where nn is a particular slot number This command works the same as the command except its for reading the individual slots This allows the remote user local or remote SYSOP to send a message to the designated callsign CALL must be a callsign valid under the same format as the MYCALL CONNECT or other callsign commands You can also send messages in NTS National Traffic System format You will need to refer to the ARRL NET DIRECTORY for more detailed information on the NTS system This allows the remote user local or remote SYSOP to send a personal message to the designated callsign This is a private message and onl
50. Lrg Tip Both Sleeves 3 AZDEN PCS 3000 PCS 4000 PCS 6000 DRAKE TR 7A ICOM 25 255 1C 726 2016 5 Pin eae at KENWOOD Ee TM 231A 15 4405 TS 711 811 TS 850S i 15 9405 15 9505 i TS 2530 2550 TS 2570 TS 7950 TANDY p __ HTX 100 8 Pin RANGER 9 AR 3500 YAESU p FT 301 FT 101Z ZD 4 Pin Pin2 Pin3 1 8 Pin MFJ 1278B MULTI MODE APPENDIX B MODEM CALIBRATION MODEM CALIBRATION The MFJ 1278B Modem is factory calibrated to operate all the operational modes it is capable of If it becomes necessary to re calibrate the MFJ 1278B modem please follow the following procedure MODULATOR DEMODULATOR FREQUENCY CALIBRATION Here we present you with two 2 Modulator and Demodulator Calibration Calibration Method I requires test equipment as noted and is the most accurate Calibration Method II does not require test equipment and is meant for those who do not have test equipment Calibration Method I Calibration Method I below as mentioned previously is the most accurate method In order to do the best job possible please follow the procedure as closely as possible Following the procedure closely will ensure that you will calibrate the MFJ 1278B accurately If any step is missed or not performed properly then the performance of the MFJ 1278B becomes questionable Test equipment needed Calibrated Frequency Counter wit
51. MFJ 1278B When an external modem is installed and when it is in selected to operate the TURBO LED on the front panel of the MFJ 1278B will light Contact MFJ Enterprises Inc for more detail For installation of an external modem see APPENDIX F in this manual for more details Special Protocol Timing You can set up a connection time out with the command CHECK which specifies a time in multiples of 10 second intervals This function prevents the MFJ 1278B from getting stuck in a connection when the other station disappears for longer than the specified time The MFJ 1278B uses this time somewhat differently depending on the setting of AX25L2V2 The command RESPTIME sets a delay between the receipt of a packet and the transmission of the acknowledgment packet This delay is used to prevent collisions between an acknowledgment and another packet from the sending station This is primarily necessary during file transfers otherwise the delay is best set to 0 During file transfers the stations receiving the file should set RESPTIME to 10 or 12 default The timing of packet transmission in Transparent Mode is determined by the command PACTIME You can choose the way packet transmission is timed If you are typing input to a remote computer it is usually best to have packets transmitted at regular intervals If your computer is operating a remote host or bulletin board program you should send packets after an interval with no further input from
52. MFJ 1278B what to do 6 129 with the unconnected information left in its buffer 1 Unproto Pactor Initiates a 100 baud unproto connect 6 129 U2 Unproto Pactor Initiates a 200 baud unproto connect 6 129 NPROTO calll Sets the digipeat and destination address fields of packets sent in the unconnected mode CQ NSHIFT on RTTY ASCII Determines the way the SPACE character 1 1 0 Ic o N z is displayed in the RTTY ASCII modes Pactor Specifies number of FEC data packet re 6 130 m transmissions il Packet Controls the manner in which the 6 130 incoming connect requests are handled Color SSTV Specifies the number of pixels sent at the 6 131 start of an SSTV picture that will use the alternate Vistones modem configuration list n see 6 132 Color SSTV This is the TVBreaks like list used for VIS decoding see 6 132 Color SSTV This is the PIXTones like list used for transmitting ROBOT sync tones of 1100 1200 and 1300 Hz Pactor Specifies number of cycles before replying J 6 132 to other TNCs ONIOFF off AMTOR Determines whether A mode Transmission 6 132 takes place any time you type a SPACE or RETURN character URepeats nn USERS n VISTICKS VISBREAKS VISTONES nn CW Sets the weight factor for the CW transmission I command AMTOR Causes the remote mode A ARQ station currently in contact with you to transmit its answer back message on n Enables the flow control 1
53. MFJ 1278B will return to cmd command prompt To stop random code generation type RANDOMCW OFF ENTER MFJ 1278B MULTI MODE BASIC OPERATION CW CONTEST MEMORY KEYER OPERATION For CW enthusiasts who like to use a key paddle to send CW the MFJ 1278B provides an input for an iambic key paddle See CW KEY PADDLE INSTALLATION in chapter 3 in this MFJ 1278B manual for installation of your iambic key paddle Sending CW with External Key Paddle The MFJ 1278B sends key paddle generated CW at 5 to 99 WPM The transmission speed for key paddle CW defaults to the same speed as keyboard CW 20 WPM The user can change the transmit speed by changing the MSPEED command To set the MEJ 1278B to 15 WPM you would type MSPEED 15 ENTER Be sure you are in command mode when issuing the MSPEED command It is always a good idea to match your CW transmit speed with the person to whom you are in QSO with The MFJ 1278B makes it easier for you to match your transmit speed to someone else s through the CWSPEEDM command The CW speed matching feature causes your MFJ 1278B to adopt the speed of the received CW as it s transmit speed When the CWSPEEDM command is ON then the MFJ 1278B will match it s CW transmit speed with the whatever speed was last locked to through the AUTOTRAC routine The MFJ 1278B will also adopt whatever transmit speed is locked in by the ALOCKCHAR character CTRL U will also be The CWSEndch nnn command provides the us
54. MODE ADVANCED OPERATION The actual value used will depend on the average number of queued up stations there are on the channel during busy periods ACKWAIT not directly user settable This timer actually consists of the sum of the 2 user settable parameters ACKTime and DEAdtime It represents the time the queued up TNC will wait before transmitting if it has selected slot 0 This allows time for a completely inaudible to this TNC ACK to have been sent on the channel without molestation It was split into two timers because it has two unrelated components One is related only to the baud rate being used on the channel The other is related only to the absolute times the hardware requires to transport carrier information from one station to another on the channel Other Related Parameters Several of the existing TNC parameters will affect the operation of the modified protocol Most of these are parameters in TNCs on the channel which AREN T using the new channel access procedure One FRACK must be set correctly in any TNC which IS using prioritized ACK protocol FRACK should be set to a value which allows time for the TNC to send its packet AND receive the ACK This value will depend on the settings being used for PAClen and the radio port baud rate This is because for some reason which I can t even begin to understand the FRACK timer starts at the BEGINNING of the packet rather than at the end For this reason it is probably bes
55. MODE BASIC OPERATION After entering the SSTV mode and you have properly selected the correct TV format type K to leave command mode and enter the CONVERSE mode Once in CONVERSE mode the MFJ 1278B is in standby receive mode This means that the MFJ 1278B is listening to the radio for the synchronization signal at the beginning of each SSTV picture If the MFJ 1278B hears the synchronization signal well enough it will establish a lock onto the signal Once the signal is locked in MFJ 1278B will display a A indicates that a lock on the signal is established and MFJ 1278B begins to decode the signal Once decoding is completed the printer attached to the MFJ 1278B will begin to print the captured SSTV picture The MFJ 1278B detects the beginning of each picture before starting to print This insures each picture will be printed from top to bottom If you want the printer to start to print in the middle of the picture you may force printing to begin at any time by typing the letter L while in the SSTV standby receive mode If you notice spaces in the printed picture you should set GRAPHLF to OFF The GRAPHLF command determines whether the MFJ 1278B will issue a line feed before the carriage return on each line of graphics The default for GRAPHLF is OFF For most printers GRAPHLF should be turned ON If the picture printed appears to be distorted in large black areas you should make sure that the command TVHSYNC is set to OFF
56. MYLAR 5 022 UF MYLAR 5 15 UF MYLAR 10 47 UF MYLAR 10 33 UF MYLAR 10 ELECTROLYTIC 1 UF 16 V RADIAL 2 2 UF 16V RADIAL 10 UF 16 V RADIAL 47 UF 16 V RADIAL 100 UF 16 V RADIAL 1000 UF 25 V AXTAL 470 UF 16 V RADIAL APPENDIX I PARTS LIST Component ID C1 C4 C11 C32 C21 C23 C9 C13 C14 C25 C26 C15 C17 C27 C28 C29 C30 C49 C50 C37 C38 C40 C41 C78 C43 C46 C48 C63 C66 C202 C205 C206 C208 C209 C91 C70 C92 C94 C95 R93 C33 4 C68 C55 C52 C45 C89 C57 C97 C98 C58 C44 C65 C3 C6 C7 C22 C8 C18 C201 C10 C31 C203 C204 C99 C16 C12 C75 MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MFJ P N Descrpition CAPACITOR OTHER TYPES 203 8010 204 0060 1 UF 16 V RADIAL TANTALUM TYPE 60 PF TRIMMER 2 LEADS 20 SPACING IC SOCKETS LOW PROFILE 625 0184 625 0031 525 0030 625 0291 625 0292 625 0132 625 0181 IC S 311 0358 311 0004 311 0040 311 1556 311 2045 8 PIN SOCKET 14 PIN SOCKET 16 PIN SOCKET 20 PIN SOCKET 28 PIN SOCKET 32 PIN SOCKET 40 PIN SOCKET LM358 Dual Op AMP LM348N QUAD OP AMP LM324N QUAD OP AMP LM556CN OSC TIMER XR2206CP FSK GENERATOR EYAP RRAND ONT V Component ID C20 C47 U8 U2 U3 U4 U7 U9 U10 U11 U13 U14 U20 U30 U31 U37 U41 U201 U1 U12 U16 U26 U29 U32 U33 U34 U35 U36 U5 U15 U27 U
57. Messages forwarded out of Mailbox will be killed after a forwarding process is complete OFF Default Messages forwarded out of the Mailbox are not killed after a forwarding process is completed The setting of KILONFWD determines whether or not the TNC deletes a message after it has been forwarded If your Mailbox RAM space is critical then you might want to set this command ON Setting this command to ON could cause problems because once a message is killed it cannot be recovered KISS ON OFF Mode Packet Default OFF The KISS interface is installed in firmware of the MFJ 1278B KISS enables the MFJ 1278B to act as a modem for a host computer Turning KISS on allows the MFJ 1278B to run programs such as TCP IP and other programs which use the Serial Link Interface Protocol SLIP Before enabling KISS make sure radio baud rate and terminal baud rate are set to the desired values The terminal s baud rate that s determined at sign on is the same that will be used for KISS Once the operating parameters have been selected set KISS ON and then issue a RESTART command The CON and STA LEDs will blink on and off three times to indicate that the MFJ 1278B has entered the KISS mode Now you may call up a TCP IP or another host program that can use KISS or SLIP If you are using the KA7Q TCP IP program and wish to switch to the AX 25 mode of operation you can issue the command param ax0 255 then press RETURN This command must be
58. Mode A eC eee eene phe S 85 Setting up for Mode A Operations sssseeeeeeeeeeeee nennen nene 85 Operating Mode Ann ede ehe e e tee eed 86 NManitaring Mada A ADO Q7 MFJ 1278B MULTI MODE TABLE OF CONTENTS Summary of AMTOR Contact Sequence seen eene 90 NAVTEX OPERATION etre pere Ee FRE Ere e e eei e HR egent 91 Navtex Stations and Frequencies sees 91 Navtex Op ration 6 n Phe rede tee pe E rire tee iei ele 91 FAX OPERA TION onec ORIG 94 FAX Formats GAIA oles eee DSA hi wien BAT Bae 95 FAX Brequency iet eve et epe nme 96 FAX Installation nhe pne oett ee ree RERO Ee 96 Printer Connection e ehren nnee eee d vor or e E E p RE Her ere 96 Receiving onore OU ke tt d e D teh ee REGE 97 Receiving FAX to the 97 Display FAX Picture on Computer Screen amp Save it to Disk 99 Two Level FAX Picture Formatieren nnn a 99 Multi level FAX Picture Raw Data Format eee 100 Transmittng FAX orte mene uU 101 Two Level FAX Transmitting 5 eee toten trt ret ieterereteekiens 101 Multi level FAX Transmitting eene ener 102 Creating FAX Pictures for Transmitting seen 104 SLOW SCAN TELEVISION OPERATION eese eee 105 SSTV Form ts 4 icit aeos teta feret e EE ER iR eet eerie E Te 106
59. Most of the time two or three bits of the RTTY character may be inverted and it is possible for all 7 bits to be inverted If the baud rate and the type of signal has been determined by ASA and the MFJ 1278B still does not copy correctly the signal may be encrypted with bit inversion In this case you may want to try to use the RBitmask command to set various inversion patterns to match the receive signal but manual setting of the RBitmask command is not necessary The RBitmask command can be invoked when the MFJ 1278B is in the RTTY or ASCII receive mode by simply issuing the CTRL U while the MFJ 1278B is in converse mode Once CTRL U is pressed MFJ 1278B will automatically cycle through each of the bit combinations and then display a sample text of each one of the combination on the screen Examine the list of the displayed text on the screen and if one of the 32 sample text looks normal then make note of the combination number next to the text Do the following to select this combination Denna OTDI AN ta mA inta thn Ad maneant than eA tha Acad Aka with tha MFJ 1278B MULTI MODE BASIC OPERATION MFJ 1278B will enter converse mode and begin to display text normally If another RTTY or ASCII signal from another station is received RBIT must be reset to copy that signal by following the same procedure as described above RBIT can be set to normal no inversion by setting it to RBIT 0 Note that when using ASA noise
60. Parameters nnn 2 nnn 48 MAXUp specifies how many consecutive good receptions of 100 baud information packets are required prior to the MFJ 1278B requests a SPEEDUP to 200 baud Note that if NO200 is set to ON then a SPEEDUP will not occur because the MFJ 1278B will never request a SPEEDUP regardless of the MAXUP value The MAXUP value should be small enough to enable timely SPEEDUP in relatively good conditions while being large enough to avoid pointless speedups during bad conditions MBEGIN cccc Mode AMTOR Default lt lt gt gt The MBEGIN parameter which can be up to 15 characters long is effective when MATCH is ON and a mode B signal is being received When MATCH is ON the MFJ 1278B will not print a mode B transmission until the string in MBEGIN is matched MFJ 1278B MULTI MODE OPERATIONAL COMMANDS MCOM ON OFF Mode Packet Default OFF Parameters ON Connect disconnect UA and DM frames are monitored OFF Only information frames are monitored This command enables monitoring of connect and disconnect frames when MONITOR is ON When MCOM is OFF only I frames packets containing user information will be displayed When MCOM is ON four protocol packets will also be displayed Connect disconnect UA and DM packets that are monitored are indicated by C D UA and DM respectively As with other monitor commands the stations monitored are determined by BUDLIST and LCALLS Path for SABM received
61. R129 102 0057 182K R102 102 5229 229 K R118 102 4392 392K R116 R141 102 0026 133K R111 R117 102 4180 18K R120 102 0052 16 2K R112 102 4150 15 0K R123 102 0018 10 00 K R82 R81 R121 102 0053 22 1 K R92 102 0054 47 50 K R93 102 0055 100 00 K R94 MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MFJ P N Descrpition TRIMPOTS BOURNS OR EQUAL 108 6014 108 7005 108 7006 108 7008 108 7001 10 K BOURNS 3299W 1 103 20 BOURNS 3299 W 1 203 50 K BOURNS 3299 W 1 503 25 K BOURS 3299W 1 253 1 K BOURNS 3299W 1 102 TRIM POT SINGLE TURN MINIATURE 104 1103 10 K Single turn Trimmer POT 17MM SINGLE TURN PCB MOUNT 104 3104 CAPACITORS 205 0010 205 0100 205 0220 205 0470 205 1010 205 1015 1205 1022 205 1047 205 1147 100 K LINEAR TAPER RIGHT ANGLE Component ID R79 R113 R114 R77 R78 R106 R105 R115 R138 R139 R122 R119 R212 R157 R158 R160 R131 MULTI LAYER MONOLITHIC CERAMIC 10 PF NPO 1096 50V 100 PF 220 PF 470 PF 001 UF 0015 UF 0022 UF 0047 UF NPO 10 N47 X7R 1N C51 C61 C60 C72 C59 C5 C67 C54 C53 C71 CTA CO CRI C CA MFJ 1278B MULTI MODE MFJ P N 201 1210 CAPACITORS 201 0018 201 0006 201 0001 201 2247 201 2233 CAPACITORS 203 0006 203 0002 203 0012 203 0014 203 0003 203 2100 203 0004 Descrpition 1 UF 750 20 MYLAR 50V 100V 01 UF
62. SSTV The MFJ 1278B lets you receive black and white SSTV pictures with the built in printer port in 4 levels of gray However with additional software for your computer it can receive and transmit COLOR or B amp W SSTV pictures with up to 16 levels of gray If you are using a standard terminal program that does not support screen printing of SSTV pictures you must attach an EPSON or IBM graphics compatible printer to the MFJ 1278B s parallel printer port in order to allow printing of SSTV pictures If you are using the MFJ 1278B s parallel printer port then SSTV pictures with 4 levels of gray will be supported Pictures received with more than 4 levels of gray will be printed on the printer with only 4 levels of gray The MFJ 1278B will receive through its printer port all of the SSTV pictures formats listed in Table 4 9 It will receive COLOR and BLACK and WHITE SSTV pictures and print black and white on any EPSON or IBM graphics compatible printer To use the SSTV mode in the MFJ 1278B a special computer and program are not required However if you intend to print pictures to the screen or save to disk you will need a program that allows this type of operation Enterprises Inc offers terminal software for some computers to support screen printing of SSTV pictures This software allows you to print COLOR and multi gray level SSTV pictures to the screen and to save SSTV pictures to disk The SSTV pictures saved on disk ca
63. SYSOP can kill them individually NOTE The only way an N flag can get changed to Y flag during a read is that the person who the message is addressed to needs to read it The flag will not change for any other person who reads the message Read Allows you to read the message in slot Where is a particular slot number This command works the same as the R command except its for reading the individual slots Send call This allows the remote user local or remote SYSOP to send a message to the designated callsign CALL must be a callsign valid under the same format as the MYCALL CONNECT or other callsign commands You can also send messages in NTS National Traffic System format You will need to refer to the ARRL NET DIRECTORY for more detailed information on the NTS system SP call This allows the remote user local or remote SYSOP to send a personal message to the designated callsign This is a private message and only the person to whom the message is addressed can read or kill it The SYSOP can also read the private messages When a private message is listed a P flag is shown in the Message Type flag block The P flag can also be inserted by the originator or the SYSOP through the Edit command Detailed Pactor Mailbox Overview In the previous section Brief Overview of Pactor Mailbox we briefly discussed the Pactor Mailbox in general In this section we will go into more detail about the commands that are present
64. The steps in broad outline are 1 Determine the required demodulator center frequency Fc for the radio you intend using in the direct keyed CW mode 2 Set the CW modulator tone to this frequency 3 Set the demodulator center frequency using the modulator tone as reference 4 Set the modulator tone to 700Hz MFJ 1278B MULTI MODE APPENDIX B MODEM CALIBRATION Detailed CW Demodulator Alignment Procedure 1 Determine the required for the demodulator If the radio has a narrow filter for CW one of the 2 methods presented on Pages 19 and 20 in the appendix of this manual should be used to determine the filter center frequency This frequency should be used for Fc If the radio has no narrow CW filter use the CW carrier offset frequency of the radio This information should be available in the your radio manuals Set the modulator tone to the required Fc using the following procedure a b Command the MFJ 1278B into MCW mode by typing MODE MC lt CR gt Install push on jumper at JMP4 This is the watchdog timer defeat jumper Place a push on jumper at JMP 9 pins 1 and 2 This connects the modulator square wave output to the SIO chip so that the CPU can measure the tone frequency for you Install a push jumper at JMP16 pins 1 and 2 and pins 3 and 4 The two jumpers when installed correctly will be positioned from side to side with the leds on the MFJ 1278 facing you Type CALSET n lt CR gt Where n is a numbe
65. U21 11 R20 R22 soldering or the interconnecting cable If the above checks are OK use an oscilloscope to verify that data is present on U21 pin 28 and U9 pin 1 when you strike a key on your terminal If not the data isn t getting from your terminal to the MFJ 1278B Check J1 the cable and U9 again Finally be sure that your terminal actually uses levels less than 3 volts and greater than 3 volts for signal levels 0 and 5 volts may not work especially if they are being used direct from a computer Symptom The MFJ 1278B appears to have lock up i e not responding to any commands This may be due to some invalid parameters having been stored in the memory Try turning the MFJ 1278B off and disconnect JMP 5 on the MFJ 1278B board This will disconnect the memory back up circuit and allow the memory to be erased Re install JMP 5 after about 2 minutes and try operating again MFJ 1278B MULTI MODE PACKET RADIO PROTOCOL PACKET RADIO PROTOCOL EXPLANATION OF PROTOCOL The intention of this chapter is to give the user an overview of the packet protocol used to transmit data by the TAPR software The MFJ 1278B employs the genuine TAPR TNC 2 packet software We give references to more detailed information required by those wishing to implement these protocols on other hardware The material presented below is somewhat tutorial in nature for those who have not had previous exposure to layered network protocols but it presumes some know
66. XFLOW is used to determine the type of flow control used in Transparent Mode If TXFLOW is OFF the MFJ 1278B will use only hardware flow control and all data sent to the terminal remains fully transparent If TXFLOW and XFLOW are ON the MFJ 1278B will use the MFJ 1278B Restart and MFJ 1278B Stop characters set by and XOFF to control input from the terminal Unless TRFLOW is also ON only hardware flow control is available to the computer or terminal to control output from the MFJ 1278B Note that if the MFJ 1278B Restart and Stop characters are set to 00 hardware flow control will always be selected regardless of the setting of TXFLOW TXINVERT ON OFF Mode RTTY ASCII Default OFF When the TXINVERT command is ON the transmitted RTTY ASCII data by the MFJ 1278B is sent inverted i e the marks are sent as spaces and vice versa TXTMO n Mode Packet Default 0 Parameters n 0 65535 TXTMO is a HEALTH counter that registers the number of packet transmitter timeout recovery events that have occurred since the MFJ 1278B was powered up MFJ 1278B MULTI MODE OPERATIONAL COMMANDS TXUIFRAME ON OFF Mode Packet Default ON TXUIFRAME is used to tell the MFJ 1278B what to do with unconnected information left in its buffers When this parameter is ON all unconnected data are transmitted as UI unconnected frames The TXUIFRAME command should be OFF for bulletin board stations as it precludes the unnecessary transmission of text
67. You may see any of the following messages depending on the type of error you have made bad You typed a command correctly but the remainder of the command line couldn t be interpreted call You entered a callsign argument that does not meet the MFJ 1278B s requirements for callsigns A callsign may be any string of numbers and letters including at least one letter Punctuation and spaces are not allowed The sub station ID if given must be a decimal number from 0 to 15 separated from the call by a hyphen EH This message occurs when a command issued is not understood by the MFJ 1278B This will happen if you are in the mailbox or just during standard operation clock not set This message appears if you give the command DAYTIME to display the date and time without having previously set the clock The DAYTIME command sets the clock if it is given with the daytime parameters and displays the date and time if it is given without parameters MFJ 1278B MULTI MODE SYSTEM MESSAGES not enough You did not give enough arguments for a command that expects several parameters For example the command to initiate a beacon every 10 seconds is B E 1 If you issue the command B E the MFJ 1278B gives this message The MFJ 1278B knows there is supposed to be another argument not while connected You attempted to change MYCALL or AX25L2V2 while in a connected or connecting state In order to eliminate this message either disconne
68. are the ones you want to ignore or alternatively are the only ones you want to listen to If you want to listen only for packets from a limited list you should enter this list with LCALLS and set BUDLIST ON You can use this feature for example to have your TNC SEE re OE 22 Sener tet MFJ 1278B MULTI MODE OPERATIONAL COMMANDS BUF n Mode CW RTTY ASCII Default empty Parameter n 0 thru 9 Allows you to load up to ten buffers for use in the CW RTTY ASCII modes Maximum buffer text for each buffer is 120 characters Note that when loading buffer text there is no space between the word BUF and the buffer number selected Buffers may be transmitted by setting up for the appropriate mode and typing the ASENDCHAR character Ctrl T This causes the MFJ 1278B to enter transmit mode Another ASENDCHAR Ctrl T causes the MFJ 1278B to wait for a buffer number At this point enter a digit zero through nine and the buffer will be sent A special case occurs when the character pound sign occurs in the buffer text In this case the MFJ 1278B replaces the with the current value of the SERIALNO counter Once used this value is incremented by one up to a maximum of 65535 where the counter rolls over to zero Also see BUFTIME and SERIALNO commands BUFKEY nnn Mode CW ASCII Default 9 BUFKEY allows user to transmit memory buffers without having to type Ctrl T The default character for BUFKEY nnn is t
69. as CWIdmode The PACTOR commands are executed from the PACTOR p cmd command prompt MFJ 1278B MULTI MODE OPERATIONAL COMMANDS COMMAND EXPLANATION SBITCONV ON OFF Mode Packet Default OFF Parameters ON The high order bit is not stripped in Converse Mode OFF The high order bit is stripped in Converse Mode This command enables transmission of 8 bit data in Converse Mode If SBITCONV is OFF the high order bit bit 7 of characters received from the terminal is removed before the characters are transmitted in a packet The standard ASCII character set requires only 7 bits and the final bit is used as a parity bit or ignored Setting bit 7 in text characters transmitted over the air may cause confusion at the other end If you need to transmit 8 bit data but do not want all the features of Transparent Mode you should set SBITCONV ON and AWLEN 8 This may be desirable for example if you are using a special non ASCII character set Bit 7 is always removed in Command Mode since commands require only the standard 7 bit ASCII character set SLEVELS ON OFF Mode FAX SSTV Default OFF Parameters ON The MFJ 1278B will transmit and receive FAX and SSTV in 8 gray levels OFF The MFJ 1278B will transmit and receive FAX and SSTV in 4 gray levels In the FAX and SSTV modes if SLEVELS is ON the MFJ 1278B will receive and transmit FAX and SSTV data in 8 levels of gray The SLEVELS command is effective only when MULTIFAX and TVX are
70. as an ASCII character code In a standard AX 25 packet the callsign address field will be displayed correctly in the shifted ASCII column A text message will be displayed correctly in the ASCII column Non printing characters and control characters are displayed in both ASCII fields as You can examine the hex display field to see the contents of the sub station ID byte and the control bytes used by the protocol Protocol details are discussed in Chapter 9 TRace ON OFF Mode Pactor Default OFF This command displays continuous debug information to the computer screen This is the MFJ 1278B MULTI MODE OPERATIONAL COMMANDS TRANS Mode Packet Immediate Command This is an immediate command It causes the MFJ 1278B to exit from Command Mode into Transparent Mode The current link state is not affected Transparent Mode is primarily useful for computer communications In this mode the human interface features such as input editing capability echoing of input characters and type in flow control are disabled You may find Transparent Mode useful for computer Bulletin Board operations or for transferring non text files See the discussion of Transparent Mode in Chapter 5 TRFLOW ON OFF Mode Packet Default OFF Parameters ON Software flow control can be enabled for the computer or terminal in Transparent Mode OFF Software flow control is disabled for the computer or terminal in Transparent Mode If TRFLOW is ON the setti
71. assumed complete and the MFJ 1278B then sends an IDLE signal for approximately 15 to 18 seconds This signals the end of the transmission NOTE If your computer does not transmit the data to the MFJ 1278B rapidly enough partial picture transmission will result Also if your computer does not support flow control incorrect operation may result Multi level FAX Transmitting The MFJ 1278B is capable of transmitting up to 16 levels of gray in the FAX mode To achieve this you must use a terminal program that supports the multi level data format required by the MFJ 1278B Each level of gray is represented by a tone produced by the MFJ 1278B modem The tones that can be produced by the MFJ 1278B FAX SSTV modem are 1100 1200 1300 1500 1550 1600 1650 1700 1750 1800 1850 1900 1950 2000 2050 2100 2150 2200 and 2250 frequencies are in KILOHERTZ kHz The tone being transmitted determines the shade of gray in the picture The higher the tone the lighter the shade of gray The 1500 Hz tone is for the sync 1550 Hz is black and 2250 MFJ 1278B MULTI MODE BASIC OPERATION The command PIXTONES is used to set the multi gray levels FAX and SSTV pictures being transmitted The current PIXTONES is set to 16 gray levels PIXTONES defines the gray levels of the SSTV and FAX transmitted by the MFJ 1278B To achieve this you must use a terminal program which supports the multi gray levels SSTV and FAX transmitting such the advanced
72. busy states by 6 MFJ 1278 FLOW ONIOFF Packet Sets type in flow control to the terminal 6 58 59 FLow ON OFF Performs the same as the packet flow 6 59 command Q S o g FORWARD I I command Packet Mailbox Mail forwading to the destination bbs FRACK E Sets the time interval between retries FULLDUP ONIOFF off X Pr Allows communication in full duplex 6 60 ard jas D o o o off GRAPHLF ONIOFF off FAX SSTV Adds an extra line feed in graphic 6 60 printing to the printer HEADERLN ONIOFF off Packet Affects the display format of monitored 6 61 packets HEALLED ONIOFF off Packet Redefines the function of the STA and 6 61 CON LEDs OFF off Packet Controls the sending of identification d packets by the MFJ 1278B AMTOR Sends a keyed modulated CW ID of your station in AMTOR 6 I command 1 Packet Sends a special identification packet to be 6 6 sent in packet Pactor Initiates an immediate CWID to be sent 6 63 663 Pactor Specifies the CWID time interval in the 6 63 Pactor mode mode while in Pactor mode M Packet Determines whether or not the MFJ 6 63 1278B deletes a message after it has been forwarded I command 590 LONFWD ONIOFF off ONIOFF off Allows the MFJ 1278B to works as a 6 modem for special programs such as TCP IP 6 Initiates LongPath connect in the Pactor mode TREAM
73. character is sent as part of the connected message When set ON the bell character immediately preceeds the asterisk portion of the connected message e g lt BELL gt Connected to lt callsign gt When CBELL is ON a tone will also be heard on the external speaker A speaker must be connected to the SPEAKER jack in the rear panel of the MFJ 1278B in order to hear this tone CBell ON OFF Mode Pactor Default OFF Parameters ON Allows the Connect bell to be heard over the monitor speaker OFF Disallows the Connect bell to be heard over the monitor speaker This command is exactly the same as the CBELL command used in packet This command determines whether or not an ASCII 07 or CTRL G BELL character is sent as part of the connected message This command must be ON if the CHObell command is to be used otherwise the CHANGE OVER BELL will not work When the CBELL command is set to ON the bell character immediately recedes the asterisk portion of the connected message e g lt BELL gt Connected to lt CALLSIGN gt When CBELL is ON and a connect is made a tone will be heard on the external speaker A speaker must be connected to the SPEAKER jack on the rear panel of the MFJ 1278B in order to hear this tone MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CCITT ON OFF Mode RTTY Default ON The CCITT parameter selects either an internationally recognized character set CCITT or the U S TTY standard The latter
74. command word or any abbreviation longer than the minimum abbreviation if you like The MFJ 1278B accepts either format of command entry used by the user For example the MFJ 1278B requires the minimum abbreviation of MY for the command MYCALL The abbreviation M is not recognized by the MFJ 1278B as the abbreviation of the MYCALL command The MFJ 1278B recognizes the abbreviation M as the minimum abbreviation for the MONITOR command The MFJ 1278B also accepts the abbreviations MY MYC MYCA MYCAL or MYCALL for the MY CALL command If the command requires parameters they will be indicated after the command name Defaults For commands that set values the MFJ 1278B assumes a most often used or default MFJ 1278B MULTI MODE OPERATIONAL COMMANDS Parameters There are several types of parameters Some parameters can have one of only two values such as ON and OFF or EVERY and AFTER known as KEYWORDS If a parameter must be one of two values the choices are separated by a forward slash You may use YES instead of ON and NO instead of OFF A parameter designated as n is a numeric value These values may be entered as ordinary decimal numbers or as hexadecimal or hex numbers by preceding the number with the symbol When the MFJ 1278B shows some of these numeric parameters those that set special characters they will be given in hex The digits of a hex number represent powers of 16 analogous to the powers of 10 represent
75. data 176 Converse Mode automatic data packetizing 135 211 264 Canvarca Nada antamatin ante O1 MANUAL INDEX MFJ 1278B MULTI MODE MANUAL INDEX Converse Mode entry from Command Mode 119 210 259 309 Converse Mode escape to Command Mode 43 206 Converse Mode flow control to computer 306 307 Converse Mode line cancellation 197 Converse Mode packet cancellation 198 Converse Mode send packet character 283 Converse Mode special characters 122 CRC checksum disregarding 266 CW KEY IN 71 CW operation of 71 CWSEndch 73 CWSPEEDM 73 D Data Carrier Detect 52 Data Communications Equipment 9 321 Data loss 262 Data Set Ready 320 Data Terminal Equipment 9 Data Terminal Ready 320 Data transfer mode automatic entry 121 Data transfer mode Converse Mode 42 121 Data transfer mode entry from Command Mode 119 Data transfer mode Transparent Mode 122 DATA HDLC field 338 Date setting 216 DCD LED 52 Demodulator DCD filter for 300 baud operation 319 Demodulator troubleshooting 335 digipeating 48 Digipeating adjusted retry interval 231 Digipeating avoiding collisions 224 Digipeating default wait time 134 Digipeating display route 312 Digipeating enabling and disabling 220 Digipeating end to end acknowledgments 132 224 344 Digipeating frame acknowledge time 132 Digipeating identification 128 Digipeating monitoring route addresses 252 Digipeating multiple
76. digital stations 44 Digipeating protocol dependence 131 MFJ 1278B MULTI MODE MANUAL INDEX Diodes incorrect installation 332 DIP header U15 319 DISC frames 342 DISC frames monitored 247 Disconnect acknowledged by UA frames 342 Disconnect after exceeding redry count 276 Disconnect causes 312 Disconnect in progress 312 Disconnect initiating a request 220 Disconnect message 313 Disconnect sent as DISC frames 342 DISPLAY 46 Display features ESCAPE translation 227 Display features lt NULL gt transmission 262 Display features cancel output 198 Display features character filtering 137 248 Display features Converse Mode 122 Display features double typing 226 Display features echos 226 Display features line wrapping 282 Display features lower case translation 238 Display features overtyping 262 Display features redisplay line 50 Display features rubout echo 191 Display features Transparent Mode 124 293 Display features type in flow control 230 Display format FRMR 314 Display format monitored packets 233 Display format TRACE 292 Displays computer printing 191 262 Displays computer video 191 262 DM frames 209 313 342 DM frames monitored 247 dot to space ratio 74 Double typing 226 duplex 34 E echoing characters 34 Electrolytic capacitors incorrect installation 332 Entering commands Input editing 172 MFJ 1278B MULTI MODE MAN
77. disables the Pactor changeover PTSend Mode Pactor Immediate Command The PTSend command is basically the same as the U1 Unproto command Entering PTSend from the p_cmd prompt will invoke the 100 baud unproto mode The PTSend is to make the MFJ 1278B s Pactor command set compatible with other Pactor controllers MFJ 1278B MULTI MODE OPERATIONAL COMMANDS QRT Mode AMTOR Immediate Command The QRT command is an immediate command is used to 1 Enda mode ARQ connection When the contact is completed and you are ready to break the link issue QRT to break it and return the MFJ 1278B to standby receive mode 2 Stop a broadcast in mode FEC and mode S SELCALL When you re broadcast is complete type QRT to return the MFJ 1278B to standby receive mode Also please refer see also R R Mode AMTOR Immediate Command R is equivalent to QRT The R command returns the MFJ 1278B to standby receive mode Also please refer to QRT RADIO n Mode All Default 1 Parameters n 2 Specifying the radio port to be used The RADIO command allows the user to select the radio ports of the MFJ 1278B From command mode typing RADIO 1 will cause the MFJ 1278B to select radio port 1 as the active radio port Typing RADIO 2 will cause the MFJ 1278B to select radio port 2 as the active radio port When initially powered up the MFJ 1278B defaults to the radio port it was set to when last powered down RANDOMCW ON OFF Mode CW Default OFF
78. down the contact and does not wait for acknowledgments from the other station The use of the DD command is considered bad manners Always do a D disconnect if possible Monitoring While in the PACTOR mode you are always in Listen mode There is no listen command in the Pactor protocol Therefore you do not need to issue listen command just to listen on a DA VV AD Ta manitar a tinan inot faina tha atanal in until tha MFJ 1278B MULTI MODE BASIC OPERATION information how the CON and STA leds react to incoming signals please refer to the chart on Page 30 of this chapter Monitoring AMTOR ARQ requests AMTOR ARQ requests monitored while the MFJ 1278B in PACTOR mode If the controller detects your selcall in an AMTOR ARQ request packet the controller will switch to AMTOR and try to establish the link This feature allows someone who doesn t have PACTOR capability to connect to you in AMTOR mode Upon termination of the link the 1278 will switch back to the PACTOR The is active when the MFJ 1278B switches to the AMTOR operation When the MFJ 1278B switches back to the PACTOR you will see the p cmd prompt again Exiting PACTOR Mode To exit the PACTOR mode please type CTRL C and the p cmd prompt will appear Once the p cmd prompt is on the computer screen type the following EXIT ENTER the MFJ 1278B will respond with the standard cmd prompt Once back at the c
79. explained later in this instruction NOTE Whenever CR is found in this instruction this means to press the RETURN key not to type CR 1 Under the cmd prompt type MYMCALL n CR where n is the callsign you wish to use for your mailbox station identification The MFJ 1278B will respond with the previous setting of the MYMcall command followed by the cmd prompt on the next line 2 From the cmd prompt please type USERS 1 CR The MFJ 1278B will respond with the previous setting of the USERS command followed by the cmd prompt on the next line 3 Ifyou want your messages time and date stamped then set DAYTIME with the current information Please refer to Chapter 6 Page 43 in your MFJ 1278B operations manual as to how to set the DAYTIME parameter Note An optional TNC real time clock MFJ 43 for the MFJ 1278B is available from MFJ Enterprises With this real time clock module installed in your MFJ 1278B the clock will continue to keep time even with the MFJ 1278B turned off You will not have to set your MFJ 1278B s DAYTIME every time your MFJ 1278B is powered up 4 access the mailbox type the following from the cmd prompt MAILBOX ON CR Now your MFJ 1278B is ready for simultaneous Mailbox Packet operations You as the SYSOP can access your Mailbox by typing SYSOP CR MFJ 1278B MULTI MODE ADVANCED OPERATION Your MFJ 1278B will respond with IK MFJ 2 1a IH Mailbox ready n
80. f e Packet Retrieves the count of tries on the 6 122 f f f f ej eJ D a oo 121 a key on your keyboard Used to tune the MFJ 1278B modulator 6 122 and demodulator nn o currently selected input stream M Keys the PTT and low tone for the current 6 122 o modem for 30 seconds or until you strike n see 6 122 SSTV Sets the brightness and contrast of SSTV 6 123 picture received on the built in printer port TVHS TVMODE 1 Selects the formats under the SSTV mode 6 124 SSTV Enables multi gray levels SSTV raw data 6 125 to be sent to the terminal without any SSTV format 3 Packet Tells the MFJ 1278B how long to wait after keying up the transmitter before sending data Pactor Sets time between PTT key up and actuial data transmit Packet Controls a new timer that runs after the S regular TXDELAY time has expired l Packet Invokes efficient key up technique in transmitted packet to increase throughput ONIOFF All Enables the software flow control for the 6 128 transparent mode TXINVERT ONIOFF off RTTY ASCII Inverts the mark and space on the 6 128 emi end an g ge 4 S5 zx lt 88 fi fi c fi n YNC ONIOFF fi SSTV Allows MFJ 1278B to look for Hsync on 6 124 dark area around the picture fi 3 fi fi 2 MFJ 1278B MULTI MODE APPENDIX COMMAND SUMMARY r TXUIFRAME ONIOFF on Packet Used to tell the
81. files you will have to use Transparent Mode Transparent Mode is a data transfer mode like Converse Mode In this mode there are no special characters everything you type and everything your computer sends to the MFJ MFJ 1278B MULTI MODE ADVANCED OPERATION The display characteristics of the MFJ 1278B are also modified in Transparent Mode Data is sent to the computer exactly as it is received over the radio including all 8 bits of each byte received Features such as auto linefeed insertion and screen wrap are disabled and echoing of input characters is disabled The parameters that control these features in Command Mode and Converse Mode are not changed by entering Transparent Mode and all display features are re enabled when the MFJ 1278B is returned to Command Mode Most of the link status messages that appear as the MFJ 1278B moves between disconnected and connected states are also disabled in Transparent Mode In order to permit the Command Mode entry character to be transmitted freely in Transparent Mode the escape to Command Mode from Transparent Mode has been made a little more complicated You can still return to Command mode by transmitting a BREAK signal just as in Converse Mode You can also utilize the Command Mode entry character in the following way You must wait for a time period after typing the last character to be sent This time is set by the command CMDTIME Following this wait you must type three Command Mode ent
82. given in its operating instruction manual to receive and transmit FAX FAX operation procedure given in this instruction only applies to receiving 2 level FAX and printing it to an EPSON graphic printer attached to the MFJ 1278B printer port MFJ 1278B MULTI MODE BASIC OPERATION FAX Frequency FAX transmitting stations are usually found on the HF bands Weather FAX stations are generally upper sideband Some of these stations maintain a regular schedule Table 4 7 lists the frequencies of some FAX stations Frequency KHz 3 357 00 4 268 00 4 975 00 6 946 00 10 865 00 12 125 00 20 015 Photographs 10 680 70 17 673 90 18 434 90 20 738 00 Other FAX Frequencies The following frequencies were obtained from Popular Communication Magazine Table 4 7 FAX STATION FREQUENCIES FAX Installation The radio interface for FAX operation is the same as for the other modes of operation The radio connection between the MFJ 1278B and your radio is described in Chapter 3 of the MFJ 1278B manual Printer Connection If you have a terminal program that supports FAX printing to the computer screen then you should attach your printer to your computer printer port and not to the MFJ 1278B In this case turn the PRINTGRA command OFF If you intend to receive the FAX picture and send it to the printer that is attached to the MFJ 1278B parallel port then turn the PRINTGRA MFJ 1278B MULTI MODE BASIC OPERATION Receiving FAX From command
83. is used by many older surplus mechanical teletypes that have been taken out of commercial service and placed into amateur use This parameter is only significant when in Baudot RTTY mode While the standards are nearly identical stations in in the United States are advised that the FCC requires part 96 69 a stations in Baudot RTTY service utilize International Telegraph Alphabet Number 2 ITA No 2 as specified by the International Telegraph and Telephone Consultative Committee CCITT Note that when CCITT is ON Baudot RTTY codes received but not assigned in the ITA No 2 standard are printed as they would have been had the U S TTY standard been selected CHANGE Mode AMTOR Immediate Command The CHANGE command causes your station to switch from being the mode A ARQ receiver to being the transmitter CHANGE forces the direction of the link to switch without using the over signal It is valid only during a mode connection when you are the receiver CHAT Mode Mailbox Immediate command The SYSOP may at any time break onto the mailbox s connected link The resulting mode is like the a typical CONVERS mode packet connection CHAT immediately terminates any user or forwarding operation in progress At the point when the SYSOP invokes Chat mode the SYSOP and the connectee are in an actual packet QSO This is good to discuss problems with the Mailbox or equipment failure CHAT mode continues until the SYSOP returns to command m
84. is used for both the User Restart and User Stop characters the MFJ 1278B will alternately start and stop transmission upon receipt of the character MFJ 1278B MULTI MODE OPERATIONAL COMMANDS STREAMCA ON OFF Mode Packet Default OFF Parameters ON Callsign of other station displayed OFF Callsign of other station not displayed This command is used to enable the display of the connected to station after the stream identifier This is particularly useful when operating with multiple connections allowed It is somewhat analogous to the use of MRPT to show digipeat paths when monitoring In the example below the charaters inserted by enabling STREAMCAII are shown in bold face type A K4NTA hi howie ello ted how goes it B WA7GXD CONNECTED to WA7GXD Bmust be a dx record ge lyle Aunreal ted fl az no digis B WA7GXD big band opening ge etc The same sequence with STREAMCAII OFF would look like the following Ahi howie hello ted how goes it B CONNECTED to WA7GXD Bmust be a dx record ge lyle Aunreal ted fl az no digis Bbig band opening ge etc Thus what would have looked like IB now appears as IB callsign This option is very useful for human operators trying to operate multiple simultaneous connections It is probably less useful for host operations Note that in the first example the STREAMSWitch characters IA and IB with no after them were entered by the operator of the TNC to
85. issued under TCP IP net gt prompt and in lower case letters Once the MFJ 1278B receives the param ax0 255 command it turns KISS off and will revert back to ordinary AX 25 mode of operation When the MFJ 1278B is powered on again it will sign on to the AX 25 operation mode If KISS is turned on and you have problem revert the MFJ 1278B back to normal AX 25 operation with the above procedure you can also turn KISS off by removing JMP5 on the 2245 5 Mts AAS 4 Miop we _ ox MFJ 1278B MULTI MODE OPERATIONAL COMMANDS Lc callsign Mode Pactor Immediate Command Initiates an ARQ link to the specified callsign using extended LONGPATH timing to support long txdelays or long skip paths This type is generally used when the destination is over 40 000 Km away where the standard Connect command timing will not work LCALLS call1 call2 call8 Mode Packet Default Parameters call Callsign list Up to 8 calls separated by commas Each callsign may include an optional sub station ID specified as n immediately following the call The n specification being a sub station ID of up to 2 digits This command works in conjunction with BUDLIST and allows selective monitoring of other packet stations These two commands determine which packets will be displayed when you have set MONITOR ON BUDLIST specifies whether the callsigns in the list are the ones you want to ignore or alternatively are the only ones you want t
86. jack on the MFJ 1278B The MFJ 1278B requires only one speaker for RADIO 1 and RADIO 2 The MFJ 1278B will automatically switch the monitor speaker to the radio port in use If wiring of a speaker plug is necessary use a 3 5 mm 1 8 mono or stereo plug for this connection The tip of the plug is positive and the sleeve of the plug is negative The tip of the plug must be connected to the positive side of the speaker The sleeve of the plug must be connected to the negative side of the speaker Note that only one speaker is needed for both radio ports The MFJ 1278B will automatically switch the speaker to the correct radio port in use The speaker jack on the MFJ 1278B is for monitoring of received and transmitted audio including CW side tone The speaker is used to provide a signal to the operator when a packet connection has been established A small audio amplifier is built in the MFJ 1278B to drive the external speaker Volume of the monitor speaker is adjustable by using the Monitor control on the left side of the MEJ 1278B If the internal amplifier of the MFJ 1278B does not provide adequate volume you may use an external audio amplifier You can disable received audio transmitted audio or the packet connect tone from the speaker monitor jack by cutting a trace between the pins of the following jumpers See Appendix G for the locations and functions of JMP jumpers JMP X Transmitting Audio JMP Y Receiving Audio JMP Z Packet Connec
87. may be at 2 4576 MHz or 4 9152 Mhz The MFJ 1278B operates at the faster clock of 4 9152 MHz Capacitors C59 and C60 are used to slow the edges of the outputs of U4a and capacitor C61 is used to slow the edges from U10f helping to reduce RFI Counter Ul is a multiple stage divide by two circuit that divides the signal at its input many times This allows the switches within U30 and U31 to select the desired signaling baud rate to be used for your computer or terminal as well as the radio channel baud rate The output from counter U1 at pin 12 provides a real time clock interval signal for the SIO During normal operation the SIO will be programmed to interrupt the CPU on every transition of this 600 Hz signal This interrupt occurs 1200 times a second and is used for protocol and calibration timing functions MFJ 1278B MULTI MODE HARDWARE Inverter U10e buffers the radio port 16x baud rate signal in case it is routed via modem disconnect J4 pins 11 and 12 to an external modem If this buffer were not included reflections from the distant termination might cause counter U1 to generate count errors Counter U4b provides a properly scaled clock for the transmit NRZ to NRZI encoder see Serial Interface below CPU Complex EPROM U23 provides system ROM for program storage Selector U12a acts as a ROM decoder mapping the ROM into the CPU s memory address space beginning at address 0 Static RAM provides system RAM for temporary scrat
88. mode the MFJ 1278B can be set to FAX mode by typing MODE FX ENTER Select the desired FAX mode by typing FAXMODE n ENTER where n is the FAX format as indicated by the FAX Format Table 4 6 For HF weather FAX select FAXMODE 3 The default FAX mode for MFJ 1278B is FAXMODE 3 or 120 lines per minute format This is the format used by most weather FAX stations For other FAX format use other n value as listed in Table 4 6 Set the PRINTGRA command to ON if you are printing the FAX pictures to the printer attached to the MFJ 1278B parallel printer port Set the PRINTGRA command to OFF if you are printing the FAX pictures to the computer screen Note that to print FAX picture to the computer screen requires a terminal program that will perform this function Set the audio output of your radio to normal volume Tune your radio to a desired frequency If you are not familiar with recognizing FAX signals you may want to select one of the weather FAX frequencies listed above Weather FAX Faxmode 3 is usually transmitted at 120 lines per minute This is a horizontal scanning rate of 2 lines per second So by listening to the scanning rate you can determine what format you should set the MFJ 1278B on to receive the signal After tuning in the desired FAX frequencyon your radio set the THRESHOLD control to maximum clockwise rotation Tune the radio so that the DCD LED remains lit Now observe the TUNING INDICATOR of the MFJ 1278B while fine tu
89. mode to command mode Type CALSET n lt CR gt Where n is a number determined by n INT 525000 F high 1 Command the MFJ 1278B into calibrate mode by typing CAL lt CR gt Command the MFJ 1278B to key the modem by typing Select the high tone by pressing the space bar until a voltmeter connected to U16 pin 9 reads 5 volts Adjust R105 carefully until both the CON and STA LEDs on the front panel of the MFJ 1278B are lit One of the leds may flicker slightly This is normal This exits the MFJ 1278B from calibrate mode to command mode This completes the modulator tone alignment using the built in calibration facility If you had any problems with this section then DO NOT go beyond this point If you do the calibration will be inaccurate However if all went well then you may proceed Now that the modulator tones have been properly centered over the intended modem center frequency Fc now the demodulator center frequency will be aligned Demodulator Center Frequency Alignment 1 9 4 Place push on jumpers at JMP 4 and JMP 7 if they are not already in place Remove jumper at JMP 9 pins 1 and 2 Place it at pins 2 and 3 Remove the the jumpers at pins 1 and 2 and pins 3 and 4 of JMP 16 Replace the jumpers at JMP 16 at pins 1 and 3 and pins 2 and 4 When finished the two jumpers at JMP 16 should be positioned from side to side with the leds on the MFJ 1278 facing you Set t
90. nennen nennen 127 Monitor Functions 127 Real Time Clock and Time Stamping serene 128 Multi Connect ieie eerie oeeo e oa ii 129 Setting the MFJ 1278B to Normal Operation esee 129 How do I Invoke Multi Connect sese 129 Mailbox ios et eret d vore eie i Ed e RE eto et 130 Setting Up your Easy Mail Mailbox eee 131 Mailbox Operation eioen 136 Additional Mailbox Features 140 Forwarding uiae eet ete eR ters 140 Eliciting Reverse Forwards 141 R mote Heard niai D rael 141 Chat Mod itid nee quim pie ERU RIP ER 141 Page S YSOP 5 seeded pie decide eie eed doe dee tie ied 141 Remote SYSOP eo qe e PUSHED e Ui eee E 142 Mailbox CText eite nemen DR Oe EV 142 Idle Timeout pte reete iieri ERES 142 UI P M 142 Mailbox M SS88684 occae rg tese epe 142 Slotting and Acknowledgment Priority eese eene 144 DeseriptiOn ico tnr hee REOR REP UI eet 144 New Parameters inen er p e eco ure t eet i idee cre e rre 146 Other Related Parameters sess nee ens 148 Initial Parameter Settings
91. not active participants in the QSO also see ERUS MAILbox ON OFF Mode Pactor Default OFF Parameters ON Brings the Pactor Mailbox on line OFF Takes the Pactor mailbox off line The MAILbox command activates the MFJ 1278B s Pactor Mailbox mode The MAILbox command works in conjunction with the Packet MAILBOX command Both the Packet and Pactor Mailbox commands need to be ON for the Pactor mailbox to function MFJ 1278B MULTI MODE OPERATIONAL COMMANDS MAILBOX ON OFF Mode Packet Default ON Parameters ON Brings the Packet mailbox on line OFF Takes the Packet mailbox off line When the MAILBOX command is set to ON all of the mailbox functions are active Note that the MAILBOX is a single user device therefore if you wish to use the MAILBOX it is necessary for you to set USER 1 and select Stream A Note that these are the default settings and selections respectively However as we mentioned in Chapter 5 the Mailbox has been significantly improved For more extensive information on the new improved Mailbox please refer to Chapter 5 The Pactor Mailbox command does not need to be ON for the Packet mailbox to function If you wish to have your messages time and date stamped then make sure that DAYTIME is set with the correct time or else each message entered without DAYTIME will not be shown A basic explaination of the Mailbox commands are as follows K Kills all messages addressed to you depending on the setting of th
92. off the air with the command ID The MFJ 1278B will only send identification packets if it has been digipeating Automatic Operations Normally any packet station can be used by other stations for relaying or digipeating packets to a more remote destination If you don t want your station digipeating packets you can give the command DIGIPEAT OFF Unless there are special circumstances such as a station operating on emergency power most packet operators set DIGIPEAT ON in the spirit of Amateur cooperation Your station will normally accept a connect request from another station if it is not already connected You can disable this capability by setting CONOK OFF If you receive a connect request when CONOK is OFF the MFJ 1278B will display the message connect request lt callsign gt and send a busy signal rejection packet to the other station If you receive a rejection packet from a station you try to connect to your MFJ 1278B will display lt callsign gt busy DISCONNECTED If you want to have a special message sent automatically to stations connecting to you you can specify the message with the command CTEXT This message can consist of any text string up to 120 characters and you may include lt CR gt s by prefixing them with the pass character cmd CTEXT Sorry I can t talk right now lt CTRL V gt lt CR gt I ll be on the air again after 8 PM lt CTRL V gt lt CR gt Joe In order for this message to be sent
93. operation R157 and R158 are used to set the audio output levels to the transmitter U20 an XR2211 provides a Phase Locked Loop PLL FSK demodulator It converts the received audio FSK signals into digital data at standard logic levels This data is sent to the state machine clock recovery and NRZI to NRZ format conversion circuits Trimpots R79 R113 R114 and R115 are used to calibrate the PLL demodulator s free running frequency that is set midway between the FSK tones being received These tones are measured by the calibration software and the output signal produced by U8a and U8b which is a frequency doubling shaping circuit Power Supply Regulator Q3 and associated components provide a 5 volt regulated output for the MFJ 1278B digital logic circuitry In order to reduce conducted RFI from the digital power source series inductor L1 is provided Transistor Q4 in conjunction with CMOS the inverters in U14 provide a power failure circuit for the battery backed RAM chips to ensure that RAM is in the power down state when the main power is removed In addition this circuit provides the main power on reset signal via U7f MFJ 1278B MULTI MODE HARDWARE Transistors Q5 and are used to isolate the battery from the 5 volt line when main power is available R33 protects the lithium battery from overload conditions and provides a convenient means of monitoring battery current drain when the TNC is switched off JMP5 provides a me
94. or AC voltmeter This will be near the correct amount of audio for NBFM operation Levels higher than this will not degrade the modem performance as long as the receiver audio amplifier is capable of producing the chosen output level without distortion clipping While still listening to unsquelched receiver noise rotate the DCD threshold control on the front panel of your MFJ 1278B clockwise until the DCD LED just flickers with false data carrier indications This control should be set to produce approximately a 10 duty cycle of false DCD activity when receiving unsquelched NBFM receiver noise The modem sensitivity to false DCD will be affected by the bandwidth of the audio coming out of the receiver some receivers produce wideband audio which will NOT produce any false DCD activity regardless of the threshold control setting In this case set the DCD threshold control to its maximum clockwise rotation Modem performance will not be affected IMPORTANT NOTE Harmonics Interference If you experience harmonic interference from the crystal oscillator in the MFJ 1278B adjust trimmer capacitor C47 Trimmer capacitor C47 is located near the crystal Slowly adjust C47 to move the frequency of the harmonic MFJ 1278B MULTI MODE RADIO INTERFACING MONITOR SPEAKER CONNECTION The MFJ 1278B has a built audio amplifier to provide audio for an external monitor speaker A Monitor speaker such as the MFJ 280 can be can be connected to the SPEAKER
95. or more digipeated packets This usually gives the digipeater a clear MFJ 1278B MULTI MODE ADVANCED OPERATION The wait time is set by the command DWAIT which specifies 40 ms intervals If no digipeating is being done by anyone in the local area this parameter can be set to 0 but in any event it should be set to the same value by all members of a local packet group In order to avoid unnecessary packet retries the MFJ 1278B implements a collision avoidance strategy which applies to all packets except those being digipeated On the second and subsequent transmissions of a particular packet the MFJ 1278B waits an additional random time after detecting a clear channel before beginning transmission This prevents re peated collisions of transmissions by the same two stations The random time is a multiple 0 15 of the TXDELAY time The interval in milliseconds between the MFJ 1278B detecting carrier drop and beginning to transmit is Wait time DWAIT 10 for the first transmission of a packet For subsequent transmissions of the same packet the interval is Wait time DWAIT 10 TXDELAY 10 where r is a random number from 0 to 15 Thus if your MFJ 1278B is forced to re transmit packets you will occasionally hear a fairly long delay before transmission begins Multiple packets may be transmitted before waiting for an acknowledgment This permits more efficient channel use when large amounts of data are being transfer
96. packet involved in a collision will be retried If you have an odd number of stations participating in this sort of conversation one station can connect to himself via another station as digipeater or example WB6YMH WDOETZ WAOTTW WIBEL and K9NG wish to carry on a group conversation In order to make all the transmissions as reliable as possible the following connections are made WB6YMH connects to WIBEL WAOTTW connects to KONG WDOETZ connects to WDOETZ via WIBEL If each station specifies MCON ON and MALL ON each station will see the packets sent by all the others Ordinarily only text packets are displayed If you want to see some of the protocol packets you can set MCOM ON and connect disconnect disconnect acknowledgments and DM connect request rejection packets will be displayed For example WB9FLW gt N7CL lt C gt KV7B gt N2WX lt D gt indicates connect and disconnect packets Disconnect acknowledgments are designated UA and DM packets are DM You can cause the MFJ 1278B to filter certain characters from monitored packets with the command MFILTER This allows you to remove for example form feeds bell characters or extra LF s that may be necessary to the stations involved in a connection but which may interfere with your display You can specify up to four characters by giving the ASCII character codes in hex or decimal Real Time Clock and Time Stamping You can enable the MFJ 1278B s real
97. print FAX or SSTV pictures In addition to being able to print such as weather FAX FAX and SSTV pictures the printer connected to the MFJ 1278B printer port can also print incoming text in all modes as it is received on the screen This means that you can keep a log of all your QSOs To print text to the printer you will need to connect an IBM compatible parallel printer to the MFJ 1278B printer port Printers without Epson compatible graphics will not be able to print Weather FAX FAX or SSTV Printer Port Test After properly connecting your printer to the MFJ 1278B you may verify its compatibility as follows 1 Turn on your computer Load and run the terminal program 2 Turn on the MFJ 1278B The MFJ 1278B should sign on with the cmd prompt sign 3 Type PRINTTES CR If the printer is connected correctly and is compatible it will print a string of 223 characters Again this only shows that the printer connected can print text It does not necessarily indicate that your printer can print graphics unless it is Epson or IBM graphics compatible 4 Printing will start with ASCII SPACE value 32 decimal and end with the value 255 decimal that is not an ASCII character but may be a graphics character 5 Once the printer has completed the printing the MFJ 1278B will return to cmd prompt sign This completes the printer test If the printer test was satisfactory proceed to connect your radios to the MFJ 1278B The above
98. result 3 When performing any troubleshooting and the problem is found NEVER do any work with the MFJ 1278B ON and connected to the computer or terminal 4 If performing any repair on the MFJ 1278B always ensure the power switch is OFF 5 When doing any soldering always keep the soldering tip clean and use only enough solder to do the job properly A good solder joint has a nice shiny look where a cold solder joint presents a dull grayish appearence GENERAL TESTS In most cases we have found that careful visual inspection combined with simple measurements generally reveals the problem The most useful single instrument for successful troubleshooting is a good DVM that can read AC and DC volts and can non destructively test resistance while the ICs are still in their sockets While a number of checks may be made without the aid of an oscilloscope you will need one to check signals at various points on the board if you fail to locate the problem by visual means or with a meter Be very careful about shorting pins on ICs when applying meter or scope probes to the board It is a good idea to attach a secure ground lead to the meter or scope one that will not accidentally short across components on the board A good place to pick up this ground is on the head of the screws which mount the printed circuit board to the case MFJ 1278B MULTI MODE TROUBLESHOOTING Step 1 Power Supply The first thing to check in any malfunctio
99. return For FAX and SSTV receive modes the GRAPHLF setting determines whether the MFJ 1278B will issue a line feed ASCII value 10 decimal character before the carriage return on every line of graphics For most printers GRAPHLF should be set to ON The setting of GRAPHLF to ON could result in blank spaces between printed graphics lines If this occurs then set GRAPHLF to OFF and you should notice the spaces in the printed pictures disappear HEADERLN ON OFF Mode Packet Default OFF Parameters ON The header for a monitored packet is printed on a separate line from the packet text OFF The header and packet text of monitored packets are printed on the same line This command affects the display format for monitored packets If HEADERLN is OFF the address information is displayed with the packet KV7D N2WX Go ahead and transfer the file If HEADERLN is ON the address information is displayed followed by the packet text on a separate line N2WX gt KV7D Sorry I m not quite ready yet If you have set ON or enabled MSTAMP you may wish to set HEADERLN ON as the packet header quickly becomes long enough to fill a screen when these functions are active MFJ 1278B MULTI MODE OPERATIONAL COMMANDS HEALLED ON OFF Mode Packet Default OFF Parameters ON The MFJ 1278B will dither the CON and STA LEDs OFF The MFJ 1278B will control the CON and STA LEDs in normally This command allows the user to redefin
100. same delay time The default setting for AXDELAY is 0 MFJ 1278B MULTI MODE OPERATIONAL COMMANDS AXHANG n Mode Packet Default 0 Parameters n 0 20 specifying the voice repeater hang time in 100 ms intervals This value can be used to increase channel efficiency when an audio repeater with a hang time greater than 100 ms is used For a repeater with a long hang time it is not necessary to wait for the repeater keyup delay after keying the transmitter if the repeater is still transmitting If the TNC has heard a packet sent within the hang period it will not add the repeater keyup delay AXDELAY to the keyup time If you are using a repeater that hasn t been used for packet operations before you will have to experiment to find the best value for n If other packet stations have been using the repeater check with them for the proper setting Note that the TAPR TNC 1 and other TNCS using the same version 3 x firmware interpret n in 120 ms intervals The value you set on MFJ 1278B for AXHANG will thus be 6 5 the value used by a TNC 1 user for the same hang time when converting round down to the nearest integer BBSMSGS ON OFF Mode Packet Default OFF This command controls how the MFJ 1278B displays certain messages in command and CONVERSE modes The messages affected are described below MESSAGE EFFECT WHEN BBSMSGS ON E CONNECTED to A newline is added just before DISCONNECTED A newline is added just befo
101. selected 2 Connect the noise source to the receiver input Make sure there is no antenna connected to the system and that the receiver is tuned to a frequency which is free of coherent internally generated signals birdies 3 Setthe noise source output for a reading of approximately S 9 on the receiver S meter 4 Connect the counter to the receiver audio output 5 Adjust the receiver output level for enough audio to reliably trigger the counter 6 Make sure the radio s IF shift control if one is present is in its proper position centered or on detente 7 Record the frequency indicated by the counter The counter should indicate the average frequency of the noise spectrum passed by the filter in the receiver and translated to audio by the product detector This will be the frequency used for the modem center frequency Fc NOTE If the counter is a phase locked loop PLL based prescaling type its PLL may not lock properly to the noise signal If this is the case use method 2 below If your counter can resolve 1 Hz with a counting gate time of less than 1 second it is a PLL prescaling counter MFJ 1278B MULTI MODE APPENDIX D HF RADIO SECOND METHOD FILTER SKIRT AVERAGE FREQUENCY 1 2 10 Set the receiver to LSB mode with the 500 Hz filter selected Make sure the radio s IF shift control if one is present is in its proper position centered or on detente Using either a signal generator or a stable
102. send after CR or lt LF gt This command specifies the number of NULL characters ASCII code 00 to send to the terminal after a CR or lt LF gt is sent In addition to setting this parameter value NUCR and or NULF must be set to indicate whether nulls to be sent after CR lt LF gt or both Devices requiring nulls after CR are typically hard copy devices requiring time for carriage movement Devices requiring nulls after lt LF gt are typically CRTs which scroll slowly Extra null characters are sent only in Converse and Command Modes OK Mode ASA Immediate Command OK is an immediate command used in conjunction with the ASA commmand When the results are displayed using the ASA mode the user can issue the OK command to accept the results analyzed by ASA Typing OK will cause the MFJ 1278B to select the operational mode and match the speed automatically against the signal being analyzed MFJ 1278B MULTI MODE OPERATIONAL COMMANDS OMLC ON OFF Mode AMTOR Default OFF Parameters ON Character convert to lower case enabled OFF Character convert to lower case disabled Output Map to Lower Case OMLC when ON instructs the MFJ 1278B to convert all letter characters except those echoed to their lower case equivalent PACLEN n Mode Packet Default 128 Parameters n 0 255 specifying the maximum length of the data portion of a packet The value 0 is equivalent to 256 The MFJ 1278B will automatica
103. set to 0 in Transparent Mode PASS n Mode Packet Default 16 Parameter n 0 7F specifying an ASCII character code This command selects the ASCII character used for the pass input editing command The parameter n is the ASCII code for the character you want to type in order to include the following character in a packet or text string You can enter the code in either hex or decimal You can use this character to send any character in packets even though that character may have some special function For example suppose you have set COMMAND 3 specifying that lt CTRL C gt is your Command Mode entry character If you use a Bulletin Board program that requires a lt CTRL C gt to escape from some operation you will type lt CTRL V gt lt CTRL C gt to insert a lt CTRL C gt character in your packet Of course if you do this frequently you would be better off to change your Command Mode entry character The default PASS character is lt CTRL V gt MFJ 1278B MULTI MODE OPERATIONAL COMMANDS Parameters nnn 0 lt nn lt 255 The Pactor PASS command is the same as the PASS command in the other modes The PASS command does not work for Y Changeover PASSALL ON OFF Mode Packet Default OFF Parameters ON The MFJ 1278B will accept packets with invalid CRCs OFF The MFJ 1278B will only accept packets with valid CRCs This command causes the MFJ 1278B to display packets received with invalid CRC fields Packets are a
104. shorts cold joints etc MFJ 1278B MULTI MODE TROUBLESHOOTING Symptom The MFJ 1278B appears to be signing on but only gibberish is printed on the terminal eThis indicates that some combination of the data rate baud rate parity option or number of start and stop bits are not set the same at the MFJ 1278B and at the terminal If possible set your terminal to 1200 baud Also verify that the terminal is set for eight data bits no parity and 1 stop bit These are the default settings stored in EPROM Perform a hard reset by the power switch OFF then ON out then in The sign on message should appear If the MFJ 1278B still prints gibberish verify that the terminal is set to the MFJ 1278B s baud rate and do a power off then on cycle on both the MFJ 1278B and terminal If the message still fails to appear try troubleshooting with an oscilloscope looking first at the TXD pin pin 26 of U21 Z8440 then at the x16 baud rate clock 19200 Hz at 1200 baud on pin 27 of U21 Symptom The MFJ 1278B signs on OK but won t accept commands After the MFJ 1278B signs on try giving it a command such as MYCALL or any other command If the default settings are in effect it will attempt to echo each character you type back to the screen If it does not echo be sure that U21 pin 23 has a voltage level between 0 and 0 8 volts on it The voltage on U9 pin 3 should be greater than 3 volts If these voltages aren t correct the fault could be in U9
105. switch streams for his multiple pee PROS TA oun lem T e m LC xr c x MFJ 1278B MULTI MODE OPERATIONAL COMMANDS STREAMDB ONIOFF Mode Packet Default OFF Parameters ON Double all received STREAMSWitch characters OFF Do not double received STREAMSWitch characters This command is used to display received STREAMSWitch characters by doubling them The example below illustrates this action With STREAMDB on and STREAMSWitch set to I the following might be displayed from your MFJ 1278 ll this is a test In this case the sending station actually transmitted this is a test The same frame received with STREAMDBL OFF would be displayed as this is a test When operating with multiple connections this is useful for differentiating between STREAMSWitch characters received from other stations and STREAMSWitch characters internally generated by your MFJ 1278B NOTE The STREAMSWitch character must NOT be one of the stream letters A J for this command to function properly STREAMSW n Mode Packet Default 7C Parameters n 0 SFF usually specifying an ASCII character code This command selects the character used by both the MFJ 1278B and the user that a new stream connection channel is being addressed The character can be PASSed in CONVERS mode It is always ignored as a user initiated ntanna cOeieAl i2 MTD nda 42 4 n nn dae Thin mannna that tha
106. the messages are in The lower case t is the Type Flag block The lower case m is the Message Flag block The To column will contain the callsign of the person who the message is addressed to The From column will contain the callsign of the person who left the message The Subject column will contain a brief message title Then at the end of the message the Mailbox prompt will be issued 7 The remote user can also disconnect from the Mailbox without having to issue CTRL C D and a RETURN that needs to be done is to type B to logout of the Mailbox and disconnect from the it If you access your Mailbox via the SYsop command then you must issue a CTRL C to exit the Mailbox and return to command mode The command prompt will indicate the stream you are on The command prompt may look like this lAcmd where indicates that you are on packet stream A MFJ 1278B MULTI MODE ADVANCED OPERATION This is the only way the remote users can access your Mailbox If you stay in the SYSop mode then when a user tries to connect to your Mailbox he will a message like this CALLSIGN Busy Disconnected The SYSOP will receive a message like the example below when he is in the SYSOP mode and someone tries a connect connect request CALLSIGN Additional Mailbox Features Other MFJ 1278B mailbox features are as follows Forwarding The MFJ 1278B Mailbox now has the ability to Forward mail to most full service and personal mailb
107. the software reads the state of the CTS line If you find that the MFJ 1278B seems to lose data during file transfers you should immediately suspect a flow control problem XON XOFF Flow Control If you are using a terminal rather than a computer or if your computer does not support DTR CTS flow control you should use XON XOFF flow control which is enabled by setting XFLOW ON The special flow control characters are set to CTRL S and lt CTRL Q gt by default but they may be changed The commands XON and XOFF set the characters which will be sent to the terminal by the MFJ 1278B and the commands START and STOP set the characters to be sent to the MFJ 1278B by the terminal Your computer may receive as many as 4 characters from the MFJ 1278B after sending a STOP character since some characters may already be in route through serial I O chips If you send a STOP START character to the MFJ 1278B when it is already stopped started the character will be ignored If the STOP and START character are the same character this character will toggle the output turning it off if it is on and on if it is off You can disable XON XOFF flow control in one direction only by setting the appropriate flow control characters to 0 If you do this the MFJ 1278B will automatically use CTS flow control to stop input from the terminal XON XOFF flow control is normally disabled in Transparent Mode since all characters are treated as data If you can
108. then MOVE OFF TO A CLEAR FREQUENCY to carry on the QSO Remember to be aware of the frequencies your station is actually transmitting so you can avoid interference to other services such as propagation beacons etc 2 Configure your station so that you can hear the activity on the channel This will allow you to easily avoid interfering with other stations and also to quickly diagnose the problem when throughput suddenly falls off for some reason usually propagation or interference 3 If possible use the highest frequency band possible to communicate with any specific station The closer you are to the maximum usable frequency MUF the less intersymbol interference you will have from multipath effects If you have a schedule with another station arrange your times and frequencies accordingly 4 Set the following parameters off unless you have some specific reason for doing otherwise DIGIPEAT OFF There is NO reason good enough to enable this function on HF DW AIT 0 OFF AX25V2 OFF CHECK 0 OFF CMSG OFF RETRY 0 Try forever but NOT if unattended operation This allows YOU to be the one to decide when or whether to give up rather than the MFJ 1278B Typically you know more than the MFJ 1278B does about whether the other station is still trying or is likely to recover from the latest fade MAXFRAME I1 Multiple frames OFF RESPTIME O Some stations may have trouble copying your ACKnowledgments ACKs when you respond this f
109. then hook it up to the MFJ 1278B in the same way Use whatever program you ordinarily use to communicate with the modem Pin Signal Name Serial data from your computer to the MFJ 1278B Serial data fromtheMFJ 1278B to your computer Signal Ground The common ground for both data lines Table 2 1 Serial port signals required by MFJ 1278B If your computer is listed in Table 2 2 refer to the specific information in the following sections to connect your MFJ 1278B to your computer Apple Macintosh tm Apple ILILI IIe II gs tm VIC 20 tm C 64 tm C 128 tm MFJ 1278B MULTI MODE COMPUTER INTERFACING Many computers require a serial port adapter card These cards incorporate the circuitry necessary to add an RS 232C port to the computer Some popular models in this category are the Apple II series the IBM Personal Computer many Radio Shack computers and the Sanyo MBC 55X series If you have one of these computers with an add in serial port or if you have another computer we haven t mentioned you should skip to one of the sections on other computers If your computer has a 25 pin RS 232C serial port refer to the section on Other Computers with 25 pin RS 232C Ports Otherwise refer to the section Other Computers with Nonstandard Serial Ports Some computers have no serial port and no adapter is commercially available Such computers are not suitable for use with the MFJ 1278B COMPUTER WITH SPECIFIC SERIAL INTE
110. there that also lost a frame and will probably have exactly the same criterion for deciding when to retry the transmission as this station is using In order to avoid a second collision the collision avoidance protocol calls for the stations retrying transmissions to wait a random time interval after hearing the frequency become clear before they key their transmitters There must be enough different random wait times to provide a reasonable chance of two or more stations selecting different values The difference between adjacent time values must be similar to the keyup time delay of typical stations on the frequency This is the time lapse after a station keys its transmitter before other stations detect its presence on the channel and is a function of the kevine circuitrv of MFJ 1278B MULTI MODE PACKET RADIO PROTOCOL through the same digipeaters to the originating station Since the digipeated packets are not acknowledged to the digipeater an unsuccessful transmission must be retried from scratch by the originating station In order to help alleviate the congestion of the frequency that tends to result when digipeated packets suffer collisions the digipeater is given first shot at the frequency every time it becomes clear Other stations instead of transmitting as soon as they hear the channel clear must wait a short time DWAIT This restriction applies to all stations except the digipeater which is permitted to transmit relayed packets
111. to be monitored The MCON command controls the action of monitor mode when the MFJ 1278B is connected monitor functions are disabled in Transparent Mode If MONITOR is Ann n 1 rau 1 131 1 MFJ 1278B MULTI MODE OPERATIONAL COMMANDS MRPT ON OFF Mode Packet Default ON Parameters ON Display the stations in the digipeat path for monitored packets OFF Display only the source and destination stations for monitored packets This command affects the way monitored packets are displayed If MRPT is OFF only the originating station and the destination are displayed for monitored packets If MRPT is ON the entire digipeat list is displayed for monitored packets and stations that have already relayed the packet are indicated with an asterisk For example WB9FLW2AD7LK9NG N2WX 7 Hi Paul This packet sent from WB9FLW to AD7I has been relayed by KONG but not by N2WX 7 With MRPT OFF the same packet would be displayed as WB9FLW gt AD7I Hi Paul Setting MRPT ON increases the length of the address display and you may wish to set HEADERLN ON as well to display this information on a separate line MSPEED n Mode CW MCW Default 20 Parameters n 5 to 99 specifying a characters transmit speed The value of the MSPEED setting controls the speed of CW sent by the MFJ 1278B Values below 5 WPM automatically cause a 5 WPM speed to be selected When MSPEED is less than 15 WPM and FARnswor is ON the MFJ 1278B uses the Fa
112. to reach it For example you might see the following display WBO6YMH gt WDOETZ KV7B Hello Bill This packet was sent from WB6YMH via KV7B to WDOETZ If there are several digipeaters or if the message lines are long the display may be difficult to read The HEADERLN command can make reading the displayed information much easier You can put the address header on a separate line from the text by setting HEADERLN ON WB6YMH gt WDOETZ KV7B Hello Bill Ordinarily the MFJ 1278B will stop displaying monitored packets if you connect to another station permitting you to converse without interruption The reason for this is that the setting of the MCON command The MCON command is defaulted to the OFF state If you want to monitor activity while connected to a packet station set MCON ON While the MFJ 1278B is monitoring the packet frequency it is keeping a record of all the stations heard These stations are recorded into the MHEARD log or list To display the list of stations heard since the last time your MFJ 1278B was powered up type the following from the cmd prompt MHEARD lt ENTER gt the MFJ 1278B will respond with a List of stations much like the example below AD7I WA7GXD N2WX NK6K KV7B followed by the cmd prompt The last several stations whose packets were heard by your MFJ 1278B are displayed The entry KV7B means that KV7B was heard digipeating a packet rather than sending one of his own You can clear the hea
113. to stations connecting to you you must set CONOK ON so that t e connection takes place default and enables the automatic message with CMSG ON 3 m m CET ene ne ore MFJ 1278B MULTI MODE ADVANCED OPERATION You can have your station periodically send an automatic message by enabling beacons A beacon can be used to make general interest announcements provide packets for other stations to use to test their ability to receive or announce the presence of a bulletin board operation The beacon message is set with the command BTEXT which works the same way as the CTEXT command You enable beacon transmission and set the frequency at which beacons are sent with the command BEACON To transmit the beacon at 10 second intervals for example give the command cmd BEACON EVERY 1 The beacon function also has a transmit after mode enabled by using the keyword AFTER in place of EVERY in which a beacon packet is only transmitted after activity is heard on the channel This feature might be used to leave an announcement for other packet users If someone transmits on an otherwise idle channel a beacon can be sent a short time later No beacons are sent in this mode if there is a lot of packet activity on the channel since the required period of quiet will not occur Unattended Operations Individuals who want to leave their MFJ 1278B on overnight can monitor packets even with the terminal or computer off Just type CTRL S then turn the
114. to what is happening Below is a table as to how the leds will act Status Indicator STA CON Pactor Status 0 0 RX N A TX N A MON The TNC is idling and has not monitored any information packets in the past second 0 1 RX Sending ack control signal TX Last packet acknowledged MON Received new packet 1 0 RX Dupe rcvd sending Request control signal TX Received request control MON Received dupe packet 1 1 RX Info packet missing sending request TX Control sign missing retransmitting MON MFJ 1278B MULTI MODE BASIC OPERATION PACTOR MAILBOX The MFJ 1278B now includes a new feature called PACTOR MAILBOX In this section we will cover basic operation of the new Pactor Mailbox and the operative commands The Pactor Mailbox includes the basic commands of the Packet mailbox The Pactor Mailbox is very simple and easy to use Any amateur radio operator who has Pactor capability can access your Pactor Mailbox after establishing the initial connection to your station You MFJ 1278B must be in the PACTOR operating mode You must also have the MAILBOX command ON in the Pactor command set The Pactor MAILBOX command is separate from the Packet mailbox command The Packet MAILBOX command needs to be ON too The Packet MAILBOX command defaults to ON Once the remote user connects to your Pactor Mailbox the user can obtain a list of the messages in your mailbox read or kill any message addressed to him A few functions such as the SYS
115. transmits only if there is no carrier The RF carrier is not normally detected however an input is available on the MFJ 1278B radio interface connectors to allow such an input In order to make detection of a busy channel more reliable the MFJ 1278B sends an audio signal continuous flags any time the transmitter is keyed and a packet is not being sent as during the transmitter keyup delay TXDELAY or while a slow audio repeater is being keyed AXDELAY By itself CSMA is not enough to insure a minimum or even low interference rate due to the likelihood of simultaneous keyup by two or more stations This is where collision detection and collision avoidance come in The MFJ 1278B detects a collision by the absence of an ACK from the station it is sending to The receiving station does not acknowledge the frame that suffered the collision since either the FCS was incorrect or the packet was not heard There are other possible reasons for non receipt of the packet but the MFJ 1278B s response is based on the assumption of a collision After transmitting a packet the MFJ 1278B waits a reasonable length of time FRACK for an acknowledgment Reasonable is determined by the link activity frame length whether the packet is being digipeated and other time related factors If no ACK is received the packet must be re sent If the unACKed frame was lost due to a collision the assumption is that there is at least one other packet station out
116. unkey then re key the transmitter by typing the K key If you wish to defeat the watch dog timer place a shorting jumper at JMP4 2 With the MFJ 1278B keying the transmitter and transmitting the higher of the two tones adjust the transmit audio level as follows 3 Adjust R s the variable resistor installed for proper modulation level typically between 3 0 and 4 5 kHz deviation for Amateur FM If FM test equipment is not available adjust R S until the audio signal on the monitoring receiver is decreased by half of the maximum level This can be estimated by ear or accurately determined by measuring the output voltage across the speaker with an oscilloscope or AC voltmeter If there is not adequate audio level from the MFJ 1278B to make adjustment of R s then you can increase the output level of the MFJ 1278B by adjusting R157 for radio port 1 or R158 for radio port 2 The transmitting audio output of both radio ports is factory set at 250 mV p p 4 Press the K key to return to receive mode and type Q to exit the calibration routine You have now set your transmitter deviation to approximately the correct level Remove JMPA if you placed it in Step 4 5 Carefully remove the variable resistor and measure its value This is the proper value of R S for your particular radio 6 Select the nearest standard value fixed resistor 1 4 watt is fine and permanently install this resistor as R S in the interface circuit 7 If you have acc
117. user can send code either from the computer keyboard or a key paddle The key paddle must be connected to the CW KEY IN jack on the back panel of the MFJ 1278B When working CW on the MFJ 1278B with a key paddle you have a full fledged Memory Keyer at your disposal The MFJ 1278B provides the user with ten programmable memory buffers These memory buffers are able to be programmed with message of up to 120 characters Besides the buffer memory MFJ 1278B provides automatic serial numbering The WEIGHT command determines the DOT SPACE ratio This is to allow compensation for leading or trailing edge delays in many transceiver keying circuits The built in random code generator allows CW code practice A TUNE command is also built in for radio tuning The MFJ 1278B supports all Alpha and Numeric characters It also will transmit and receive punctuations and major prosigns as listed in Table 4 4 below PROSIGNS ASCII CHARACTER Keyboard Symbol PROCEDURE BT Break 5 6 SN 01 derstood 5 K JInwiaiontoTranmit mmo E et PUNCTUATIONS oy RIGHT PARENTHES Ss MFJ 1278B MULTI MODE BASIC OPERATION Receiving CW The MFJ 1278B receives international Morse Code from 1 to 99 WPM Reception of alphabetic and numeric characters including the puncuations and prosigns listed in Table 4 4 From command mode put the MFJ 1278B in the CW Mode by typing MODE CW xx
118. will have major effect on the degree of its effectiveness If no signal is present while the MFJ 1278B is in ASA mode the display will display Wtg CD User will simply press the Return key to return to CMD command prompt There is no need to type ASA to go back into the ASA mode because once invoked ASA is always active MARS OPERATION The MFJ 1278B sets a few commands to simplify MARS operation These commands are PROfmars and MARsmode With PROfmars and MARsmode the MFJ 1278B is more compatible with MARS than ever We have made operating MARS with the MFJ 1278B more fun and enjoyable The following section should be very useful to the MARS operator Configuring for MARS When PROfmars is invoked profiles the MFJ 1278B for MARS operations When this command is invoked it sets the following parameters as specified MARS Setting AUTOLF CCITT DIDDLE Once the MFJ 1278B is profiled for MARS operations the user must set the MFJ 1278B into HF RTTY mode by typing MODE HB 75 lt ENTER gt MFJ 1278B MULTI MODE BASIC OPERATION Once you have set your operating mode the user must press the K key and a ENTER in order to enter RECEIVE mode The MARS operator is now ready to receive MARS traffic The operator must then tune the VFO on the radio so the tuning indicator on the MFJ 1278 is centered on the bar graph display The received traffic should be coming to the screen in the proper MARS format Operating M
119. will never delay it s own acknowledgments Description The idea behind the prioritized acknowledgment ACK protocol is quite simple The idea is to give ACKs priority access to the channel so that time is not wasted retrying packets that have already been correctly copied but for whatever reason the ACK is not received within the time limit defined by the FRACK timer The present protocol does not handle a simplex LAN with hidden terminals as well as it possibly could This is primarily because the present protocol is more likely to synchronize collisions with acknowledgment packets than with any other type of packet To this collision svnchronization mechanism the current version of AX 25 adds a propensitv MFJ 1278B MULTI MODE ADVANCED OPERATION Once the FRACK timer times out even if the ACK finally makes it through before the MFJ 1278B sends the retry the MFJ 1278B sends the original packet anyway This obviously wastes much time that could be better used clearing the channel of some of the legitimate offered load It is this feature of the current AX 25 protocol that accounts for most of the abysmally poor performance of the currently popular NETROM and THENET nodes when are used as omni directional single channel or even multi channel if there is more than a single other node on each channel systems It should be noted that these node chips CAN handle point to point links to a single other node perfectly adequately The p
120. without any further delay here we go into PACTOR Operation First we need to get the MFJ 1278B to sign on To sign on the MFJ 1278B please perform the following l Verify the power switches to both the computer and the MFJ 1278B are OFF 2 Connect the MFJ 1278B to both the radio and the computer 3 Connect the radio to a dummy load 4 Set the POWER switch on the computer to the ON position then load the terminal program MFJ 1278B MULTI MODE BASIC OPERATION Now that we have the MFJ 1278B signed on to the computer let s put it into the PACTOR mode To put the MFJ 1278B into PACTOR mode please type the following MODE PT ENTER The MFJ 1278B will respond with MFJ PACTOR 2c 1022 free p cmd At the above prompt you are in the PACTOR mode Any commands entered such as TXDELAY or ECHO will only affect the PACTOR mode Many of the commands of PACTOR have the same name as the general commands but DO NOT share the same parameters At the p cmd prompt you can monitor AMTOR ARQ requests to your SELCALL PACTOR ARQ requests and PACTOR FEC Enter your call in the MYCALL parameter up to 8 characters The format of the MYCALL command is as follows MYCALL n ENTER where n is your amateur callsign up to 8 characters FEC Unproto operation There are two FEC modes 100 baud and 200 baud Properly tune the radio before entering either of the FEC modes The reason for this is as soon as you initiate an FEC unproto
121. without changing the operation mode If the analyzed result is acceptable the user will simply type OK lt ENTER gt MFJ 1278B MULTI MODE BASIC OPERATION In the case of analyzing a 300 baud signal the MFJ 1278B will prompt the user that the signal could be PACKET If this occurs then the user can enter the following command from the cmd prompt OK Packet ENTER The MFJ 1278B will switch to the 300 baud HF packet mode If the user just issues the OK command then the MFJ 1278B will switch to the 300 RTTY or ASCII mode The number of data bits ASA analyzed determines if the MFJ 1278B switches into RTTY or ASCII modes If data bits was 5 then ASA will switch the MFJ 1278B into RTTY mode If the data bits were 7 ASA will switch the MFJ 1278B into ASCII mode If the ASA result is a 100 baud signal the MFJ 1278B will prompt the user that the signal could be AMTOR If this occurs then the user can enter the following from the cmd command prompt OK AMTOR ENTER When the OK AMTOR command is given the MFJ 1278B will switch to AMTOR mode B Follow the AMTOR operating procedure to go to any of the other AMTOR modes If the user does not issue the OK AMTOR command the MFJ 1278B will switch to 100 baud RTTY Note that if RTTY or ASCII signals are analyzed and the user accepted the result by typing OK and the MFJ 1278B still does not copying the signal correctly This may due to the signal being encrypted with bit inversion
122. 0 250 each increment represents 10 milliseconds This is the time between when a remote TNC has pressed PTT and when the local TNC can reasonably be expected to detect this fact This must be set to a value that accounts for the slowest acceptable station on the channel It includes the time required for the remote station s radio to come on the air properly after assertion of PTT TXDelay and the time required for the local station s squelch if used and TNC DCD circuits to allow generation of a DCD true signal in the local TNC Ideally once the proper value for this timer is ascertained all stations on the channel will use the same value Very preliminary testing done here on VHF indicates that measurements of the above delay times should be multiplied by 1 5 for use as the DEAdtime parameter We had carefully measured the times for all stations participating in our tests This gave us a worst case delay total of 210 milliseconds When we ran the test we were still getting about a 5 percent collision rate on the acknowledgments We were required to increase the DEAdtime parameter to 30 300 milliseconds to completely eliminate collisions with ACKs PNAS ot eee Ao eae en a ee ee oh eee m 452 AL ets ot MFJ 1278B MULTI MODE ADVANCED OPERATION Some HTs and every Azden PCS 2000s that I have ever seen are incapable of operating in a LAN which is using a 300 millisecond setting for this paramet
123. 0 OF P27 7 Table 5 1 ASCII Codes for Control Characters V tri 0 lt CTRL L gt 0 lt CTRL M gt A Es Qimis icimiwiuw E A Mm BR oo eee ee mpelje A V a o V wn dd A EN 6 8 0 Zz mex PACKET OPERATING MODES In Chapter 4 we discussed two of the packet operating modes Command Mode and Converse Mode Packet also can operate in the third mode Transparent Mode which is a data transfer mode like Converse Mode but is intended primarily for computer data interchange rather than human conversation In the following sub sections we will briefly describe all three of these modes Command Mode Command Mode is used to enter commands that alter the MFJ 1278B s operating parameters All the other MFJ 1278B operating modes are entered from Command Mode When the MFJ 1278B is in Command Mode the Command Mode prompt cmd ie nrinted at the heoinnino af each innit line Nate however that if the MET 1278R hac MFJ 1278B MULTI MODE ADVANCED OPERATION stored in the system EPROM The bbRAM memory stores most of the parameter values in a permanent but easily changed form The following commands set special characters that are active in Command Mode Please refer to the discussions of the special character commands in Chapter 6 for details on the operation of the characters in Command Mode Also see the section on speci
124. 05 1010 205 1110 CAPACITORS ELECTROLYTIC RADIAL 203 0006 0047 UF X7R 10 50V 022 UF X7R 10 50V 1 UF ZSU 20 50V 001 UF X7R 1096 50V 01 UF X7R 10 50V 1 UF 50V C1 C2 C13 C3 C6 C12 C15 C16 C17 C18 C19 C20 C21 C22 C23 C24 C5 C14 C7 C10 C4 MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MFJ P N Descrpition DIODES 300 0003 1N4148 300 8001 1N34A TRANSISTORS 305 0001 2N3904 305 0003 2N5088 305 6005 VNIOKM IC S 311 2049 XR2123ACP PSK MODEM 311 0001 741CN SINGLE OP AMP 311 2069 MFIOCCN DUAL ACTIVE FILTER 310 3157 74HC157P QUAD 2 IN MULTIPLEXER 310 0010 4024B 7 STAGE BINARY COUNTER 310 3004 74HC04 HEX INVERTER 310 4193 74HCT193 UP DOWN COUNTER 311 0039 TLO84CN BI FET QUAD OP AMP IC SOCKETS LOW PROFILE 625 0031 14 PIN 625 0030 16 PIN Component ID D1 D4 D6 T2 T5 T6 1 T3 IC7 IC10 IC3 IC4 IC9 IC6 IC8 IC5 1 1 MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MFJ P N Descrpition 625 0292 28 PIN MISCELLANEOUS 405 0095 CRYSTAL HC18 U 4 608 MHZ 612 1021 1 CENTER RIGHT ANGLE 5 POS HEADER 612 3210 1 CENTER TOP ENTRY 10 POS DUAL ROW SOCKET CONNECTOR 612 0033 1 CENTER 3 POS HEADER 612 4001 2 POS SHORTING JUMER FOR 862 2400B PCB FOR 50 2400B 1 APPROX 4 X 3 5 Component ID Y1 JMP 14B CNI CN 6 CN6 MFJ 1278B MULTI MODE MANUAL INDEX Manual Index ix Identificati
125. 1 Command Mode display output cancellation 198 Command Mode echos 226 Command Mode entry from Converse Mode 43 121 206 Command Mode entry from Transparent Mode 124 Command Mode entry to data transfer mode 259 Command Mode error messages 310 Command Mode exit to Converse Mode 210 Command Mode exit to Transparent Mode 293 Command Mode line cancellation 197 Command Mode prompt 118 Command Mode special characters 119 Command AUTOLF 35 Command Defaults 118 Command NUCR 35 Command NULF 35 Command NULLS 35 Command SCREENLN 35 commands 16levels 178 Commands 8BITCONV 176 commands 8LEVELS 176 commands AALT 178 Commands ABORT 178 Commands ACKPRIORITY 179 Commands ACKTIME 179 Commands ALOCKCHAR 180 Commands ALTCALL 180 Commands ANSBSTR 180 Commands ANSWRQRA 181 Commands ARCVCHA 183 Commands ARCVCHAR 182 Camman dao ADA 1920 MFJ 1278B MULTI MODE Commands AUTOLF 185 Commands AUtolf 185 Commands AUTOTRAC 186 Commands AWLEN 176 187 Commands AX25L2V2 187 201 Commands AXDELAY 52 188 Commands AXHANG 52 188 commands basic 32 Commands BBSMSGS 189 Commands BEACON 193 Commands BEACON EVERY AFTER 190 commands BKONDEL 49 Commands BLP 192 Commands BTEXT 190 311 Commands BUDLIST 237 Commands BUF 194 Commands BUFKEY 195 Commands BUFTIME 195 Commands BWNL 195 Commands CALIBRA 196 Commands CALSET 196 Commands CANLI
126. 1 Command Mode entry and exit 259 TNC 1 protocol compatibility 339 TNC 1 TXDELAY parameter 297 TNC Restart character 300 305 Transmit keying troubleshooting 334 Transmit inhibiting 128 305 Transmit watch dog timer 319 Transparent Mode automatic entry 261 Transparent Mode automatic packet transmission 264 Transparent Mode display features 124 Transparent Mode entry from Command Mode 119 259 293 309 Transparent Mode escape timing 203 Transparent Mode packet formatting 130 Transparent Mode software flow control 293 300 Transparent Mode special characters 122 Troubleshooting 331 Troubleshooting equipment 331 TTL logic levels 333 TUNE 71 75 Tuning Indicator 41 Tuning indicator 315 TXDELAY 47 c 15 modulator configuration header 319 19 demodulator configuration header 319 A frames 342 A frames monitored 247 JI frames 234 301 342 Jnconnected packets sent as UI frames 339 342 nconnected packets setting address 301 ser Stop character 293 qaeaca Cee VIC 20 terminal program 12 Watch dog timer 319 xXYT 1 we a nan
127. 1111110 to detect frame boundaries A technique called bit stuffing is used to keep all other parts of the frame from looking like a flag ADDRESS The ADDRESS field holds the specified destination address The AX 25 protocol uses a minimum of 14 bytes and up to a maximum of 70 bytes that contains the actual callsign of the source destination and optionally up to eight digipeaters CONTROL The CONTROL field holds a byte that identifies the frame type In the AX 25 protocol the control field may include frame numbers in one or two 3 bit fields PID The PID field holds the Protocol IDentification byte The PID appears as the first byte of the HDLC DATA field in AX 25 Level Two information frames The PID identifies which Level 3 protocol is implemented if any In the case where no Level 3 protocol is implemented PID 0 DATA The DATA field contains the actual information to be transferred The DATA field need not be present Most frames used only for link control do not have data fields FCS MFJ 1278B MULTI MODE PACKET RADIO PROTOCOL The communications chip recognizes the opening and closing flags and passes the address control and data fields including PID to the software The FCS field is a Frame Check Sequence computed by the transmitting chip and sent with the frame The receiving chip recomputes the FCS based on the data received and rejects any frames in which the received FCS does not match the computed FCS There is
128. 13 Table 8 4 J13 Pin Out J13 Pin Pin Function 2 No connection SSTV FAX select SSTV FAX transmit control Data Bit 7 19 0 2 EXTERNAL MODEM INTERFACE CONNECTOR J14 The External Modem Interface Connector J14 is available for easy and quick addition of the 2400 or MFJ 9600 modems The External Modem Interface Connector J14 is a 5 pin straight type header located just in front of the RS 232C serial port connector Below in Table 8 5 is the pin out of the External Modem Interface connector J14 Table 8 5 External Modem Interface Pin Out MFJ 1278B MULTI MODE HARDWARE MODEM DISCONNECT HEADER J4 The modem disconnect header J4 on the MFJ 1278B PC board is provided for using an external modem with the MFJ 1278B This allows use of higher speed modems such as 9600 baud or more sophisticated higher performance modems for OSCAR or other uses The following information is primarily for those who wish to interface external modems to the MFJ 1278B Familiarity with modem and serial data channel terms is assumed The use of the modem disconnect header J4 requires a definite working knowledge of modems and serial data communications and associated terminology person without the required knowledge should not do any type of modifications in the area of the modem disconnect header J4 The signals used at connector J4 are at standard TTL interface levels A TTL high or 1 is greater than 2 4
129. 15 an optionally specified sub station ID SSID This command tells the MFJ 1278B what its callsign is This callsign will be placed in the FROM address field for all packets originated by your MFJ 1278B It will accept frames with this callsign in the TO field and relay frames with this callsign in the digipeat field MYCALL will also be used for identification packets see HID and ID The default callsign must be changed for proper operation of the protocols There should never be more than one station with the same callsign including SSID on the air at once The SSID can be used to distinguish two stations with the same Amateur call The SSID will MFJ 1278B MULTI MODE OPERATIONAL COMMANDS MYzcall callsign Mode Pactor Default MFJPACTR The MYCALL command is the same as the MYCALL command used in the Packet mode The MYCALL command can take callsigns up to 8 characters in length The callsign used must be at least 4 characters in length MYALIAS call n Mode Packet Default lt blank gt Parameters call Alternate identity of your MFJ 1278B n 0 15 an optionally specified sub station ID SSID This command specifies an alternate callsign in addition to the callsign specified in MYCALL for use as a digipeater only In some areas wide coverage digipeaters operators have changed the callsign of their machine to a shorter and usually easier to remember identifier International Civil Aviation Organization ICAO airport i
130. 152 MHz User Port Clock Switch selectable at 16x baud rate Memory All memory in industry standard JEDEC Byte Wide sockets Standard complement of ROM 1 Megabit 128K x 8 1 x 27C101 Standard complement of system RAM 32K 1 x 43256C 15L Standard complement of mailbox RAM 32K expandable to 512K 1 x 43256C 15L Serial Port 78440 SIO 0 type device port B configured as UART plus low Portpower TTL to RS 232C signal level interface Baud rates supported 300 1200 2400 4800 9600 and 19 200 Standard female DB 25S DCE RS 232C connector An 8 pin molex male connector for TTL serial port Modem Demodulator XR2211 PLL demodulator circuit plus related components to receive up to 1200 baud Modulator XR2206 modulator circuit plus related components to produce tones for all modes of operation Built in modem calibration system MFJ 1278B MULTI MODE HARDWARE bbRAM Non volatile storage of all important operating parameters is accomplished by using a battery backed up system for the entire 32K bytes of system RAM and all mailbox RAM Protocol AX 25 Level 2 is supported Pre Version 2 0 support is compatible with earlier TAPR TNCSs running 3 x software Full support of Version 2 0 protocol is provided Full duplex radio link operation is supported Packet Operating Modes Command Mode Allows the user to communicate with the MFJ 1278B Multi Mode via commands typed in by the user Command Mode is where all of
131. 2 x 25 machine screw For installing above spacer MOUNTING NUT FOR R131 PANEL WASHER FOR R131 M3 X 6 SCREW FOR MOUNTING PCB TO CHASSIC amp REGULATOR TO CHASSIS NUT FOR MOUNTING VOLTAGE VOLTAGE TO CHASSIS 4 X 1 4 TYPE B BLACK FOR MOUNTING FACE PLATE 4 40 X 1 4 BLACK SCREWS FOR INSTALLING COVER PC BOARD 7 X 9 5 REV 10 DISPLAY PC BOARD ASSEMBLY SAME AS 1274 GRAYSCALE PC BOARD ASSEMBLY ALUMINUM CHASSIC WITH PRESS ON SPACERS AND PEM NUT INSERT NOTE MASK OUT PAINT ON BOTH SIDES OF THE BOTTOM CHASSIS PIECE THIS IS TO INSURE GOOD CONTACT WITH COVER REDUCE EMI Oc Na 3 0 WTA K DY TA DANAN Dev MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MFJ P N Descrpition Component ID 806 0210 1278 CABINET COVER NOTE MASK OUT PAINT ON THE INSIDE OF THE TOP CHASSIS PIECE THIS IS TO INSURE GOOD CONTACT WITH CHASSIS REDUCE EMI 770 1162 STICK ON RUBBER FEET 781 2110 FCC STICKER INSTALL UNDER CHASSIS 781 1118 SERIAL NO STICKER INSTALL ONE UNDER CHASSIC AND ONE ON OUTSIDE OF GIFT BOX 852 1027 SMALL FORM PACKING INSERT 852 1028 LARGE FORM PACKING INSERT 850 1108 1278B PRINTED GIFT BOX WITH REVISED ARTWORK FOR REV 10 PCB ADDITION PARTS FOR MFJ 1278BT ONLY 50 2400B 1 2400 BAUD MODEM PCB ASSEMBLY 10 22008 MODEM CONNECTING CABLE ASSEMBLY 3 5 PIN CONNECTOR JUMPER CABLE WITH 5 POS IDC SOCKET ON EACH END 716 2050 5 NYLON MOUNTING SPACER 700 3063 6 32 X
132. 25 MACHING SCREW FOR MOUNTING MODEM PCB NOTE FOR MFJ 1278T BEFORE INSTALLING 50 2400B 1 MODEM PCB ASSEMBLY REMOVE ALL SHORING JUMPERS ON J4 BOM for Display PC Assembly P N 50 1274 2 100 0009 470 ohm 1 4 W 5 R209 R210 MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MFJ P N Descrpition Component ID 205 1210 1 UF 250 20 C209 MONOLITHIC CAPACITOR 625 0182 18 PIN IC SOCKET U204 U205 625 0291 20 PIN IC SOCKET U202 U203 311 1056 LM3914N BAR GRAPH DISPLAY U204 U205 DRIVER 320 2010 MV57164 10 SEG BAR GRAPH U202 U203 DISPLAY RED GI OR LTA 1000P OR EQUAL 861 1274 2 PC BOARD FOR 50 1274 2 620 6108 8 COND RIBBON JUMPER CABLE 735 1128 RIGHT ANGLE BRACKET FOR MOUNTING DISPLAY PCB BOM for Grayscale PC Assembly P N 50 1278 3 RESISTORS 1 8W 1 102 3215 2 15K R301 102 3113 1 13K R302 102 0604 604 ohm R303 102 3301 3 01 K R304 102 3158 1 58 K R305 102 0845 845 Ohm R306 102 4137 13 7 K R308 Teimnot 1 amp Turne Ranenc ar Fanal MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MFJ P N Descrpition Component ID Capacitor Monolithic Ceramic 205 1210 1 UF 250 20 C301 C304 Capacitor Electrolytic 203 0012 10 uf 16V Radial C302 C303 IC Sockets 625 0031 14 pin Socket U301 U302 625 0030 16 pin Socket U305 U306 625 0291 20 pin Socket U303 U304 IC s 310 3074 74HCT74 D Flip Flop U301 310 4393 74HCT393 Dual Binary U302 Divider 310 4374 74HCT374 Octal Latch U303 U304 310 0054 4053
133. 278B when the user establishes a connect and MFJ 1278B MULTI MODE ADVANCED OPERATION The timing of the automatic entry into data transfer mode depends on whether you or the other station initiated the connection If you receive a connect request that your MEJ 1278B accepts then you will enter data transfer mode when your MFJ 1278B sends the connect acknowledgment ACK and displays the message CONNECTED TO lt callsign gt on your computer monitor screen If you initiate the connection with the CONNECT command then you can control the timing of the mode change with the command NEWMODE If NEWMODE is OFF the mode will change when the connect is received and the CONNECTED TO lt callsign gt message is displayed on your computer screen If NEWMODE is ON you will enter data transfer mode immediately without waiting for a successful connection Any text sent to the MFJ 1278B at this point will be queued up in packets which will wait for a successful connection before being sent If the connect attempt fails you will be returned to Command Mode You will also be returned automatically to Command Mode when either station disconnects and ends the QSO Converse Mode The data mode used most often for ordinary QSOs is Converse Mode In Converse Mode the information you type is assembled by the MFJ 1278B into packets and transmitted over the radio The send packet character causes the input to be packetized for transmission
134. 28 U38 U39 U40 U6 U25 U23 U24 U21 U22 U8 U3 U201 U2 U16 MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MFJ P N 312 2512 312 2081 312 0075 312 0067 312 0044 310 0044 310 34066 310 4004 310 3014 310 3107 310 4374 310 4373 21M A202 Descrpition 27C1001 CMOS EPROM 100 NS OR BETTER ERASABLE TYPE ONLY DO NOT USE FUJUTSE TYPE 27C64 CMOS EPROM 200 NS OR BETTER PROGRAM WITH STATE 1 09 ONE TIME PROM OK TO USE 43256LP 10 32K STATIC RAM 100 NS OR BETTER Z084404PSC 4 MHZ Z80A SIO 0 DUAL SERIAL PORT ZILOG TOSHIBA OR EQUAL Z0840004PSC CMOS 4 MHZ Z80A CPU ZILOG TOSHIBA OR EQUAL 4040B CMOS DIVIDER 74HC4066P QUAD CMOS SWITCH 74HCT04 HEX INVERTER 74HC14P HEX SCHMITT INVERTER Do not use 74HCT14 for these ICs 74HC107N DUAL J K FLIP FLOP 74HCT374 OCTAL LATCH 74HCT373 OCTAL TRANSPARENT LATCH TAUCT2AAAN NITAT RINADV Component ID U23 U6 U24 U25 U21 U22 Ul U13 U10 U7 U9 U14 U11 U5 U27 U28 U39 U40 U38 MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MFJ P N 310 3138 310 0054 310 0053 310 0040 310 3021 310 3273 DIODES LEDS 301 0012 301 1004 301 1005 301 0003 301 1015 301 5257 320 0001 320 0003 320 0002 Descrpition Component ID 74HC138 3 to 8 LINE DECODER U29 U12 4053B TRIPLE 2 CH CMOS ANALOG SWITCH 4052B DIFFERENTIAL 4 CH CMOS ANALOG SWITCH 4066
135. 3 slot time dice on on 1 newline characters Causes the MFJ 1278B to print all 6 114 receivable mode S transmissions 11 Q Selects the user restart character 114 Pactor Displays debug information helpful in 6 114 troubleshooting Pactor problems Returns useful diagnostic information for 6 115 helping us help you with your problems STOP n 6 115 3 STREAMCA ONIOFF ff Packet Used to enable the display of the 6 116 connected to station after the stream identifier f STREAMDB ONIOFF ofi Packet Used to display received 6 117 n 0 aS pn n n n ART atus Determines whether only 1f characters 6 113 from the AMTOR receiver are sensed as X gt 3 wn m IZ un gt e Dn MFJ 1278B MULTI MODE APPENDIX COMMAND SUMMARY r STREAMSW n 7C 1 Packet Selects the character used by both the 6 118 MFJ 1278B and the user to select a new stream SYSOP I command Packet Enables the MAILBOX systems operator to enter in messages to the BBS system bbs M Packet Text string in this command is executed at a time pre set by Timedmin command M Packet Set the time for Timedcmd command 9 AMTOR Allows the user to invert the transmitted AMTOR signals TRACE ONIOFF Enables the debugging protocol function 6 120 Displays continuous debug information on 6 120 the terminal screen Packet Transparent mode o Packet Enables and disables the software flow 6 121 control f f F
136. 32C interface The troubleshooting guide below is provided as an aid to help in resolving problems that may be related to the RS 232C port Symptom MFJ 1278B won t sign on to the terminal If you find the MFJ 1278B won t send data to your terminal one of the first things to do is to verify that the RTS line at pin 4 of J1 is not being held low If the software flow control option is disabled the MFJ 1278B will not send data to the terminal unless its RTS is asserted If the terminal does not implement RTS CTS protocol the RTS CTS lines pins 4 and 5 on J1 should remain unconnected Verify that the voltages on the MFJ 1278B are correct If the MFJ 1278B is in otherwise good condition check the following pins on the SIO U21 Z8440 Pin 23 should be TTL low between 0 and 0 8 volts If this voltage is incorrect check the voltage at U9 pin 3 and verify that it is greater than 3 volts If this voltage is correct U9 or the traces around it may be bad If this is not the problem disconnect the terminal and check it again If this doesn t help U9 R20 or R22 may be at fault If the above checks are ok observe pin 26 of U21 with an oscilloscope and cycle the power switch on the MFJ 1278B Transitions on this pin shortly after reset indicate that the MFJ 1278B is sending data Verify that transitions are also present on U3 pin 1 If these tests fail the fault could be with U13 R25 R26 U21 J1 the attached cable or faulty soldering
137. 33 on Enables the transmit function 133 13 S Selects the MFJ 1278B stop character 134 Flo co e skk gu E 1 8o Q X e oO nn 13 Pactor Sets the Flow Control STOP character for 134 the Pactor mode nn 11 Pactor Sets the Flow Control START character for the Pactor mode n 11 Q Selects the MFJ 1278B restart character 6 135 6 134 x e 5 ONIOFF ONIOFF X e 2 MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MEJ 1278B 1278BT PARTS LIST MFJ P N Descrpition Component ID RESISTORS 1 4 WATT 5 100 0002 10 OHM R128 R150 100 0003 100 OHM R14 R15 R17 R18 R19 R59 100 0004 200 OHM R60 R126 100 0009 470 OHM R4 R97 R53 R34 R35 100 0056 680 OHM R211 100 0010 IK R8 R36 R46 R47 R48 R11 R33 R144 R143 R56 100 0012 22K R16 R145 R146 100 0099 43K R152 100 0014 47K R32 R74 R140 R107 100 0017 10K R9 R10 R12 R2 R7 R22 R23 R26 R29 R30 R38 R49 R50 R51 R52 R61 R67 R68 R69 R70 R71 R75 R96 R99 R100 R28 R104 R207 R213 R108 R124 R125 R127 R130 R132 R134 R135 R136 R137 R98 R109 100 0019 15 R156 R151 100 0094 22K R73 R148 R149 100 0020 24K R76 R163 R162 MFJ 1278B MULTI MODE APPENDIX I PARTS LIST R27 R37 R42 R72 R43 R20 R31 R64 R65 R133 R147 R155 R40 R41 100 0060 180K R154 100 0033 200K R205 100 0073 470K R203 R204 100 0063 750K R95 100 0040 IM R83 RESISTORS 1 8 WATT 1 102 5301 301K
138. 5 The WAITDISC command determines the number of cycles the MFJ 1278B waits to reply to the other TNC that having requested a disconnect fails to hear our disconnect acknowledgement WDMODE ON OFF Mode AMTOR Default OFF WDMODE word mode determines whether a Mode A transmission takes place any time you type a SPACE or RETURN character or only when you type a carriage return WDMODE OFF the default condition sets the MFJ 1278B so that it buffers you re transmitted text a line at a time before sending it If it s ON the MFJ 1278B immediately sends each word as you end it with a SPACE or RETURN WEIGHT n Mode CW Default 0 Parameters n 0 thru 255 The WEIGHT command is used to set the weight factor applied to paddle and CW keyboard generated code elements The value of weight is represented as a 2 s complement byte and it alters the dot space ratio Therefore one should use values between 128 and 255 to DECREASE the weight factor and 1 to 127 to INCREASE the weight factor The number specified results in an absolute increase or decrease in the ratio of dot to space time that is equivalent to approximately 8 67 ms NOTE For weight calculation purposes a dash gets the factor applied to only 1 of its 3 dot times So that the time added to or removed from each element whether it is a dot or a dash is either removed from or added to the space following the element WRU Mode AMTOR Default command Mc XEIE NET nlclicisconhon
139. 6 81 set by this command MULTIFAX ONIOFF off FAX Enables multi level FAX transmitting and 6 82 receiving nocall Sets the callsign of the MFJ 1278B MFJPACTR Your Pactor amateur callsign blank Packet Specifies an alternate callsign for use as a 6 digipeater only 6 83 83 Sets the DLC number for Host Mode 6 83 84 84 MYMCALL o Sets the heiarcal address text sent by a Mailbox forward Tells the MFJ 1278B what SELCALL 6 84 your station should respond to NAVTEX Allows you to receive NAVTEX signals NAVTEX Allows you to receive certain NAVTEX 6 85 stations 1 Allows you to receive certain NAVTEX 6 E ONIOFF off Packet Selects the way the MFJ 1278B behaves 6 87 o RES when connections are made and broken emn OFF command Similar to Forward command but with callsign up to 8 vias to link with the receiving BBS ONIOFF off Packet Determines if the MFJ 1278B will switch 6 89 manually or automatically to command mode 1 I Packet Causes transmission of null characters 6 90 producing a delay following any cr sent to the terminal ff Same as NUCR instead of cr it sends a delay after lt If gt Packet Used in conjunction with NUCR and 6 90 NULF and specifies how many null characters are sent Use with ASA command to accept the 6 analyzed signal 6 OMLC ONIOFF off AMTOR Instructs the MFJ 1278B to convert all
140. 62 Commands NULF 262 Commands NULLS 262 Commands OK 263 Commands OMLC 263 Commands PACLEN 245 263 Commands PACTIME 211 264 Commands PARITY 264 Commands PASS 50 193 265 Commands PAss 265 Commands PASSALL 249 266 Commands PIXTONES 267 Commands PKTPIX 269 Commands PRINTER 270 Commands PRINTGRA 270 Commands PRINTTES 271 Commands PROFMARS 271 Commands PTover 271 Commands PTSend 272 Commands QRT 272 Commands R 272 Commands RADIO 272 Commands RANDOMCW 273 Commands RBITMASK 273 Commands RECONNECT 273 Commands REDISPLA 50 274 Commands REMSYSOP 274 Commands RESET 275 308 Commands RESPTIME 275 Camman DECTAD T 274 MANUAL INDEX MFJ 1278B MULTI MODE MANUAL INDEX Commands RVFALWAY 282 Commands RXBLOCK 278 Commands RXBRIGHT 279 Commands RXCAL 280 Commands RXINVERT 282 Commands SCREENLN 282 Commands SELCALL 283 Commands SENDPAC 283 Commands SERIALNO 283 Commands SETUP 284 Commands SENL 284 Commands SLOTS 285 Commands SOLF 285 Commands SRXALL 286 Commands START 50 286 Commands STATUS 287 Commands STAtus 286 Commands STOP 50 287 Commands STREAMCA 288 Commands STREAMDB 289 Commands STREAMSW 290 Commands TIMEDCMD 290 Commands TIMEDMIN 291 Commands TINV 291 Commands TRACE 198 292 Commands TRace 292 Commands TRANS 293 Commands TRFLOW 293 Commands TRIES 294 Commands TUNE 294 Commands TUNEPROC 294
141. 78B MULTI MODE OPERATIONAL COMMANDS TRACE ON OFF Mode Packet Default OFF Parameters ON Trace mode is enabled OFF Trace mode is disabled This command is used to enable the protocol debugging function When the TRACE command is ON all received frames will be displayed in their entirety including all header information In normal operation you will probably never need this function however if you need to report an apparent software bug we may ask you to provide trace information if possible A trace display will appear in four columns on an 80 column display Following is an example trace display For comparison the frame shown in the trace example would be monitored as follows KV7B gt CQ KF7B this is a test message The trace display would look like this byte hex display shifted ASCII ASCII 000 86A24040 40406096 AC6E8440 4060968C CQ OKV7B n 010 6E844040 E103F074 68697320 69732061 7B P x 449 49 0 n this is a 020 20746573 74206D65 73736167 650D 29 6299032 test message The byte column shows the offset into the packet of the beginning byte of the line The hex display column shows the next 16 bytes of the packet exactly as received in standard hex format The shifted ASCII column attempts to decode the high order seven bits of each byte as an ASCII character code The ASCII column attempts to decode the low order seven bits of each byte
142. 82B for Commodore C 64 and C 128 on 5 1 4 disk If you are using one of the above terminal programs that supports Gray Level FAX operations you should follow the instructions given by the terminal program to receive and transmit FAX The instruction given in this manual for FAX operation are for receiving FAX with the MFJ 1278B s built in printer port MFJ 1278B MULTI MODE BASIC OPERATION FAX Formats The MFJ 1278B lets you receive and transmit FAX The FAX modulator and demodulator of the MFJ 1278B are pre set at the factory to allow FAX operations without any recalibration Recalibration is not needed under normal conditions The MFJ 1278B will support FAX formats listed in Table 4 6 Lines per Lines per FAXMODE n Type of Service 60 line min Wire Photographs 2 90 line min 1 5 line sec 5 360 6 j 480tnemi 8linesec p80 line min 3line sec Table 4 6 MFJ 1278B FAX Formats You may change the FAX format with the FAXMODE command From the cmd command mode prompt type FAXMODE n ENTER Where n is a number from 1 to 7 as listed in the Table 4 6 above For example if you want to change the FAX format to 1 or 60 lines per minute type FAXMODE 1 ENTER The MFJ 1278B will be set to receive or transmit Fax picture files in FAX 1 format Note If you are using one of the special terminal programs that supports multi gray level FAX operation you should follow the procedure
143. 8B MULTI MODE COMPUTER INTERFACING Radio Shack Color Computer The Color Computer series except for the Micro Color Computer uses a 4 pin DIN style connector for its serial port If you wish to construct your own cable the information in Figure 2 2 will be helpful necessary parts should be available from Radio Shack dealers Color Computer DB 25P Fig 2 2 Serial port wiring for Radio Shack Color Computers Radio Shack Model 100 102 and NEC 8201Radio Shack Model 100 serial port interfacingThese computers have built in standard RS 232C serial ports that are compatible with the MFJ 1278B You will need a standard male to male RS 232C cable to connect the computer to the MFJ 1278B IBM PC XT AT 386 486 and compatibles Computer Include other computers with 25 pin RS 232 Ports If your computer is an IBM or compatible you should have a serial port with standard DB 25 or DB 9 pin connector You may use a standard IBM serial modem cable with the correct gender on each end of the cable Enterprises Inc offers optional Starter Pack MFJ 1289 for the IBM or compatible computers A computer connecting cable is included with the Starter Pack The supplied cable is of male to female gender to connect your MFJ 1278B to the computer For other computers with a 25 pin RS 232C port consult the manual for your computer or accessory to see which pins it uses to send and receive data on as well as the pin used for signal ground
144. 8B Modems The MFJ 1278B will transmit and receive these tones when shorting jumpers for JMP E F G and H are removed on the mother board MFJ 1278B MULTI MODE BASIC OPERATION OPERATIONAL MODES Verifying Operation Status Upon initial power up the MFJ 1278B defaults to VHF Packet mode The radio baud rate defaults to 1200 baud Radio port 1 is the default radio connection You can verify the operating status of the MFJ 1278B at any time by using the command MODE after the display of the CMD prompt To check operation mode type MODE ENTER The MFJ 1278B will respond with modem status display lines followed with the cmd prompt Mode Switching With the MODE Command Since the MFJ 1278B is a multi mode controller you will need to familiarize yourself with the commands for changing operating modes from one to another The MFJ 1278B provides an easily used command to change the mode of operation The MODE command allows you to enter any operational mode The MODE command also enables the selection of any desired radio baud rate and modem Table 4 3 lists the valid codes that are used by the MODE command The format for the MODE command is MODE xx bbbb m ENTER Where xx is a 2 letter operational mode code as listed in Table 4 3 bbbb is the desired baud rate or speed and m is the desired modem as listed in Table 4 1 Leaving the m parameter off of the MODE command will cause the MFJ 1278B to select the default
145. 9 C in 2 amp 3 Default Normal modem operation D N 5 5 es mmz igital loopback mode ormal modem operation Transmit data NRZ Transmit data NRZI TTL RTS enable T TL RTS disable in 1 amp 2 Default FSK out normal in2 amp 3 JMP16 1 amp 2 Without multi gray levels JMP10 F Default FT IGHT Default N Default JMP11 JMP13 JMP14 MFJ 1278B MULTI MODE APPENDIX JUMPER FUNCTIONS Table G 1 Jumper Function Cont Function JMP18 Pin 1 amp 2 default Enable 19 2K baud termial EUREN Disable 300 baud terminal BEEN E nable 300 baud termial JMP19 Jumper Disable 19 2K baud terminal utside pair default Enable 32K mailbox RAM 1 Middle pair Inside pair Enable 512K mailbox RAM OFF default in 1 amp 2 Pin 2 amp 3 default inl amp 2 Enable CW Grid Block Keying Pin2 amp 3 default Enable CW Direct Keying Enable memory RESET Normal operation in 1 amp 2 default Normal Demodulator operation CO Pin 2 amp 3 in 1 amp 2 default Normal 5Vb bbRAM operation m dj in2 amp 3 Real time clock installed OFF default N default Enable external DCD OFF default Disable external DCD JMPD T used ln n ru cal JMPE N default Disable Low Tone RTTY Demod Enable Low Tone RTTY Demod 5 g z Z 9 JMP23 OFF default o oj Z 9 9 Z O Z
146. 99 WPM The CW transmitting speed defaults to 20 WPM The MSPeed command specifies the CW transmit speed If the FARnswor command is ON and MSPeed signifies 15 WPM then the MFJ 1278B uses 15 WPM characters but spaces the characters so the transmitted text is at a slower speed To set the MFJ 1278B to 15 WPM type MSPeed 15 ENTER Or MODE CW 15 ENTER Be sure the MFJ 1278B is in command mode when issuing the MSPeed or MODE command The MFJ 1278B provides yet another way to set the CW transmit speed and that is the CWSPEEDM command If the CWSPEEDM command is ON then the MFJ 1278B will match your transmit speed with the transmit of the person you are in QSO with The CW speed matching feature causes your MFJ 1278B to adopt the speed of the received CW signal as it s transmit CW speed This is the same CW speed that the MFJ 1278B analyzed last either through the AUTOTrac or by use of the ALOCKCHAR character CONTROL U To give the user with more flexibility in controlling how the MFJ 1278B will transmit CW MCW the CWSEndch command is provided This command applies whether the keyboard or key paddle is the transmit medium CWSEndch is only effective for CW and MCW modes The CWSEndch command determines which keyboard character transmits the CW MCW characters This gives the user more control how pending characters are transmitted For example setting the CWSEndch to 02 will tell the MFJ 1278B to buffer all CW characters until th
147. ACTIME ON you will probably set SENDPAC to some value not ordinarily used say CTRL A and set CR OFF This will allow you to force packets to be sent but will not result in extra CR characters being transmitted in the text SERIALNO n Mode CW Default 0 Parameters n 0 65535 SERIALNO is useful as a contest QSO number counter When transmitting a buffer the MFJ 1278B scans the buffer text to see if there are any pound sign characters and if it encounters any then the current value of the SERIALNO counter inserted in the buffer text being sent After this value is loaded SERIALNO is incremented by one until it reaches 65535 where it rolls over to zero If for some reason the serial number must be changed during the contest merely escape to command mode and enter the new serial number by using the SERIALNO command MFJ 1278B MULTI MODE OPERATIONAL COMMANDS SETUP Mode ALL Default see table below All possible baud rates and modem configurations are displayedon the SETUP menu The selected baud rates and modem configurations are also shown Anytime the MFJ 1278B default values are loaded the baud rate and modem default profile is loaded as well The defaults are shown in the below table Ascii RTTY HF Ascii RTTY 8 5 Sec format M Multi level FAX SSTV Formats The terminal baud rate and modem configurations may be changed by using the SETUP command SENL ON OFF Mode AMTOR Default OFF SFN
148. AFTER n means that the command BEACON requires an argument that must be either EVERY or AFTER abbreviated either E or A respectively and an argument n that the user may choose from a range of values An acceptable command might be BEACON E 2 MFJ 1278B MULTI MODE OPERATIONAL COMMANDS means that the command CONNECT requires a callsign argument calli You may optionally include the keyword VIA followed by a list of one to eight callsigns call2 through call9 The callsigns in the list if included must be separated by commas as shown or by blank spaces An acceptable command might be C V ADTI WB9FLW You can see the current value of the command s arguments by typing the command name by itself without any arguments For example cmd CONOK Y Sets the value to YES ON CONOK was OFF Displays previous value cmd CONOK Command with no arguments CONOK ON Displays present value A special command DISPLAY allows you to see the values of all parameters or groups of related parameters Remarks This section describes the command s action and the meaning of each argument Examples may be included of situations in which the command might be used of the commands available in the MFJ 1278B are listed in the following pages The commands for all of the other modes besides PACTOR are shown in bold UPPER case letters such as TXDELAY The commands listed for the PACTOR mode are shown in bold UPPER and LOWER case letters such
149. AME n Mode Packet Default 4 Parameters n 7 specifying a maximum number of packets MAXFRAME sets an upper limit on the number of unacknowledged packets that the MFJ 1278B can have outstanding at any one time The MAXFRAME also sets the maximum number of contiguous packets that the MFJ 1278B will send during any given transmission If the MFJ 1278B acknowledges some of the packets but not others the MFJ 1278B will transmit a smaller number of packet frames as long as the number of unacknowledged frames does not exceed n The MFJ 1278B will insert new packet frames during the re transmission as long as n is not exceeded If you perform file transfers you should experiment with MAXFRAME and PACLEN If the link is good there is an optimum relationship between the parameters set by these commands so that the maximum number of characters outstanding does not exceed the packet receive buffer space of the MFJ 1278B receiving the data MFJ 1278B MULTI MODE OPERATIONAL COMMANDS MAXSum nn Mode Pactor Default 30 Parameters nnn 5 nnn 120 MAXSum specifies the number of cycles of error laden information packets received that are accumulated in the Digital Memory ARQ sum buffer for reconstruction When MAXSUM consecutive information receive errors occur on the next receive cycle the sum buffers are re initialized to inhibit the corruption of real time reception by historical receive MAXUp nnn Mode Pactor Default 10
150. ARD command tells the MFJ 1278B to display a list of stations that has been heard since the last time the command MHCLEAR was given Stations that are heard through digipeaters are marked with a in the heard log If you clear the list of stations heard at the beginning of a session you can use this command to easily keep track of the stations that are active during that period The maximum number of heard stations that can be logged is 18 If more stations are heard earlier entries are discarded Logging of stations heard is disabled when PASSALL is ON If the DAYTIME command has been used to set the date and time entries in the heard log will be time stamped For example cmd MHEARD K4NTA 06 09 85 21 08 19 WAAITD 06 09 85 21 08 17 WIBEL 2 06 09 85 21 06 18 K4NTA 2 06 09 85 20 57 35 N2WX cmd Note that no daytime string is displayed next to N2WX This indicates that when N2WX was last heard the clock had not been set MODE Mode Immediate Command MODE is a immediate command The MODE command selects which mode the MFJ 1278B will be operating in The MODE command is followed by two characters that denote the mode selected See Chapter 4 for a more detailed discussion of the MODE command MNONAX25 ON OFF Mode Packet Default OFF XXTE co aL AAT ee ED ae ek ee ANN eee ta Ie MFJ 1278B MULTI MODE OPERATIONAL COMMANDS Parameter ON Enables printing Non Printable Characters OFF Discards all Packets containing Non P
151. ARS with MultiCom for IBM Operating MARS using the MFJ 1278B and the MultiCom software makes operating much easier Let s say that you have 20 pieces of traffic but you only need to send 10 of them this is where MultiCom comes in handy The MultiCom software has a very good text editor Multi Word You can use the Multi Word editor to send MARS messages All received data is stored in a 32K COMM buffer that MultiCom M opens when loaded So at anytime the operator can see all traffic that has been received The operator can go into the Multi Word editor by pressing the F10 key followed an ALT B The ALT B key sequence fills the Multi Word editor with the contents of the COMM buffer Insert a CTRL T at the beginning of each piece of traffic and a CTRL R at the end of each piece of traffic Use the Multi Word commands F1 and F2 respectively to block off the pieces of traffic you want to send After blocking off the traffic use the F9 key to send the traffic to the MEJ 1278B to be transmitted The operator will need to perform this operation for each piece of traffic to be sent If all pieces of traffic are all together one right after the other then the procedure will only need to be done once The MARsmode Command The MARsmode command provides two levels of MARS compatibility The QSO mode provides minimal translation In the QSO mode the MFJ 1278B assumes the user is manually sending and receiving Maximum transl
152. AX lGleve TV 8 5 12 17 24 36 s Color SSTV Robot 72 Scotty 1 2 Martin 1 2 Table 4 3 MODE Command Codes and Baud Rates With optional internal modem Supported by the built in printer port 2 level FAX and 4 level B amp W SSTV When using MFJ Multicom terminal program MFJ 1278B will support 16 level FAX and Color SSTV Radio Port Switching The MFJ 1278B provides the user with two independent radio ports Radio 1 and Radio 2 The MFJ 1278B selects Radio port 1 when first initialized After receiving the cmd command prompt you can select the desired radio port by typing RAD 1 or RAD 2 followed by a Return key press MFJ 1278B will display a new operation status and end with cmd prompt MEMORY BUFFERS The MFJ 1278B gives you ten user programmable memory buffers The Memory Buffers are numbered 0 thru 9 These Memory Buffers are accessible by the BUF command Each memory buffer is capable of storing up to 120 characters including puncuations The user MFJ 1278B MULTI MODE BASIC OPERATION Loading the Memory Buffers The ten memory buffers are empty when the MFJ 1278B is first initialized To load the memory buffers the user can invoke the BUF command To load the memory buffers please note the example below for loading buffer 1 The MFJ 1278B must be in COMMAND mode BUF1 The here is Starkville Mississippi ENTER Where 1 is the memory buffer number that can ra
153. After your local area TNCs are updated to the newer protocol version you should set AX25L2V2 ON When AX25L2V2 is ON the MFJ 1278B answers L2 UI frames with P and C set with either RR if connected regardless of rcvr flow control state or DM if not connected If retry limit is exceeded or the MFJ 1278B receives a disconnected response to a poll the connection is ended AXDELAY n Mode Packet Default 0 Parameters n 0 to 180 specifying the voice repeater keyup delay in 10 ms intervals AXDELAY specifies a period of time the MFJ 1278B is to wait in addition to the normal delay set by TXDELAY after keying the transmitter and before data is sent This feature will be used by groups using a standard voice repeater to extend the range of the local area network Repeaters with slow mechanical relays split sites or other circuits which delay transmission for some time after the RF carrier is present require some amount of time to get RF on the air If you are using a repeater that hasn t been used for packet operations before you will have to experiment to find the best value for n If other packet stations have been using the repeater check with them for the proper setting Note that this command acts in conjunction with AXHANG Note that the TAPR TNC 1 and other TNCS using the same version 3 x firmware interpret n in 120 ms intervals The value set by AXDELAY on MFJ 1278B will thus be 12 times the value used by a TNC 1 user to give the
154. B Triple 2 CH U305 U306 CMOS SWITCH Miscellaneous 620 6110 Right Angle L Brackets for Mounting add on pcb Same as bracket for tuning indicator pcb 620 6110 10 conductor Ribbon Jumper Same as ribbon jumper used on the tuning indicator board except 20 conductors 862 1278 3 PCB GRAYSCALE BOARD APPOX 1 X 5 312 MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MFJ P N Descrpition Component ID BOM for 2400 Baud Modem PC Assembly P N 50 2400B 1 For 1278T only RESISTOR 1 4 WATT 5 100 0009 470 OHM R5 100 0065 620 OHM R48 100 0010 IK R49 100 0012 2 2K R29 100 0046 2 7K R19 100 0014 4 7K R3 R50 100 0015 7 5K R43 100 0050 8 2K R41 100 0017 10K R37 R4 R51 R10 R39 100 0019 15 R25 R23 R11 100 0043 18K R13 R16 100 0022 30K R2 100 0061 33K R18 R26 100 0101 36K R28 100 0023 47K R20 R40 100 0025 62K R1 100 0053 68 K R14 R17 100 0029 100 K R32 R6 R33 R24 R34 R31 MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MFJ P N 100 0042 100 0087 Descrpition 1 8M 3 9M RESISTOR 1 8 WATT 1 102 0037 102 0038 9 09 K 9 53 K Component ID R53 R52 R21 R22 R12 R15 RESISTOR NETWORK SINGLE ON LINE ISOLATED 107 6104 100K RP2 RESISTOR TRIM POT SINGLE TURN MINIATURE HORZONTAL 104 4008 1M CAPACITORS DISC CERAMIC 200 0020 33 PF 50 20 R38 C8 C9 CAPACITORS MULTI LAYER MONOLITHIC CERAMIC 205 1047 205 1122 205 1210 2
155. B for software on disk or MFJ 1283 for software on tape If you wish to construct your own cable the information below in Figure 2 2A will be helpful MFJ 1278B Mnemonic N C 64 128 VIC 20 Pins J 5 Pin 1__ RXD ReeiveDaa 2 DCD Data Carrier Detected L3 Ground 3 N 4 f Rs RedyToSmd E M 6 DosR DwaSeReay L Fig 2 2A TTL Port wiring for VIC 20 C64 and C128 C 128 is used in the C 64 mode for these connections Pin E is not needed when using terminal program referred to in this chapter for the Commodore computers The TTL port 75 is numbered from left to right as viewed from the back panel of the MFJ 1278B The user s terminal program may not use all of these connections The MFJ 1278B requires RXD TXD and GND connected for proper operation Programs that utilize file transfer and printer routines will probably use RTS and CTS as well Consult your software documentation IBM PCjr The PCjr uses standard serial voltage levels for its RS 232C interface however the connector used is non standard and not readily available from electronic supply dealers The pin out information for this connector is refered to in the IBM PCjr Technical Reference Manual TRM dealare call an IRM Diir Adantar Cahla far Carial IYaxicac Thic Adanter ic MFJ 127
156. B from indefinitely retransmitting a packet and tying up the channel under hopeless conditions For example an intermediate digipeater might have been shut down or the RF channel might have deteriorated to the point of being unusable The other operator might have even turned off his station without disconnecting If you are operating under special conditions such as a marginal HF channel you can set RETRY 0 to disable all automatic disconnects the retry limit is never reached Monitoring Channel Activity The MFJ 1278B can monitor packet activity on the channel while connected to another station You can read the mail displaying packets between other stations The MFJ 1278B will also keep track of stations heard during a session This section will describe some of the monitor functions Monitoring is enabled or disabled by the MONITOR command You can try this out in digital loop back mode while disconnected Type cmd MONITOR ON cmd CONVERS MFJ 1278B MULTI MODE BASIC OPERATION Since you are not connected to another station your packets are sent to the address CQ i e anyone The packet you sent was heard by the MFJ 1278B and displayed along with the sending station and the destination If you also want to see any intermediate digipeater stations being used you can set MRPT ON This feature would be useful if you later want to connect to one of the stations you are monitoring and will need a digipeater route in order
157. BE BD BB BF 86 1100 sync 588 1200 sync 89 1300 SAC 1500Gyn 9D 150 AD 0160 1650 370 1750 180 180 190 BC 19500 0200 200 B9 200 O SBD 2850 200 2250 Table 4 8 FAX SSTV Multi Gray PIXTONES Creating FAX Pictures for Transmitting FAX pictures captured by the MFJ 1278B and saved on disk can be re transmitted at a later time However the FAX pictures must be re transmitted with the same format with that they were saved MFJ Starter Packs for the IBM or compatibles computers can be used in conjunction with other graphics generating programs that support the PCX format to create your own drawings and graphics MFJ 1292 Picture Perfect Video Digitizer for the IBM and compatible computers allows you to digitize a picture with a Camcorder or video camera The digitized picture is stored on disk and can be transmitted by the MFJ 1278B Contact us or your MFJ dealer for more information concerning the MFJ 1292 Video Digitizer and other graphics generating programs for use with the MFJ 1278B MFJ 1278B MULTI MODE BASIC OPERATION SLOW SCAN TELEVISION OPERATION The MFJ 1278B opens up a whole new world of digital communications Slow Scan Television or
158. C Operation of the Tuning Indicator in the AMTOR mode is the same as all other modes Simply tune the signal so that the center LED segment of the Tuning Indicator is lit with each burst of AMTOR signal received Mode A ARQ Automatic request for re transmission mode known as Mode is similar to packet radio in a number of ways The calling station must know the ID of the station being called in order for communications to occur The ARQ command initiates a link attempt with the station being called A link attempt in AMTOR is similar to CONNECT attempt in Packet Mode A is a one on one protocol meaning that it is used for QSOs and not for calling CQ or broadcasting see FEC and SELCALL for more on broadcasting ARQ Mode A introduces a few new terms Information Sending Station ISS and Information Receiving Station IRS In ARQ a station must be either the ISS or the IRS and the station that is transmitting data is called the ISS One becomes an ISS either by issuing a successful AMTOR call with the ARQ command or when the ISS relinquishes control of the link through the changeover Finally if an IRS link CHANGE is requested Setting up for Mode A Operations LEeot wan chenld daeida nnan a calaetiva nall idaetifiae and antar it ao vanr MIVCLT MFJ 1278B MULTI MODE BASIC OPERATION Examples are Amateur callsign is NZWX Amtor MYSELCAL is NNWX Amateur callsign is WB2SPE Amtor MYSE
159. Coco HI Others are WIZ and XTERM for OS 9 Radio Shack Model 100 102 and NEC 8201 These computers have built in terminal programs in ROM Consult your computer s documentation for instructions in their use MEF J 1278B SERIAL PORT PIN FUNCTIONS This section describes the pins used on the MFJ 1278B RS 232C serial port connector It is intended for users with special applications requiring hardware handshaking This information should not be needed by most users 6 DSR DatSetReady 8 DCD s DataCarierDetect 9 12V unregulated reference 10 12V unregulated reference Table 2 4 RS 232C Pin Designations Pin 1 Frame Ground The Frame Ground pin is provided for attachment to the chassis of the MFJ 1278B and the chassis of the attached device computer or terminal This pin is available at a feed through hole on the MFJ 1278B PC board near pin 1 of the serial connector It is not electrically connected anywhere else on the MFJ 1278B circuit board Pin 2 Transmit Data MFJ 1278B MULTI MODE COMPUTER INTERFACING Pin 3 Receive Data The Receive Data pin is an output line from the MFJ 1278B on which the attached device receives data The attached device is generally a computer or data terminal Pin 4 Request To Send The Request To Send pin is an input line to the MFJ 1278B on which the attached device requests clearance to transmit data to the MEJ 1278B Pin 5 Clear To Send The Clear
160. D n Mode Default 03 Parameters n 0 7F specifying an ASCII character code This command is used to change the Command Mode entry character You can enter the code in either hex or decimal Command Mode is entered from Converse Mode when this character is typed If you type the Command Mode entry character while you are already in Command Mode nothing will happen To see how this works enter Converse Mode by typing CONVERS Anything you type will become packet data Now type a CTRL C You will see the Command Mode prompt indicating successful exit from CONVERSE mode to Command Mode The display might look like this cmd CONVERS Hello World I m on the air on packet radio enter lt CTRL C gt cmd See the entry under CMDTIME or the discussion of Transparent Mode in Chapter 5 for information on how the Command Mode entry character is used for escape from Transparent Mode For terminals without a control key you will have to reasign another key such as a graphic symbol or punctuation mark which is normally not used in operations The default COMMAND character is lt CTRL C gt MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CONMODE CONVERS TRANS Mode Packet Default CONVERS Parameters CONVERS Sets automatic entry to Converse Mode when a connection is established TRANS Sets automatic entry to Transparent Mode when a connection is established CONMODE controls which mode the MFJ 1278B will be placed in a
161. D to OFF you should remember that if you change the terminal program baud rate is changed then MFJ 1278B will no longer be able to match the new baud rate You must change the baud rate of your terminal program to match the baud rate you set for the MEJ 1278B or you may remove JMP 5 on the MFJ 1278B board to reset the battery back up RAM Once reset the MFJ 1278B will restore all parameters to the default values including the AUTOBAUD command The default setting for the AUTOBAUD command is ON When the MFJ 1278B is powered on after resetting memory it will attempt to match the new baud rate and sign on after receiving the return key presses sent by the user Changing Terminal Baud Rate The MFJ 1278B RS 232 port will operate at the rate of 300 1200 2400 4800 9600 or 19 200 baud The MFJ 1278B employs an AUTOBAUD routine that automatically matches it s terminal baud rate to that of the rate set on the terminal program The AUTOBAUD routine is executed by pressing the Return key several times upon each power on cycle of the MFJ 1278B This means if the terminal program baud is set at 9600 baud the MFJ 1278B will set it s terminal speed to 9600 baud to match the program We suggest that once you select a terminal baud rate that you wish to operate your MFJ 1278B on you should set AUTOBAUD command to OFF Once AUTOBAUD is turned OFF the MFJ 1278B will automatically sign on without you having to press the Return key This is importan
162. DLE whenever the transmitter is keyed but not sending anything else The DIDDLE characters for ASCII and RTTY are NUL and LTRS respectively Diddling while the transmitter is keyed makes it much easier for persons receiving to tune and remain tuned to your transmitted signal Some stations running mechanical teletype equipment may ask you not to Diddle while you are talking to them since it may cause their older equipment to make a lot of noise but do nothing It should be noted that NO damage can occur should mechanical teletypes receive Diddles and it is not considered bad practice to leave it ON unless sked otherwise by the nathan atatinn in tha ACA MFJ 1278B MULTI MODE OPERATIONAL COMMANDS DIGIPEAT ON OFF Mode Packet Default ON Parameters ON The MFJ 1278B will digipeat packets if requested OFF The MFJ 1278B will not digipeat packets When this parameter is ON any packet received that has your TNC s callsign including SSID in the digipeat list of its address field will be retransmitted Each station included in the digipeat list relays the packet in its turn marking the packet so that it will not accidentally relay it twice unless so requested and so that the stations will relay the packet in the correct order Digipeating takes place concurrently with other MFJ 1278B operations and does not interfere with normal operation of a packet station In the spirit of cooperation typical of Amateur operation you will prob
163. Designates the Pactor changeover 6 30 character Deisgnates the Pactor return to command 6 30 D MFJ 1278B MULTI MODE APPENDIX COMMAND SUMMARY Command Paramete r CONPERM ONIOFF off Packet Allows a connection to become 6 32 permanent ONIOFF off Enable a message to be transmitted whenever there is a connection made CMSGDISC ONIOFF off Packet Controls whether the MFJ 1278B will initiate a disconnect sequence after it is connected to n 03 C Sets the character used to enter the command mode from CONVERS mode CON Packet Sets the MFJ 1278B to enter the transparent mode or converse mode automatically Packet Issues a connect from the command mode to another packet station ONMODE CIT CONNECT CIICx Packet Determines the action taken by the MFJ 1278B when it receives a connect request NSTAMP ONIOFF off Packet Enables the time stamping when a 6 38 disconnect occurs VERS Forces the MFJ 1278B to enter the 6 38 NVERSE I command AMTOR Switches from the command mode to the 6 38 text transmission mode in AMTOR CPACTIME ONIOFF off Packet Enables the automatic transmission of 6 39 packets in the converse mode R ONIOFF on Packet Causes the MFJ 1278B to send a CR 6 40 every time a new line character is sent CTEXT text blank Packet Determines the packet text to be sent 6 40 when a connect is made CSTATUS I command Packet Shows streams identifie
164. ENDIX JUMPER FUNCTIONS TIL JMP22 HOd eliDiog JMP13 JMP14 Power RS 232C Threshold MF 278 REV 10 ENTERPRISES INC 1992 Fig G 1 Jumper Connector Location MFJ 1278B MULTI MODE APPENDIX COMMAND SUMMARY COMMAND SUMMARY Default Mode FAX SSTV Paramete r mc ieu Command ALOCKCHAR 15 U CW MCW ALTCALL mi ANSBSTR n n ARCVCHAR E sss f command AMTOR Packet n 14 T RTTY CW ASCII iii E All ONIOFF CW MCW ONIOFF n Packet n 0 Lud EOM c CIN
165. F Connect requests from other TNCs will be rejected This command determines the action taken by the MFJ 1278B when a connect request for it is received though the radio If CONOK is ON the request will be acknowledged the standard connect message will be typed and either Converse or Transparent Mode will be entered depending on the setting of CONMODE If CONOK is OFF and the MFJ 1278B is not in Transparent Mode the TNC will notify you of the connect attempt with the following message connect request call The callsign of the station trying to connect will replace call connect requests from stations with totally blank callsigns are rejected with a busy response The MFJ 1278B will also issue a DM packet or busy signal to the requesting station The user may then issue his own connect command If the MFJ 1278B receives a DM packet in response to a connect request it will type the message call station busy with the callsign of the station that sent the DM packet in place of call For example if you want to leave your station running as a digipeater you might set CONOK OFF until you are ready for a conversation If you get a connect request in the meantime you can change your mind Stations attempting to connect to your MFJ 1278B will be able to see that the station is up but not available for connection it might still be useful as a digipeater MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CONSTAMP O
166. I MODE OPERATIONAL COMMANDS AUTOBAUD ON OFF Mode Default ON Parameter ON Tells the MFJ 1278B to set itself to the users terminal baudrate OFF Tells the MFJ 1278B to remember the last terminal baudrate it last set itself to When the AUTOBAUD command is ON the MFJ 1278B will attempt to synchronize with the user s terminal baud rate When powered up the MFJ 1278B will wait until it detects a carriage return from the keyboard You should repeatedly press the carriage return key upon initial power up until the MFJ 1278B recognizes it When recognized the MFJ 1278B will set it s baud rate to match the terminal baud rate of your computer before signing on Once the MFJ 1278B has signed on you may turn AUTOBAUD OFF If AUTOBAUD is turned OFF the MFJ 1278B will store the terminal baud rate that it signed on to last Therefore each time the MFJ 1278B is powered up it will sign on without executing the autobaud routine You should remember that if you turn AUTOBAUD OFF and if the terminal baud rate is changed the MFJ 1278B will not be able to automatically reset itself to the new baud rate The terminal baud rate must be reset to the original setting This being the setting before it was changed or RESET the bbRAM so the AUTOBAUD command is turned ON The MFJ 1278B will then be able to automatically seek a new terminal baud rate If you must force the MFJ 1278B to autobaud due to AUTOBAUD being turned OFF and the terminal baud rate
167. I code for the character you want to type in order to redisplay the current input line You can enter the code in either hex or decimal You can type this character to cause the MFJ 1278B to retype a line you have begun When you type the redisplay line character the following things happen First type in flow control is temporarily released if it was enabled This displays any incoming packets that are pending Then a BACKSLASH character is typed and the line you have begun is retyped on the next line If you have deleted and retyped any characters only the final form of the line will be shown You are now ready to continue typing where you left off You can use the redisplay line character to see a clean copy of your input if you are using a printing terminal and you have dele4ed characters If you have set BKONDEL OFF deletions are designated with BACKSLASH characters rather than by trying to correct the input line display The redisplayed line will show the corrected text You can also use this character if you are typing a message in Converse Mode and a packet comes in You can see the incoming message before you send your packet without canceling your input REMSYSOP call n Mode Mailbox Default Blank Parameters Call Callsign to be used for Remote SYSOP ops n 0 15 optionally specified sub station ID SSID Entering a callsign here permits the owner of the call to perform sysop functions remotely Sysop functions inclu
168. IXTONES values for SSTV mode is the same as in the FAX mode Refer to FAX Operation section in this instruction for pixtones information Note that sync tone of 1500 Hz is automatically transmitted when MFJ 1278B enters SSTV transmitting The Sync tone can not be changed The SSTV pictures received by the MFJ 1278B and stored on disk can be retransmitted under the same SSTV format How a file is recalled and transmitted will depend on the terminal program used Refer to the instruction manual of your terminal program To enter the SSTV transmit mode first Type MODE TV ENTER Select the desired SSTV format with the TVMode command If you are using a terminal program which supportsmulti level SSTV transmitting you should follow the transmitting procedure given by the program manual Note that under multi level SSTV selection of TVMode for transmitting is not required After entering the SSTV mode and selecting the desired TV Mode enter the CONVERSE mode by typing K Then switch to transmit mode by typing CTRL T Terminal program will sends raw data stream to the MFJ 1278B thru the RS 232 port Transmit to receive switching is automatic and occurs when the data stream has been exausted Note that TVMODE setting is NOT required for multi level transmitting Follow the normal File Upload procedure given by the terminal program CAUTION If your terminal program is not fast enough to support a data transfer rate of 480 cps sustain
169. If you type a full packet length of characters without typing the send packet character your input will be packetized and transmitted anyway The default send packet character is CR but you can specify any character with the command SENDPAC You may also choose to have the send packet character transmitted in the packet or not If the send packet character is CR it is natural to include it in the packet as part of the text as well as interpreting it as a command This is accomplished by setting CR ON If you use some other character to force packet transmission you may want to set CR OFF and inhibit transmission of the send packet character If you set the send packet character to something other than CR you can cancel packets of more than one line with the cancel packet character that is set with the command CANPAC Single line packets can be canceled with either the cancel line character or the cancel packet character In order to return to Command Mode from Converse Mode you must type the Command Mode entry character or send a BREAK signal over the serial port A BREAK is not a regular ASCII character but it can frequently be transmitted by typing a special key on the keyboard MFJ 1278B MULTI MODE ADVANCED OPERATION The following commands set special characters which are active in Converse Mode Refer to the discussions of these commands for details on the operation of the characters in Converse Mode CANLINE Cancel cur
170. If messages from the MFJ 1278B appear garbled with incorrectly displayed characters you may need to change the MFJ 1278B s serial port parity and word length There could also be a problem with the terminal baudrate See Chapter 2 if the baud rate needs to be changed The MFJ 1278B s default value is 8 bits and no parity If your computer receives 8 bits as data you may have to set space parity since text may otherwise be interpreted as graphics or other special characters The Awlen and Parity commands set the word length and parity respectively set the wordlength to 8 bits and parity to NONE use the following combination AWLEN 8 8 bit words PARITY 0 no parity bit For setting a wordlength of 7 bits and even parity set AWLEN 7 7 bit words PARITY 3 even parity One of these combinations will satisfy most computers You are more likely to require a different setting if you have a terminal rather than a computer or if you have configured your terminal port for some special application If your computer requires odd parity set PARITY 1 If your computer detects framing errors try setting AWLEN 7 7 bit words PARITY 0 no parity bit for shorter characters For longer characters set AWLEN 8 8 bit words PARITY 1 or PARITY 3 Echos You may see two characters on your screen for every character you type for example cmd RREESSEETT Your computer is echoing the characters you type and the MFJ 1278B is also echo
171. J 1278B is not interrupted during the pre set delay time it will continually repeat until buffer O is interrupted TUNING INDICATOR Your MFJ 1278B comes equipped with a very accurate and sensitive tuning indicator The tuning indicator is extremely useful not only for tuning to signals for optimum reception but also for filter alignment and audio level indication The position of the tuning indicator LED is only meaningful for tuning a signal under the following conditions 1 The station is transmitting data both tones NOT just a single carrier 2 The DCD LED is lit indicating that the signal is within the capture range of the PLL demodulator 3 That there is sufficient audio output from the receiver for proper operation of the demodulator If the conditions above are met tuning in a station with the tuning indicator is quite simple Just set the receiver frequency so that the tuning indicator LED is centered in the display Actually there are 2 LEDs which represent the center of the display Either or both may be used The use of the tuning indicator will be further discussed later in each mode of operation MFJ 1278B MULTI MODE BASIC OPERATION PACKET OPERATION VHF Packet If you are not familiar with packet operation then you can learn quite a bit about it with the MFJ 1278B without transmitting anything For your first experiments the MFJ 1278B will be talking to itself allowing you to become familiar wit
172. L controls whether the MFJ 1278B adds a new line character to and WRU MFJ 1278B MULTI MODE OPERATIONAL COMMANDS SLOTS nnn Mode Packet Default 3 Parameter nnn 0 127 specified the number of sides on the slot time dice The SLOTS parameter determines how many sides are on the slot time dice SLOTS represents an 1 sided dice the TNC throws before transmitting The SLOTS command allows any number of slots from 1 thru 127 to be defined SLOTS n REMARKS Disables Slotting This should be the default setting Use only if the channel is VERY busy VERY VERY VERY busy You get the idea Might as well print it out amp send it in the mail The value used on a particular channel should be agreed on by the channel users Access to the channel will be equitably distributed among all users if everybody is using the same value for the SLots and DEAdtime parameters The idea is to pick a value large enough that the probability of two queued up stations picking the same value is relatively small On the other hand the value chosen should be small enough that most of the time ONE of the queued up stations will have a significant probability of picking the first available slot In this way the channel is reliably arbitrated and at the same time the overhead required for the arbitration is minimized so that overall throughput on the channel is maintained The actual value used will depend on the average number of queued up stat
173. LCAL is WSPE AMTOR depends on everyone having a unique selective call If you find there is already a station using the same call that you would use then you may need to base your ID upon the call district that you re in Select a letter based upon the table below 1 Q 2 W 3 4 R 5 T 6 Y 7 U 8 1 9 O 0 P Example N2WX becomes NWWX using zone 2 When MYSELCALL is set the MFJ 1278B is ready to receive and respond to AMTOR calls Operating Mode A To start the ARQ call type ARQ lt selcall gt and ENTER The lt selcall gt must be four characters long Both the CON and STA leds on the MFJ 1278B will light and your transmitter will start keying on and off repetitively If the other station responds you can start sending data or you can abort the call by typing QRT or R When the CON lights a link is established You may now type CONVERSE or K to enter the data mode and start transmitting data The CON and STA will be turning on and off at various times depending on how much data you transmit and how good the link is When you are through transmitting always use the AMTOR ending signal NEVER use a since this will not relinquish the ISS function and the station you re working will be unable to transmit until the information sender sends a If you wish to end the contact go back to AMTOR command mode with a CTRL C and type ORT While you are the current receiving station you can t send any new data to the o
174. MANDS BTEXT text Mode Packet Default Parameters text Any combination of characters numbersand spaces up to a maximum length of 128 characters BTEXT specifies the content of the data portion of a beacon packet The default text is an empty string i e no message Beacon packets are discussed in more detail under the BEACON command NOTE BEACONS will not be sent if BTEXT is null You can send multiple line messages in your beacon by including carriage return CR characters in the text The CR character can be included by preceding it with the pass character The pass character is set by the PASS command If you enter a text string longer than 120 characters an error message will appear and the command will be ignored For example a Bulletin Board program might set the beacon text to a message like this updating the text after each connection Mailbox on line Messages for WB9FLW AD7I K9NG To clear the BTEXT text without issuing the RESET command use a 96 or amp character as the first character in the text BUDLIST ON OFF Mode Packet Default OFF Parameters ON Ignore frames from stations which are not in the LCALLS list OFF Ignore frame from stations which are in the LCALLS list BUDLIST works in conjunction with the command LCALLS which sets up a callsign list These commands determine which packets will be displayed when you have set MONITOR ON BUDLIST specifies whether the callsigns in the list
175. MFJ 1278B MULTI MODE TABLE OF CONTENTS Table of Contents INTRODUZCTION 5 rite edet ete e toig echte acte e Pere ec 1 COMPUTER INTERFACINQG rennen eret 4 MFJ Starter Packs esie eee eee Deine pee 4 Computer Interface with MFJ Starter Pack sss 5 Computer Interface without MFJ Starter Pack sess 5 SERIAL PORT SIGNALS eerte ere ettet rede Pere 5 COMPUTER WITH SPECIFIC SERIAL INTERFACES eee 6 Apple Macintosh et Ree ER E er ER Re 6 Commodore C64 C128 and VIC 20 sees eene eterne enne eterne 7 TBM PCIE o BB ERR ep 7 Radio Shack Color Computer eese nenne 8 Color COmpUltets z x coacti etti e Reate edm tee iie doe 8 PC XT AT 386 486 and compatibles Computer sss 8 Other Computers with Nonstandard Serial Ports ess 9 TERMINAL SOFTWARE REQUIREMENTS eene 10 Apple Macintosh RD erre eit titii EGER 10 Apple dT TIE Tle uua tate Tee i SEE harten ee re Pee es 10 Commodore C64 C128 and VIC 20 sese 11 DRE t REED UR ER 11 and Compatible Computers sese 11 Radio Shack Color Computer sese nennen 12 Radio Shack Model 100 102 and NEC 8201 sese 12 MFJ 1278B SERIAL PORT PIN
176. MFJ 1278B transmits the memory buffer the MFJ 1278B will revert to receive mode There is no need to issue a CTRL R to make the MFJ 1278B go back to receive mode Note If you are using MFJCOM terminal program you will not be able to use the TAB key as the BUFKEY Change BUFKEY to another key on the keyboard See BUFKEY command in Chapter 6 for more detail CW Weighting The MFJ 1278B allows you to increase or decrease the weight of the code elements generated by the keyboard or key paddle The user can set the WEIGHT by using the WEIGHT command The weight factor defaults to dot to space ratio of 1 1 A number from 0 thru 255 represents the weight value used The default setting of the WEIGHT command O sets a weight factor of 1 1 Select a number from 1 to 127 to INCREASE the dot space ratio Select a number from 128 to 255 to DECREASE the dot space ratio weight You can easily change the weight the MFJ 1278B uses by typing WEIGHT ENTER Where is a number from 1 to 127 to increase weight or from 128 to 255 to decrease MFJ 1278B MULTI MODE BASIC OPERATION Tuning your Radio The MFJ 1278B lets you tune your radio with the TUNE command The TUNE command is issued from the command mode The user can use the TUNE command in any of the MFJ 1278B operating modes The TUNE command activates the PTT line for 30 seconds After 30 seconds MFJ 1278B will automatically return to command mode To abort tuning before 30 seconds
177. MFJ MultiCom terminal program for IBM and compatibles PIXTONES is defined as 16 values in hexadecimal form They are defined as follows PIXTONES aaa bbb ccc mmm ooo ppp where aaa is the value which determines extreme of the white area of the transmitted picture ppp is the value which determines extreme of the black area of the transmitted picture The values between aaa and ppp defines the gray areas of the transmitted pictures The default PIXTONES values are BF BB BD B9 BE BA BC B8 B3 B5 B6 B2 B0 AD 9D 8E Note that in 4 or 8 level SSTV or FAX transmission MFJ 1278B will automatically select only 4 or 8 PIXTONES values of which you have chosen respectively PIXTONES does not affect 2 levels FAX transmitting If the picture transmitted does not seem to have the right contrast or brightness try and reset the PIXTONES values The HEX values which represent the PIXTONES for the pictures to be transmitted is listed in Table 4 8 below on the next page In SSTV and MULTIFAX mode the MFJ 1278B automatically transmits the syne tone Therefore the sync tone does not need to be selected for PIXTONES parameters MFJ 1278B MULTI MODE BASIC OPERATION FAX SSTV Transmit Tones Hz 1100 sync 1200 sync 1300 sync 1500 sync 1550 1600 1650 1700 1750 1800 1850 1900 1950 2000 2050 2100 2150 2200 2250 PIXTONES Values HEX 86 92 AD B2 B6 B8 BA
178. N OFF Mode Packet Default OFF Parameters ON Connect and disconnect status messages are time stamped OFF Connect status messages are not time stamped This command enables time stamping of CONNECTED status messages The date and time information is then available for use by Bulletin Board programs or other computer applications The date and time must be set initially by the DAYTIME command before time stamping will occur The date format is determined by the DAYUSA command For example if CONSTAMP is ON DAYUSA is ON and the date and time have been set a connect message might appear as follows CONNECTED to N2WX 05 28 85 16 28 31 CONVERS Mode Immediate Command CONVERS is an immediate command and will cause the MFJ 1278B to exit from Command Mode into Converse Mode Any link connections are not affected Once in Converse Mode everything you type is packetized and transmitted over the radio Typing the Command Mode entry character returns the MFJ 1278B to Command Mode See the discussions of Converse Mode in Chapter 4 and Chapter 5 CONVERSE Mode AMTOR Immediate Command Switches from AMTOR command mode a cmd prompt to the text transmission mode Use CONVERSE after a connection or FEC SELCALL broadcast is begun to start exchanging data MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CPACTIME ON OFF Mode Packet Default OFF Parameters ON Packet timeout is used in Converse Mode OFF Packet timeout is no
179. N OFF Mode Packet Default ON Parameters ON The STA led serves as a Mail present indicator and performs normal functions OFF TheSTA led only performs it s normal functions When MAILLED is ON the MFJ 1278B s STA LED will not flash while the Mailbox is ON However the STA LED will flash if mail is present in the Mailbox for the SYSOP The STA LED reverts to its normal function lit when unacknowledged packets are pending if the MFJ 1278B is in a CONNECTED state or if MAILLED is OFF MALL ON OFF Mode Packet Default ON Parameters ON Monitored packets include both connected packets and unconnected packets OFF Monitored packets include only unconnected packets This command determines the class of packets which are monitored If MALL is OFF only otherwise eligible packets as determined by the BUDLIST and LCALLS commands sent by other TNCs in the unconnected mode are displayed This is the normal manner of operation when this MFJ 1278B is being used to talk to a group of TNCS all of which are MFJ 1278B MULTI MODE OPERATIONAL COMMANDS MARSMODE n Mode RTTY ASCII Default 0 n n 0to3 if nz0 MARS QSO mode The MARsmode command provides two levels of MARS compatibility Minimal translation is provided by QSO mode In the QSO mode the MFJ 1278 assumes the user is manually sending and receiving Maximum translation is provided for sending and storing files of MARS messages while preserving all of the formatting information us
180. NE 50 197 Commands CBELL 199 Commands CCITT 200 Commands CHANGE 200 Commands CHAT 200 Commands CHECK 201 Commands CHECKV I1 201 Commands CMDTIME 203 Commands CMSG 205 212 Commands CMSGDISC 205 Commands COMMAND 206 Commands CONNECT 42 207 208 312 Commands Connect 204 Commands CONOK 209 313 Commands CONPERM 204 Commands CONSTAMP 210 216 Commands CONVERS 207 210 commands CONVERS 43 Commands CONVERSE 210 Commands CPACTIME 211 283 Camman de CD 911 919 293 MANUAL INDEX MFJ 1278B MULTI MODE MANUAL INDEX Commands CWIDMODE 214 Commands CWSENDCH 215 Commands CWSPEEDM 215 Commands DAYTIME 210 216 249 253 310 Commands DAYUSA 210 217 253 Commands DDisc 217 Commands DEADTIME 218 Commands DEFLTDLC 219 Commands DELAY 218 Commands DELETE 219 commands DELETE 49 Commands DIDDLE 219 Commands DIGIPEAT 220 Commands DISCONNE 220 commands DISCONNE 43 Commands Disconnect 217 Commands DISPLAY 198 217 224 Commands DISPlay 221 Commands DWAIT 52 224 Commands EAa 225 Commands EAS 225 Commands EASIN 225 Commands ECHO 226 Commands ECho 226 Commands EPSON 226 Commands ERrstrin 227 Commands ERUS 227 Commands ESCAPE 227 Commands EXActcal 228 Commands FARNSWOR 228 Commands FAXEOP 228 Commands FAXMODE 229 Commands FAXNEG 229 Commands FAXREV 229 Commands FEC 230 Commands FIRMRNR 230 Commands FLOW 230 Commands FLow
181. ODE MANUAL INDEX signal lock 72 SLOTTING 153 Software UART Color Computer 13 Special Characters 117 Special characters Converse Mode 122 Special characters Transparent Mode 122 special input characters 49 Specifications 315 State machine 318 Station identification 234 Station identification callsign text 254 Station identification sent as UI frames 339 Stations heard clearing list 249 Stations heard displaying list 249 Stopping output 50 SW2 baud rate selection 317 T Table 2 3 MacTerm Parameters for MFJ 1278B 11 Table 4 1 36 Table 4 2 36 telephone modem 5 Temperature of components 332 Terminal program 11 Terminal program Apple Macintosh 11 Terminal program Commodore 64 or VIC 20 12 Terminal program IBM PCjr 12 Terminal program NEC 8201 13 Terminal program Radio Shack Color Computer 13 Terminal program Radio Shack Model 100 13 text parameter maximum length 193 212 311 Time setting 216 Time stamping 210 216 Time stamping list of stations heard 249 Time stamping monitored packets 253 Timing 343 Timing collision avoidance 343 Timing default wait 134 344 Timing minimum acknowledgment delay 275 344 Timing packet retransmission 132 343 Timing packet transmission 224 Timina neatacal MFJ 1278B MULTI MODE MANUAL INDEX Timing Transparent Mode escape 203 TNC 1 AX 25 Level 2 version 187 TNC 1 AXHANG parameter 188 TNC
182. ONIOFF on Packet Used in conjunction with BUDLIST 6 65 allows selective monitoring of other packets Allows the MFJ 1278B to understand lower case characters as upper case after the streamswitch is entered Determines whether the lower or upper 8 case characters are set LEDmode 1 Rapid flashing of STA and CON leds for the 200 baud Pactor mode 6 LFadd ON OFF off Pactor Appends LF after a received carriage 62 62 62 63 64 65 67 67 MFJ 1278B MULTI MODE APPENDIX COMMAND SUMMARY NN nd r LFADDALT ONIOFF n RTTY Enables the MFJ 1278B to go to the next 6 67 line when a CR character is received in RTTY mode LFIGNORE ONIOFF ff Packet Line feeds are ignored except in 6 68 transparent mode LISTEN I command AMTOR Used to monitor someone else s Mode A 6 68 AMTOR connection LFI o LI T ON OFF determines if Pactor Mailbox is on line MAILBOX ONIOFF Enables the Packet personal mailbox 6 69 3 MAILLED ONIOFF Packet Controls the STA MAIL LED Flashes 6 70 when mail is presence MALL ONIOFF on Packet Determines the class of packets which 6 71 monitored n n MARSMODE n 0 RTTY ASCII Use with Promars command to set the Used for selectively monitoring portions of mode B FEC transmissions MAXFRAME n 4 Packet Sets the upper limit for the outstanding MAXSum nn 0 Pactor Specifies the number of cycles of error pe He c NN ladden information p
183. QUAD CMOS SWITCH 7AHCT21 DUAL 4 INPUT AND 74HCT273 QUAD D FLIP FLOP 1N754 6 8 V ZENER 1N4001 1A RECTIFIER 1N4006 1A RECTIFIER 1N4148 SWITCHING 1N4746 18 V ZENER 1N5257B 33 V ZENER RED LED 5 MM ROUND YELLOW LED 5 MM ROUND GREEN LED 5 MM ROUND TRANSISTORS U26 U35 U36 U32 U33 U34 U30 U31 U41 U40 CR6 CR8 CR22 CR7 CR2 CR3 CR4 5 CR27 CR28 CR9 CR10 CR11 CR13 CR15 CR14 CR24 CR16 CR23 CR29 CR30 CR201 CR202 CR32 CR25 CR26 CRI CR12 CR31 7 CR19 CR18 CR33 CR20 CR21 MFJ 1278B MULTI MODE APPENDIX I PARTS LIST MFJ P N Descrpition 305 0001 2N3904 GENERAL PURPOSE NPN 305 0002 2N3906 GENERAL PURPOSE PNP 305 2006 MPS A92 VOLTAGE REGULATOR 307 2006 7805CT TO 220 5 VOLTS CONNECTORS 612 1010 10 PIN 1 CENTER RIGHT ANGLE MALE HEADER 22 05 3181 612 0032 2 PIN 1 CENTER MALE HEADER MOLEX 22 03 2021 OR EQUAL 612 0033 3 PIN 1 CENTER MALE HEADER MOLEX 22 03 2031 OR EQUAL 612 0035 5 PIN 1 CENTER MALE HEADER MOLEX 22 03 2051 OR EQUAL 612 0036 6 PIN 1 CENTER MALE HEADER MOLEX 22 03 2061 612 0036 20 PIN 1 1 CENTER MALE HEADER 611 1005 5 PIN DIN FEMALE PC MT RIGHT ANGI EF CWITCHECR ART Component ID Q9 Q1 Q2 Q4 Q6 Q7 Q22 Q15 013 014 Q16 Q19 Q8 Q5 Q12 Q21 Q23 Q18 Q3 15 JMP4 JMP5 JMP7 JMP8 JMP10 JMP13 JMP 16 2 JMP 23 JMP A JMP E JMP F JMP G JMPH JMP J JMP K JMP L
184. REMsysop for more detailed information There are three 3 different methods to kill messages in the mailbox when the remote user is connected We will give you a brief overview of these methods below The remote user can kill a message in a particular slot when connected to the mailbox To kill a message in a certain slot type Kit ENTER followed by a changeover character CTRL Y Where the is the slot number of the message the remote user wants to kill The Mailbox will respond with Mailbox Ready n free de callsign H elp K L R S The n free is the amount of RAM space available for messages The n will be no higher than 65K if a 512K or a 128K Mailbox is in operation If the Mailbox is 32K then nn will be 32K The de callsign is the callsign of your Pactor mailbox that the mailbox sends back to the remote user 2 The remote may also kill any message that is addressed to specifically to the user To kill a message that is addressed only to the user type ENTER followed by a changeover character CTRL Y This is whether or not the message flag is set to an N or a Y Note that the remote users may only kill messages which are addressed them The originator can kill any message that he she originated The local SYSOP can kill any or all messages in the Mailbox 3 The remote user can perform a Global Kill on a group of messages that are under the same callsign To perform a Global Kill on a group of mess
185. RFACES Apple Macintosh The Macintosh serial port is an RS 422 compatible port but it will work fine with the RS 232C serial port on your MFJ 1278B Enterprises Inc offers an optional Starter Pack for the Macintosh The Macintosh Starter Pack is available from Enterprises Inc or any dealer of products The Starter Pack includes a cable for connecting the MFJ 1278B to the Macintosh and a terminal program The Starter Pack for Macintosh is MFJ 1287B If you wish to use your own cable you will need a cable wired as shown in Fig 2 1 Macintosh 1278 Macintosh MFJ 1278B 8 Pin DB 25P DB 9P DB 25P 1 HSKO 2 HSKD 6 5 2 Fig 2 1 Serial port wiring for Apple Macintosh Note that pin 1 of the DP 9P connector is not connected inside the Macintosh or the MFJ 1278B We highly recommend the use of shielded cable when making interconnections MFJ 1278B MULTI MODE COMPUTER INTERFACING Commodore C64 C128 and VIC 20 The MFJ 1278B has a built in TTL level port for interfacing with the Commodore C64 C128 or the VIC 20 computers You do not need a RS 232C converter to interface with the MFJ 1278B An optional Starter Pack for the C 64 C 128 or the VIC 20 is available from MFJ Enterprises Inc or any dealer of MFJ products The Starter Pack includes a cable from the MFJ 1278B TTL port to the user I O port on the Commodore computer Included also is a terminal program To order specify MFJ 1282
186. RTs may be unable to send and receive data at the same time users of such computers should set FLOW ON FLow ON OFF Mode Pactor Default ON This operates basically the same as the MFJ 1278B packet command but operates only in p cmd mode This limitation is due to the rapidly changing transmit lt gt receive status of a Pactor link Applying FLOW to data would improperly hold off the important changeover signal and is therefore disallowed FORWARD Mode Packet Immediate Command dest bbs optional via FOrward is an immediate command Messages can be forwarded manually by command or automatically They can also be forwarded hourly or by your local full service mailbox reverse forward request When invoked the mailbox initiates a connect to the callsign of the destination BBS When a connect is established the mailbox will proceed to send your messages Messages that qualify for forwarding must meet two conditions they are 1 1 Have flags of read 2 2 Must have a callsign in the addresses that are different from MYMCALL A ftaa anah mnanaa wan Flaw ia ant tn IDI ta AA WLan ad MFJ 1278B MULTI MODE OPERATIONAL COMMANDS Parameters n 1 15 specifying frame acknowledgment time out in 1 second intervals After transmitting a packet requiring acknowledgment the MFJ 1278B will wait for the specified frame acknowledgment timeout before incrementing the retry counter and sending
187. Restart and User Stop characters the MFJ 1278B will alternately start and stop transmission upon receipt of the character STatus Mode Pactor Immediate Command STATUS is an immediate command used for display of debug information This is helpful for troubleshooting Pactor problems If any Pactor problems occur and you are still able to talk to the MFJ 1278B then type this command from the p cmd prompt The MFJ 1278B will send the Pactor Status to the screen Copy all displayed information on a piece of paper and call our technicians STATUS Mode AMTOR Immediate Command The STATUS command returns diagnostic information useful for helping us help you with LY o W lle clas 41 030 43 MFJ 1278B MULTI MODE OPERATIONAL COMMANDS STOP n Mode Default 13 Parameters n 0 7F specifying an ASCII character code The STOP command selects the User Stop character which is used to stop output from the 1278 to the terminal You can enter the code in either hex or decimal This is the character you will type to halt the MFJ 1278B s typing so that you can read text before it scrolls off your display Output is restarted with the User Restart character which is set by the START command If the User Restart and User Stop characters are set to 00 software flow control to the MFJ 1278B is disabled and the MFJ 1278B will only respond to hardware flow control CTS If the same character
188. S TVMODE n Mode SSTV Immediate Command Parameter n to 5 specifying a SSTV picture format The TVMODE command selects the formats under the SSTV mode for the MFJ 1278B When the built in printer port is used to receive SSTV the MFJ 1278B supports all SSTV formats listed in table below TVMODE n Formats The SSTV format can be changed by using the TVMODE n command where n is a number from 1 thru 5 as listed in the above table For example to set the MFJ 1278B to 12 seconds SSTV format you would type TVMODE 2 CR TVMODE is ineffective when the command TVX is turned ON When TVX is on MFJ 1278B supports additional SSTV formats listed Table 4 9 in this manual MFJ 1278B MULTI MODE OPERATIONAL COMMANDS TVX ON OFF Mode SSTV Default OFF Parameters ON Multi level SSTV raw data is sent to the terminal without presetting the SSTV format OFF Multi level SSTV raw data is sent to the terminal in format set by the TVMODE command TVX command sets the format that the MFJ 1278B sends the SSTV pictures to the terminal When TVX is turned ON the SSTV picture format is not preset The terminal program must be responsible to detect the end of the SSTV picture The MFJ 1278B does not detect the end of the picture no matter what TVMODE is set This means that MFJ 1278B can receive any format of SSTV picture like a free running mode It is not limited by the TVMODE command Picture lengths longer than 36 seconds are
189. SHIFT ON forces the receiver shift to the LTRS case whenever the Baudot SPACE character is received This helps in many situations in reducing garbling when conditions are not good Some stations particularly those transmitting weather information and other strings of numeric text are not compatible with unshift on space USOS When receiving those stations UNSHIFT should be turned OFF URepeats nn Mode Pactor Default 1 Parameters 1 lt lt 7 The UREPEATS parameter specifies how many retransmissions to perform for each FEC data packet sent For example UREPEATS 1 causes each FEC packet to be sent two times USERS n Mode Packet Default 1 Parameters n 0 10 specifying the number of active connections that may be established to the MFJ 1278B by other TNCs USERS affects only the manner in which incoming connect requests are handled and has no effect on the number or handling of connections you may initiate with this MFJ 1278B For example USERS 0 Allows incoming connections on any free stream USERS 1 Allows incoming connections on stream only USERS 2 Allows incoming connections on streams amp B USERS 3 Allows incoming connections on streams B amp C and so on through USERS 10 MFJ 1278B MULTI MODE OPERATIONAL COMMANDS VISTICKS nnnn Mode SSTV Default 0 Parameters nnnn O nnnn 65535 The VIsticks parameter specifies the number of pixels to send at the beginning of a SSTV pictur
190. Subject Where Slot column is the number of the slot that the message is in The number of message slots present in the standard 32K Mailbox is 99 The lower case t is the Type Flag block The lower case m is the Message Flag block The To column will contain the callsign of the person who the message is addressed to The From column will contain the callsign of the person who left the message The Subject column will contain a brief message title After the Mailbox lists all messages it will issue the Mailbox prompt nn free de callsign H elp L R S gt The n free is the amount of RAM space available for messages The n will be no higher than 65K if a 512K or a 128K Mailbox is in operation If the Mailbox is 32K then nn will be 32K The de callsign is the callsign of your Pactor mailbox that the mailbox sends back to the remote user The Pactor Mailbox will send an automatic changeover after it lists all mailbox messages After the automatic changeover is sent the mailbox will send a CTRL G character back to MFJ 1278B MULTI MODE BASIC OPERATION Read This command lets you read messages addressed to you When you list the messages in the mailbox you notice an N flag next to the messages which you have not read Once you read those messages the N flag will change to a Y flag This is an indicator to both you and the SYSOP that the messages have been read From there you can perform a global kill on all of your messages or the
191. The default for TVHSYNC is OFF For most SSTV receiving TVHSYNC should be turned OFF The 4 level SSTV pictures received by the MFJ 1278B thru the built in parallel printer port can be adjusted for brightness and contrast by using the TVBREAKS command The TVBREAKS command controls the brightness and contrast of the SSTV received on the MFJ 1278B printer port as well as when SSTV picture is printed to the screen SSTV pictures sent to the MFJ 1278B printer port are set at 4 gray levels With terminal software which supports multi gray levels SSTV you can receive SSTV pictures with up to 16 levels of gray The MFJ 1278B can be set to operate SSTV both in Color and 16 gray levels by turning the command 16LEVELS ON and the command 8LEVELS OFF If your terminal program does not support 16 gray levels the 16Levels command must be turned off and you must follow the instruction given by your terminal program to operate SSTV If your terminal program does not support SSTV you must follow the instructions given in the main MFJ 1278B manual to operate SSTV thru its built in printer port MFJ 1278B MULTI MODE BASIC OPERATION TVBreaks are arranged in the following format White gray Black area area area ss aa bb cc dd ee ff e2 hh ii jj kk l mm nn ss is the Sync value The default TVBreak value is 80 46 47 48 4C 4F 52 54 59 5C 5E 60 63 67 69 The RXBright command has been updated to support the 16 leve
192. To Send pin is an output from the MFJ 1278B signaling the attached device to send or refrain from sending data to the MFJ 1278B This line is used for systems that require hardware flow control Pin 6 Data Set Ready The Data Set Ready pin is an output from the MFJ 1278B telling the attached device that the MFJ 1278B is operational Pin 7 Signal Ground The Signal Ground pin is the common or return path for all signals between the MFJ 1278B and the attached device Pin 8 Data Carrier Detect The Data Carrier Detect pin is an output from the MFJ 1278B As normally configured DCD reflects the status of the CON LED It is true when an AX 25 connection exists between your MFJ 1278B and another station it is false when no connection exists This configuration is useful when the MFJ 1278B is used with a telephone style Bulletin Board system Since the AX 25 protocol connection analogous to a modem signal on the telephone indicates the presence of a user Shorting pins 1 and 2 of on the MFJ 1278B mother board will cause this output to always be true COMPUTER BAUD RATE Autobaud The MFJ 1278B performs an AUTOBAUD routine upon each power on cycle of the MFJ 1278B The AUTOBAUD command is user selectable The AUTOBAUD command is armana Mar O3 Amo MFJ 1278B MULTI MODE COMPUTER INTERFACING time the MFJ 1278B signs on you will not need to press the return key to execute the Autobaud routine In setting AUTOBAU
193. UAL INDEX F FARnswor 73 75 FARNSWORTH CW 75 FCS HDLC field 338 Fig 2 1 Serial port wiring for Apple Macintosh 6 Fig 2 2 Serial port wiring for Radio Shack 9 Fig 2 3 Serial port wiring with jumpers for 10 File Transfer 8 bit data 122 187 File transfer ASCH 187 File transfer binary files 122 187 File transfer limiting unacknowledged data 245 263 File transfer non text files 293 Filtering received characters 248 FLAG HDLC field 338 Flow control disabling in one direction 125 286 287 293 300 306 307 Flow control disabling of 124 Flow control hardware 127 Flow control link 344 Flow control packet 344 Flow Control Resuming output 124 Flow control RNR frames 344 Flow control RR frames 344 Flow Control Software 125 Flow control software 286 287 305 306 307 Flow Control Stopping output 124 Flow control toggle character 125 Flow control Transparent Mode 125 293 300 Flow control type in 127 230 Flow control XON XOFF 125 FRMR frames 313 342 Full duplex operation 52 232 316 G Gibberish 336 Ground signal location 331 H Hardware description 316 Hardware flow control 127 HDLC frame format 338 Tn 4 10 MFJ 1278B MULTI MODE MANUAL INDEX I I frames 340 IBM PCjr 8 IBM PCjr serial port interfacing 8 IBM PCjr terminal program 12 IBM Personal Computer 6 Identification packets 234 Identification aut
194. V Pictures to the Screen The MFJ 1278B does not support printing graphics to the computer screen without specific terminal software designed for your particular computer offers an optional Starter Pack MFJ 1289 which will allow you to receive SSTV and display to the computer screen The Starter Pack software allows for saving SSTV pictures to disk Pictures saved on disk may be re transmitted or recalled to the screen at any time When using a terminal program which allows printing of SSTV pictures to the computer screen the command PRINTGRA must be turned OFF MFJ 1278B will send pictures to the computer screen through the RS 232 port instead of the built in printer port For those who wish to write their own software to handle SSTV printing to the computer screen the following information may be useful for you When the PRINTGRA is turned OFF TVX is ON and MFJ 1278B will send free running raw data thru the RS 232 port Note that this is not the 4 levels data which is used for printing to the printer port of the MFJ 1278B Raw data format is provided so that user can use special terminal program to achieve more than the 4 levels of gray provided by the MFJ 1278B firmware This raw data graphic format is the same for SSTV mode and FAX mode Upon hearing the sync tone for SSTV raw data stream is sent to the RS 232 port until a CTRL C is received For multi level SSTV and FAX modes the terminal program is responsible for at
195. When the MFJ 1278B is powered on again it will sign on to the AX 25 operation mode If you cannot send these character values with the software you intend to use you must power the MFJ 1278B off then disconnect the bbRAM battery by removing JMP 5 on the MFJ 1278B main board for several minutes then reconnect the battery and power up again to restore normal operation The commands available in KISS mode are Command Function Comments 0 Data Frame The rest of the frame is data to be sent 1 The next byte is the transmitter keyup time in 10 mSec units with a default of 50 500 mSec 2 P The next byte is the persistence parameter p scaled to the range 0 255 The probability of transmitting at the next opportunity is p 255 The default is 64 for a probability of 0 25 3 Slot Time The next byte is the slot interval in 20 mSec increments The default is 10 100 mSec 4 TXtail The next byte is the time to hold the transmitter after the FCS as been sent in 10 mSec units The command is obsolete and is included for completeness with earlier implementations 5 FullDuplex The next byte is 0 for half duplex normal or any other number for full duplex e g for operation with MicroStas MFJ 1278B MULTI MODE OPERATIONAL COMMANDS COMMAND PREFACE This chapter serves as a complete reference to all the MFJ 1278B operational commands These commands control the many variable values that affect the MFJ 1278B s operati
196. X COMMAND SUMMARY a r i Pactor Specifies number of error packet cycles 6 104 RET Allows retransmission of frames that are 6 104 not acknowledged VELIM call n Callsigns of BBS to enable reverse 6 105 forwards E ONIOFF AMTOR Will continue to retry until a QRT is 6 105 received lE IZ x E LI S 5 E BE sis e lt 8 RXBLOCK ONIOFF RXBRIGHT 4 Determines whether the information will 6 106 be sent in standard or block format Determines brightness and contrast of 6 107 SSTV or FAX pictures Generates test signals that used by the 6 108 internal tuning software to align the demodulator circuit FALWAY ONIOFF 9 M Packet Initiates forwards and reverse of all 6 110 forwardable messages ONIOFF off AMTOR Controls the incoming received signal to 6 105 be inverted before detection processing Occurs f fi fi fi n fi INVERT ONIOFF RTTY ASCII Inverts the mark and space tones 110 EENLN Used to properly format terminal output 110 CALL AMTOR Initiate a mode L SELCALL broadcast 111 Q E ge m AA im E o an ERIALNO 65535 Used for contest serial numbering 111 Similar to the MODE command Controls whether the 1278B adds a new 6 112 line character to and WRU NDPAC 0D CR Selects the character that will force a 111 packet to be sent in CONVERSE mode un ETUP 2 ES z E on 3 Determines how many sides are on the 6 11
197. ably want to set DIGIPEAT ON most of the time However you might want to disable digipeating if you re not home or if your transmit relay makes enough noise to wake you up at night The command HID enables automatic transmission of identification packets if your station is acting as a digipeater DISCONNE Mode Packet Immediate Command DISCONNE is an immediate command It will initiate a disconnect request with the currently connected station A successful disconnect results in the display of DISCONNECTED Other commands may be entered while the disconnect is taking place although connects are disallowed until the disconnect is completed If the retry count is exceeded while waiting for the other side to acknowledge the MFJ 1278B moves to the disconnected state If a disconnect command is entered while the MFJ 1278B is disconnecting the retry count is immediately set to the maximum number In either case the disconnect message is retry count exceeded DISCONNECTED Disconnect messages are not displayed when the MFJ 1278B is in Transparent Mode MFJ 1278B MULTI MODE OPERATIONAL COMMANDS DISPLAY class Mode Immediate Command Parameters class Optional parameter class identifier one of the following ASYNC Displays asynchronous port parameters CHARACTE Displays special characters ID Displays ID parameters LINK Displays link parameters MONITOR Displays monitor parameters TIMING Displays timing paramet
198. ackets received MAXUp nnn 10 Pactor Specifies the number of good 100 baud MBEGIN Allows the display of mode B transmissions only after the reception of the beginning of the signal 6 74 MCOM ONIOFF off Packet Enables monitoring of connected and 6 75 disconnected packet when monitor is on ON ONIOFF off Packet Allows the monitoring of other packets 6 75 while connected to another station CTEXT text blank Packet Allows storing of text messages to be 6 76 stored for mailbox Text is sent when mailbox is connected cece nnnn AMTOR Used with MBEGIN and MATCH and the 6 76 mode B receiving end when the MEND string is received M Packet Allows you to eliminate certain characters 6 76 from received packets f 4 Clears MHEARD list PY A list of all monitored packet stations Selects the operation mode of MFJ 6 77 1278 6 78 1 4 00 MHCLEAR MNONAX25 ONIOFF Allows MFJ 1278B to monitor non AX 25 packet MNONPRIN ONIOFF on Packet Determines whether monitored packets containing non printable characters are 1 1 MFJ 1278B MULTI MODE APPENDIX COMMAND SUMMARY r n Packet Affects the way monitored packets are 6 80 displayed MSPEED nn 20 CW Sets the operational speed which the MFJ 1278B will use for CW MRPT ONIOFF MSTAMP ONIOFF off Enables the time stamping of monitored packets MTIMEOUT 0 250 30 M Packet Mailbox connect will timeout after a time
199. activate the calibration mode CALI CR 4 Press the key on the computer keyboard to activate the MFJ 1278B modulator circuit The PTT LED on the front panel of the MFJ 1278B should illuminate 5 Place an oscilloscope probe at the right pin of JMP7 The signal on the scope will be approximately 4 volts p p 6 Verify that the voltage on pin 9 of U16 is 5 Vdc If it is 5 Vdc instead of 5 Vdc press the space bar one time The voltage should now be 5 Vdc If not then press and hold the space bar and see if the voltage at U16 Pin 9 changes at all Set U16 Pin 9 to 5 Vdc 7 Move the probe to J9 pin 1 TX audio Adjust R157 for a signal of 250 mV p p This shonld he near mid range on R157 Or set it to a level recommended hv vonr radio MFJ 1278B MULTI MODE APPENDIX C AUDIO OUTPUT 10 Move the probe to J9 pin 4 RX audio The signal should be approximately 1 V p p Press the space bar and again measure the peak to peak voltage at JO pin 4 The audio level should not change Both mark and space audio should be at the same level Type Q the emd prompt will appear on the computer screen 11 Switch the MFJ 1278B to Radio Port 2 by typing RADIO 2 CR The MFJ 1278B will respond with 12 13 14 15 16 17 18 Enter the following command to set the MFJ 1278B to calibration mode CALI CR Press the K key on the computer keyboard to activate the modulator circuits in t
200. ages the following conditions apply aw ad 1 1 tat m aa x7 MFJ 1278B MULTI MODE BASIC OPERATION If the above conditions are met then all the remote user must type ENTER followed by a changeover characters CTRL Y This will go out to Mailbox then the messages with the message flags set to Y with all of the proper callsigns will be killed The Mailbox will respond back to the remote user with all message numbers killed during the Global Kill process Also the Mailbox prompt will be given again The Mailbox will update the bytes free indicator when the messages are killed The local SYSOP cannot perform a Global Kill The SYSOP must individually kill any messages List This command allows the remote user local or remote SYSOP to list all messages in the mailbox of slots that are currently in use will be listed They all will have the slot number flag field the destination callsign originator callsign subject field Also the Mailbox command line will be on the next line To List the messages in the Mailbox first the Mailbox prompt must be obtained by either a connection to the Mailbox or through the local SYSOP command The local SYSOP command in accessible through the Packet Mailbox Please type the following to List messages from the Mailbox L ENTER followed by a changeover character CTRL Y The Mailbox will respond with a listing of currently used slots in the following format Slot t m To From
201. al input characters in Chapter 4 CANLINE Cancel current line CANPAC Cancel output Command Mode function only DELETE Character deletion PASS Insert following special character REDISPLA Re display current line START STOP User s flow control characters sent to MFJ 1278B XOFF XON MFJ 1278B flow control characters sent to terminal The following commands enable display features that are active in Command Mode Please refer to the discussions of these commands in Chapter 6 for details on the operation of these characters in Command Mode Also see the section on terminal configuration in Chapter 4 AUTOLF Add lt LF gt after CR in data sent to terminal BKONDEL Echo after character deletion ECHO Automatic echo of serial port input FLOW Type in flow control LCOK Lower case translation NUCR Nulls after CR NULF Nulls after lt LF gt NULLS Null count SCREENLN Automatic CR insertion Entering Data Transfer Modes There are several ways to enter a data transfer mode from Command Mode You can type the command CONVERS or K to enter Converse Mode or the command TRANS or T to enter Transparent Mode and the MFJ 1278B will immediately enter the specified mode If the user is in Command Mode and establishes a Packet connect then the MFJ 1278B will enter a data transfer mode You can specify the data transfer mode for automatic entry with the command CONMODE cmd CONMODE TRANS will specify Transparent Mode to the MFJ 1
202. al parameters match your terminal program parameter the MFJ 1278B will sign on and the STA and CON LEDs will extinguish If not you will see an asterisk or other meaningless characters on the screen at this time This is because the MFJ 1278B has not been set to match the parameter of your terminal program You will need to execute the AUTOBAUD routine 5 Execute the AUTOBAUD routine by pressing the RETURN key few times in succession on your computer The MFJ 1278B will execute the AUTOBAUD routine and set itself to the terminal program parameter Your computer screen will display the sign on message xJ bbRAM LOAD WITH DEFAULTS lA MFJ ENTERPRISES INC MODEL MFJ 1278B AX 25 LEVEL 2 VERSION 2 0 RELEASE XXXXX date 33K RAM CHECKSUM XXX cmd After the sign on message the STA and CON on the MFJ 1278B will extinguish If the sign on message fails to appear you should check the connecting cable between and the computer and the MFJ 1278B When you can successfully read the sign on message from the MFJ 1278B type MFJ 1278B MULTI MODE COMPUTER INTERFACING The MFJ 1278B has a parallel printer port in which to attach a parallel printer The parallel printer port is located on the left hand side of the MFJ 1278B The printer port can be used to make hard copies of either text or graphics Printer Port Connection The printer port is configured as a Centronics compatible parallel port A cable with male DB 25 on one end and a 36 pin
203. allsign To perform this two 2 conditions must be met i All messages must have been read and the message flag must be a Y ii The callsign contained in the MYMcall must be the same as the callsign in the MYcall command If the above conditions are met then all the user must type K CR This will go out to Mailbox then the messages with the message flags set to Y and all of the proper callsigns will be killed The Mailbox will respond back to the remote user with all message numbers killed during the Global Kill process Also the Mailbox prompt will be given again The bytes free indicator will be updated also The SYSOP either remote or local can do a Global Kill The SYSOP must individually kill any messages 5 The remote user or local SYSOP can List messages from the Mailbox In order to do this first the Mailbox prompt must be obtained by either a connection to the Mailbox by the remote user or through the local SYSOP command Then to List messages from the Mailbox A From the mailbox prompt type L CR The Mailbox will respond with a list of currently used slots in the following format Slot tm To From Subject Where Slot column is the number of the slot that the messages are in The lower case t is the Type Flag block The lower case m is the Message Flag block The To column will contain the callsign of the person who the message is addressed to The From column will contain the callsign of the person who lef
204. ame 1 7 depending on channel quality FRACK 3 The settings to use for 300 baud work on a linear mode HF channel are ACKprior ON SLots 3 DEAdtime 12 ACKTime 52 DWait 0 RESPtime 0 MAXframe 1 FRACK 8 What to Expect This modification to the protocol is compatible with stations using the current protocol in the following respect A station using the new protocol will not degrade the channel for users of the current protocol So there is nothing wrong with firing up the new stuff on a channel where the majority of the users aren t yet using it You will be able to communicate with users of the other system without difficulties However if the users of the old channel access procedures have DWait and RESPtime set to 0 they will tend to hog the channel from users of the newer more polite access system MFJ 1278B MULTI MODE ADVANCED OPERATION While these settings seem extremely long they will assure that the stations NOT using the new protocol always get a shot at slot 1 With these settings the users of the NEW protocol will occasionally capture the channel Settings of 43 for 1200 baud and 64 for 300 baud could be used to assure that stations NOT using the new protocol always have a shot at slot 0 This will result in users of the new protocol almost never being able to capture the channel unless all traffic from users of the old protocol has been cleared This should NOT be done unless ALL stations are using some type of slotte
205. ancel an input line You can enter the code in either hex or decimal For example to change the cancel line character to CTRL U you would set CANLINE 15 or CANLINE 21 If you cancel an input line in Command Mode the line will be terminated with a BACKSLASH character and you will see a new emd prompt on the next line If you cancel a line in Converse Mode you will see only the lt BACKSLASH gt and a new line You can cancel only the line you are currently typing Once a CR has been entered you can not cancel an input line using the cancel line character Note that if your send packet character is not CR the cancel line character will cancel only the last line of a multi line packet To cancel the entire packet use the CANPAC character Line cancellation like all other input editing features is disabled in Transparent Mode MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CANPAC n Mode Packet Default 19 Parameters n 0 7F specifying an ASCII character string code CANPAC is used to change the cancel packet input editing command character The parameter n is the ASCII code for the character you want to type in order to cancel an input packet You can enter the code in either hex or decimal If you cancel a packet in Converse Mode the line will be terminated with a lt BACKSLASH gt character and a new line You can only cancel the packet that is currently being entered Once you have typed the send packet charac
206. ands allow you to choose both the types of messages you receive and the stations you receive The other command that applies is the NAVTEX command To enter NAVTEX mode you must first enter AMTOR mode by typing MODE AM ENTER The MFJ 1278B will respond with the a cmd prompt From the a cmd prompt type NAVTEX ON ENTER The MFJ 1278B will display the Navtex command prompt n cmd indicating that it is ready to monitor any Navtex messages Once in the Navtex mode tune your radio to the Navtex frequency of 518 KHz To receive NAVTEX the MFJ 1278B must first receive the ZCZC start message followed by the four character preamble described above If this is not received intact the message will not be received At the end of the message NNNN will be received and the MFJ 1278B will stop receiving the Navtex message The MFJ 1278B will remember the last 200 four character preambles received with less than 1 8 of its characters received in error The MFJ 1278B will not reprint any of these messages when they are re transmitted from that Navtex station If you exit the a cmd command prompt the preamble memory is erased Emergency messages are numbered 00 and will always be printed regardless of whether they have already been received To prevent your MFJ 1278B from receiving certain Navtex stations just type NAVSTN XXXXXXXXXXXXX where each X is the identifying letter of the station you want to receive Your list of stations to rece
207. ange the special characters to for example seldom used punctuation The action of each special character is described in detail under the entry in Chapter 6 for the command that sets that character You can enter the code for a character in either Hexadecimal base 16 or Decimal notation The MFJ 1278B displays character codes in Hexidecimal notation A number in Hexidecimal notation is indicated by beginning a number with a in front of it such as 1B Each of the digits of a Hexidecimal number represents multiples of the powers of 16 The values 10 through 15 are represented by the letters through F which may be upper or lower case For example take a look at break down of hexidecimal value 1B MFJ 1278B MULTI MODE ADVANCED OPERATION So 1B in hexidecimal notation is equal to 27 in standard decimal notation Table 5 1 presents a list of ASCII character codes that are available in most computer manuals A table of ASCII codes for control characters follows c 01 0 03 eE gage J P V J Q P lt CTRL D gt DC4A ge V Z K ge CT V Z gt 5 U lt CTRL F gt ACK 22 sre crRt v SYN 4 3 V 2 4 V w z Q 2 Q lt CTRL X gt 4 V tH amp 0 oo 5 5 o gt GS CTRL N 15
208. ans of disconnecting the negative side of the lithium battery for MFJ 1278B maintenance U2 and associated components form a charge pump voltage inverter which generates an unregulated negative supply for the RS 232C drivers U3c Q2 CR6 and surrounding components provide a regulated source of 5 volts for the modem chips The modem power sources and ground are isolated from digital logic switching noise by inductor L2 RS 232C HANDSHAKING PROTOCOL The CTS DSR and DTR lines of the RS 232C port Jl are used for hardware handshaking protocol to control the flow of data between the terminal DTE and the 1278 DCE The MFJ 1278B always asserts Data Set Ready DSR on J1 pin 6 via resistor R16 Thus whenever the MFJ 1278B is powered up it signals to the terminal connected to J1 that the MFJ 1278B is on line The terminal indicates it is ready to receive data from the MFJ 1278B by asserting its Data Terminal Ready output J1 pin 20 The MFJ 1278B will send data when it has data to send and DTR is asserted If the terminal is not ready to receive data it should negate make false DTR to the MFJ 1278B Thus data flow from the MFJ 1278B to the terminal is controlled by the use of the DTR line The state of the DTR line is ignored by the software if software flow control is enabled in this direction The MFJ 1278B asserts its Clear To Send CTS output J1 pin 5 whenever it is ready to receive data from the te
209. ansmit and receive FAX with up to 16 levels of gray The FAX modes supported by the MFJ 1278B are listed in Table 4 6 These FAX modes include Weather FAX FAXMODE 3 and Wire Photographs FAXMODE 1 These 16 gray level FAX modes are supported to the computer screen with the appropriate software and hardware However the MFJ 1278B s built in printer port supports 2 level black white FAX and not FAX with multi gray levels In order to support more than 2 levels in FAX you must have the specific terminal program for your computer that will support FAX in multi gray levels FAX operations with the MFJ 1278B does not require any special computer or software to receive FAX pictures on your Epson graphics compatible printer However to print a FAX picture to your computer screen or to save FAX pictures to disk you need software that allows these operations Enterprises Inc offers terminal software for some computers to support this operation This software allows you to print FAX pictures to your computer screen in near real time and to save FAX pictures to disk The FAX pictures saved on disk can be re transmitted sent to your printer or recalled to screen at any time terminal programs which support on screen multi gray level FAX operation are as follows 1l 1289 for IBM PC and compatibles on 5 1 4 disk 2 1289 same as MFJ 1289 but on 3 1 2 disk 3 1287 for Apple Macintosh computer 4 MFJ 12
210. ansmit packets for testing purposes If AFTER is specified a beacon is sent only after n 10 seconds have passed with no packet activity In this case the beacon is sent only once until further activity is detected This mode can be used to send announcements or test messages only when packet stations are on the air If you choose n properly you can avoid cluttering a busy channel with unnecessary transmissions Beacon frames from other TNCs can be monitored by setting MONITOR ON NOTE BEACONS will not be sent if BTEXT is null MFJ 1278B MULTI MODE OPERATIONAL COMMANDS BKONDEL ON OFF Mode Packet Default ON Parameters ON The sequence BACKSPACE SPACE lt BACKSPACE gt is echoed when a character is deleted from the input line OFF The BACKSLASH character V is echoed when a character is deleted This command determines the way the display is updated to reflect a character deletion in Command Mode or Converse Mode The lt BACKSPACE gt SPACE lt BACKSPACE gt sequence will properly update the screen of a video display If you have a video display terminal or computer you should set BKONDEL ON The lt BACKSPACE gt SPACE lt BACKSPACE gt sequence on a printing terminal would result in overtyped text If you have a paper output display or if your terminal does not respond to the lt BACKSPACE gt character CTRL H you should set BKONDEL OFF The MFJ 1278B will type a lt BACKSLASH gt for each characte
211. ary message to the callsign AASXO or SP AA5XO ENTER this will send a private message to the callsign AA5XO The Mailbox will respond with Enter Subject Max 40 Characters The remote user will enter the message subject or title at cursor prompt then press the ENTER key The Mailbox will respond with Send msg Control Z or EX on it own line ends The remote user will then enter the message at the cursor prompt The remote user needs to press the ENTER key after entering the message The remote user needs to enter EX or CTRL Z followed by a changeover after the ENTER key press This will tell your Pactor mailbox to store the message and to send the Pactor mailbox prompt back to the remote user Your Pactor mailbox will send an automatically changeover back to the remote user If you are using a 128K or even a 512K Mailbox then you can actually upload disk files into the Mailbox The 32K version has the same capability but with 32K RAM capacity MFJ 1278B MULTI MODE BASIC OPERATION 4 There are two 2 different ways the remote user can kill messages The first is give in the example below a To a message in a particular slot the remote user would type Kit ENTER Where the is the message number the remote user wants to kill The Pactor Mailbox will respond with Message deleted nn free n Mailbox H elp K L S This is whether or not the message flag is set to an N
212. as 20Hz this is normal 14 With each press of the SPACE BAR the MFJ 1278B will display the following frequencies 1550Hz 20Hz 1600Hz 1650Hz 1700Hz i 1750Hz 1800Hz li 1850Hz b 1950Hz 2000Hz X 2050Hz 2100Hz 2150Hz 2200Hz MFJ 1278B MULTI MODE APPENDIX B MODEM CALIBRATION 15 Press the SPACE BAR the MFJ 1278B will display Multilevel demod 307 154 KHz 1550 Hz 106 53 At this time there will be some numbers scrolling on the computer screen The numbers on the screen will vary from 103 to 110 16 Press the SPACE BAR the MFJ 1278B will display 2250 Hz 70 35 NOTE This may take a few seconds to appear due to the sampling rate of the MFJ 1278B The numbers on the screen again will vary from 65 to 75 17 Press the SPACE BAR the MFJ 1278B will respond DEMODULATOR ALIGNMENT Tune R113 until STA amp CON LEDS ALTERNATE then tune R212 until 10th LED from the LEFT is lit 18 Adjust R113 until the STA amp CON LEDS alternate back and forth This means neither one should stay ON all of the time 19 Then adjust R212 until the 10th LED from the LEFT on the tuning indicator is lit 20 Press the SPACE BAR The MFJ 1278B will respond Tune trimpot indicated until the 10th LED from the LEFT is lit R115 21 Adjust R115 until the 10th LED from LEFT on the tuning indicator is lit 22 Press the SPACE BAR the MFJ 1278B will
213. ast This is due to the fact that some radios pump up the AGC voltage during transmit and if the AGC time constant is long they are essentially deaf far a whila aftar tranomitting Van ull want ta avnarimant unith thic wahia Tn aanaral von MFJ 1278B MULTI MODE ADVANCED OPERATION 6 Restrict your use of beacon transmissions as much as possible If you MUST use a beacon keep it short and keep the repetition rate as low as possible More than once a minute is definitely too frequent once or twice in 10 minutes is more polite Do not allow your beacons to continue if you are not in attendance Nobody wants to connect to you just to be ignored 7 If your radio allows you to select the AGC time constant fast or slow AGC set it to the fastest setting available to you If you cannot select fast AGC it may be advantageous under some circumstances to partially defeat the AGC function by reducing RF gain and increasing AF gain The demodulator in the MFJ 1278B is extremely insensitive to absolute audio level It will function properly with input levels from the low hundreds of millivolts up to many tens of volts Thus the variation in audio level produced by partially defeating the AGC system will not degrade the modem s ability to copy The limiting factor on the high end is usually the ability of the receiver output stage to produce the voltage without clipping The limiting factor on the low end is the hundred millivolts or so required to exce
214. at mm dd yy OFF Date is displayed in the format dd mm yy This command determines the format for the MFJ 1278B s display of the date If DAYUSA is ON the standard U S format is used if DAYUSA is OFF the standard European format is used This command affects the format of the date display used in time stamps as well as the display when DAYTIME is entered without parameters The format for entering the time using DAYTIME is not affected For example if DAYUSA is ON then July 2 1984 at 9 28 44 AM would be displayed as cmd DAYTIME 07 02 84 9 28 44 If DAYUSA is OFF the same date and time would appear as cmd DAYTIME 02 07 84 9 28 44 DDisc Mode Pactor Immediate Command The DDISC command is used as a last resort for terminating a PACTOR link This will work where at times the standard DISCONNECT will not The use of this type of termination is considered RUDE so this is why it is a last resort Disconnect Mode Pactor Immediate Command This command is exactly like the DISCONNECT command in Packet When this command is issued from the p cmd prompt a disconnect sequence is initiated The DISCONNECT command is what operators normally used to terminate a Pactor link DISplay Mode Pactor Immediate Command mo rco 1 1 1 73 UT nn nns 1 53 0 7 as MFJ 1278B MULTI MODE OPERATIONAL COMMANDS DEADTIME nnn Mode Packet Default 33 Parameter nnn 0 thru 250 in 10ms The DEADTIME parameter selects the basic time
215. ated carrier frequency F ind minus the modem center frequency Fc So you would use MFJ 1278B MULTI MODE ADVANCED OPERATION NOTE Regardless of the type of modem whether or not the modem has audio filtering built in 300 baud AFSK modem performance on a High Frequency linear mode SSB as opposed to NBFM radio channel will NOT be optimum UNLESS a filter of approximately 500 Hz bandwidth is used in the radio IF strip There are two reasons why this is the case First for the filtering to be fully effective it has to precede the first hard limiter in the system This limiter is typically located in the first stage of the demodulator Second no filter at audio can prevent an off channel interfering signal from capturing the receiver AGC system and causing wide variation in the level of the audio presented to the demodulator demodulators are affected by audio level variations If the user uses a narrow filter say approximately 500 Hz in the radio for HF Packet and RTTY operations then it may be necessary to use a tone pair centered on the radio s filter rather than the standard 2125 2295 or 1600 1800Hz pairs It is STRONGLY RECOMMENDED that a narrow filter be used for HF Packet and RTTY operations If the radio lacks IF shift capability this will almost certainly be necessary If this is the case it will be necessary to determine the center frequency of the audio spectrum output from the receiver when the narrow filter is sele
216. ation is provided for sending and storing files of MARS messages while preserving all of the formatting information using the special MARS ASCII equivalent characters and differs from QSO mode only because of its extra ASCII output translations MFJ 1278B MULTI MODE BASIC OPERATION MARSMODE 1 QSO Mode In the MARS QSO mode the Transmit translations are as follows 1 carriage returns are converted to CR CR LF or to LF only if preceding character was also CR 2 NNNN is sent as NNNN followed by 12 LTRS 3 Characters are translated as follows LF 12 LTRS BELL NULL FIGS LTRS MARSMODE 3 Storage Mode The MARS Storage Mode has all of the same transmit translations as the QSO mode plus these Receive translations Received Char Printed Char MFJ 1278B MULTI MODE BASIC OPERATION AMTOR OPERATION AMTOR AMateur Teletype Over Radio an error correcting protocol suite is fully supported by the MFJ 1278B Two modes are available with AMTOR These are mode A and mode B From command mode AMTOR modeB is entered by typing MODE AM ENTER Note that the MFJ 1278B displays an a cmd once the AMTOR mode has been entered This a cmd command prompt lets you know that you are in AMTOR mode and only AMTOR commands are recognized by the MFJ 1278B To issue other non AMTOR commands you will have to return to the normal command mode cmd command prompt by typing CTRL
217. ause the MFJ 1278B to respond with an error message such as bad In this case the MFJ 1278B will change to default settings and return to the command mode RTTY and ASCII Receiving After properly setting the MFJ 1278B to the desired RTTY or ASCII mode type on the computer keyboard to enter CONVerse mode The STA LED on the MFJ 1278B will light MFJ 1278B is ready to receive RTTY or ASCII signals tuned in by your radio Set the volume of your radio for normal listening level Tune your radio until you hear a signal that you want to decode Fine tune your receiver until the 10th or 11th segments are lit on the tuning indicator When you have the signal tuned in properly the DCD LED will light and the MFJ 1278B will start to decode the signal If the displayed text appears garbled then the specified speed in the MODE command might be incorrect Garbled displayed text may mean that the signal you are trying to copy is encrypted If you suspect an encrypted signal you can use the RBITMASK command to match the inversion pattern of the signal If you suspect that the speed is incorrect then you can specify a new speed setting The speed is set by using the MODE command RTTY and ASCII Transmitting While the MFJ 1278B is in RTTY or the ASCII mode and it is in command mode you can initiate RTTY or ASCII transmission by typing K ENTER followed by a CONTROL T The MFJ 1278B is now ready to transmit Type your message on the key
218. ave special meanings in the AMTOR modes STA OFF CON OFF This led combination indicates that Mode B is unlocked and in STANDBY mode Standby mode is where the MFJ 1278B is ready to respond to Mode A or B FEC Amtor signals The MFJ 1278B will also print Mode S SELCAL signals depending on the setting of the SRXALL and MYSELCAL commands STA OFF CON ON Indicates Mode B is locked in and is in the Idle mode Broadcast text will be printed if in receive mode Also if in receive mode the MFJ 1278B is receiving an AMTOR idle signal The other station is still being received ok though he is not transmitting any text In Mode A this signal could also mean that a send receive CHANGE is pending or that the sender is repeating a block STA ON CON OFF This led combination indicates Traffic mode The MFJ 1278B is currently sending or receiving text STA ON CON ON This is the phasing error mode If in a Mode A contact this means that the MFJ 1278B is either trying to re establish a link or is sending indication of a receive error If in Mode L or Listen the MFJ 1278B is hunting for a synchronization signal AMTOR OPERATION HINTS To receive AMTOR from the cmd command line type MODE AM ENTER Now you should see the a cmd prompt This mode is used for FEC type reception To enter Listen mode type LISTEN ENTER To enter the ARQ listen mode to monitor ARQ signals type AMTOR ENTER Tha STA and CON TRIS will light When ctat
219. before you transmit Monitoring a propagation beacon frequency will not necessarily be sufficient to reveal this activity to you It is best to make a note of which INDICATED frequencies you should avoid so that your radiated packet spectrum from F emission above will not get within several hundred Hz of a propagation beacon HF packet operation is fundamentally different than other modes of operation in 1 major respect If you are on a clear channel talking to only 1 other station there will be long periods of silence People using other modes and tuning around looking for a clear frequency to use may be fooled by the silence Don t assume that an interfering station who shows up considerably after you have begun using the frequency is interfering on purpose he may honestly not have been aware of your QSO in progress For this reason it is a good idea to keep the flow of the conversation going so that the lapses aren t too long It can also be advantageous to have more than one packet QSO on the channel but if more than a very few get on the same channel the throughput falls off very fast as the likelihood that all stations are properly configured and have working DCD circuits is small MFJ 1278B MULTI MODE ADVANCED OPERATION Here are a few simple suggestions for operating HF packet that should help to get you started 1 Do NOT try to hold a QSO on one of the calling frequencies Use the calling frequency only to establish contact and
220. being changed you will need to either remove the jumper from JMP 5 on the MFJ 1278B circuit board This must be done for a few minutes to reset the RAM which stores the non volatile operating parameters Once reset in this manner the MFJ 1278B will restore all parameters to the default values Then the AUTOBAUD command will now be at it s default setting of ON The next time the MFJ 1278B is powered up after such a reset it will attempt to match the new baud rate and sign on after detecting several carriage returns input to the serial port MFJ 1278B MULTI MODE OPERATIONAL COMMANDS AUTOLF ON OFF Mode Packet Default ON Parameters ON A linefeed character lt LF gt is sent to the terminal after each carriage return character CR OFF A lt LF gt is not sent to the terminal after each CR AUTOLF controls the display of carriage return characters received in packets as well as echoing those that are typed in If the MFJ 1278B s sign on message lines appear to be typed over each other you should set AUTOLF ON If the MFJ 1278B s sign on message appears that it is double spaced then you should set AUTOLF OFF If the MFJ 1278B s sign on message appears to be single spaced you have AUTOLF set correctly This command only affects what is displayed not the data sent in packets If you want to add linefeed characters to outgoing packets use the command LFADD AUtolf ON OFF Mode Pactor Default ON Parameters ON A linef
221. ble As in Packet Pactor also contains COMMAND and CONVERSE modes Please note that switching between them is modeled on the NEWMODE ON procedures in packet The MFJ 1278B is in COMMAND mode if the p cmd prompt is on the computer screen To switch to CONVERSE mode from COMMAND mode the K key followed by an ENTER is issued by the user The CMDCHR character switches the MFJ 1278B from CONVERSE mode back to COMMAND mode The CMDCHR character is defined as CTRL C Once connected the link acts much like AMTOR The station originating the connection is the master and he remains in transmit mode until he or the slave initiates a changeover Either station may reverse the direction of the link by issuing a control Y changeover Y in converse mode PACTOR FEATURE DEFINITIONS DIGITAL MEMORY ARQ The MFJ 1278B s Pactor incorporates a Digital Memory ARQ mode Digital Memory ARQ enables reconstruction of a good packet from a bad packet A bad packet is one repeatedly received with on or more bit errors Digital Memory ARQ accumulates the bit value 1 or 0 derived from the RF port during successive reception of the same error laden packet These bit accumulations are sent to the receiver shift register Thus a good packet is reconstructed from 2 or more bad packets The MAXSUM parameter controls the number of accumulations performed for each bit Larger MAXSUM values increase the effectiveness of the Digital Memory ARQ scheme but only t
222. board The MFJ 1278B will transmit your message as it is received from your computer Messages stored in memory buffers 0 thru 9 can be transmitted when in RTTY or ASCII modes To transmit a memory buffer when already in transmit mode type MFJ 1278B MULTI MODE BASIC OPERATION Note If the MFJ 1278B is not in transmit mode i e in receive mode then in order to initiate transmission from a buffer you must type CONTROL T twice then enter a number for the buffer You can tell if the MFJ 1278B is in transmit mode by observing the PTT LED on the front panel If PTT LED is lit MFJ 1278B is in transmit mode Once the MFJ 1278B completes the transmission press CONTROL R When the MFJ 1278B receives the CONTROL R from the computer it will return to receive mode When the MFJ 1278B is in receive mode note that the PTT and STA leds are not lit Some terminal programs do not support the CONTROL T or CONTROL R characters The MFJ 1278B require the CONTROL T and CONTROL R characters to swtich between transmit and receive modes If the terminal program does not support the CONTROL T and CONTROL R characters you can re assign the ASENDCHAR and ARCVCHAR commands in the MFJ 1278B to other keys See Chapter 6 of this manual for detail on the ASENDCHAR and ARCVCHAR commands Note When operating RTTY or ASCII it is recommended that you operate at about 5096 of full power This is to prevent damage to the finals of your radio Some modern
223. ccepted for display despite CRC errors if they consist of an even multiple of 8 bits and up to 339 bytes The MFJ 1278B will attempt to decode the address field and display the callsign s in the standard monitor format followed by the text of the packet This mode is not normally enabled since rejection of any packet with an invalid CRC field is what insures that received packet data is error free This mode might be enabled for testing a marginal RF link or during operation under other unusual circumstances If you set PASSALL ON and monitor a moderately noisy channel you will periodically see packets displayed in this mode since there is no basis for distinguishing actual packets received with errors from random noise Logging of stations heard for display by MHEARD is disabled whenever If PASSALL is ON since the callsigns detected may be incorrect MFJ 1278B MULTI MODE OPERATIONAL COMMANDS PIXTONES n Mode FAX SSTV Default see below Parameters n aa bb cc mm nn ss The PIXTONES are arranged in the following format White Lt gray Dark gray Black area area area area bb cc dd See ff gg 11 jj kk 1 mm nn ss Syn The default PIXtones values are as follows BE BB BD B9 BE BA BC B8 B3 B5 B6 B2 B0 AD 9D BE The Pixtones command serves the same function as in TVBreak but is for transmitting of the SSTV and FAX pictures The brightness of t
224. ch pad storage message buffers etc Also because the RAM is backed up by a battery and will not lose its contents when the main power is removed it is used to provide semi permanent storage of user supplied information such as your callsign Selector U12b acts as a RAM address decoder with RAM starting at address 8000 hex The sections of CMOS switch U13 are used to insure that the RAM is not selected when main power is removed This ensures that the contents of the RAM are not accidentally scrambled as the CPU loses power it also ensures that the RAM is in the power down state for minimum battery power consumption Serial Interface Serial Input Output or SIO device U21 provides two channels of serial I O The B SIO channel is used for the computer or terminal interface Operational amplifier sections U3a U3b and U3d act as RS 232C drivers while Schmitt trigger inverters U9a and U9b act as RS 232C receivers These circuits consume less power than conventional RS 232C drivers and receivers The A SIO channel is used for the radio modem interface and is normally operated as a full duplex HDLC channel for compatibility with the AX 25 protocol specification Latch 05 and ROM U6 provide a state machine for recovering the clock from the received NRZI data The state machine also converts NRZI data to NRZ for the SIO Inverter U9c and flip flop Ulla provide NRZ to NRZI conversion for the transmit side of the radio channel This conversi
225. cket re transmission 276 Pactor Mailbox Entry 67 Parameters lists 311 parameters hex designator 174 Parameters callsign 174 Parameters current value 33 parameters n designator 174 Parameters text 174 Parity 34 MANUAL INDEX MFJ 1278B MULTI MODE MANUAL INDEX Power supply troubleshooting 332 Power on reset 319 Power on reset LED display 333 Protocol 337 Protocol errors result in FRMR frames 342 Protocol AX 25 Level 2 316 337 Protocol compatibility 316 Protocol control byte format 340 Protocol data link layer 337 Protocol debugging function 292 Protocol errors 312 313 Protocol HDLC frames 338 Protocol HDLC implementation 318 Protocol monitoring control packets 137 Protocol problems 131 R R76 tone level adjustment 319 335 R77 modulator tone adjustment 319 R78 modulator tone adjustment 319 R79 demodulator adjustment 319 Radio 1 38 Radio 2 38 Radio baud rate optimum 52 Radio baud rate switch 317 Radio interfacing 20 Radio interfacing using accessory jack or interface box 25 Radio port 318 Radio Shack Color Computer terminal program 13 Radio Shack Model 100 serial port interfacing 9 Radio Shack Model 100 terminal program 13 Radio Shack Model 100 102 and NEC 8201 13 Radio signals Ground 20 Radio signals Microphone audio 20 Radio signals Push to talk 20 Radio signals Receive audio 20 Radio signals Squelch input 20 RAM memor
226. coming permanently locked the transmitting TNC will periodically re transmit the packet that provoked the RNR The receiving TNC will continue to respond with RNR until it can accept the packet MFJ 1278B MULTI MODE APPENDIX A RADIO HOOKUP RADIO HOOKUP Table A 1 HOOKUP FOR SPECIFIC RADIOS CONNECTOR MIC RX AUDIO GROUND AUDIO To To pin 4 of To pin 2 of pin 1 of 1278B 1278B 1278B d in 3 4 in 4 5 d in 7 8 Lg Lg H T N e 5 TS 450S pes quw 15 EELRESE Becr merci Pin2 Speaker Pin 2 Speaker s IC 27A IC 28A IC 735 ee YAESU i Pin3 i FT 208 s Pin3 FT x09 s FT x3 s FT 727 s FT 747 i FT 757 FT 767 ALINCO 1 DR 1200 i ALR 22H Oo f ICOM i in 6 Pin 8 Pin 4 Pin 6 7 Sleeves Pin 6 7 Pin 6 7 Pin 6 7 Pin 1 Pin 7 Pin 4 Sleeves in 7 in 7 in 7 in 8 d in 8 Some ICOM and Yaesu HTs key the transmitter by completing the ground connection on the microphone If your HT is one that is noted in the above chart you must follow the instruction given in Chapter 3 of this instruction manual MFJ 1278B MULTI MODE APPENDIX A RADIO HOOKUP Table A 1 2 Other Radio Connections MEGS OR CONNECTOR MIC AUDIO PTT ToPin RX AUDIO GROUND To RADIOS To pin 1 of 3 of 1278B To pin 4 of ALINCO DR 110T DR 119T DR 570T DR 590T DJ 160T Small Tip Small Tip Lrg Tip DJ 560T Small Tip
227. command is useful for obtaining statistics on the performance of a given path or channel It should be especially useful for automatic optimizing so such parameters as PACLEN and MAXFRAME by computer operated stations such as automatic message forwarding stations using less than optimum paths noisy HF or satellite channels for example When used with an argument TRIES will force the tries counter to the entered value Use of this command to force a new count of tries is NOT recommended TUNE Mode Immediate Command The TUNE command is an immediate command The TUNE command keys the PTT and low tone for the current modem for 30 seconds or until you strike a key on your computer keyboard TUNEPROC Mode Immediate Command TUNEPROC is a immediate command It is used to calibrate the MFJ 1278B modulators and demodulators See APPENDIX B under Modulator and De Modulator Calibration for the use of TUNEPROC MFJ 1278B MULTI MODE OPERATIONAL COMMANDS TVBREAKS n Mode SSTV Default see below Parameters n aa bb cc dd kk l1 mm nn ss TVBreaks are arranged in the following format White gray Black area area area ss aa bb cc dd ee ff gg hh ii jj 11 nn Sync The default TVBreak values are as follows TVB 80 46 47 48 4C 4F 52 54 59 5C 5E 60 63 67 69 Note that the values for the TVBREAKS command are in HEX The smalle
228. computers with software UARTs Type in flow control will improve the operation of such computers with the MFJ 1278B DETAILED VHF PACKET OPERATION The previous chapter s discussion of Basic Operation contains enough information for most packet operation This section describes a few other aspects of packet operation Station Identification Your station identification call sign is set with the command MY CALL as described in the previous chapter If you will have more than one station on the air operating with the same call sign they must be distinguished no two stations can have identical station identifications or the packet protocol will fail You can distinguish additional stations by setting the secondary station ID or SSID This is a number from to 15 appended to the call sign with a dash cmd MYCALL W3IWI 3 If you do not specify the SSID extension it will be 0 and the MFJ 1278B will not explicitly show SSIDs that are 0 If you want to connect to a station with a SSID other than or use such a station as a digipeater you must specify the SSID MFJ 1278B MULTI MODE ADVANCED OPERATION The MFJ 1278B can send an automatic identification packet every 9 1 2 minutes when your station is operating as a digipeater You can enable this feature with the command HID ON An ID packet is displayed as follows by a monitoring station W3IWI 32ID W3IWU R You can request a final identification as you take your station
229. creen Note that when MULTIFAX is turned ON the PRINTGRA command will be ignored This means that in FAX mode and with MULTIFAX turned ON MFJ 1278B will start to send raw data to the terminal regardless of the setting of PRINTGRA command For those who wishes to write program to support this multi level raw data format the following information will be useful to you Upon typing the L character MFJ 1278B will start to send the raw data stream Terminal program should look for the distinctive sync pattern at this time to detect the beginning of the picture Raw data stream will continue to be sent thru the RS 232 port until the end of picture pattern is detected or a CTRL C is received Therefore for multi level FAX the terminal program is responsible for attaining synchronization to begin a picture and to detect the end of picture to stop printing In 8 gray levels raw multi level data are packed two pixels per byte To enable ASCII transparancy of the raw data the MFJ 1278B biases each byte with 30 On transmit you must likewise bias the outgoing data with 30H There are two exceptions If the actual data byte before unbiasing is p or q then the 1200 MFJ 1278B MULTI MODE BASIC OPERATION After unbiasing bit 7 6 5 4 3 data x x aaa x don t care a b first and second pixel groups 2 0 b b 1 b Coding If prior to unbiasing the value of the data byte is an ASCII p q or r then the received byte is a sync byte
230. ct or halt the connect attempt then change MYCALL or AX25L2V2 range A numeric argument for a command was too large too long You entered too long a command line and the line was ignored This might happen for example if you try to enter too long a message with BTEXT or CTEXT If you get this message the previous text entry was not changed many You gave too many arguments for a command that expects several parameters For example MFILTER if you issue the below MFILTER command to the MFJ 1278B cmd MFILTER 1B 0C 1A 03 07 too many The MFJ 1278B gives the TOO MANY message because the maximum arguments for the MFILTER command is 4 VIA This message appears if you attempt to enter more than one callsign for the CONNECT or UNPROTO commands without being proceeded by the VIA keyword For example C 5 5 No VIA between callsigns should be C AASXO VIA AASMT Notice the VIA between callsigns MFJ 1278B MULTI MODE SYSTEM MESSAGES Link Status Messages These messages inform you of the status of AX 25 connections your MFJ 1278B may be involved in You can always interrogate the link status by giving the CONNECT command without parameters If you attempt a connection when your MFJ 1278B is not in the disconnected state the MFJ 1278B will display the link status but will take no other action The following messages appear in response to the CONNECT command Link state is CONNECTED to call1 VIA ca
231. cted and the radio is in the LSB mode Most radios that provide for direct FSK RTTY operation use the radio s narrow CW filter if installed The Kenwood TS 820 is one example Packet operation using direct FSK is a viable mode but extreme caution should be exercised to make sure TX and RX frequencies are identical and that the transmitted frequency pair is centered in the radio s 500 Hz filter passband Once the user determines the center frequency for the particular radio s FSK mode the the user should use modem alignment procedure presented in the troubleshooting calibration section of the owners manual Since there is no standardization among the various radio manufacturers in this regard a method for making the determination of transmitter FSK output frequencies and their relation to the LSB carrier oscillator and center of the 500 Hz filter is NOT presented here Contact the manufacturer of the radio to obtain this information Radios that have provision for an auxiliary narrow SSB filter can have the 500 Hz bandwidth filter installed instead of the approximately 1 8 KHz wide narrow SSB filter This will allow direct selection of the narrow filter for AFSK work when in SSB mode If the filter is also desired for CW operation and you don t want to invest in 2 identical filters it is usually a relatively simple modification to cause the radio to also select this filter when in CW mode In the TS 430 for example this requires moving one end of
232. cteristics of the HF packet FSK signal will allow you to avoid the modem performance degradation that results from excessive radio bandwidth However you will still be affected by other station s problems in these areas when operating on a crowded packet channel If you do have your radio configured for the proper bandwidth you will notice that many stations you connect to will seem to not be able to copy you as well as you copy them Don t worry your transmitter output isn t low you are just observing the difference between a good demodulator behind the correct radio bandwidth and any kind of demodulator behind a radio which has far too much bandwidth for the mode The actual mechanics of operating the MFJ 1278B in the HF packet mode are the same as for the VHF packet mode The main differences that will be apparent to you will be the slower baud rates the higher incidence of propagation related effects and QRM and the requirement for accurate tuning It will take some practice before you can rapidly acquire another station s signal and initiate a contact MFJ 1278B MULTI MODE ADVANCED OPERATION The adjustment is very easy to perform Simply tune the radio to a channel which has only noise no signals whatsoever then adjust the threshold control so that the DCD LED just flickers occasionally Set it so that the DCD duty cycle is between 10 and 20 percent DO NOT set the threshold control so that the DCD LED never comes on even when receiv
233. cy Tune through a few packet signals Tune slowly You will find a point at which the display becomes bright As you continue tuning you will see the moving bar display slide across your tuning indicator When one of the center LEDs is illuminated you are tuned in and you should be able to copy the packets Each bar on the tuning indicator represents about 10 Hz Thus if a packet comes through MFJ 1278B MULTI MODE BASIC OPERATION If you cannot contact anyone using another frequency call CQ on one of the above mentioned frequencies If you do make a contact with someone then QSY immediately after establishing contact Be careful on 20 meters especially that you don t operate 2KHz around 14 100 MHz you will cause interference to propagation beacons and give packet a bad name HF Packet Operation Hints There are a few operating hints which apply to HF Packet These few hints are listed below 1 Try to keep all packets below 80 characters in length Set MAXFRAME to 1 This will minimize transmission time Avoid multiple connections and digipeated packet operation Osy away from the standard calling frequencies as soon as possible Set FRACK to a sensible long value Ch Ges GA For more details on HF packet operation please refer to the next chapter in this instruction manual MFJ 1278B MULTI MODE BASIC OPERATION PACTOR In this section of this manual we will talk about PACTOR operation We will cover bas
234. d channel access procedure with compatible numbers of slots and compatible slot times Remember that the objective of the new channel access procedures is to increase aggregate throughput for the CHANNEL not necessarily for an individual user not even you It may seem to you at first when you get on a very busy channel where you are the only station that is using the new system that you aren t getting to transmit very frequently This is because you aren t getting to transmit very frequently However the OTHER users on the channel will see an incremental increase in the overall amount of data that the channel can pass per unit time because you are being such a nice guy Remember that transmitting isn t necessarily communicating There is ONE benefit that you should be able to see even under the above circumstances If you are communicating with another station who is also running the new system the channel should appear more reliable to you even if quite slow You should not be getting retried out waiting for his ACK to come back amp have to keep reconnecting As a higher and higher percentage of the users on the channel begin using the new system the performance of the channel should increase quite a bit However we all must remember that if a channel is mathematically capable of transferring for example 1000 characters per unit time the very best it can possibly do if CSMA is working right is reliably pass about 620 characters per uni
235. dard used in Europe for RTTY and ASCII operations Please refer to APPENDIX H on how to select the Low Tone pairs The MFJ 1278B can transmit or receive RTTY or ASCII by using inverted tone pairs The RXINVERT and TXINVERT commands allow inverting of the tone pairs in the RTTY or ASCII modes When operating in the inverted mode the tone pairs are MARK for the high tone and SPACE for the low tone The MFJ 1278B also allows you to transmit from any one of the ten memory buffers when in one of the asynchronous modes Memory buffer programming and use are the same as for CW operation Setting Up for ASCII and RTTY Operation From command mode you can set the MFJ 1278B into the desired RTTY or ASCII mode by using the MODE command Type MODE ENTER Where is the two letter code for the desired RTTY or ASCII mode Code designations for RTTY and ASCII modes are as follows VHF RTTY VB MFJ 1278B MULTI MODE BASIC OPERATION If you do not specify a baud rate for the RTTY or ASCII modes the MFJ 1278B selects the default baud rates The default baud rates for the RTTY and ASCII modes are 45 and 110 baud respectively You can select a desired speed by typing the baud rate after the two character code For example to enter 110 baud VHF Baudot RTTY you would type MODE VB 110 ENTER Note The only baud rates that you can select are those the MFJ 1278B is capable of receiving and transmitting Selecting an illegal baud rate will c
236. de editing reading and killing any mailbox message When this parameter is blank the remote user may only read non P messages and messages to or from himself Furthermore he may only kill messages to or from himself plus any messages of type T raffic Thin mnanamatan marr ha manat ta tha hlanl an Ata aerann atata her antamin n NOL ne NOM MFJ 1278B MULTI MODE OPERATIONAL COMMANDS RESTART Mode RESTART is an immediate command It re initializes the MFJ 1278B using the commands previously set by the user and stored in bbRAM The effect of this command is the same as turning the MFJ 1278B OFF then ON again RESTART does not cause a reset of the parameters in bbRAM See also the RESET command RESET Mode RESET is an immediate command When invoked it resets all parameters to their default settings and re initializes the MFJ 1278B WARNING parameter customizing and monitor lists are lost when this command is used If you just need to re initialize the MFJ 1278B using the parameter values in battery backed up RAM you can just turn the MFJ 1278B OFF then ON again rather than using this command RESPTIME n Mode Packet Default 5 Parameters n 0 250 specifying 100 ms intervals This command sets a minimum delay that is imposed on acknowledgment packets This delay may run concurrently with default wait set by DWAIT and any random wait in effect This delay can be used to increase throughput duri
237. dentifiers sometimes combined with telephone area codes have been used Use of this command permits HID to identify normally with the MYCALL specified callsign yet permit an alternate alias repeat only callsign MYDLCNUM Mode Host Default 0 Set to a non zero number 255 TNCS should start at 1 hosts should start at 254 and go down When set to a non 0 value the addressing procedures for multiplexing TNCs on the RS 232 port are enabled MFJ 1278B MULTI MODE OPERATIONAL COMMANDS MYHIERAD Text Mode Mailbox Default Text Any combination of characters and spaces up to 60 characters in length You may use this parameter to generate a customized portion of the tagline your will insert in forwarded messages If MYHIERAD is blank the default portion will read Q mymcall It is suggested that you insert your hierarchical address location and zip postal code in this parameter Example MYHIER for N2WX in Sebastian Florida in the Melbourne LAN at zipcode 32958 using NSAUV as the home bbs would be entered like this MYHIER N5AUV 4MLBFL FL USA NA N2WX User Sebastian Z 32958 and the tagline would look like this R 920801 1200 NSAUV 4MLBFL FL USA NA N2WX User Sebastian Z 32958 8 MYMCALL callsign Mode Mailbox Default blank The MYMCALL command specifies the dedicated callsign for the Packet Mailbox If MYMCALL equals MYCALL the TNC responds to incoming connections in mailbox mode Whe
238. dio data rate radio data transmission MFJ 1278B MULTI MODE ADVANCED OPERATION A computer file transfer program may be unable to process data fast enough to keep up with output from the MFJ 1278B In order to be sure of reading every character a computer must respond to interrupts from its I O devices Some simple programs may poll the input register for new data If the polling is not done often enough data may be lost Some computers disable interrupts during disk accesses If the program enters a routine which will not allow it to check for data or respond to it it should signal the MFJ 1278B to stop sending data There are two methods of providing flow control which are supported by the MFJ 1278B XON XOFF flow control sometimes called software flow control is accomplished by sending a special character usually CTRL S to request that the output stop and another special character usually CTRL Q to restart output Hardware flow control may be used if both computers use the Clear To Send CTS and Data Terminal Ready DTR lines of the RS 232C standard Data is also halted if you press the space bar while in command mode Press CR to resume Some commonly used terminal programs and file transfer programs for home computers do not implement flow control in software and many serial ports do not support hardware flow control Although the DTR and CTS lines appear at the connector they may not be used on some computers unless
239. e 16 gray levels AALT ON OFF Mode AMTOR Default OFF Parameters ON Allows use of the SELCALL set up in the ALTCALL command OFF The MFJ 1278B uses the SELCALL set up in the MYSELCAL command AALT determines whether the SELCALL set by the ALTCALL command or the MYSELCAL command is used in Mode A ARQ ABORT Mode Mailbox Immediate command This command gives the SYSOP total control over the Mailbox by allowing him to force a disconnect on the Mailbox link It immediately terminates any mailbox activity currently in progress You may use it to avoid any QRM to cancel FORWARD or NODEFORW in progress You can also use it to terminate mailbox usage by an unwelcome mailbox users MFJ 1278B MULTI MODE OPERATIONAL COMMANDS ACKPRIORITY ON OFF Mode Packet Default ON ACKPRIORITY permits an acknowledging TNC to transmit without regard to the slotting delay Turning ACKPRIORiyty ON to enable prioritized acknowledgement If ACKprior is turned off and SLots see SLots is set to 0 the modified AX 25 protocol is effectively disabled The MFJ 1278B will behave like normal AX 25 protocol Prioritized acknowledgments and slotted channel access can be enabled or disabled independently of one another So you could if you wished run normal AX 25 with slotted channel access or the new protocol without slotted channel access ACKTIME nnnn Mode Packet Default 14 Parameters nnnn 0 250 in 10 ms intervals The ACKTIME parameter controls a de
240. e Y flag K the message in slot nn depending of the setting of the Y flag Remote users may only kill message addressed to them or originated by them The local SYSOP however can kill all messages L Lists the all messages in Mailbox Listed messages will contain the slot number originator destination and subject field of all currently used slots R Allows you to Read only the messages which are addressed to you R Allows Reading of a message in a particular slot number Scall Lets you Send a message to the specified callsign Call must be a callsign valid under the same format as the MYCALL CONNECT and other callsign commands SP call Lets you Send a personal message to the specified callsign This is a private message which can only be read by the originating station the station which it is addressed to and the mailbox SYSOP MFJ 1278B MULTI MODE OPERATIONAL COMMANDS B Logout Initiates a disconnect sequence from the mailbox Edit This allows you to Edit the message headers for a Forwarding or Reverse Forwarding process J This function when initiated responds with the TNC s MHeard list This list will contain the eleven most recently heard stations M This will let a remote user switch memory banks in the Mailbox RAM T When this command is initiated will allow a remote user to PAGE the SYSOP H elp Displays the mailbox command list with a brief description of commands available to the user MAILLED O
241. e in Command Mode and type cmd CONNECT WBOQRP After a moment you should see the message CONNECTED to WBOQRP and you will be in Converse Mode Your friend will see the message CONNECTED to KSFLU and he will also be in Converse Mode You have just begun your first packet QSO If you have trouble connecting make sure your microphone drive level is set properly as described in Chapter 3 It may be helpful to have an experienced packet operator monitor your transmissions with his TNC You can also try the following procedure a Both you and your friend should set MONITOR ON b Enter Converse Mode and send some packets c Each station should display packets sent by the other If only one station is hearing properly you can concentrate on the modulator and transmitter of that station and the demodulator and receiver of the other station You can try experimenting with the TXDELAY timing command for the sending TNC MFJ 1278B MULTI MODE BASIC OPERATION Exchange several messages to get a feel for this new mode If you monitor the radio transmit indicators and listen to the speaker audio from the two rigs you will have a better idea of what is happening Your radio will be inactive most of the time even while you are actually typing When you come to the end of a line while typing press the ENTER to send the data to the MFJ 1278B The MFJ 1278B will key the radio briefly after it receives the data you typed Whe
242. e that will use the alternate VISTONES modem configuration list After VISTICKS pixels are sent remaining picture data use the PIXTONES list Note that setting the VISTICKS command to its Default of 0 the VIS routine is disabled This command is significant only during transmit The value is ignored in the FAX mode VISBREAK TVBREAKS like list Invoke the TVBREAKS like list by sending the letter V to the MFJ 1278B when the TNC is receiving Sending anything but V causes the MFJ 1278B to use TVBREAKS To support VIS reception the terminal program must first manually lock onto the signal send L where upon the TNC is free running and receiving according to the TVBREAKS parameters The terminal program should set VISTONES the defaults may not be appropriate to detect 1100 1200 1300 and gt 1500 hz and send V to the TNC to begin reception according to VISTONES The terminal program must monitorr the data stream for lock and VIS data Upon detecting locck and acquiring VIS the terminal program must then send any character other than V to restore the TNC and beegin ordinary reception VISTONES PIXTONES like list The tones specified by VISTONES are used in place of the PIXTONES values for the first VISTICKS pixels of a transmitted picture Defaults Nibble Tone 0 10 1300Hz 11 14 1200Hz 15 100Hz MFJ 1278B MULTI MODE OPERATIONAL COMMANDS WAitdisc nn Mode Pactor Default 20 Parameters nn 10 lt lt 25
243. e the counter rolls over to zero If for any reason the serial number must be changed you may return to the CMD command prompt and enter the new serial number by typing SERIALNO ENTER Where fHHHHE is the desired serial number from 0 to 65535 MFJ 1278B MULTI MODE BASIC OPERATION Memory Repeat and Buffer Repeat Time Of the ten memory buffers provided by the MFJ 1278B memory buffer O has a repeat function The user can enable the repeat function moreover specify a time interval The BUFTIME specifies the time interval between repeats of memory buffer 0 Values from 0 to 65 535 are suitable for the BUFTIME command The increments of the BUFTIME are in seconds BUFTIME of seconds represents no repeat after sending Buffer 0 thus disabling the repeat of Buffer 0 The BUFTIME command is usable only in the CW MCW and Memory Keyer modes The BUFTIME command is not effective for memory buffers 1 thru 9 BUFTIME is the TOTAL time for one cycle of the Buffer 0 message This means that if your buffer message is 10 seconds long then you must set the BUFTIME command longer than ten seconds So if you need to have a 5 second delay between repeats then set BUFTIME to 15 If you do not set the BUFTIME command longer than your message then the message will be repeated maybe before it is finished This will result in incomplete copy by the receiving station of the Buffer 0 message If your buffer O message is 10 seconds long and you
244. e the functions of the two CPU controllable LEDs i e the STAtus and CONnect LEDs When HEALLED is set ON the two LEDs flash in a seemingly random fashion At a glance the user may be able to make a judgment on whether the software has crashed since the LEDs will probably not flash if the software fails catastrophically With HEALLED set OFF the LEDs function normally as before HID ON OFF Mode Packet Default OFF Parameters ON Enables HDLC identification by a digipeater OFF Disables HDLC identification This command is used to enable or disable the sending of identification packets by the MFJ 1278B If HID is OFF the MFJ 1278B will never send an identification packet If HID is ON the MFJ 1278B will send an identification packet every 9 5 minutes if the station is digipeating packets The ID command allows the operator to send a final identification packet if the station is being taken off the air An identification consists of an unsequenced I frame whose data field is your station identification The identification packet is addressed to the CQ address set by the UNPROTO command Your station identification is your callsign as set by MYCALL with R appended ID Mode AMTOR Immediate Command When issued under the a_cmd amtor command the ID command causes a keyed modulated CW identification of your station to be sent immediately The identification sent aces Gd accel Wa
245. e user enters a CTRL B from the computer keyboard Entering the CTRL R MFJ 1278B MULTI MODE BASIC OPERATION If CWSEndch is left at the default setting of 255 or FF the MFJ 1278B will transmit all characters immediately when typed The requirement for pressing the ENTER is eliminated Note If you are using a terminal program such as PROCOMM for IBM PC and compatibles that buffers the transmit data then CARRIAGE RETURN will be needed to transmit The MFJ 1278B employs full CW break in for transmitting in the CW MCW modes The CWSEndch command enables the full CW break in feature Setting the CWSEndch to something other than the default will disable the break in feature Users do not have to press Ctrl R to force the MFJ 1278B to receive or to press Ctrl T to force the MFJ 1278B to transmit MFJ 1278B will always go back to receiving mode at the end of each transmission CW break in is effective for both CW and MCW mode Transmitting from Memory Buffers The user can use the BUFKEY nnn command to define a particular key to transmit the memory buffers The MFJ 1278B uses the TAB key 09 as the default for the BUFKEY command The user can transmit any memory buffer 0 through 9 by using the TAB and the appropriate buffer number For example to transmit memory buffer 3 the user would press the TAB key followed by the number 3 key When pressing the TAB key DO NOT hold the TAB key down just press it then let up Once the
246. each line bypassing its send packet function except at the actual end of the packet You can include any character in a packet including all special characters by prefixing it with the pass character CTRL V For example I wasn t at the meeting lt CTRL V gt lt ENTER gt What happened Ordinarily this message would be sent as two packets By prefixing the first ENTER with lt CTRL V gt the operator sends it all at once but maintains the ENTER in the text The Ic wl nw Me Sl I es ee AOU Ean o lnlll ogesloY WWA MFJ 1278B MULTI MODE BASIC OPERATION BASIC HF PACKET OPERATION The requirements for optimum performance with a typical HF or OSCAR 10 path are very different compared to local VHF FM environment Lower signal to noise ratios require lower baud rates noise spikes and fades require shorter packet lengths and a higher rate of false carrier detects lowers the total usable dynamic range in the audio input The MFJ 1278B hardware and software improves throughput in the noisy and fading HF environment The setting of the MAXFRAME and PACLEN commands in the MFJ 1278B provide the possibility of several continuous frames of long data length For HF operation at 300 baud we recommend setting MAXFRAME to 1 Depending on HF band conditions a setting of 128 or less for the PACLEN command The MFJ 1278B detects a busy channel by monitoring the lock detect signal from the demodulator The presence of a loc
247. eady to receive the signal ASA is not effective in analyzing FAX SSTV CW signals and noise ASENDCHA nn Mode RTTY ASCII Default 14 Parameter nn 0 to 127 decimal or 00 to 7F hexadecimal ASENDCHA specifies the character that initiates transmit while in RTTY ASCII CW Note that other events particularly in CW mode may cause entry to the transmit state The user would not need to use the ARCVCHA command to transmit CW This is due to the full break in CW operation incorporated in the MFJ 1278B The full CW break in operation is dependant on the setting of the CWSENDCH command See CWSENDCH MFJ 1278B MULTI MODE OPERATIONAL COMMANDS ASPECT n Mode FAX Default 3 Parameter n 2 thru 8 ASPECT is used to establish a reasonable aspect ratio between horizontal and vertical presentation of 2 Level or 8 Level FAX graphics The ASPECT command does not apply to 16 Level FAX graphics It is necessary to have an ASPECT control because the vertical density a dot matrix printer can represent is much less than the representable horizontal density The ASPECT setting is a ratio of printed non printed rows of FAX graphics The default of 3 means that for every printed FAX row two rows are discarded This is the optimum aspect ratio for HF weather FAX If your pictures seem to be elongated horizontally you should decrease the value of aspect The reverse vertical elongation is corrected by an increased aspect value MFJ 1278B MULT
248. ebe e EU er etui n ere eek eae 309 Power Supply zi eode dete dt aede ees 309 RS 232C HANDSHAKING PROTOCOL eese 310 JUMPER FUNCTIONS esses tete ttr tuit ERR gern 312 PARALLEL PRINTER PORT PIN 12 315 TTL INTERFACE PORT PIN FUNCTION J5 2 nennen 316 MULTI LEVEL INTERFACE CONNECTOR J13 sese 317 EXTERNAL MODEM INTERFACE CONNECTOR J14 sees 317 MODEM DISCONNECT HEADER JA esee 318 HF TUNING INDICATOR eterne tr eret e Re eee roe ees 320 GENERAL TESTS nitet rentre he eor pk deerit enin 321 Step I Power Supplyz seen otn ier ato ei eR 322 Step 2 Obvious Problems sese eene emeret 322 Step 3 Assembly 322 Step 4 Cabling Problems nere o eee een reped Re terarum 323 SPECIEIC SYMPTOMS debe eer tede e iere ER e clie ide scere err ends 323 Symptom TNC appears dead sse 323 Oscillator and Reset Circuits essent 323 Digital Logic Lines terree ep DP EET rei 323 Symptom Modem won t calibrate or key transmitter esee 324 Symptom Uncopyable transmitted or received packets sess 325 TERMINAL INTERFACE 325 Symptom MFJ 1278B won t sign on to the terminal
249. ecoding scheme from the standard low tone used for MARK to the inverted high tone used for MARK At times stations you work may inadvertently be in the wrong sideband mode If you not printing him correctly then try turning RXINVERT ON SCREENLN n Mode Default 80 Parameters n 0 255 specifying the screen or platen width in characters of the terminal This value is used to properly format terminal output A CR lt LF gt sequence is sent to the terminal at the end of a line in Command and Converse Modes when n characters have been printed A value of zero inhibits this action If your computer automatically formats output lines you should set SCREENLN 0 to avoid a conflict between the two line formats SELCALL ssss Mode AMTOR Immediate Command The SELCALL command initiates Mode L SELCALL broadcast The ssss is the four naar 131 MFJ 1278B MULTI MODE OPERATIONAL COMMANDS Parameters n 0 7F specifying an ASCII character code This command selects the character that will force a packet to be sent in Converse Mode The parameter n is the ASCII code for the character you want to type in order to force your input to be packetized and queued for transmission You can enter the code in either hex or decimal For ordinary conversation you will probably set SENDPAC 0D and CR ON This causes packets to be set at natural intervals and causes the CR to be included in the packet If you have set CP
250. ect if you are connected to by another TNC CSTATUS Mode Packet Immediate Command CSTATUS is an immediate command which shows the stream identifier and link state of all ten streams links the current input and output streams and whether or not each stream is permanent see CONPERM An example of a display resulting from issuing a CSTATUS command is cmd CS A stream IO Link state is CONNECTED to 305MLB stream Link state is CONNECTED to AD7I P Cstream Link state is DISCONNECTED D stream Link state is CONNECTED to NOADI via KONG 2 Istream Link state is CONNECT in progress Jstream Link state is CONNECTED to KV7B via NK6K 1 MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CWCALL ssss Mode Amtor Default blank Where ssss are 15 characters sent as CW when you issue the ID character The ssss text is sent following the QRA The name of my station is signal CWidmode nn 0 lt nn lt 255 Mode Pactor Default 0 Should CW identification be required the MFJ 1278B now supports 8 CW identification modes Seven automatic modes are selected by the bit mapped CWIDMODE parameter Bit positions within the CWIDMODE parameter enable timed cw id cwid on incoming events cwid on outgoing events and any combination of the three for a total of 7 modes The timed mode requires some explanation The counter controlling the transmission of the timed CWID must be initially started at the beginning of each link with eithe
251. ect the operation of the packet protocol Details of the protocol are given in Chapter 9 The MFJ 1278B implements AX 25 Level 2 protocol a set of rules for formatting messages to other TNCs The version of AX 25 Level 2 protocol used by the MFJ 1278B can be set to Version 2 0 with the command AX25L2V2 ON or to Version 1 0 with the command AX2SL2V2 OFF Digipeating may not be successful if some MFJ 1278Bs are running Version 1 0 and some are running Version 2 0 In addition the command CHECK controls a timing function that depends on the protocol version selected You can specify the address to be used for unconnected packets as well as intermediate digipeaters with the UNPROTO command The format is similar to that of the CONNECT command cmd UNPROTO QST VIA NK6K The default address for unconnected packets is CQ The following functions may be useful for tracking down protocol problems They are seldom useful for ordinary packet operations The PASSALL command disables the error checking function of the packet protocol for monitored packets The MFJ 1278B will display any packets if they meet the following conditions if the PASSALL command is ON 1 It must start with a flag sequence and it must contain an integral number of 8 bit bytes 2 The TRACE command enables the display of the address and control fields of packets as well as the text The trace function displays all bytes in hex as well as ASCII equivalents Packet Tim
252. ective in analyzing RTTY ASCII AMTOR FEC mode b and HF Packet Once invoked ASA only takes a few seconds to analyze the tuned in signal Once the result is displayed the user can decide whether to accept by issuing the OK command If the user questions the results ASA will continue to analyze the signal and will display the results after each cycle When the ASA routine is entered the MFJ 1278B will enter the converse mode automatically and display Wtg CD the you have to do now is to tune in the signal you wish to decode This is done in accordance with the MFJ 1278B operations manual Once invoked ASA will first display the speed and the confidence factor followed by a pause After a 5 to 10 second pause it will display the speed of modem used to analyze the signal data bits of the signal which will be either 5 6 7 or 8 Any data bit analysis of 6 should not be used and the signal should be re analyzed Last it will display the setting of what it will change the RXInvert command to On or Off This is what ASA will switch the MFJ 1278B to if the user accepts its result The display is in the following format lt Speed gt lt Confidence Factor gt lt Speed gt lt Data Bits gt lt RXInvert On Off gt A typical result will look like this 80 baud 90 Confidence 75 baud used 7 bits RXInvert Off Once the result is displayed the user can exit ASA signal mode by pressing any key MFJ 1278B will return cmd command prompt
253. ed by a decimal number The numbers 10 through 15 are denoted by the hex digits A through F For example 1B 1 16 4 11 27 120 1 16 16 2 16 0 288 A parameter designated as text such as the argument to CTEXT may be entered in upper or lower case and may include numbers spaces and punctuation The MFJ 1278B accepts the parameter text as entered by the user Several commands require callsigns as parameters While these parameters are normally amateur callsigns they may be any collection of numbers and at least on letter up to six 6 characters The six 6 characters used in parameters identify stations sending and receiving packets A callsign may additionally include sub station ID SSID The MFJ 1278B accepts decimal numbers from 0 15 as the sub station ID or SSID The SSID distinguishes two or more stations on the air with the same Amateur call such as a base station and a repeater The call sign and SSID are entered and displayed as call n e g KOPFX 3 If the SSID is not entered it is set to 0 and SSIDs of 0 are not displayed by the MFJ 1278B Some commands have parameters that are lists of items For example you may specify as many as eight callsigns to be selectively monitored with the command LCALLS The second and later items in the list are optional and you may separate the list items with blank spaces or with commas These examples may help you to understand the previous explanations on commands BEACON EVERY
254. ed by the mailbox prompt shown below Mailbox Ready n free de callsign H elp K L R S The n free is the amount of RAM space available for messages The n will be no higher than 65K if a 512K or a 128K Mailbox is in operation If the Mailbox is 32K then nn will be 32K The de callsign is the callsign of your Pactor mailbox that the mailbox sends back to the remote user MFJ 1278B MULTI MODE BASIC OPERATION 1 First a remote must establish a connection to your Mailbox via your Pactor callsign 2 If your Pactor Mailbox is ON then it will answer back with the Pactor Mailbox prompt Mailbox Ready n free de callsign H elp K L R S The n free is the amount of RAM space available for messages The n will be no higher than 65K if a 512K or a 128K Mailbox is in operation If the Mailbox is 32K then nn will be 32K The de callsign is the callsign of your Pactor mailbox that the mailbox sends back to the remote user Once the remote user receives the the Pactor Mailbox prompt the user must issue a changeover CTRL Y to enter the Pactor Mailbox Now at this point all of the Mailbox are available to you You may then type K to kill a message L to list all messages R to read the messages S to send a message or H for the HELP menu 3 To send a message the S or the SP commands must be used The S or SP commands are used in conjunction with a callsign as in the examples below S AA5XO ENTER this will send an ordin
255. ed the MFJ 1278B s digital system noise seen at the demodulator input 1278 KISS MODE TNC 2 MODE HOST MODE One unique feature offered by the MFJ 1278B is that it can be switched into KISS mode to run programs such as TCP IP or it can be converted into a like TNC 2 controller Once MFJ 1278B is converted it can run any firmware written for the TNC 2 such as NET ROM THE NET and other firmwares for the TNC2 amp clones The procedure to convert the MFJ 1278B into a like TNC 2 is described in Appendix E in the instruction manual Host Mode installed in the MFJ 1278B requires a special terminal program to operate Documentation for Host Mode is available on disk from MFJ upon request KISS INTERFACE FOR TCP IP The KISS interface is installed in firmware of the MFJ 1278B Additional modifications or replacement of firmware is not necessary KISS enables the MFJ 1278B to act as a modem for a host computer Turning KISS on allows the MFJ 1278B to run programs such as TCP IP MSYS and other programs which use the Serial Link Interface Protocal SLIP Before enabling KISS make sure radio baud rate and terminal baud rate are set to the desired values The terminal baud rate that s determined at sign on is the same that will be used for MFJ 1278B MULTI MODE ADVANCED OPERATION Once the operating parameters have been selected set KISS ON and then issue a RESTART command The CON and STA LEDs will blink on and off
256. ed then you will be unable to transmit multi level SSTV or multi level FAX transmitting Creating SSTV Pictures for Transmitting SSTV pictures captured by the MEJ 1278B and saved on disk can be re transmitted MFJ 1278B MULTI MODE BASIC OPERATION MFJ 1292 Picture Perfect Video Digitizer for the IBM and compatible computers allows you to digitized a picture with a Camcorder or video camera The digitized picture is stored to disk and it can be converted to any of the SSTV formats supported the MFJ 1278B Converted SSTV picture can be transmitted by the MFJ 1278B Contact Enterprises Inc or your MFJ dealer for more information concerning the MFJ 1292 Video Digitizer MFJ 1278B MULTI MODE ADVANCED OPERATION ADVANCED PACKET OPERATION This chapter describes some other aspects of Packet operation that you will not need to be concerned with for everyday conversational operation You will want to consult this chapter if you are using your station for special applications such as a Packet Personal Mailbox Bulletin Board binary file transfers Packet picture transfers or running a host program In this chapter also discuss use of the newly developed packet anti collision feature HF and OSCAR packet operation is also discuss in detail in this chapter We will use the term computer to refer to computers or terminals In the command examples the MFJ 1278B s prompts and other messages are shown in ordinary type your response
257. edspesinenesesgsc RIPE 70 Transmitting from Memory Buffers essere nennen 71 COW Weightmng eem ee leet ydp rea denti ees 71 Tuning your eise et RUE te reete t eines ee EEE E 72 Random Code Generator essere nennen nennen 72 Setting Up the for Code Practice seseeeeeeeenn en 73 CW CONTEST MEMORY OPERATION eee 74 Sending CW with External Key Paddle esee 74 MODULATED CW 75 BAUDOT RTTY amp ASCII OPERATION 76 Setting Up for ASCII and RTTY Operation see 76 RTTY and ASCII Receiving eee 77 RTTY and ASCII Transmitting eeeeeseeeeteeeeeeen nennen 77 BAUDOT RTTY OPERATION HINTS eerte 78 Commercial RTTY es 79 AUTOMATIC SIGNAL ANALYSIS 2 22 80 ASA OPERATION isc cutee hei Rees Bates Res PAY Bales 80 MARS OPERATION 5 0 ccc ctetu topo shbanasoeteavsssistasesvehsvsessceseeeaees 82 Configuring for MARS eerte lee eret sen ettet ti eet dee ree 82 Operating MARS with MultiCom for IBM sese 83 The MARsmode Command sess 83 MARSMODE 1 QSO Mode iiser sristi isesi 84 MARSMODE 3 Storage Mode seen 84 AMTOR OPERATION ertt et ete tei Ie Inte A estre te eie ee ote credi 85
258. ee a new prompt cmd Hi John how are you lt CTRL X gt You started typing text while in Command Mode cmd CONVERSE Hi John how are you The cancel ine character can be changed to any ASCII character by the command CANLINE If you have changed your input by rubbing out and retyping characters you may want to see a fresh copy of your input especially if you have set BRONDEL OFF The MFJ 1278B will retype the line you are entering when you type lt CTRL R gt cmd CONNECT KB7 WA7 lt CTRL R gt You mis typed the call sign cmd CONNECT WA7GXD Here the user mis typed the first three characters of the call sign and rubbed them out The MFJ 1278B displayed for each character rubbed out The user then retyped the characters correctly and redisplayed the line He finished typing the call sign on the new line The redisplay line character can be changed to any ASCII character by the command REDISPLA If the MFJ 1278B displays information faster than you can read it before it scrolls off the screen you can halt the display by typing CTRL S To resume output from the MFJ 1278B to your computer enter CTRL Q These characters can be changed to any ASCII character by the commands STOP and START respectively You may occasionally want to include one of the special input characters in a packet For example to send several lines at once in the same packet you would have to include ENTER in the packet at the end of
259. eed character lt LF gt is sent to the terminal after each carriage return character ENTER OFF A lt LF gt is not sent to the terminal after each ENTER The AUTOLF command controls the display of carriage return characters received during PACTOR monitoring as well as echoing those that are typed in For further information on this command please refer to the AUTOLF command in Chapter 6 in the MFJ Data Controller main instruction manual MFJ 1278B MULTI MODE OPERATIONAL COMMANDS AUTOTRAC ON OFF Mode CW Default ON Parameters ON Allows automatic speed tracking of incoming CW signals OFF Automatic speed tracking of incoming CW signals is disabled When AUTOTRAC is set ON the MFJ 1278B attempts to continually track the speed of all incoming CW signals as the speed changes of a station that is being received When the last reception speed greatly differs from the speed being received now the MFJ 1278B will automatically initiate a LOCK just as if you had requested one with Control U If CWSPEEDMatch is on when this automatic locking takes place then the newly locked speed also becomes your new transmit speed Small received speed changes do not cause your transmit speed to change AUTOTRAC to try and re establish a speed lock to the incoming CW signal The AUTOTRAC feature is useful for listening while roaming the bands or for net operation AWLEN n Mode Default 8 Parameters n 7 8 specifying the
260. eived text Packet FAX and SSTV pictures The MFJ 1278B provides dual radio ports for HF and VHF operation These dual radio ports let you connect 2 radios at the same time in any combination Independent transmit audio output controls provide even further flexiiblity This will enable the user to individually adjust the audio output for each radio port The radio ports are not dedicated to either VHF or HF operation They are totally independent of each other You also get a Threshold control for optimizing your demodulator filter for the different modes of operation This is a very useful tool when trying to receive signals during bad band conditions A 20 pin header provided for the MFJ 1278B to operate packet at 2400 or 9600 baud packet by simply plugging in an optional modem board The MFJ 1278BT already has a 2400 modem installed If your MFJ 1278B does not have the 2400 modem installed it can be purchased separately MFJ 2400 and installed by you With the 2400 modem installed your MFJ 1278B can operate 300 1200 and 2400 packet You may also purchased the MFJ 9600 modem board that allows the MFJ 1278B to operate at 9600 baud packet The list goes on This is just a few of the features available In short the MFJ 1278B offers you tons of features that the other multi mode controllers just can t match This in conjunction with the new MFJ Multicom TM software will put you leagues ahead in the ever changing field of Ham Radio Digital co
261. el Printer Port The user can use the built in printer port to print received text or graphics The built in printer port is compatble with most Epson and IBM parallel printers Below in Table 8 2 is the pin out of the Parallel Printer Port J12 Table 8 2 Parallel Port Pin Out Printer Port Pin 4 Pin Function Data Bit 1 12 thru 17 18 thru 25 MFJ 1278B MULTI MODE HARDWARE TTL INTERFACE PORT PIN FUNCTION J5 The MFJ 1278B provides the user with a TTL level I O port J5 The TTL level I O port J5 is compatible with computers and terminals that do not support RS 232C serial voltage levels such as the Commodore C64 and C128 computers Voltage levels of 0 and 5 VDC are available at J5 Below in Table 8 3 is the pin out of the TTL level I O port J5 Table 8 3 TTL Port J5 Pin Out J5 Pin 4 2 3 7 m 2 FER 4 Request to Send 6 7 Bs Clear to Send Frequency Shift Keying 9 Space Output for Scope 10 Mark Output for Scope MFJ 1278B MULTI MODE HARDWARE MULTI LEVEL INTERFACE CONNECTOR J13 The MFJ 1278B provides the user with the capability to perform Multi Level FAX operations as well as Color SSTV work Multi Level FAX and Color SSTV operations are accomplished through the addition of a Multi Level Interface The Multi Level Interface controls both transmit and receive operations for the Multi Level FAX and Color SSTV modes Below in Table 8 4 are the pin outs for the ribbon cable connected at J
262. elected speed So with the FARNSWOR command ON the code generator sends the CW characters faster but slows the text down to a slower speed The FARNSWOR command controls the transmission of CW characters whether the computer keyboard or key paddles are used MFJ 1278B MULTI MODE BASIC OPERATION Setting Up the for Code Practice You can monitor the random code sent by the MFJ 1278B without a radio connected In order to monitor the random code attach a small speaker to the SPEAKER jack located on the back panel of the MFJ 1278B Note If a radio is connected and you do not wish to transmit the random code the radio should be turned OFF The MFJ 1278B will key PTT line and the keying output is active while RANDOMCW is ON Under the cmd command prompt type MODE MC ENTER 15 the desired code speed The MFJ 1278B will respond with the Modem Status display verifying the operation mode and cmd prompt will appear Next type RANDOMCW ON lt ENTER gt Next type K lt ENTER gt followed by a Ctrl T The MFJ 1278B will generate 5 letter groups and display them on the computer screen If you do not wish to see the characters as are sent you can turn off your computer screen You can then turn on the computer screen once you finish copying the code and compare the result To stop the random code sending type Ctrl R To start the random code again type Ctrl T To exit random code practice type Ctrl C The
263. en 47 BASIC HF PACKET OPERATION nope pter e Por arrei 49 HF Packet Operation Hints 50 uber pi REM aah PER 51 What 18 Pactor eee eee T pne e rires 51 PACTOR Operation 2 ninh ee pe eoe eee ete iier 51 FEC Unproto Operation eoe Re ERU PRU rit EE 52 PACTOR ARQ 5 eccoh ee Sate A il ilps eee Math einen etie aes 53 ChangeovVer is dept ee eee eee eee IE E 53 Monitorihg D eire RUE Het 53 Monitoring AMTOR ARQ requests nennen nenne 54 Evitine Mada KA MFJ 1278B MULTI MODE TABLE OF CONTENTS et e iie e edited duce ed 56 SPEEDup SPEEDdoywWn tte e regret pere 56 AUTOMATIC ON LINE COMPRESSION essere 56 FLOW CONTROL nnper erede te cies riore be ae DR Ht iere 56 AMTOR while in PACTOR mode seen nennen nene 56 Amtor Detection in Pactor sess eene eene 57 PACTOR STATUS INDICATORS eeeeeeeeeeeeneennee nennen nennen rennen rennen 57 PACTOR oak Sts as ee pP 58 Setting Up your Pactor Mailbox esee eene nennen 58 General Overview a tet OU reete ROV D onan 60 Detailed Pactor Mailbox Overview essen 63 Mailbox Messages terne Ret eerte re retirer eR 67 CW OPERXATION nd eet tut use oeste orien e i deo SS 68 Receiving CW etes eet REI GR Beek idee 69 Transmitting CW hc sc
264. end of picture detect and the user must manually terminate reception by returning to command mode FAXMODE n Mode FAX Default 3 n thru 7 specifying a particular FAX format The FAXMODE command of the MFJ 1278B specifies the FAX format in terms of speed FAXMODE n and speed are shown in the Table below Horizontal Dot FAXMODE 60 lines min or 1 line sec 60 69 900 600 7 80 or 3 MFJ 1278B MULTI MODE OPERATIONAL COMMANDS FAXNEG ON OFF Mode FAX Default OFF Parameters ON Reverses the FAX image on screen i e black to white OFF Disables FAX image reversal Normal operation Setting FAXNEG ON causes the MFJ 1278B to invert the screen image This means the white areas of the FAX pictures will be black and the black areas to be white The synchronization bar is not inverted FAXREV ON OFF Mode FAX Default OFF When FAXREV is turned ON the MFJ 1278B will invert all received FAX data including synchronization bars It is analogous to RXINVERT as used by RTTY ASCII modes FEC Mode AMTOR Immediate Command FEC immediately causes the MFJ 1278B to start broadcasting with the AMTOR mode B Forward Error Correction FEC protocol When the FEC command is issued the MFJ 1278B keys the transmitter and is immediately ready to accept text to transmit Type K or CONV to enter the text transmit mode When you re done transmitting enter CTL C and type R to release the trans
265. equency of the filtered audio If you are lucky this may turn out not to be necessary The tuning indicator and DCD LED can be used to give you an indication when the modem is aligned with the filter similar to the indications described above If the tuning indicator hovers around the center of the display when the modem is listening to noise being passed through the narrow filter as described above realignment of the modem is unnecessary If you have determined that it is necessary to realign the modem center frequency to the radio filter center frequency You should refer to Appendix D at the end of this instruction manual for the alignment procedure Operating HF Packet Much has been said and written about the relative merits of HF versus VHF packet operation HF packet operation is made to appear more difficult than VHF NBFM packet operation by several factors Some of these are 1 HF propagation is much more time variable and is more prone to produce intersymbol errors than is VHF propagation 2 On the published HF packet frequencies many more stations are trying to use a single channel simultaneously than is the usual case on VHF 3 Due to the wide area propagation characteristic of HF radio waves sometimes nonreciprocal with relatively dead skipped zones the carrier sense multiple access CSMA feature of packet radio is a less than perfect arbitrator for time sharing the channel between users 4 Many of the commercial
266. er Most HF linear mode radios are MUCH faster than VHF FM radio A reasonable setting for HF work is 120 milliseconds DEAdtime set to 12 This should work fine with virtually any HF radio stable enough to consider using on HF packet ACKTIME 0 250 also 10 millisecond increments This represents the time required to send a response frame with no I field appended at the baud rate being used on the radio port The current 100 millisecond default is close but should be adjusted for 1200 baud work to 130 milliseconds ACKTime set to 13 For 300 baud HF work this parameter should be set to 520 milliseconds ACKTime set to 52 SLOTS n 0 lt n lt 127 This parameter determines how many sides are on the slot time dice SLOTS represents an 1 sided dice the MFJ 1278B throws before transmitting The SLOTS command allows any number of slots from 1 thru 127 to be defined REMARKS Disables Slotting This should be the default setting VERY VERY VERY busy You get the idea Lum Use only if the channel is VERY busy Might as well print it out amp send it in the mail The value used on a particular channel should be agreed on by the channel users Access to the channel will be equitably distributed among all users if everybody is using the same value for the SLotmask and DEAdtime parameters Tha idan ta ninl a wahia larwa annauach that tha nrahohiliter af tern ananad nn otatinna ninbing MFJ 1278B MULTI
267. er more flexibility in controlling how CW MCW characters are transmitted from the key paddle The CWSEndch command is only effective for CW and MCW modes The user needs to leave the CWSEndch command at the default value of 255 or FF when sending CW using a key paddle The MFJ 1278B will transmit all CW characters immediately if the CWSEndch command is at the default setting of 255 or FF Once the MFJ 1278B completes the CW transmission the MFJ 1278B will revert to the receive mode Buffer transmission in the Memory Keyer Mode is the same as in the CW mode Weighting of key paddle CW is achieved by using the WEIGHT command Please refer to the CW mode section as to setting of the WEIGHT command MFJ 1278B MULTI MODE BASIC OPERATION MODULATED CW OPERATION The MFJ 1278B allows the transmission of CW code practice over a FM radio To send code practice over a VHF FM radio the user would use the Modulated CW mode or MCW When using the Modulated CW the MFJ 1278B will key the PTT line of the Radio port and send a keyed audio tone to the microphone input of your radio Modulated CW can be used on either radio port or radio port 2 You do not have to re wire the Radio cable when operating Modulated CW You can use the same cable that you use for the other modes of operation To enter MCW mode type MODE MC lt ENTER gt The MFJ 1278B will respond with the mode status as shown below followed the cmd command prompt Radio
268. er of too short frames received The counts are of diagnostic use only and here again non zero counts are not a matter of concern RXRESYNC RXRESYNC is a diagnostic health counter recording the number of receiver re synchronizations handled internally to the MFJ 1278B Non zero counts indicate the attached radio may be either turned off or squelched Note that in almost every situation your radio must to have its squelch fully opened SENTFRMR Increments each time a Frame reject frame is transmitted SENTIFRA Increases by one each time an I frame is sent SENTREJ Whenever a REJect frame is transmitted this counter is incremented SENTRNR This health counter tracks the number of times your MFJ 1278B has had to send Receiver Not Ready RNR frames Non zero counts may be an indication that the RS 232 terminal or baud rate is too slow TXCOUNT Incremented whenever a frame is correctly transmitted TXQOVFLW Counts how many times frames were disconnected because the outgoing frame queue was too small TYTMA MFJ 1278B MULTI MODE OPERATIONAL COMMANDS DISPLAY is an immediate command and with no class parameter will cause all control parameters and their current values to be displayed Sub groups of related parameters can be displayed by specifying the optional parameter class Individual parameters can be displayed by entering the parameter name with no options DISPLAY Mode AMTOR Immediate Command U
269. er than 1200 baud IBM and Compatible Computers The optional Starter Pack MFJ 1289 for the IBM PC and compatible computers is available from MFJ Enterprises Inc or from any dealer of MFJ products Included in this Starter Pack is a graphics terminal program This program allows compatibility between the MFJ 1278B and the computer Also included is a cable used to connect the MFJ 1278B to your computer The MFJ 1289 program allows you to transmit and receive 16 gray level FAX as well as color SSTV pictures The MFJ 1289 also allows for display of these signals on the computer screen It will also store the pictures on disk for later viewing or transmitting This software also sets up compatibility between the MFJ 1278B and the computer when operating the other mode that the MFJ 1278B has to offer You may also use many commercial shareware and public domain terminal programs for the IBM PC and compatible computers Special programs written for packet radio and nacket hulletin hoard cervices can he need with the MET 1278R Nate that thece tunes of MFJ 1278B MULTI MODE COMPUTER INTERFACING Radio Shack Color Computer There are several terminal programs available for the Color Computer You will probably want to use a commercial program rather than writing your own since the Color Computer has a software UART that is difficult to program in BASIC Some of the terminal programs available are COLORCOM 64 AUTOTERM and RICKEYTERM for
270. ers S Displays a group of parameters such as memory buffer contents CW parameters and parameters which affect the printing of graphics to the printer and to the computer screen HEALTH displays 24 counters The twenty four counters in the MFJ 1278B are 16 bits wide and are ALWAYS initialized to 0000 on power up or RESTART These health counters are not listed in the standard command listing Also when telling the MFJ 1278B to display with the DISP command they will not show there either However we have listed them here for your convenience ASYFRERR This is a health counter reflecting the number of hardware detected asynchronous framing errors Framing errors are not fatal They merely indicate that the terminal attached to your MFJ 1278B is not configured correctly with regard to AWLEN PARITY ASYQOVER Records the number of times received connected packets have been rejected due to insufficient space in the buffer holding the data going to the terminal No actual data loss occurs provided the connection remains intact ASYQOVER counts can be avoided by increasing the speed of the attached RS 232 terminal and or printer SEE also SENTRNR ASYRXOVR Increases when the software does not service the asynchronous receiver in time Indicates data from the user to the MFJ 1278B is being dropped This error counter should never MFJ 1278B MULTI MODE OPERATIONAL COMMANDS BBFAILED Counts number of times bbRAM checksum was
271. erwise just like packets you will be transmitting later on The CONNECTED to message tells you that the connection was successful You should also notice that the CON LED has lit up and that you do not see a new cmd prompt on the next line You are now in Converse Mode ready to start talking Try it Trima wan maccnaa andina tha lina unith a ENITRD 112 tha avamnla miwan MFJ 1278B MULTI MODE BASIC OPERATION The ENTER causes your message to be put into a packet or packetized and transmitted We explain in the next chapter how you can use a different character to send packets The underlined text is a message that the MFJ 1278B received in a packet and displayed Whenever you are in Converse Mode anything you type will be assembled into a packet addressed to the station you are talking to and transmitted If there is not a QSO connection in progress the packet will be sent to the address CQ In the example above the MFJ 1278B entered Converse Mode automatically after the connect took place You can also command the MFJ 1278B to move back and forth between Command Mode and Converse Mode To return to Command Mode you must enter a special character Control C abbreviated lt CTRL C gt or else send a BREAK signal Control characters are usually entered by holding down a special control key and then typing another key without releasing the control key If your keyboard does not have a key marked CTRL or someth
272. es can also be saved on disk with software supplied with the Starter Pack Pictures saved on disk may be re transmitted or recalled to print to the screen at any time If you are using one of the above terminal program you should first turn PRINTGRA OFF Follow the instructions given in the software documentation to receive FAX pictures on the screen or to save the pictures to disk files For those who wish to write special software to handle FAX graphics and display it on screen the following information may be useful for you When the PRINTGRA command of the MFJ 1278B is ON FAX pictures received will be sent to the graphics printer attached to the MFJ 1278B printer port If the PRINTGRA command is OFF then the MFJ 1278B will direct the picture graphics to your terminal thru the RS 232C port of the MFJ 1278B This FAX format thru the RS 232 port will be in either 2 level MULTIFAX OFF or multi level raw data format MULTIFAX ON The default is the 2 level data format To save to disk or display on your computer screen the terminal program you used must be compatible with the multi level raw data format or it must be compatible with the 2 level FAX frame format LF CR ESC x x ESC x x x lt lt nnn character of graphics Two Level FAX Picture Format The FAX frame sent to the user s terminal contains carriage control information graphics setup information and nnn columns of 6 row high dot graphics Special note In order to all
273. ess to FM test equipment check to see that the modulation level is still within the limits of 3 to 4 5 kHz deviation If the modulation level is not within 3 to 4 5kHz limits then make a final adjustment with the MFJ 1278B transmit audio level controls These controls are R157 for Radio 1 and R158 for Radio 2 MFJ 1278B MULTI MODE RADIO INTERFACING Receiver Audio Setting The modem in your MFJ 1278B is equipped with an advanced phase coherence type data carrier detection DCD A threshold control and a sensitive tuning indicator is also provided Together these can be used to set the correct receive audio level for the modem These can also be used to optimize the DCD characteristics for the various methods of operation With your radio in the receive mode open the squelch control so that a steady hiss is heard on a speaker Set the volume control to the minimum volume position The tuning indicator on the MFJ 1278B should drift off to one side of the display and become stationary It may drift enough to disappear off the end of the display Slowly advance the audio output level with the volume control until the tuning indicator springs to life and dances around a point near the middle of the display This is the absolute minimum audio level for marginal copy Continue to advance the volume control until there is approximately twice as much audio present at the receiver output This can be estimated by ear or measured with an oscilloscope
274. ess you take steps to assure that the audio level for the FM radio will not produce excessive deviation If both radios are to remain connected to the MFJ 1278B you can set the audio level for each radio independently by using the audio output level adjustments R157 amp R158 on the left side of the MFJ 1278B with a small screw driver The modem center frequency used by the MFJ 1278B for all of the narrow shift AFSK modes including HF packet operation is 2210 Hz 2125 and 2295 Hz tones Most frequencies listed for packet operations in the HF bands were established using a modem center frequency of 1700 Hz 1600 and 1800 Hz tones in lower sideband mode This is a 520 Hz offset 2220 1700 between the two modem standards So a listed frequency of 7093 for example will cause you to have a frequency display on your radio of 520 Hz PLUS the listed frequency IF you are also using lower sideband mode Thus you should find the 77093 KHz packet activity centered around 7093 52 KHz Your tuning indicator when properly centered is easily capable of 10 Hz alignment accuracy per segment It should be used as the tuning reference on any individual signal regardless of the frequency indicated on the radio dial NOTE The signal actually transmitted by your SSB transceiver F emission when using the MFJ 1278B for AFSK HF packet operation using lower sideband will cover a band of frequencies approximately 400 Hz wide and centered at the transmitter indic
275. et Other features like auto forwarding or reverse forwarding of mail to and from other BBS systems remote sysop access sysop paging mailbox ctext chat mode and a has mail LED indicator The MFJ 1278B has 32K mailbox memory which is user expandable to 128K or 512K by simply replacing the mailbox memory IC a feature that no other controller offers You also get 20 seement 10 Hz Precision Tuning Indicator that makes tuning simple MFJ 1278B MULTI MODE INTRODUCTION The new packet collision prevention features Prioritized Acknowledgments and Slottime are installed This new technology helps prevent many packet collisions inherent in the current packet protocol The EPROM containing the MFJ 1278B firmware previously 512K bits has been expanded to 1 Megabits giving the MFJ 1278B twice the room to grow in You also get a Key Paddle input jack so you can use your MFJ 1278B as an Iambic Keyer or Memory Keyer The ten user programmable memory buffers are provided for use with the contest memory keyer function In addition you also get contest serial numbering and a random code generator A speaker jack lets you plug in a speaker and monitor transmit and receive audio and CW side tone as it is received and transmitted by your MFJ 1278B The speaker output also provides for the packet connect signal alarm A Centronics compatible parallel printer port DB 25 lets you directly interface your printer to the MFJ 1278B for printing rec
276. et character is not appended to packets When CR is ON all packets sent in Converse Mode will include as the last character of the packet the send packet character which forces the packet to be sent If CR is OFF the send packet character is interpreted solely as a command to the MFJ 1278 not as data to be included in the packet and furthermore it will not be echoed to the terminal A ut MANN MAT 3 CSRTENVIR A X GAS oo dal 15 _ cd LL LLL LLL lato ant Wis ste asec t MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CTEXT text Mode Packet Default Parameters text Any combination of characters and spaces up to a maximum length of 120 characters CTEXT specifies the text of the packet to be sent after a connection is made if CMSG is ON The default text is an empty string i e no message You can send multiple line messages by including carriage return CR characters in the text The CR character can be included by using the pass character immediately preceding it see the PASS command If you enter a text string longer than 120 characters an error message will appear and the command will be ignored For example you might set your CTEXT message to I m not here right now but you may leave a message To clear the CTEXT text without issuing a RESET command use a 96 or amp as the first character in the message You cannot connect to yourself and see your CTEXT unless going thru a digipeater CMSG only takes eff
277. ets a number of character times for the delay With the basic parameters set up which enable the MFJ 1278B to be able to communicate with your computer we can now discuss some basic functions and features of the MFJ 1278B MFJ 1278B MULTI MODE BASIC OPERATION THE 1278 MULTI MODE MODEM The MFJ 1278B modem has five sets of pre set modem components These modem components allow the MFJ 1278B to operate efficiently in its various modes of operation These modes of operation include VHF and HF Packet PACTOR AMTOR VHF RTTY HF RTTY VHF ASCII HF ASCII CW Modulated CW CW Memory Keyer 16 gray level FAX including Weather FAX color SSTV and monitoring of NAVTEX modem components have been individually calibrated for each mode of operation The MFJ 1278B has been factory calibrated and does not require re calibration when operating any the operational modes The modes used with each modem are shown in Table 4 1 The tones and shifts produced by each modem are shown in Table 4 2 MODEM OPERATION MODES VHF Packet 2 level FAX HF Packet HF Baudot RTTY HF ASCII PACTOR AMTOR NAVTEX VHF RTTY VHF ASCII CW Memory Keyer Modulated CW Multi level FAX Color SSTV Table 4 1 MFJ 1278B Modem and Operation Modes Pp 70200 20 100 H w o22 9 25 JJ 70 850 700 M 1100 1200 1300 1500 and 1550 thru 2250 in 50 Hz steps Table 4 2 Tones amp Shifts Produced by the MFJ 127
278. etup NOTE Whenever we refer to ENTER in this instruction this means to press the RETURN MFJ 1278B MULTI MODE BASIC OPERATION 1 From the cmd prompt please type the following MODE PT ENTER the MFJ 1278B will respond with MFJ PACTOR 2c 1022 free followed by the p cmd prompt on the next line The 2c is the checksum of MFJ s Pactor release You will probably notice a slight delay in obtaining the p cmd prompt This is because the MFJ 1278B is figuring up the Pactor checksum this is perfectly normal 2 Under the p cmd prompt type MYCALL n ENTER where n is your standard amateur callsign The MFJ 1278B will respond with MYCALL n where n is the callsign you entered in the MYCALL parameter The MFJ 1278B will give the p prompt on the next line 3 Ifyou want your messages time and date stamped then set DAYTIME with the current information The DAYTIME command is in the standard Packet command set not in the Pactor commands NOTE An optional TNC real time clock the MFJ 43 for the MFJ 1278B is available from Enterprises With this real time clock module installed in your MFJ 1278B the clock will continue to keep time even with the MFJ 1278B turned off You will not have to set your MFJ 1278B s DAYTIME every time your MFJ 1278B is powered 4 Fromthe p cmd prompt type MAILBOX ON ENTER As we mentioned earlier there are two MAILBOX commands One of the MAILBOX command
279. fication to your transceiver 2400 BPS PACKET SETUP the default parameter settings for 1200 baud packet operation can be used for 2400 bps packet operation 2400 bps operations need no special setup or parameter changes There are however some changes that the user can make later on to the MFJ 1278B parameters that will enable you to improve the speed of the throughput performance of the 2400 bps operation The honing of the parameters may not seem like much but we have found that at 2400 bps the MFJ 1278B seems to be more responsive to the TXDELAY DWAIT RESPONSE and SLOTTIMES When using direct connects and good paths the user can increase the MAXFRAME and PACLEN commands to allow larger packets to be moved during each transmission When returning to the active throughput frequencies these two commands should be reduced to their original settings You may find that if you were using a TXDELAY of 50 then a TXDELAY of 40 will now perform better The DWAIT command can be shortened or lengthened to suit the AGC recovery time of your radio For instance if you have been running the DWAIT of 16 it may now perform better at DWAIT of 12 or even 10 The FRACK will appear to exercise more at 2400 also 2400 BPS operation really shows its place in the packet world when used to pass large ASCII BINARY and PICTURE files It is always good to use clear frequency and or use direct connects to the target station rather than going thru a node o
280. flag set are private to the sender recipient and the SYSOP Only the person to which the message is addressed to can read or kill it The local or remote SYSOP can read or kill any message in the system Here is an example of a Mailbox message with a Type flag and a message flag inserted Slot 1 PN To KB5JNZ From KF5C BBS Bulletin The P is in the Type flag block which indicates that the message is a Private message The N is in the Message flag block that tells you that the message has not been read by the callsign KB5JNZ When KB5JNZ reads the message the N flag will become a Y flag H elp This command displays the Mailbox command list brief description of the commands available to user is given J This command replies with the TNC s MHeard list The eleven most recently heard callsigns will be displayed The J command only applies to remote users K Allows you to kill messages which are addressed to you This works in conjunction with the Y flag In order to perform a Global Kill first of all of the messages to be killed during this must have the Y flag set in the header Secondly all messages to Pow 211 ca bascs the nu cundi eA RAEAEXZMRAL MFJ 1278B MULTI MODE ADVANCED OPERATION K Allows you kill the message in slot nn where nn is a particular slot number Remote users may only kill messages that are addressed only to them or originated by them The local and remote SYSOP can kill any messages depending on the se
281. free Mailbox B E H elp J K L M R S T First of all lets find out what the n free is for The n free is a Bytes Free indicator This applies only to the Mailbox This is a great feature because all users will always know how much space is left in your Mailbox The Mailbox will update the Bytes Free indicator whenever messages are forwarded added or deleted Now you are ready to operate your mailbox However lets take first things first You very well cannot operate the Mailbox without knowing the functions of the commands So lets take a look at the functions of the Mailbox commands The functions are as follows B Logout This initiates a disconnect sequence from the Mailbox E Edit Message Header This allows editing of the message header This is necessary for the Forward and Reverse Forward functions of the Mailbox The current is first displayed then the Mailbox gets the new values according to what is entered at the prompts it gives the user The local and remote SYSOPs may edit any messages in the Mailbox Remote users may only messages TO and FROM himself and any message of T raffic Below are the edit prompts and an explanation as to what their functions are To The callsign of the person the message is going to goes here It must be different than MYcall or MYMcall Q The callsign of the BBS you wish to Forward the message to is placed here This BBS should be the one where the person whom you are sending the
282. fter a connection is established The connection may result either from a connect request received over the air or a connect initiated by CONNECT command that you issued For most operations you would set CONMODE to CONVERS However if you are using Transparent Mode for a bulletin board program for example you would set CONMODE to TRANS so that the correct mode will be entered when your bulletin board receives a connect request If you initiate a connection with the CONNECT command the control of Converse or Transparent Mode is determined by NEWMODE If the MFJ 1278B is already in Converse or Transparent Mode when the connection is completed the mode will not be changed If you have typed part of a command line when the connection is completed the mode change will not take place until you complete the command or cancel the line This prevents the last part of your command from inadvertently being sent as a packet MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CONNECT Via call2 call3 call9 Mode Packet Immediate Command Parameters calll Callsign of TNC to be connected to call2 Optional callsign of MFJ 1278B to be digipeated through As many as eight digipeat addresses can be specified The part of the command line in brackets VIA call2 call3 call9 is optional The double bracketed text call3 call9 is also optional but would only be used if VIA call2 is present The brackets are not typed Each callsign
283. g circuit your radio has If your radio is a solid state or cathode keyed type then you should use the DIRECT keying output If your radio is tube type you should use the GRID BLOCK keying output If you are unsure of which output to use try both outputs The keying outputs of the MFJ 1278B are diode protected If the wrong output is used you will notice a constant key down effect on the transmitter The DIRECT output keys a positive voltage to ground The GRID BLOCK output keys a negative voltage to ground Key Paddle Connection The KEY paddle input jack of the MFJ 1278B accepts a 3 5mm stereo plug Radio Shack Part No 274 284 DO NOT USE A MONO plug IT WILL SHORT OUT THE KEY INPUT A two conductor fully shielded cable should be used Wire the tip of the plug for the dash contact and the ring of the plug for the dot contact See Figure 3 8 below Be sure to use the shield of the cable for the paddle ground contact To Paddle Chassis E Te Dash 4 Contact L To Dot Conte MFJ 1278B MULTI MODE RADIO INTERFACING FSK CONNECTION If your HF radio permits FSK operation an FSK output is provided The FSK output is at pin 8 of the TTL port on the rear panel of the MFJ 1278B Only two lines Pin 8 FSK and Pin 3 ground are needed in making the FSK connection to your radio Use the 8 pin IDC connector supplied with your MFJ 1278B to make the FSK cable See Figure 3 9 below 1 3 8 10 0 0 0 0 0 0 0 0 0 0
284. h 10 1 probe Computer with terminal software or terminal RS 232 Serial Cable MFJ 1315 Power Supply or 12 VDC supply ao op Calibration Proedure 1 Install jumpers on JMP4 and JMP7 2 Place frequency counter at Pin 1 of JMP 9 Pin 1 is the top pin of JMP 9 3 the following procedure all frequencies must be calibrated to within 2 Hz 4 Type TUNEPROC CR The MFJ 1278B will respond with Calibration Install loopback for TX alignment R139 For 700Hz At AWN C PIA ss ATT Ne 11 OMA NIM NAM a foa ed MFJ 1278B MULTI MODE APPENDIX B MODEM CALIBRATION 7 Adjust R77 for 2200Hz 2Hz Press the SPACE BAR 8 Adjust R105 for 2295Hz 2Hz Press the SPACE BAR 9 Adjust R106 for 2125Hz 2Hz Press the SPACE BAR 10 Adjust R122 for 2125Hz 2Hz Press the SPACE BAR NOTE If recalibrating the VB modem for Low Tone RTTY then remove the jumper from JMP and adjust this control for 1275Hz 2Hz 11 Adjust R119 for 2975Hz 2Hz NOTE If recalibrating the VB modem for Low Tone RTTY then remove the jumper from JMP and adjust this control for 1445Hz 2Hz 12 Press the SPACE BAR the MFJ 1278B will respond with Multilevel xmit 1900 13 Adjust R307 for a reading of 1900Hz 1Hz NOTE For step 14 the frequency readings on the frequency counter should be compared to the frequency readouts indicated by the MFJ 1278B Note that the difference in the two readings can be as much
285. h it before you go on the air If you are already familiar with the packet operation then you may not want to perform this exercise In this case go the other modes of operation in this chapter Disconnect your radio from the MFJ 1278B and turn off the MFJ 1278B Install the digital loopback jumper JMP10 Do not install the analog loopback jumper JMP7 while JMP10 is in place Connect your computer to the MFJ 1278B with your serial cable Turn on the computer and start your terminal program A Connecting and Disconnecting Exercise A connect sequence initiates all Packet radio QSOs The connect sequence sets up the handshaking between the two stations that ensures error free communications disconnect sequence terminates all Packet radio QSOs The disconnect sequence leaves both stations free to start new Packet QSOs Packet QSOs can also make use of digipeaters other packet stations that can automatically relay packets from one station to the other over a specified route To see how this works you can have the MFJ 1278B connect to itself Since you have set the MFJ 1278B up for digital loop back it will receive all packets that it sends Try the following cmd FULLDUP ON cmd CONNECT K5FLU CONNECTED to KSFLU replacing KSFLU with your own call sign The MFJ 1278B generates packets initiating and confirming the connection The packets are not actually converted to audio signals and transmitted over the radio but they are oth
286. have a 5 pin DIN connector on one end with the other end of each cable being unterminated The unterminated end of each cable is for wiring the appropriate microphone connector which matches your radio CHECK THIS CABLE WITH AN OHM METER TO IDENTIFY EACH WIRE BEFORE WIRING IT TO THE MIC CONNECTOR THAT FITS YOUR RADIO MFJ 1278B MULTI MODE RADIO INTERFACING HANDHELD RADIO CONNECTION Some HTs key the transmitter by drawing a small amount of current from the microphone input pin see Fig 3 3 below Radios with this type of special keying circuit are ICOM 2AT tm and Yaesu FT x09 FT x3 FT 727 tm and others Appendix at the end of this instruction manual provided pin designation for some of the radios Also consult the instruction manual of your radio If your HT has this type of microphone circuit you can wire the microphone like the one shown in Fig 3 3 or you can remove the cover of the MFJ 1278B and install a shorting jumper at JMP L for Radio Port 1 or JMP for Radio Port 2 Installing JMP or JMP L will eliminating the need of soldering Cx and Rx to the microphone cable Cx and Rx are installed on the MFJ 1278B mother board Fig 3 4 shows the location of JMP L and JMP K connectors On the MFJ 1278B mother board the Rx resistor for Radio Port 1 is R140 and the Rx resistor for Radio Port 2 is R107 If your radio still will not key properly after installing JMP L or JMP K you may need to change R140 or R107
287. he MFJ 1278B The PTT LED on the front panel of the MFJ 1278B should illuminate Verify that the voltage on pin 9 of U16 is 5 Vdc If it is 5 Vdc instead of 5 Vdc push the space bar one time The voltage should now be 5 Vdc If not then press and hold the space bar and see if the voltage at U16 Pin 9 changes at all Set U16 Pin 9 to 5 Vdc Place the scope probe on J2 pin 1 TX audio Adjust R158 for a signal of 250 mV p p or for a level recommended by your radio instruction manual Move the scope probe to J2 pin 4 Rx Audio The voltage should be approximately 1 V P P Press the space bar and again measure the peak to peak voltage at J2 pin 4 The audio level should not change Both mark and space audio should be at the same level Type MFJ 1278B MULTI MODE APPENDIX D HF RADIO HF RADIO ALIGNMENT If you have determined that it is necessary to realign the MFJ 1278B modem center frequency to your radio filter center frequency one of the following 2 methods should be used to make the radio filter center frequency Fc determination Both methods require access to a frequency counter capable of measuring audio frequencies to a resolution of 1 Hz Almost any frequency counter should be capable of this FIRST METHOD NOISE AVERAGE FREQUENCY Method I requires an active noise source like a receiver noise bridge There are several suitable units available for this purpose 1 Set the receiver to LSB mode with the 500 Hz filter
288. he TAB key 9 To transmit a buffer user will press the TAB key then follow by a memory buffer number 0 9 For example to transmit memory buffer 0 press the key then type the 0 key MFJ 1278B will transmit the content of memory buffer O then revert to receive at the end of the buffer transmission BUFKEY is useful for CW MCW RTTY or ASCII BUFTIME n Mode CW Default 0 Parameter n 0 thru 65535 When a non zero BUFTIME is specified the MFJ 1278B will transmit Buffer O at the repetition rate specified in seconds BUFTIME is effective only in the CW mode If the transmitter is not keyed the buffer timer will key it send Buffer 0 then release it This is manna anl Fan nnllinn OM ata DIIOTIMAT 254 hee itta A MFJ 1278B MULTI MODE OPERATIONAL COMMANDS BWNL ON OFF Mode AMTOR Default OFF BWNL controls whether the MFJ 1278B in mode B FEC waits for you to send a newline character CR before it starts transmitting the data If BWNL is OFF then every character you transmit in mode B will be sent as soon as possible If BWNL is ON the MFJ 1278B will buffer the entire line sending it only when you have completed it and pressed the RETURN key This willallowyou to fix typing mistakes before transmission If the end of the line comes before you finish then the line is automatically sent CALIRA Mode CALIBRA is an immediate command and is used to transfer control to t
289. he baud rate for use by RXCAL to 300 baud by typing CALSET 32 lt CR gt This rar oc vxrexacr oc MFJ 1278B MULTI MODE APPENDIX B MODEM CALIBRATION 5 Command the MFJ 1278B to do a demodulator calibration by typing RXCAL lt gt 6 CAREFULLY adjust R113 until the DCD LED on the front panel is fully illuminated NOTE The threshold control on the MFJ 1278B must be set to a position which will allow the DCD circuit to function properly A setting approximately 1 3 to 1 2 of the total range starting from maximum CCW should be adequate Continue to VERY CAREFULLY adjust R113 until the STA and CON LEDs on the front panel either change state very slowly alternate which one is lit or until both are simultaneously illuminated NOTE This is a very critical adjustment It is very unlikely that you will be able to cause both LEDs to be turned on simultaneously for longer than a very brief instant Just fine tune R113 very carefully and notice the action between the STA and CON leds If they flash back and forth this is acceptable 7 Return the MFJ 1278B to command mode by typing a This completes demodulator center frequency alignment using the built in calibration software If there were any problems in the preceeding procedure then DO NOT go beyond this point If you do the calibration will be inaccurate Now that the demodulator and modulator are properly aligned to one another the tuning indicator can be set for proper cen
290. he escape to cmd mode sequence for TRANSPARENT connections Use CTRL C three times default or asynchronous BREAK MFJ 1278B MULTI MODE OPERATIONAL COMMANDS PRINTGRA ON OFF Mode FAX SSTV Default ON For FAX and SSTV modes the setting of PRINTGRA determines what the MFJ 1278B does with demodulated graphics In Multi Level FAX mode when MULTIFAX command is turned ON the setting PRINTGRA ON or OFF will not be useful Under 2 level FAX SSTV format when PRINTGRA is ON the MFJ 1278B expects and prints to the Epson graphics printer attached to the printer port When OFF graphics are sent to the user s terminal in format LF CR ESC x x ESC x x x nnn characters of graphics The FAX SSTV frame sent to the user s terminal contains carriage control information graphics setup information and nnn columns of 6 row high dot graphics Special note In order to allow the FAX SSTV frames to pass through without special handling each character in the frame is biased upward with the value 30Hex so only characters of ASCII value 30H through 7FH are sent to the terminal A few side effects of the special handling 1 FAX SSTV frames and pictures may be transmitted in PACKET or ASCII or logged to disk without concern for binary transfers 2 The x values in the FAX SSTV header are not useful for determining the format of the FAX SSTV picture since 2 bits of the 8 bit lengths are lost This is not serious provided you are aware
291. he modem calibration routine Calibration may be performed at any time without altering the current link state Briefly the commands available in the calibration routine are SPACE Switches between the Mark and Space transmit audio tones D Alternates between the two transmit tones at a rate determined by the radio baud rate This will help you to calibrate the demodulator K Activates the modulator and Toggles the PTT line on off Q Quits the calibration routine and returns to command mode MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CALSET n Mode Default NONE Parameters n 0 65535 specifying the count setting for use by the calibration routine The number to be specified by CALSET is determined by the frequency f to be calibrated as follows n 525 000 f 1 modulator tones n 262 500 f 1 demodulator tones In calibrating the modulator tones the frequency f will be the actual modulator tone desired When calibrating the demodulators frequency f is the average frequency between the Mark and Space frequencies Round n to the nearest integer To calibrate the modem tones you will set n for the desired frequency using CALSET CANLINE n Mode Packet Default 18 Parameters n 0 7 specifying an ASCII character string code This command is used to change the cancel line input editing command character The parameter n is the ASCII code for the character you want to type in order to c
292. he output Turn the adjustment on the trimpot clockwise CW until no increase in output level is heard at the monitoring receiver 4 Rotate the adjustment on the trimpot counter clockwise until the audio signal on the monitoring receiver decreases by half of the maximum level This can be estimated by ear or accurately by measuring the output voltage at the transmit audio pin of the radio port with an oscilloscope or AC voltmeter 5 Press the K key to return to receive mode and type Q to exit the calibration routine Be sure to remove JMP4 if you placed it to defeat the watch dog timer You have now set your transmitter deviation to approximately the correct level If you notice a significant hum level in the monitored audio in Step 3 take measures to remove it This may require shielded wire recommended in any event in your microphone audio circuit The use of shielded cable is always necessary in projects such as this If your transmitter has an adjustable microphone gain control try reducing the sensitivity of the transmitter microphone circuit and increasing the signal level from the MFJ 1278B to minimize hum or other noise problems Setting the Receiver Audio Input Level The modem in your MFJ 1278B implements an advanced phase coherence type data carrier detection DCD There is a threshold control and a sensitive tuning indicator Together they set the correct receive audio level for the modem also to optimize the DCD characteri
293. he transmitted SSTV and FAX pictures can be adjusted by using the PIXTONES command Note that in transmitting 4 or 8 gray levels of SSTV or FAX 16LEVELS command is OFF the MFJ 1278B will automatically select only four 4 or eight 8 of the PIXTONES values you have chosen PIXTONES does not affect 2 levels FAX transmitting PIXTONES determine which levels of gray that the MFJ 1278B will transmit MFJ 1278B s multi gray levels board is capable of transmitting up to 19 tones However only a total of 16 tones can be selected by the PIXTONES command To use PIXTONES the terminal program which you are using on your computer must be able to support the raw data format required by the MFJ 1278B See Chapter 4 in this manual under Multi level FAX SSTV Transmitting for more details about the raw data format The 19 tones which can be produced by the MFJ 1278B FAX SSTV modem in Hz are 1100 1200 1300 1500 1550 1600 1650 1700 1750 1800 1850 1900 1950 2000 2050 2100 2150 2200 and 2250 The tone being transmitted determines the shade of gray in the picture The higher the tone MFJ 1278B MULTI MODE OPERATIONAL COMMANDS The PIXTONES values are in Hexidecmal format If the picture transmitted does not seem to have the right contrast try reseting the PIXTONES values The HEX values that represent the PIXTONES for the pictures to be transmitted are listed in Table below PIXTONES Values FAX SSTV In HEX TransmitTones M
294. ht characters in length Again properly tune the radio because you will immediately start transmitting packets When a station is over 40 000 Km away the LC command should be used The LC is the abbreviation for Longpath Connect To initiate a Longpath Connect sequence please type the following LC n ENTER where n is the CALLSIGN of the station you want to connect with Callsigns are not to be over 8 characters in length Again properly tune the radio because you will immediately start transmitting packets If the C command does not work the LC command might Generally if one command works the other will not Changeover In AMTOR the changeover from TX to RX command is In PACTOR the changeover command is CTRL Y i e hold down the CTRL key then press the Y key The changeover character can be re defined with the CHOCHAR command How the CHOCHAR character is re defined will discussed later When in Pactor Mailbox operations the changeover is semi automatic The remote user must issue a manual changeover CTRL Y when talking to the Pactor Mailbox The Pactor Mailbox always issues an automatic changeover when it is finished sending its information back to the remote user To terminate an ARQ contact type CTRL C then D then ENTER This will cause a graceful disconnect at the other end If you do a dirty disconnect or DD the other Station will still be trying to acknowledge your packets The use of DD automatically tears
295. ic operation along with an explanation of the commands related to PACTOR including the new Pactor Mailbox Before we talk about Basic Operation let s explain a little about PACTOR NOTE Pactor operations apply to the Model MFJ 1278B or MFJ 1278 TNC2 only The 1278 must have the MFJ 56A B or C installed to take advantage of the Pactor option What is Pactor PACTOR is a new form of digital communications PACTOR was brought about to compensate for the shortcomings in both Packet and Amtor for HF operation PACTOR combines some of the features of both the AMTOR and the HF Packet modes Pactor retains the short frame sizes and synchronous transmission format of AMTOR It also allows the data flexibility of which Packet users have grown accustomed to The radio used for PACTOR HF operations must be capable of switching between transmit and receive modes in 130 milliseconds A radio capable of operating in the AMTOR mode will operate well in the PACTOR mode as well Now that we have explained a little about PACTOR let s get into the Basic Operation PACTOR Operation The PACTOR operation section will deal mainly with PACTOR operations We will briefly explain about the different operating modes and what they will do We will explain about the new PACTOR mailbox feature and how it works There are also several operational commands that are related to Pactor operation These operational commands are explained in Chapter 6 in detail So
296. ictures received will be sent to the graphics printer attached to the printer port If PRINTGRA is OFF the MFJ 1278B will direct the picture graphics in raw data format to the user s terminal through the RS 232C port of the MFJ 1278B If your terminal program allows you to save a file to disk then you can save the picture on disk and re transmit it later Terminating SSTV Printing Printing of an SSTV picture can be terminated at any time during the printing User will type ESC then CTRL C Printing will stop and the MFJ 1278B will return to command mode Transmitting SSTV Pictures The MFJ 1278B is capable of transmitting color and up to 16 gray level B amp W SSTV To achieve this you must use a terminal program which support the multi level SSTV data format required by the MFJ 1278B Each level of gray is represented by a tone produced by the MFJ 1278B modem The 19 tones which can be produced by the MFJ 1278B FAX SSTV modem in Hz are 1100 1200 1300 1500 1550 1600 1650 1700 1750 1800 1850 1900 1950 2000 2050 2100 2150 2200 and 2250 The tone being transmitted determines the shade of gray in the picture The sync tone of MFJ 1278B MULTI MODE BASIC OPERATION The PIXTONES command defines the gray levels of the SSTV and FAX picture being transmitted by the MFJ 1278B To transmit an SSTV picture you must use a terminal program such as MFJ 1289 that supports the multi gray levels SSTV and FAX transmitting P
297. immediately This prevents digipeated packets from suffering collisions except on transmission by the originating station A special time delay RESPTIME is used as the minimum wait time prior to transmitting acknowledgment frames to prevent TNCs accepting data at high speed from the asynchronous port from colliding with acknowledgment frames when fewer than MAXFRAME packets are outstanding The receiving TNC will wait long enough before sending the ACK so that it will hear the data packet which would have caused the collision thus avoiding a fairly frequent source of delay in versions of AX 25 prior to 2 0 CHANNEL FLOW CONTROL Flow control of data through the link is determined by the rate at which data is being supplied to a sending TNC and accepted from a receiving TNC A TNC receiving data from the link will send an RNR when the next I frame successfully received will not fit into the buffer for output to the serial port Whenever a TNC transmitting data received from the serial port over the link runs out of temporary buffer space the serial port will be halted by an XOFF character or CTS signal In the MFJ 1278B implementation this happens whenever there are 7 packets built and less than 210 characters left in the buffer for input from the serial port When the TNC receiving data from the link clears out its buffers it sends an RR to the transmitting TNC In order to guard against the possibility of the RR being lost and the link be
298. in 2 amp 3 default 9600 baud ext modem clock nable 19 2K baud termial PC Disable 300 baud terminal Pin2 amp 3 Enable 300 baud termial Disable 19 2K baud terminal 19 Outside pair default Enable 32K mailbox RAM Middle pair Enable 128K mailbox RAM Inside pair Enable 512K mailbox RAM JMP20 ON default 512K mailbox RAM installed OFF 32K or 128K mailbox RAM JMP21 inl amp 2 154 KHz to multi level PCB in 2 amp 3 default 307 KHz to multi level PCB inl amp 2 nable CW Grid Block Keying in 2 amp 3 default nable CW Direct Keying Enable memory RESET FF default JMP22 tri ol Z JMP23 JMP24 in 1 amp 2 default 1 Megabit firmware EPROM Pin 2 amp 3 512K bit firmware EPROM JMP25 in 1 amp 2 default ormal Demodulator operation Fr in 2 amp 3 emodulator Bypass JMP26 in 1 amp 2 default Normal 5Vb bbRAM operation non J 7 Z MFJ 1278B MULTI MODE HARDWARE Table 8 1 Jumper Function Cont Jumper Position Function JMPB N default On board transmit low tone OFF JMPC Enable external DCD OFF default Disable external DCD JMPD NOT used JMPE N default Disable Low Tone RTTY Demod Enable Low Tone RTTY Demod JMPF ON default Disable Low Tone RTTY Demod OFF Enable Low Tone RTTY Demod ON default Disable Low Tone RTTY Mod Enable Lo
299. in error DIGISENT Each frame digipeated by the MFJ 1278B causes the counter to increase HOVRERR Increases when HDLC receiver is not serviced rapidly enough and data is lost This counter should never increment at any supported data rate HUNDRERR Increases when the HDLC transmitter is not serviced rapidly enough and frames are aborted This counter should never be non zero at any supported data rate RCVDFRMR Increases when Frame reject frames are received from a connected station RCVDIFRA Increases for each reception of an I frame from a connectee RCVDREJ Increases for each reception of an REJect frame from a connectee RCVDRNR Counts the number of AX 25 L2 receiver not ready frames received since power up and during connections The count may be useful in gauging system throughput RCVDSABM Each received SABM frame addressed to the MFJ 1278B causes this counter to be increased by one RXABORT RXABORT is a count of the number of hardware detected HDLC abort events A large number of counts is perfectly normal and should not cause concern RXCOUNT MFJ 1278B MULTI MODE OPERATIONAL COMMANDS RXERRORS Increments each time a received frame is thrown out due to it being too short suffering overrun s or it having a bad CRC Latter occurs only when CRC checking is enabled i e HGARBAGE is OFF This counter will often increment in the presence of noise RXLENERR RXLENERR counts the numb
300. in use at this time They are reserved for future use NEWMODE ON OFF Mode Packet Default OFF Parameters ON Switching to data transfer mode occurs at the time of the CONNECT command return to command mode is automatic at the time of disconnection OFF Switching to data transfer mode occurs at time of connection and no return to command mode occurs at disconnection The NEWMODE command may be used to select the way the MFJ 1278B behaves when connections are made and broken If NEWMODE is OFF the MFJ 1278B will remain in Command Mode after you issue a CONNECT command until a connection is actually established When the connection is established the MFJ 1278B will enter Converse Mode or Transparent Mode depending on the setting of CONMODE When the connection is terminated the MFJ 1278B remains in Converse or Transparent Mode unless you have forced it to return to Command Mode This is the same as the behavior of TNC 1 running version 3 x software under these conditions If NEWMODE is ON the MFJ 1278B will enter Converse Mode or Transparent Mode as 478478 ba An MFJ 1278B MULTI MODE OPERATIONAL COMMANDS NO200 ON OFF Mode Pactor Default OFF Parameters ON Inhibits 200 baud operation in Pactor mode OFF Allows 200 baud operation in Pactor mode The NO200 command controls whether 200 baud links are to be discouraged The TNC accomplishes this in two ways 1 Speedups are inhibited 2 Incoming connect requests a
301. include locations in Portsmouth Virginia Boston Miami and New Orleans station in Sydney Nova Scotia can also be received in many parts of the United States Several Navtex stations are planned or already under construction on the West coast including locations in San Francisco Astoria Oregon Adak and Kodiak Alaska Long Beach California and Honolulu The system is fully installed in Europe and is well on its way to becoming an international standard for navigational information A partial list of stations and their broadcasting time is listed in Table 4 5 below Station QTH Broadcast Time UTC o 0000 0600 1200 1800 0130 0730 1330 1930 0300 0900 1500 2100 San Juan 0415 1015 1615 2215 B 10100 0700 1300 1900 Table 4 5 Navtex Station amp Frequencies Bermuda station is not yet on line Navtex Operation Navtex is part of the Mode B FEC AMTOR mode Each Navtex transmission is prefaced by the characters ZCZC followed by a four character code of two letters that identify the station and type of message followed by a number code from 00 to 99 that identifies the narticular message This prevents vour MFET 1278B from receiving messages that have MFJ 1278B MULTI MODE BASIC OPERATION letter identifies the type of message Refer to the following explanation of the NAVMSG command for the different types of messages that are identified by this second letter The NAVMSG and NAVSTN comm
302. ing Functions Transmit Timing Amateur radio equipment varies greatly in the time delays required in switching from receive to transmit and from transmit to receive If the MFJ 1278B starts sending data before the transmitter is operating or before the receiver has had time to switch from transmitting and lock up on the incoming signal the packet will not be received properly The delay between transmitter keyup and the beginning of data transmission is controlled by the command TYNAT AV During the time the MBRI_197 amp R ic Lavina the trancmitter hut nat candina data MFJ 1278B MULTI MODE ADVANCED OPERATION 1278B will assume is required for the repeater to drop If the MFJ 1278B has detected channel activity recently enough that the repeater transmitter should still be on it will wait only the TXDELAY time before sending data rather than adding an AXDELAY time as well The commands TXDELAY AXDELAY and AXHANG set times in units of 10 ms If AXDELAY is in effect the total keyup delay will be Keyup delay TXDELAY AXDELAY 10 in milliseconds If channel activity has been heard more recently than AXHANG 10 ms ago the keyup delay will only be Keyup delay TXDELAY 10 in milliseconds Packet Timing The AX 25 protocol provides for re transmitting packets if no acknowledgment is heard from the intended destination station within a certain period of time A packet might not be acknowledged due to channel noise or collision
303. ing a signal If your radio has a bandwidth which is wide compared to the packet signal spectrum the DCD LED may not flicker at ANY setting of the threshold control when monitoring only noise In this case set the threshold control to its maximum clockwise rotation The data carrier detector will function normally when monitoring a signal in this case Tuning in a signal is relatively easy to do once you get the hang of it You must wait until the other station is sending a packet and then tune the transceiver so that the tuning indicator LED is centered If the DCD LED is not lit the tuning indicator information is NOT valid Each bar on the tuning indicator represents about 10 Hz Thus if a packet comes through and you are 4 bars off re tune your transceiver 40 Hz in the indicated direction The direction depends on the sideband you selected and the manner in which you have the tuning indicator oriented One or two tries will quickly tell you which way to go Bars to the left of center indicate you should tune higher while the other side of center means to tune lower Once you have the other station tuned in you may initiate a connect request just as you would on VHF Many BBS stations forward traffic on HF at the above frequencies Call CQ a couple KHz away from such channels If you can t raise anyone call CQ on one of the above frequencies but QSY immediately after establishing contact Be careful on 20 meters especially that you do
304. ing similar consult the documentation for your computer or terminal program to see how to enter control characters A BREAK signal is a special transmission not an ASCII character which your computer may be able to produce NOTE If lt CTRL C gt will cause your computer to do something to interfere with packet operations such as halting the terminal program and you can t send BREAK signals you will have to change the character that returns you to Command Mode See the section on Special Input Characters below Now type a lt CTRL C gt The MFJ 1278B does not echo the CTRL C but you should immediately see a Command Mode prompt return to Converse Mode enter the command CONVERS lt CTRL C gt cmd CONVERS Whatever I type in Converse Mode is transmitted Whatever I type in Converse Mode is transmitted lt CTRL C gt cmd To terminate the QSO you must end the connect by giving the DISCONNE command The MFJ 1278B will transmit packets terminating the conversation and notify you when the disconnect is complete cmd DISCONNE DISCONNECTED An actual QSO might be terminated by the other station of course In that case you would ann tha YAICA CKANINILD4 TLETY mannna v ithant harina innmind tha nnmman a MFJ 1278B MULTI MODE BASIC OPERATION Be sure to remove the jumper from JMP10 after you complete this Connecting and Disconnecting Exercise Digipeating You may wish to have a QSO with an
305. ing the special MARS ASCII equivalent characters and differs from QSO mode only because of its extra ASCII output translations Below are some of the character translations in the Mars QSO mode TX Translations 5 converted to CR CR LF or to LF only if preceding character was also CR 2 is sent as NNNN followed by 12 LTRS 2 Characters are translated as follows CR LF 12 LTRS BELL NULL FIGS LTRS Il Here are the charcater translations in Mars Storage Mode The TX translations are the same as for the QSO mode plus these RX translations CR LF BELL NULL For further information on Marsmode operations please see the MARS section in this manual MFJ 1278B MULTI MODE OPERATIONAL COMMANDS MATCH ON OFF Mode AMTOR Default ON MATCH is used for selectively monitoring portions of Mode B FEC transmissions If MATCH is ON the MFJ 1278B will not start printing a Mode B signal until the string set in MBEGIN is matched Likewise the search for the terminating string in the MEND parameter begins when the MFJ 1278B starts printing When this ending string is matched the TNC stops printing and goes back to waiting until the next MBEGIN sequence is received MAXDown nnn Mode Pactor Default 4 Parameters nnn 5 lt nnn lt 48 MAXDown controls the number of 200 baud information packets receive errors that the MFJ 1278B will tolerate prior to requesting a SPEEDdown to 100 baud MAXFR
306. ing them In thic cet dunley ta FIM T an vanr terminal ta ctan the terminal fram echaing MFJ 1278B MULTI MODE BASIC OPERATION New Lines and Line Wrapping If everything displayed appears to be double spaced your computer is adding an extra linefeed lt LF gt whenever it displays a carriage return ENTER Set AUTOLF OFF to keep the MFJ 1278B from also adding an lt LF gt If you change equipment you may have to set AUTOLF ON to restore the MFJ 1278B s automatic linefeeds The screen width parameter is set by default to 80 the width of many CRT displays The MFJ 1278B will send an extra ENTER or ENTER LF if AUTOLF is ON when 80 characters have been displayed on a line If your computer does not automatically break long lines you will need to set the screen width to the width of your display For example for a computer using a TV set for a display you would set SCREENLN 40 If your computer does automatically break long lines you should set SCREENLN 0 to disable this feature on the MFJ 1278B Otherwise you will get two ENTER s when the line wraps around A few computers will frequently lose the first characters of a line when several lines are typed in rapid succession for example in the sign on message You can give the computer more time between lines by setting ON delay after lt ENTER gt or NULF ON delay after lt LF gt The delay is adjusted by NULLS parameter The NULLS parameter s
307. interval used by the slotting procedures A delay of length random multiple of DEADTIME will be applied to the all outgoing packets that are not acknowledgmented DEADTIME must be set to a value that accounts for the slowest acceptable station on the channel It includes the time required for the remote station s radio to come on the air properly after assertion of PTT TXDelay and the time required for the local station s squelch if used and TNC DCD circuits to allow generation of a DCD true signal in the local TNC Ideally once the proper value for this timer is ascertained all stations on the channel will use the same value The current default for this parameter is a short 30 milliseconds This represents only the worst case delay for the TNC s DCD circuit and completely ignores the radio delays Most HF linear mode radios are MUCH faster than VHF FM radio A reasonable setting for HF work is 120 milliseconds DEAdtime set to 12 This should work fine with virtually any HF radio stable enough to consider using on HF packet DELAY nn Mode AMTOR Default 20 The DELAY command establishes the interval in milliseconds that the MFJ 1278B delays between keying the transmitter and transmitting AMTOR data AMTOR mode A ARQ demands a transceiver that switches from receive to transmit and back to receive quickly Some rigs are faster than others When you install the MFJ 1278B for the first time on a particular radio it s a good idea
308. ion ic heat nn frannanow the ceannart MFJ 1278B MULTI MODE BASIC OPERATION in idle mode If you can hear both sides you can hear the alternate chirps as they are in sync with each other If you operate Mode B or Mode S then you should have no problems with AMTOR These are the broadcast modes and are almost identical to teletype in the way you make contacts The whole purpose behind Mode B FEC is making the initial contact After you make a contact you should arrange with your contact to move off the calling frequency to a working frequency Moving off the calling frequency is proper etiquette so that way others can then use the calling frequency for the same purpose Mode B allows you to make a blanket broadcast to all stations within range Think about teletype and you ve got the right idea One side talks and the other listens and then the stations change sides To the ear mode B sounds almost identical to teletype Type FEC to enter Mode B transmit and K to enter converse mode It works like teletype because you transmit 100 of the time while keyed up Mode S is almost identical to mode B with the exception that it allows several stations to link in a round robin type of network between stations Mode B and Mode S are not necessarily error free since there is no acknowledgement from the receiving station Mode A ARQ mode is the mode used by most amateurs and is sent with no errors once a link is made between statio
309. ions there are on the channel during busy periods SOLF ON OFF Mode AMTOR Default ON SOLF determines whether only LINEFEED characters from the AMTOR receiver are sensed as newline characters If SOLF is OFF then carriage return and linefeed characters are passed directly through to the terminal otherwise every received linefeed character will generate a lt CR gt lt LF gt newline sequence MFJ 1278B MULTI MODE OPERATIONAL COMMANDS SRXALL ON OFF Mode AMTOR Default ON The MFJ 1278B will print all receivable mode S transmissions when SRXALL is on Taking advantage of the ability to receive an addressed mode S transmission requires SRXALL ON and a match between the address being sent and your MYSELCAL If SRXALL is OFF and MYSELCAL does not match the address in the received mode S transmission the MFJ 1278B ignores the transmission START n Mode Default 11 Parameters n 0 7F specifying an ASCII character code The START command selects the User Restart character that is used to restart the output from the MFJ 1278B to the terminal after it has been halted by typing the User Stop character You can enter the code in either hex or decimal The User Stop character is set by the STOP command If the User Restart and User Stop characters are set to 00 software flow control to the MFJ 1278B is disabled and the MFJ 1278B will only respond to hardware flow control CTS If the same character is used for both the User
310. is similar to the CCITT V 23 standard Any other hardware device that is compatible with the Bell 202 standard should be compatible with the MFJ 1278 at least at level one of the ISO reference model Data Link Layer The duty of the Data Link layer is to supply an error free stream of data to higher levels Since level one simply passes any bits received to level two and is unaware of the content or overlying structure of the data transmission errors are not detectable at level one Level two carries the responsibility of detecting and rejecting bad data re transmitting rejected data MFJ 1278B MULTI MODE PACKET RADIO PROTOCOL Level two accomplishes this task by partitioning data to be transferred by level one into individual frames each with its own error detection field and frame identification fields The MFJ 1278B supports two versions of a level two layer AX 25 version 1 0 and AX 25 version 2 0 Each of these protocols is based on the High Level Data Link Control HDLC protocol defined by the ISO HDLC FRAMES Exact knowledge of the format of HDLC frames is unnecessary by the advent of LSI and VLSI communication chips that interface directly with level one hardware The level two software need only supply data to fill in various fields and the chip takes care of the rest For completeness however an HDLC frame looks like this FLAG ADDRESS CONTROL PID amp DATA FCS FLAG FLAG HDLC uses a unique bit sequence 0
311. isconnect due to the retry count being exceeded an automatic time out disconnect CHECK or a protocol error MFJ 1278B MULTI MODE SYSTEM MESSAGES CONNECTED to calli VIA call2 call3 call9 This message appears when the MFJ 1278B goes from the disconnected or connect in progress state to the connected state The connection may be a result of CONNECT command you issued or of a connect request packet received from another station connect request call1 VIA call2 call3 call9 This message indicates that the MFJ 1278B has received a connect request from another station which it has not accepted This can happen if you have set CONOK OFF or if you are already connected to another station When the MFJ 1278B types this message it also sends a DM packet busy signal to the station that initiated the connect request If the MFJ 1278B rejects a connect request because you have set CONOK OFF you can issue your own request to the station that called DISCONNECTED This message is displayed whenever the MFJ 1278B goes to the disconnected state from any other link state This message may be preceded by a message explaining the reason for the disconnect below retry count exceeded DISCONNECTED This message is given if the disconnect was caused by a retry failure rather than by a disconnect request from one of the stations lt callsign gt busy DISCONNECTED This message indicates that yo
312. ith software that will run on a monochrome graphics system such as MFJCOM by MFJ Enterprises Inc The advanced terminal program MFJ MultiCom does not perform 2 level FAX operations Enter the FAX mode by using the MODE command Type MODE FX lt ENTER gt MFJ 1278B MULTI MODE BASIC OPERATION The FAX format is changeable by using the FAXMODE command The MFJ 1278B supports receive or transmit of all FAX formats listed in Table 4 6 in both transmit and receive In 2 level FAX pictures saved under one format may NOT be transmitted under a different format For instance you can NOT receive and save a FAX picture under FAX format 3 then re transmit it under FAX format 2 or another FAX format as listed in Table 4 6 After entering the FAX mode and selecting the desired FAX format to transmit enter the CONVERSE mode by typing K followed by typing a CTRL T The MFJ 1278B is now ready to transmit a picture and respond with Send PIX Now In FAX transmit mode MFJ 1278B will not key the transmitter until it has been given around 1 500 characters of FAX graphics User should follow the normal File Upload procedure given by the terminal program In 2 levels FAX when the MFJ 1278B keys the transmitter it sends 6 ASPECT 1 rows of synchronization pulses before starting to transmit the picture The MFJ 1278B determines that it is finished transmitting by looking at its input buffer If the buffer is empty the transmission is
313. ive may contain up to 26 letters each representing a station For example if you want to receive only stations A C and P then you type NAVSTN ACP Only signals from these three stations will be received by your MFJ 1278B If you want to prevent certain stations from being received leave then off the list Then those stations will not be received while others within the receiving area will Eruca 2222 21 2 4 2 RT ATOR AW 21 Y C 44 3 L4 L4 A MFJ 1278B MULTI MODE BASIC OPERATION The types of Navtex messages currently are Navigational warnings Storm Warnings Reports of Ice Search Rescue Information Weather forecasts Pilot Service Messages DECCA System LORAN C Omega Systems SATNAV Systems gt K thru Z are not in use at this time They are reserved for future use To exit the NAVTEX mode issue a CTRL C to obtain the n cmd command prompt After the n cmd prompt is received from the MFJ 1278B type NAVTEX OFF ENTER The MFJ 1278B will return to the cmd command mode You can issue another Control to return to the cmd command prompt for non amtor operation You also have the alternative to stay in the Amtor mode and do some Amtor operations NAVTEX commands are explained in the COMMANDS chapter in this instruction manual MFJ 1278B MULTI MODE BASIC OPERATION FAX OPERATION The MFJ 1278B provides an independent multi gray level modem to tr
314. k detect signal is indicated by the Data Carrier Detect DCD LED Each time DCD goes off the MFJ 1278B will start DWAIT interval which must elapse before the channel is considered to be available On a noisy channel spurious lock detect signals may be generated For HF and OSCAR operation you should set DWAIT to 0 The random wait before retry transmissions can be disabled by setting TXDELAY 0 and using AXDELAY to set the required keyup delay Of course AXHANG should be 0 for this application If you are operating a full duplex radio station simultaneous transmit and receive such as an OSCAR 10 station you should set FULLDUP ON The MFJ 1278B is always electrically capable of full duplex operation but this parameter causes the protocol to behave differently in acknowledging packets In addition the MFJ 1278B will ignore the state of the DCD line Although intuition tells you that lower baud rates will reduce the number of packet retries there is usually a small range between too fast and too slow slower packet takes longer to transmit and is therefore a larger target for fades and static crashes The entire packet must be received correctly in order to be accepted Data rates of 1200 baud have been used on both HF and through OSCAR 10 HF activity may generally be found on 7 090 to 7 106 or 14 090 to 14 107 MHz Use LSB or USB it really does not matter although most stations use LSB when referring to the suppressed carrier frequen
315. l This is basically the same as the You have mail message but this indicates that new mail has been added to the mailbox since the last time it was accessed This message occurs when a command issued to the Easy Mail mailbox is not understood This could be an out of range slot number missing slot number where one is required or bad command Cannot not yours This message occurs when a remote user attempts to kill or read a message that is not his or he tries to read personal message by or for someone else Mailbox full This message occurs when either all of the available slots are full or the actual message space is full Messages must be killed to recover from this error Not found This message occurs when one attempts to read or kill a non existent message from an empty slot None found A parameterless Kill or Read command did not find any messages addressed to the user No mail A parameterless read command did not find any mail addressed to user or due to mailbox being empty MFJ 1278B MULTI MODE ADVANCED OPERATION Slotting and Acknowledgment Priority The addition of the SLOTTING AND ACKNOWLEDGMENT PRIORITY feature makes the MFJ 1278B more efficient on packet frequency channels The MFJ 1278B achieves this greater efficiency by preventing or minimizing packet collisions on busy packet channels Use of the optional SLOTTING and ACKNOWLEDGMENT PRIORITY routine now in the MFJ 1278B firmware significantly imp
316. l by your QSO In fact your friend could issue this connect request cmd CONNECT WBOQRP VIA K5FLU and you can carry on two separate conversations completely independently Monitor the radio transmit indicators and listen to the speaker audio See if you can follow the packets and the acknowledgments back and forth MFJ 1278B MULTI MODE BASIC OPERATION Monitoring on the Air This is a good time to try out the MFJ 1278B s monitor functions While you and your friend are separately connected type lt CTRL C gt cmd MONITOR ON cmd MCON ON cmd CONVERS You will be able to see both your conversation and your friend s conversation Also try HEADERLN ON and MHEARD Special Input Characters The MFJ 1278B has a number of special characters that can be used to control its actions Many of these special characters can be used to edit commands and packet text as they are entered These features can all be customized to suit you and your computer Most of the special input characters we will describe are active in both Command Mode and Converse Mode the exceptions will be noted The character used to return to Command Mode from Converse Mode is by default a lt CTRL C gt Sending a BREAK signal also works This character does nothing in Command Mode so if you accidentally enter it twice you will not mess up the next command line You can change the Command Mode entry character with the command COMMAND This is one of seve
317. lay that occurs whenever any packets have been received by the MFJ 1278B that are not addressed to the MFJ 1278B ACKTIME should be calculated by the radio channel baud rate and by the keyup and keydown TXDELAY and fixed timer in TNC delays It should reflect the time it takes for an acknowledging TNC on the channel to keyup send it s acknowledgement and release the PTT This represents the time required to send a response frame with no I field appended at the baud rate being used on the radio port The current 140 millisecond default is close but should be adjusted for 1200 baud work to 130 milliseconds ACKTime set to 13 For 300 baud HF work this parameter should be set to 520 milliseconds ACKTime set to 52 ALOCKCHAR nn Mode CW MCW Default 15 This command controls which character is used to force the MFJ 1278B to lock its CW receive speed to the incoming receive signal See CW operating instructions for more detail information when using ALOCKCHAR Control U is the default value for the ALOCKCHAR command MFJ 1278B MULTI MODE OPERATIONAL COMMANDS ALTCALL 5555 Mode AMTOR Default blank Parameter ssss Designates a four letter SELCALL for use in Mode A Amtor The SELCALL used in the ALTCALL command is the alternate SELCALL for Mode Amtor operations ALTCALL is used to set up an alternate SELCALL that the MFJ 1278B responds to in mode A Whether the MFJ 1278B uses this SELCALL or not depends on the setting of the
318. ld attempt to tune for the center of the range where the DCD flashes with the incoming CW tone Once tuned to that spot the THRESHOLD control setting should be reduced counter clockwise to a point just above where the DCD LED stops flashing with the incoming CW tone The adjustment of the THRESHOLD control is critical and must be based upon your judgment of best copy Once the optimum setting is found it can be pre set and all remaining tuning done with the receiver frequency control The MFJ 1278B will automatically LOCK and TRACK the speed of the signal once proper tuning of the signal has been established The automatic LOCK and speed TRACKING MFJ 1278B MULTI MODE BASIC OPERATION If the AUTOTRAC command is OFF then before the MFJ 1278B can copy the tuned in CW signal it must be manually locked to the speed of the received signal To manually lock the MFJ 1278B to the incoming signal type a CTRL U The MFJ 1278B will respond with locking The MFJ 1278B will analyze the incoming CW signal When the analysis of the incoming CW signal is complete the MEJ 1278B will respond with Locking xxwpm The xx is the speed of the received CW speed from 1 thru 99 When the MFJ 1278B issues the response Lockingxxwpm there will be CW copy on your computer screen You shouldn t have to re lock unless the station you re listening to changes its CW sending speed Transmitting CW The MFJ 1278B will transmit International Morse code from 5 to
319. led MAILBOX Being as the MAILBOX command in your MFJ 1278B is already turned ON makes your Mailbox ready for use as soon as your MFJ 1278B is powered on Anyone who operates AX 25 packet can access your mailbox by establishing a connection to your station by using the standard packet CONNECT command Once the connection is made he can send a message obtain a list of the messages in your mailbox read the messages or kill any messages addressed to him The Easy Mail mailbox in the MFJ 1278B provides approximately 32K bytes of memory in additional to the 32K of system RAM for message storage However you increase the mailbox memory on your MFJ 1278B to 128K or even an enormous 512K by simply replace the mailbox RAM chip on the MFJ 1278B motherboard This additional memory is also battery back up by the lithium battery on the MFJ 1278B mother board Addition memory chip can be purchased separately from MFJ Enterprises Inc and it can be easily installed by the user inside the MFJ 1278B Order MFJ 45B for 128K RAM IC or MFJ 45C for 512K RAM IC The number of slots and space available for each memory size are as follows of Slots Bytes Avail 32 000 128K 99 per Bank 128 000 512K 99 per Bank 512 000 MFJ 1278B MULTI MODE ADVANCED OPERATION Setting Up your Easy Mail Mailbox The Easy Mail Mailbox can now be operated independently from the standard packet operation There are certain commands which need to be set These will be
320. ledge of general communications hardware and software Persons already well versed in networking may want to skip this chapter and refer to the primary defining document Amateur Packet Radio Link Layer Protocol AX 25 Version 2 0 available from the ARRL 225 Main Street Newington CT 06111 8 00 US postpaid in the United States as of this writing Organization of the MFJ 1278B hardware and software structure is according to the International Standards Organization layered network model The ISO model sometimes refered to as the ISO Reference Model of Open Systems Interconnection describes the seven protocol levels The model and many other interesting topics are discussed in Computer Networks by Andrew S Tanenbaum The ISO model provides for layered processes each supplying a set of services to a higher level process The MFJ 1278B currently implements the first two layers the Physical layer and the Data Link layer Physical Layer The duty of the Physical Layer layer one is to provide for the transmission and reception of data at the bit level The only concern of the Physical Layer is how each bit is physically transmitted i e voltages on a hardwire line modem tones on a telephone line or RF links Chapter 7 Hardware gives a description on the physical layer in the MFJ 1278B It is compatible with the various TNCs currently available to radio Amateurs The actual modem interface is compatible with the Bell 202 standard that
321. ll data are 7 bit ASCII characters and b Huffman coding is at least as efficient as straight 8 bit coding FLOW CONTROL Flow control Hardware flow control is always on Software flow control defaults to on using the XON and XOFF parameters Unlike TNC operations the same characters are used for receive flow control as for transmit flow control Type in flow control is only effective while entering commands at the p cmd prompt MFJ 1278B MULTI MODE BASIC OPERATION AMTOR selective callsign in the a_cmd MYSELCAL parameter Furthermore you must have the appropriate sideband usually LSB selected because unlike PACTOR AMTOR is polarity dependent Amtor Detection in Pactor The MFJ 1278B s Pactor continuously monitors the channel for Pactor packets and for AMTOR call packets that match yur AMTOR SELCALL When PACTOR hears your AMTOR SELCALL the TNC enters the a cmd AMTOR mode in an attempt to complete the link After entry into the AMTOR mode the MFJ 1278B will automatically return to Pactor mode if the link is not established within 30 seconds If the link is established the MFJ 1278B remains in AMTOR mode for the duration of the contact and for an additional 30 seconds after the link terminates PACTOR STATUS INDICATORS While in the PACTOR mode of operation you have PACTOR mode Status Indicators avialable to you These Status Indicators are comprised of the CON and STA leds These leds react in different ways according
322. ll2 call3 call9 This display shows the station your MFJ 1278B is connected to and the digipeater route if any The callsign sequence is the same sequence you would enter to initiate the connection Link state is DISCONNECTED No connection currently exists You may issue the CONNECT command to initiate a connection Link state is CONNECT in progress You have issued a connect request but the acknowledgment from the other station has not been received If you issue a DISCONNE command the connect process will be aborted Link state is DISCONNECT in progress You have issued a disconnect request but the acknowledgment from the other station has not been received If you issue a second DISCONNE command the MFJ 1278B will go immediately to the disconnected state Link state is FRMR in progress The MFJ 1278B is connected but a protocol error has occurred This should never happen when two TAPR TNCs are connected An improper implementation of the AX 25 protocol could cause this state to be entered The MFJ 1278B will attempt to re synchronize frame numbers with the TNC on the other end although a disconnect may result Connects are not legal in this state and a disconnect will start the disconnect process The MFJ 1278B will inform you whenever the link status changes The link status may change in response to a command you give the MFJ 1278B CONNECT or DISCONNE a connect or disconnect request packet from another station a d
323. lly transmit a packet when the number of input bytes for a packet reaches n This value is used in both Converse and Transparent Modes If you perform file transfers you should experiment with both MAXFRAME and PACLEN If the link is good there is an optimum relationship between the parameters set by these commands so that the maximum number of characters outstanding does not exceed the packet receive buffer space of the MFJ 1278B receiving the data NOTE Although there is no requirement for two TNCs exchanging data to have the same PACLEN value allowing more than 128 characters of data in a packet may be incompatible with some varieties of TNCs PACTIME EVERYIAFTER n Mode Packet Default AFTER 10 Parameters n 0 250 specifying 100 ms intervals EVERY Packet timeout occurs every n 100 milliseconds AFTER Packet timeout occurs when n 100 milliseconds elapse with no input from the computer or terminal MFJ 1278B MULTI MODE OPERATIONAL COMMANDS Parameters n 0 3 selecting a parity option from the table below This command sets the word parity mode for the terminal or computer data transfer according to the following table 0 noparity odd parity 1 The parity bit if present is automatically stripped on input and not checked in Command Mode and Converse Mode In Transparent Mode all eight bits including parity if any are transmitted in packets If no parity is set and AWLEN is 7 the eighth bit will be
324. low is a typical example as to how to use the FO command FO CALLSIGN CR Where CALLSIGN is the callsign of the destination mailbox This callsign must also reside in header of the message to be forwarded The message header can be altered through the Mailbox Edit command Please refer to the EDIT command in this manual When the FO CALLSIGN is issued the MFJ 1278B will initiate a connect request to the destination BBS If the connection is successful the your mailbox will proceed to send the message to the destination BBS Eliciting Reverse Forwards This very unique feature when combined with the hourly automatic forward enables the mailbox to query another BBS regularly and automatically for the purpose of polling the other BBS for the TNC user s mail Thus even if your local full service BBS operator is unwilling to forward to you you can still have most of the benefits of auto forwarding because your own TNC will elicit your mail for you on an hourly basis Reverse forwards may be restricted to a particular callsign This prevents others users from stripping messages off of the mailbox prior to their being forwarded to the legitimate destination When all messages are forwarded if the destination mailbox supports reverse forwarding as determined by in it s SID then the MFJ 1278B will attempt to elicit a reverse forward Remote Heard Log This handy feature allows the remote user to query the TNC heard log at any
325. ls gray The new RXBright values are as follows OTVB 80 46 47 48 4C 4F 52 54 59 5C 5E 60 63 67 69 1TVB 80 48 4A 4C 4E 50 52 54 56 58 5A 5C 5E 60 62 2TVB 80 49 4B 4D 4F 5 1 53 55 57 59 5B 5D 5F 6 1 63 3TVB 80 4A 4C 4E 50 52 54 56 58 5A 5C 5E 60 62 64 4TVB 80 4B 4D 4F 5 1 53 55 57 59 5B 5D 5F 61 63 65 S5TVB 80 4C 4E 50 52 54 56 58 5A 5C 5E 60 62 64 66 6TVB 80 4E 50 52 54 56 58 5A 5C 5E 60 62 64 66 68 7TVB 80 4F 5 1 53 55 57 59 5B 5D 5F 61 63 65 67 69 8TVB 80 50 52 54 56 58 5A 5C 5E 60 62 64 66 68 56A 9TVB 80 5 1 53 55 57 59 5B 5D 5F 6 1 63 65 67 69 6B The default RXBright value is 4 Remember that the higher RXBright value from 1 9 the brighter the received picture will be If your terminal program does not support 16 gray levels remember to set the command 8 Levels on and 16 Levels off The MFJ 1278B will automatically select 8 TVBreak values In SSTV transmitting the PIXtones command has been update to 16 levels The default Pixtones values are as follows PIXtones is arranged in the format White gray Black area area area aa bb cc dd ee ff gg hh ii jj kk mm ss Tha Can in tha Geman ern Than MFJ 1278B MULTI MODE BASIC OPERATION Pixtones command serves the same function as the TVBreak command but in transmitting of SSTV and FAX pictures Printing SST
326. lt When LCSTREAM is ON the character immediately following the streamswitch character is converted to upper case before being acted upon Thus the case upper or lower becomes insignificant Use of LCSTREAM is useful if you are typing in lower case and don t want to be bothered with remembering to switch to upper case when changing streams LEdmode 0 1 Mode Pactor Default 1 The LEdmode parameter controls whether the MFJ 1278B flashed it s LEDs radidly for each cycle a 200 baud packet is sent received or expected The user may find the flashing of benefit in evaluating link quality It is also an indication that the high throughput 200 baud mode is active Also see the NO200 parameter LFadd ON OFF Mode Pactor Default OFF When LFADD is ON and PACTOR mode is selected the MFJ 1278B will append an ASCII line feed character OA to the transmission immediately after a carriage return is sent LFADD should usually be switched to the OFF as a vast majority of data controllers including the MFJ 1278B are configured to automatically go to a new line whenever a carriage return is printed Also see AUTOLF command MFJ 1278B MULTI MODE OPERATIONAL COMMANDS LFADD ONIOFF Mode ASCII Packet Default OFF When LFADD is ON and the ASCII or Packet mode is selected MFJ 1278 will append an ASCII line feed character 0A to the transmission immediately after a carriage return is sent LFADD should usually be switched OFF as the vast majori
327. lter centering The following discussion assumes that your radio has provision for IF shift To center your radio passband over the modem use the following procedure 1 Set your radio for maximum RF gain 2 Setthe radio for lower sideband operation 3 sure the MFJ 1278B is in HF Packet mode and that the HF Packet modem has been selected 4 Setthe audio output level so that the tuning indicator is responding to the background noise coming through the filter This can be verified by observing whether or not the tuning indicator follows the noise as the IF shift control is rotated 5 Tune to a frequency which has ABSOLUTELY NO signals in the passband It is very important that only noise is coming through the filter If you have access to a RX noise bridge an alternative is to use the bridge as a noise source for the receiver No antenna is required in this case 6 Adjust the IF shift control on the radio so that the tuning indicator on the MEJ 1278B is centered in its display area 7 Adjust the DCD threshold control on the front panel of the MFJ 1278B so that the DCD LED is flickering with false DCD indications Make the adjustment so that the DCD duty cycle is more than 10 but less than 50 percent MFJ 1278B MULTI MODE ADVANCED OPERATION If your radio has no provision for IF shift you will have to determine the center frequency of the audio which is passed through the filter and realign the modem to the center fr
328. ly available Terminal Node Controllers TNC for use on HF packet have data carrier detect DCD circuits which are of limited use or no use at all on a HF packet channel This further degrades the effectiveness of CSMA The DCD circuit in the MFJ 1278B has been optimized for the HF packet mode It can be adjusted to ignore background noise while still being able to promptly respond to a valid data carrier It has a hang time feature that prevents DCD dropouts when short multipath hits occur or collisions put phase discontinuities in the received data carrier Thus most multipath conditions will not cause the MFJ 1278B to begin transmitting before the other station is in a listening mode The DCD hang time also prevents the MFJ 1278B from piling on a collision between 2 other stations on the channel The DCD circuit in the MFJ 1278B is NOT affected by the fact that there is a large amplitude difference between different signals on the same channel ih it will not allow you to collide with a relatively weak station Seta eee tees nS Sed Sa Rees See ee a MFJ 1278B MULTI MODE ADVANCED OPERATION 5 Many of the stations on HF packet have no tuning indicator at all and many others have an indicator that is only marginally useful Unlike VHF FM operation frequency error between transmitter and receiver cause frequency errors in the modem tones This is the reason that a good tuning indicator is ab
329. m This pin is normally jumpered to pin 17 when the on board modem is used Pin 19 Transmit Data Output This line is the NRZ or NRZI depending on the state of JMP11 data output This pin is normally jumpered to pin 20 when the on board modem is used Pin 20 Transmit Data Input This input line accepts data to be be transmitted by the modem This pin is normally jumpered to pin 19 when the on board modem is used If you elect to use an off board modem be sure to properly shield the interconnecting cables for RFI protection HF TUNING INDICATOR The MFJ 1278B has a built in tuning indicator for HF operation It is set for a center MFJ 1278B MULTI MODE TROUBLESHOOTING TROUBLESHOOTING WARNING Never remove or insert an IC with power on Your MFJ 1278B is a very complex piece of electronic equipment Servicing must be approached in a logical manner The best preparation for troubleshooting is to study the detailed hardware description in Chapter 7 While it is not possible to present all possible problems symptoms and probable cures this section of the manual will give you direction to troubleshooting based on our experiences In order to troubleshoot the MFJ 1278B in a logical manner a few things must be kept in mind 1 Always perform any troubleshooting work in a clean work area 2 NEVER REMOVE any parts including ICs from the MFJ 1278B with the power switch in the ON position Damage to the MFJ 1278B will be the
330. may include an optional sub station ID specified as n immediately following the callsign The digipeat fields are specified in the order in which you want them to relay the packets to the destination call1 CONNECT is an immediate command It initiates a connect request to MFJ 1278B calll optionally through digipeaters If NEWMODE is ON the MFJ 1278B will immediately enter Converse Mode or Transparent Mode as specified by the command CONMODE If NEWMODE is OFF the MFJ 1278B will enter Converse Mode or Transparent Mode when the connection is successfully completed An error message is returned if the MFJ 1278B is in a connected state or is already attempting to connect or disconnect If no response to the connect request occurs after the number of attempts specified by RETRY the command is aborted and a message is typed The MFJ 1278B returns to Command Mode if NEWMODE is ON If NEWMODE is OFF the mode does not change i e the MFJ 1278B remains in Command Mode For example to connect to WA7GXD using NOADI 1 who is near your QTH and WDOETZ who is near GXD s QTH as digipeaters you would type CONNECT WA7GXD VIA NOADI 1 WDOETZ Packets coming back from WA7GXD access the digipeaters in the opposite order Thus packets from WA7GXD will first be repeated by WDOETZ then by NOADI 1 MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CONOK ON OFF Mode Packet Default ON Parameters ON Connect requests from other TNCs will be accepted OF
331. md prompt you can go to any other mode by use of the MODE command as discussed earlier in this instruction Operating Hints Threshold Control Setting Adjustment of the Threshold control on the MFJ 1278B is critical during PACTOR operations Adjust the Threshold control until the DCD lights with each received packet and goes out when not receiving If the threshold control is improperly adjust communications will not be good This could result in the inability to make a contact or monitor a PACTOR conversation TXDELAY TXD Timing in PACTOR is more critical than any other mode This is where the TXDELAY or TXD command comes into play The TXDELAY command is one of the more critical parameters If you are having problems connecting try adjusting TXD a little higher than the default value of 2 This is especially good practice on the lower frequency bands such as 80 meters A typical setting for 80 meters may be 4 or 6 The setting of TXDELAY is also dependent on the time required for the radio to switch between transmit and receive NO200 If you turn the parameter NO200 to ON the MFJ 1278B will stay in 100 baud For noisy band conditions setting NO200 to ON may get your data through quicker This is because if the controller switches to 200 baud you may have more retries on a noisy channel It s better to MFJ 1278B MULTI MODE BASIC OPERATION As indicated in the preceding paragraph the usual terminal radio modem parms are availa
332. message to gets his mail From The callsign of the person who originated the message is placed here Type The Type of message you are sending is placed here This will turn on a flag in the first flag box There are a few message types and here are a couple listed below T messages These NTS National Traffic System type messages This message system was developed by the ARRL These messages must be formatted in a certain way Please refer to the ARRL Net Directory for more Aataila A eiae and infanmntinan an thin mannna cote MFJ 1278B MULTI MODE ADVANCED OPERATION Flag The message Flag is now very important of flags can be set via the S send or E edit commands This flag will either be an N or a Y This will appear in the flag block closest to To block in the message header There are different types of flags are as follows N Messages with this flag set are all able to forwarded providing all other criteria is met for a message to be forwardable Only messages with the N flag set trigger the You have new mail message T The T flag indicates that the message is an NTS message Y Messages with the Y flag set are eligible to be killed by the K global kill command F This flag is set when a message is forwarded Messages which are eligible to forwarded are 1 Messages where the N flag is set 2 Messages that have no addresses that are different from MYMcall P Messages with this
333. ming data will be prefixed with the current STREAMSWitch character and identifier such as IA Thus truly transparent operation is not possible with this software release supporting multiple connections The STREAMSWitch character defaulted to I should be set to a character you won t normally use Note that this character may be set to a hex value between 0 and FF This may allow you to use 8 bit characters AWLEN 8 if your terminal or computer is capable of generating such characters This could help prevent confusion in interpreting incoming data from other stations if they happen to send data that includes your selected STREAMSWitch character Although not fool proof enablinn STREAMDBL may also help in sorting out STREAMSWitch characters included in the received data from a valid stream switch generated by the MFJ 1278B MFJ 1278B MULTI MODE ADVANCED OPERATION If all this seems a bit confusing don t worry itis The only way to really understand multiple connect operation is to try it Tested and on the air Once you have gained confidence in normal packet operation try setting USERS 2 and get a couple of friends to connect to you Play with the commands you can t hurt the MFJ 1278B by issuing commands to it and see their effects Easy Mail Mailbox The Easy Mail mailbox feature is only valid for the HF and VHF packet mode The operation of the Easy Mail mailbox is quite simple There is a command in the MFJ 1278B cal
334. mitter and return the MFJ 1278B to standby receive FIRMRNR ON OFF Mode Packet Default OFF FIRMRNR controls the handling of busy states by the MFJ 1278B Setting FIRMRNR ON improves channel efficiency but is incompatible with earlier TNC 2 releases The incompatibility is a result of vague protocol specifications FIRMRNR should be always be set ON when conversing with network nodes for example NET ROM In other cases it is recommended that FIRMRNR be left OFF unless you can be assured the other TNC you are connected to supports FIRMRNR MFJ 1278B MULTI MODE OPERATIONAL COMMANDS FLOW ON OFF Mode Packet Default ON Parameters ON Type in flow control is active OFF Type in flow control is disabled When type in flow control is enabled any character entered from the terminal will halt output to the terminal until 1 a packet is forced in Converse Mode 2 a line is completed in Command Mode 3 the packet length is exceeded or 3 the terminal output buffer fills up Canceling the current command or packet or typing the redisplay line character will also cause output to resume Type in flow control is not used in Transparent Mode Setting FLOW ON will keep received data from interfering with data entry If you and the person you are talking to wait for a packet from the other end before starting to respond you can set FLOW OFF Some Bulletin Board programs may work best with FLOW OFF Some computers with software UA
335. mmunications MFJ 1278B MULTI MODE INTRODUCTION Items supplied with MFJ 1278B MFJ 1278BT package 1 One MFJ 1278B or MFJ 1278BT Multi Mode Data Controller 2 One AC adapter power supply for 110V AC 240V AC adapter supplied for MFJ 1278BX export model for country which operate on 220 240V AC 3 Two open end radio port cables with 5 pin DIN male connectors 4 One 10 pin connector for the TTL port 5 One MFJ 1278B Instruction Manual 6 One MFJ 1278B Fast Start Manual There are many additional items available for the MFJ 1278B In the table below is a list of these items Optional items available for the MFJ 1278B Description MFJ 1278B MULTI MODE COMPUTER INTERFACING COMPUTER INTERFACING You are now ready to connect your MFJ 1278B to your station s computer or terminal Throughout this manual we will use the term computer to refer to the computer or terminal you use to communicate with your MFJ 1278B The MFJ 1278B communicates with your computer through a serial port using signals corresponding to a standard called RS 232C Why an RS 232C interface Nearly every computer in production today either incorporates an RS 232C style serial port as a standard feature or has one available as an optional accessory either from the computer manufacturer or from a manufacturer of computer accessories In addition to the RS 232C port the MFJ 1278B has a built in TTL port to allow interfacing with compute
336. mode the radio will start transmitting immediately To initiate 100 baud FEC please type the following from the p cmd prompt U1 ENTER The cursor will go to the next line At this point start typing whatever you want You normally issue your CQ s in FEC mode Someone will see your FEC mode CQ s and probably try to connect with you To terminate an unproto session type CTRL C followed by the letter D and the ENTER key This is done after sending CQ or when terminating a Pactor contact If the standard D command does not work then use the DD command to terminate the unproto session The situations in which the two FEC modes are different Generally the U1 or 100 Baud FEC mode is for use in normal HF band conditions while the U2 or 200 Baud FEC mode is for use in clear HF band conditions Your transmitter must be capable of transmitting 10096 duty cycle Because when transmitting PACTOR FEC you are ALWAYS transmitting a signal just like RTTY MFJ 1278B MULTI MODE BASIC OPERATION PACTOR ARQ For ARQ operation you will need to know the other person s callsign Normally you can get the other person s call by monitoring the channel for connect requests or other ARQ contacts To establish contact with another station you must be at the p cmd prompt To initiate a connect sequence please type the following Cn lt ENTER gt where n is the CALLSIGN of the station you want to connect with The callsign is not to be over eig
337. modem for the selected mode using the modem as listed in Table 4 1 Most of the time there is no need to alter the baud rate settings because the default settings are sufficient So to specify HF RTTY operation at the default baud rate of 45 baud and using the default narrow shift modem for example you would type MODE HB ENTER The user can alter any of the three parameters without having any effect on the other two We can change the operational mode to HF RTTY at 110 baud just by adding the number 110 on the end of the MODE command entry You would do this by entering the following command MODE HB 110 ENTER Similarly to select the wide shift modem without changing either the operating mode or the baud rate you would type MODE HB 110 V ENTER MFJ 1278B MULTI MODE BASIC OPERATION On the CW MCW and Memory Keyer operation modes instead of selecting a baud rate you will select CW sending speed by entering a number from 5 thru 99 If you do not select a speed the MFJ 1278B will use the last speed selected The default value is 20 WPM MODE OPERATION DEFAULT SELECTABLE DE MODE BAUD RATE BAUDRATE SPEED FORMAT VP 300 1200 2400 9600 HP 300 PT Pactor 100 200 B 45 50 57 75 100 110 150 200 300 45 50 57 75 100 110 150 200 300 A 45 50 57 75 100 110 150 200 300 45 50 57 75 100 110 150 200 300 100 5 WPM thru 99 WPM 5 WPM thru 99 WPM 60 90 120 180 240 360 480 LPM F
338. mpers from JMP16 pins 1 and 2 and pins 3 and 4 Place these jumpers on JMP16 pins 1 and 3 and pins 2 and 4 The jumpers on JMP16 will now be positioned horizontally if the leds on the MFJ 1278 are facing you This completes the CW modem alignment procedure MFJ 1278B MULTI MODE APPENDIX C AUDIO OUTPUT AUDIO OUTPUT CALIBRATION The transmit audio output levels of MFJ 1278B Radio Port 1 and Radio Port 2 both are factory set to 250 mV You may find it necessary to set the output levels differently to match your radio specifications then you should follow the procedure given in this appendix Note that the user can set the audio levels of both Radio Ports independently Adjust R157 for Radio Port 1 and R158 for Radio Port 2 Both controls are accessible on the left side of the MFJ 1278B There are two access holes located on the left rear side of the MFJ 1278B It is not necessary to remove the cover to make the output level adjustments In most cases the user can set the audio output level of the MFJ 1278B by simply monitoring the transmitted audio with a connecting station However if you require a more precise audio output level setting then use the procedure given here Audio Output Level Adjustment Procedure 1 After the cmd prompt sign set MEJ 1278B to VHF packet mode by typing MODE VP CR 2 Verify that you have the MFJ 1278B connected to Radio Port 1 by typing RADIO 1 CR 3 Enter the following command to
339. n This character must be entered before a disconnect can be issued from either FEC calling mode or to issue a disconnect from a connected state The default character for the CMDCHR command is a lt CTRL C gt MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CMDTIME n Mode Packet Default 1 Parameters n 0 250 specifying Transparent Mode timeout value in 1 second intervals If n is Zero the only exit from Transparent Mode is to send a BREAK signal or interrupt power to the MFJ 1278B This command sets the Transparent Mode timeout value In order to allow escape to Command Mode from Transparent Mode while permitting any character to be sent as data a guard time of n seconds is set up The same Command Mode entry character used for exit from Converse Mode is used to exit Transparent Mode but the procedure is different The Command Mode entry character is set by COMMAND Three Command Mode entry characters must be entered less than n seconds apart with no intervening characters after a delay of n seconds since the last characters were typed After a final delay of n seconds the MFJ 1278B will exit Transparent Mode and enter Command Mode You should then see the prompt cmd The diagram below illustrates this timing last first second third TNC terminal command command command now in input mode mode mode Command entry entry entry Mode character character character I longer I shorter shorter
340. n be re transmitted or recalled to screen at any time for viewing Screen printing of full COLOR SSTV pictures is not possible on the Commodore C64 and C128 computer Screen printing of multi level SSTV pictures is possible on the Commodore C64 and C128 computers with the below mentioned software terminal program which supports transmit and receive of COLOR and or multi gray levels SSTV printing to the computer screen are as follows 1 MFJ 1289 for IBM PC and compatibles in 5 1 4 disk 2 MFJ 1289M for IBM PC and compatibles in 3 1 2 disk 3 MFJ 1287B for Macintosh 4 MFJ 1290 for Amiga 5 MFJ 1282B for C64 128 MFJ 1278B MULTI MODE BASIC OPERATION SSTV Formats The MFJ 1278B provides a dedicated multi gray level modem for SSTV operation The modulator and demodulator frequencies of the MFJ 1278B are pre set at the factory to allow SSTV operation without any recalibration The MFJ 1278B supports all SSTV formats listed in Table 4 9 AT Table 4 9 MFJ 1278B SSTV Formats These formats require using a special terminal program The SSTV format can be changed by using the TVMODE n command The n is a number from 1 through 5 as listed in the Table 4 9 For example to set MFJ 1278B to 12 second SSTV format you would type TVMODE 2 ENTER The MFJ 1278B would be set to receive or transmit SSTV in the 12 seconds format Other SSTV formats can be invoked by tuning the TVX command ON SSTV Installation Installa
341. n is the power supply Check the power supply levels at the outputs of the voltage regulators Q2 and Q3 as well as the output of the inverter U2 Are they close to their nominal values Do all the ICs in the suspected area have the proper voltage on their power pins Is there a voltage return path ground on the ICs ground pin Is there excessive ripple in any of the DC voltage lines If so check the regulator and associated components working backwards toward the input power switch If the voltage is low in conjunction with a hot regulator suspect a short circuit on the board If the problem is in the 5 volt supply work backwards from Q2 s collector also at U16 pin 1 that should be 5 volts regulated to the junction of C9 and CR2 V unregulated If no voltage appears at V then U2 or a related component may be at fault Verify that U2 is oscillating by looking at the wave form at U2 pin 5 If V is more negative than 7 volts 1 normal but the 5 volt regulated voltage is wrong check the negative regulator components U3 Q2 R5 R6 R7 R8 CR6 C10 C11 and C158 If both V and the 5 volt regulated voltage are wrong look for shorts Step 2 Obvious Problems CAUTION word of WARNING here DO NOT touch any component that is suspect of being HOT This could result in BURNS from the HOT component If you have never left finger prints on top of an IC it is an experience you will not soon forget Look for any unusual phy
342. n t operate 2KHz around 14 100 MHz you will cause interference to propagation beacons and give packet a bad name Calling CQ on HF is a bit different than on VHF One technique which has proven effective when NOT operating on one of the congested calling frequencies is to do the following 1 Find a clear frequency and monitor it for long enough to make sure it really is clear 2 Set UNProto to CQ if it isn t already This is the default field for this parameter 3 Command the MFJ 1278B into converse mode by typing either K lt CR gt or MFJ 1278B MULTI MODE ADVANCED OPERATION 4 Rapidly type a string of 15 to 20 carriage returns CR This will cause the MFJ 1278B to send a continuous string of unconnected information UI frames Since this will be a relatively long burst of packet transmission the potential receiving station will have plenty of time to tune your signal in To a receiving station this will appear on his screen as YOURCALL CQ YOURCALL CQ YOURCALL CQ YOURCALL CQ YOURCALL CQ One for each carriage return you typed Even a station which has no tuning indicator can eventually get you tuned in using this type of signal as he can tune around and watch his screen to see where printing is effective If you are meeting a friend on a schedule you just set the UNProto field to HISCALL and do the same thing When your friend finds you this will appear on his screen as YOURCALL
343. n the MFJ 1278B keys the radio data will be sent to the radio and your friend will hear a brrraaappp sound on his speaker As your friends TNC displays your message on his screen his radio will key for even a shorter time When your friends TNC sends data back to your station you will hear a short brrapp sound on your speaker The short brrapp sound on your speaker is an ACK or packet acknowledgment The MFJ 1278B takes note that the packet was received correctly but nothing is displayed on your screen Digipeating Now that you are on the air you and your friend can try out the MFJ 1278B s digipeating capabilities This is actually more interesting if you have at least three stations participating but you can get the feel for it with two stations Return to the Command Mode and disconnect from the other station lt CTRL C gt cmd DISCONNE DISCONNECTED Now issue the following command cmd CONNECT KS5FLU VIA WBOQRP As before substitute your call for KSFLU and your friend s call for WBOQRP You are requesting a connect to yourself as you did before in digital loop back mode but this time you are using a sort of RF loop back You transmit packets to your friend s TNC which relays them back to you When the connection is established you will see CONNECTED to KSFLU VIA WBOQRP and you will be in Converse Mode Your friend will not see anything displayed on his computer and his TNC s state will not be affected at al
344. n there is no callsign put in MMcall the mailbox is inaccessible to remote users MYSELCAL 55 Mode AMTOR Default blank The MYSELCAL command specifies the AMTOR SELCAL that the MFJ 1278B responds to in AMTOR Mode A operations See section Mode A Setup for information on selecting a SELCAL for your station based on your amateur callsign Note that your MFJ 1278B will not respond to mode A ARQ calls unless MYSELCAL is set up MFJ 1278B MULTI MODE OPERATIONAL COMMANDS NAVTEX ON OFF Mode Navtex Default OFF Parameters ON Navtex receive mode is enabled OFF Navtex receive mode is disabled NAVTEX is an immediate command The NAVTEX command must be issued under the a cmd Amtor command prompt Under the a cmd command prompt type NAVTEX or the abbreviation to put your MFJ 1278B into NAVTEX receive mode While in NAVTEX receive mode the signals on 518 KHz are available to the MFJ 1278B to receive Tune your radio to 518 KHz To receive NAVTEX MFJ 1278B must first receive the ZCZC start message followed by the four character preamble described above If this is not received intact the message will not be received At the end of the message will be received and the MFJ 1278B will stop receiving the Navtex message The MFJ 1278B will remember the last 200 four character preambles received with less than 1 8 of its characters received in error The MFJ 1278B will not reprint any of these messages when they are re
345. nderscore character _ is output to the terminal Receive errors are likely in mode L which is the mode A monitoring mode if you can t hear both sides of the contact very well Less likely reception errors can occur while receiving PAESE E DEORE a a 265 EEE NT TE fet PNG EERE Sth V et EE St ce E E ch a A dll abi MFJ 1278B MULTI MODE OPERATIONAL COMMANDS ESCAPE ON OFF Mode Packet Default OFF Parameters ON The ESCAPE character 1B is output as 24 OFF The lt ESCAPE gt character is output as ESCAPE 1B This command specifies the character which will be output when an ESCAPE character is to be sent to the terminal The ESCAPE translation is disabled in Transparent Mode This command is provided because some terminals and computer programs that emulate such terminals interpret the ESCAPE character as a special command prefix Such terminals may alter their displays depending on the characters following the ESCAPE If you have such a terminal you can protect yourself from unexpected text sequences and from other packeteers by setting ESCAPE ON See also the MFILTER command which allows general character stripping rather than character translation in monitored packets EXActcal ON OFF Mode Pactor Default ON Parameeters ON Enables exact callsign matching with connect packets OFF Disables exact callsign matching with connect packets When the EXActcal command is ON
346. ng The Mailbox will automatically do a disconnect from the link after the time which the SYSOP specifies Abort This command gives the SYSOP control over the mailbox by allowing him to force a disconnect on the mailbox link It may also be used to avoid any QRM to abort a forward in progress You can also use it to terminate mailbox usage by an unwelcome user The new Mailbox system is fully compatible with NTS packet messages also It allows you to format NTS type messages and send them to another destination The MFJ 1278B also incorporates a new bytes free counter It is updated as the mailbox fills or empties It keeps up with the available RAM in multiple memory banks Mail waiting is indicated by the flashing of the STA MAIL LED on the front panel of the MFJ 1278B The STA MAIL LED of the MFJ 1278B serves two functions It lights when unacknowledged packets are pending during a packet connection If the MAILBOX is ON and you have mail waiting the STA MAIL LED will flash on and off if the MFJ 1278B is not connected to another packet station The mail waiting LED function can be disabled by using the MAILLED command MAILLED is defaulted to ON When MAILLED is OFF or when MFJ 1278B is in a connected state STA MAIL LED will not flash Mailbox Messages You have mail Upon access to the mailbox this message will appear if there are messages addressed to you MFJ 1278B MULTI MODE ADVANCED OPERATION You have new mai
347. ng bbs KB4VOL NOMODE ON OFF Mode Packet Default OFF Parameters ON The MFJ 1278B will only switch modes command converse or transparent upon explicit command OFF The MFJ 1278B will switch modes in accordance with the setting of NEWMODE When NOMODE is ON the MFJ 1278B will never change between CONVERSE or TRANSPARENT mode to COMMAND mode or vice versa on its own Only user commands CONV TRANS or C may change the type in mode If NOMODE is OFF then automatic mode switching is handled according to the setting of the NEWMODE command NUCR ON OFF Mode Packet Default OFF Parameters ON lt NULL gt characters are sent to the terminal following CR characters ann AMTYTYE T o shen 2k ee Gee dur the uuu cR Eo ax MFJ 1278B MULTI MODE OPERATIONAL COMMANDS Parameters ON lt NULL gt characters are sent to the terminal following lt LF gt characters OFF lt NULL gt characters are not sent to the terminal following lt LF gt characters This command causes transmission of NULL characters ASCII code 00 producing an effective delay following any lt LF gt sent to the terminal The number of lt NULL gt characters is determined by the command NULLS This delay is required by some display terminals You need to set NULF ON if your terminal sometimes misses characters at the beginning of the line NULLS n Mode Packet Default 0 Parameters n 0 30 specifying the number of lt NULL gt characters to
348. ng operations such as file transfer when the sending TNC usually sends the maximum number of full length packets Occasionally the sending TNC may not have a packet ready in time to prevent transmission from being stopped temporarily with the result that the acknowledgment of earlier packets collides with the final packet of the series If the receiving TNC sets RESPTIME to 10 say these collisions will be avoided RESTORE Mode AMTOR Immediate Command TROMA L 4 4L MATOT 1777007 AMA T A 44 WE CYWACUM ndum zoe Las 3 2 MFJ 1278B MULTI MODE OPERATIONAL COMMANDS RETries nnn 0 lt nn lt 255 Mode Pactor Default 80 Parameters nnn specifying the number of times a packet is transmitted before disconnect The number of error cycles that the MFJ 1278B will tolerate before unilaterally terminating the link Also see WAITDISC RETRY n Mode Packet Default 10 Parameter n 0 15 specifying the maximum number of packet retries The protocol allows for retries i e retransmission of frames that are not acknowledged Frames are re transmitted n times before the operation is aborted The time between retries is specified by the command FRACK A value of 0 for n specifies an infinite number of retries If the number of retries is exceeded the MFJ 1278B goes to the disconnected state with an informative message if not in Transparent Mode See also the FRACK command REVFLIM call n Mode Mailbox Default Parameters
349. nge from 0 thru 9 The QTH here is Starkville Mississippi is the buffer message Messages of up to 120 characters including puncuations are permitted Note Notice that there is NO space between BUF and 1 but remember to put a space between the buffer number and the buffer message Transmitting the Memory Buffers The Memory Buffers can be transmitted by using the BUFKEY command If BUFKEY is left at the default value of 9 then the user can transmit any buffer 0 9 by pressing the TAB key followed with a buffer number 0 thru 9 The MFJ 1278B will return to the receive mode when finished transmitting the buffer Users do not have to type CTRL R to back to receive The BUFKEY command is functional only in the CW MCW modes The BUFKEY command is not valid in the RTTY or ASCII modes In the RTTY and ASCII modes you will press a CTRL T and a buffer number to initiate a buffer transmit and you will press CTRL R to revert the MFJ 1278B to the receive mode If you are using the MEJ 1278B with MFJCOM IBM terminal program you must change the BUFKEY value of TAB 9 key to 5C key Buffer Serial Numbering If the memory buffer text includes a sign the MFJ 1278B will replace the with a number This is performed each time the user sends the buffer The number is the current value of the serial number counter SERIALNO Once used this serial number counter value is incremented by one up to a maximum of 65535 wher
350. ngs of START and STOP are used to determine the type of flow control used in Transparent Mode If TRFLOW is OFF only hardware flow control is available to the computer and all characters received by the MFJ 1278B are transmitted as data If START and STOP are set to 00 disabling the User Stop and User Restart characters hardware flow control must always be used by the computer If TRFLOW is ON and START and STOP are non zero software flow control is enabled for the user s computer or terminal The MFJ 1278B will respond to the User s Restart and User s Stop characters set by START and STOP while remaining transparent to all other characters from the terminal Unless TXFLOW is also ON only hardware flow control is available to the MFJ 1278B to control output from the terminal MFJ 1278B MULTI MODE OPERATIONAL COMMANDS TRIES n Mode Packet Default NONE Parameters n 0 15 specifying the current RETRY level on the currently selected input stream This command is used to retrieve or force the count of tries on the currently selected input stream When used with no argument 1 If the MFJ 1278B has an outstanding unacknowledged frame it will return the current number of tries 2 If the MFJ 1278B has no outstanding unacknowledged frames it will return the number of tries required to obtain an acknowledgment for the previous frame If RETRY is set to O the value returned by issuing a TRIES command will always be 0 This
351. ning your radio You will notice that with each scan the tuning indicator will move toward the center Tune the radio so that the tuning indicator is centered at the end of each FAX scan Once you achieve this the FAX signal is tuned in and the MFJ 1278B is ready to decode the FAX signal Receiving FAX to the Printer This section applies if you have your EPSON or IBM graphics compatible printer attached to the built in printer port on the MFJ 1278B Most commands that affect FAX printing default to a value that will allow successful printing However before printing make sure the commands EPSON and PRINTGRA are ON Printing a FAX image directly to a printer will not function unless EPSON and PRINTGRA are ON MFJ 1278B MULTI MODE BASIC OPERATION After selecting the desired FAX mode type K to leave command mode and enter the CONVERSE mode Once in CONVERSE mode the MFJ 1278B is in standby receive mode This means that the MFJ 1278B is listening to the radio for the distinctive tic tic that indicates the synchronization period at the beginning of a picture If the MFJ 1278B hears the tic tic well enough it will establish a lock onto the signal and start printing to the printer The printer will print upon each scan of the FAX picture The MFJ 1278B s builtin LOCK feature detects the beginning of each picture before starting to print This insures each picture will be printed from top to bottom If you want the printer to start t
352. nnect packet just as if you had typed the command DISCONNE CHECKV1 ON OFF Mode Packet Default OFF The CHECKV1 parameter enables the automatic idle link disconnect feature for AX 25 Level 2 Version 1 connections The idle time before disconnecting will be equivalent to the AX 25 CHECK parameter see CHECK command CHObell ON OFF Mode Pactor Default ON Parameters ON An ASCII bell character is sent to the terminal when the PACTOR link changes direction OFF An ASCII bell character is not sent to the terminal when the PACTOR link sen e ek As MFJ 1278B MULTI MODE OPERATIONAL COMMANDS Parameter nnn Where the nnn variable equals 0 lt n lt 255 The CHOChar command is used to designate the Pactor changeover character This character initiates a control direction change in the Pactor signal This character can be varied from 0 to 255 decimal for computers which may not support the default The default is CTRL Y A value of 0 disables the Pactor changeover CMDchr nnn 0 c nn 255 Mode Pactor Default 03 Parameters n lt nn lt 255 specifying an ASCII character code The CMDchr command is used to designate the character which is used to change the COMMAND MODE entry character You can enter the code in either hexadecimal or decimal form Command Mode is entered from CONVERSE Mode when this character is typed If you type the Command Mode entry character while you are in Command Mode nothing will happe
353. not use DTR CTS flow control you may enable the XON and XOFF characters the commands from the MFJ 1278B nm tow Aw mat Ama nm 1 ATAN MFJ 1278B MULTI MODE ADVANCED OPERATION Hardware Flow Control Hardware flow control is less likely to depend on the programming of a particular communications program DTR and CTS are normally used for flow control signals in Transparent Mode The command XFLOW OFF enables hardware flow control in Converse Mode and Command Mode Your computer may receive as many as 2 characters after it signals the MFJ 1278B to stop sending since some characters may already be in route through serial I O chips Refer to Chapter 7 Hardware for details on the interface required for hardware flow control Type in Flow Control Type in flow control enabled with the command FLOW is really a display feature It can keep the MFJ 1278B from interrupting you with incoming packets when you are in the middle of typing a command line or an outgoing packet As soon as you type the first character of a line the MFJ 1278B will put a hold on all output except for echoing your input The hold remains in effect until you type a CR to end the command line or a send packet character to mark the end of a packet or until you erase or re display the line you have started Some computers have difficulty simultaneously sending and receiving characters over the serial port This is most commonly the case for
354. ns Enter your own AMTOR 4 letter call at the AMTOR prompt with MYSELCAL xxxx ENTER Once you have a frequency selected at the command line type ARQ xxxx ENTER where the xxxx is the selected SELcall of the other station The status light should remain lit once a link is established Type K followed by the ENTER key to enter converse mode The MFJ 1278B will transmit all data typed just like you type it on the keyboard You can type as long as you like or as long as the other station does not get tired of listening or the band fades out Type to transfer control of the link to the other station Only one station has control of the link at a time so try to be considerate If you want to take control of the link to send a quick reply you would go back to the a cmd prompt and type CHANGE then type K to return to converse mode Type CTRL C once to take you back to the AMTOR command line a cmd If you make a mistake and type the Ctrl C twice or more it will take you back to the main cmd line Type R or QRT at the a cmd to terminate the link It s usually a good idea to let the other station know before you do though Think about how MFJ 1278B MULTI MODE BASIC OPERATION You can obtain hardcopy printouts from the bulit in printer port of the MFJ 1278B Hardcopy printouts are done with the same printer that you used in the other modes of operation To make hardcopy printouts type the following at the a cmd command prompt
355. nsmitter doesn t key the problem may be in the watchdog timer U7 or the PTT transistors Q10 or Q20 Check especially for an open timing capacitor C31 or a bad solder connection associated with R83 MFJ 1278B MULTI MODE TROUBLESHOOTING Symptom Uncopyable transmitted or received packets If no one seems able to decode your packet transmissions it is often the case that your transmitter is being overdriven The solution is to reduce the drive level via trimpots R157 and R158 Note that direct connection to typical microphone inputs requires R157 or R158 to be turned to near the minimum signal position to produce sufficiently low signal levels If you are having problems hearing other stations the demodulator circuitry associated with U20 may be at fault Check the center frequency of the VCO in U20 using the calibration procedure Working in the direction of flow of the input signal from the radio verify that it is being passed through to pin 2 of U20 the input pin The signal there should be above 50 mV and below 3 V peak to peak for proper operation of the demodulator It should be relatively clean although a few tens of millivolts of noise is normal and the signal amplitude should not change by more than about 2596 between high and low tones Note Make sure that JMP 8 is on TERMINAL INTERFACE TROUBLESHOOTING If you can t get the MFJ 1278B to sign on and accept data from your terminal or computer the problem may be in the RS 2
356. number of data bits per word This value defines the word length used by the serial IO terminal port For most packet operations including conversation bulletin board operation and transmission of ASCII files you should set AWLEN 7 If 8 bit words are transmitted to the MFJ 1278B in Command Mode or Converse Mode the eighth bit is normally removed leaving a standard ASCII character regardless of the setting of AWLEN To transmit and receive packets retaining all 8 data bits of each character as you need to do if you send executable files or other special data you should use Transparent Mode and set AWLEN 8 Alternatively you can use Converse Mode and set AWLEN 8 and 8BITCONV ON however the data you then send must handle the Converse Mode special characters with the PASS prefix Til ais nlzllln amp kegngde fl adhoc ate 4dlooioeoln cee ck cl nlL ox INTRO AINA noz ado A MFJ 1278B MULTI MODE OPERATIONAL COMMANDS AX25L2V2 ON OFF Mode Packet Default ON Parameters ON The MFJ 1278B will use AX 25 Level 2 Version 2 0 protocol OFF The MFJ 1278B will use AX 25 Level 2 Version 1 0 protocol Some implementations of the earlier version of AX 25 protocol e g TAPR s TNC 1 will not properly digipeat version 2 0 AX 25 packets This command exists to provide compatibility with these other TNCs until their software has been updated During the protocol transition period you should set AX25L2V2 OFF
357. o a certain point The reception of an almost perfect packet will be inadequate to overcome the accumulated noise if MAXSUM is too large Also the presence of excessive QRM QRN or QSB effects the reception of good packets On the other hand if MAXSUM is too small the accumulation of samples will be too few to correct for moderate error rates The factory setting for MAXSUM represents a good compromise feel free to play with it FEC UNPROTO Unproto FEC UNPROTO packets are transmitted UREPEATS 1 times Selecting larger values of UREPEATS reduces throughput but enhances reliability To transmit in UNPROTO mode issue the appropriate unproto command and type away When done break out to p emd mode and type D or DD to terminate transmission MONITORING Monitoring unproto If MONITOR is ON the MFJ 1278B is always in listen mode MFJ 1278B MULTI MODE BASIC OPERATION To prevent Uncontrolled Disconnects we are unable to listen to all kinds of third party Pactor transmissions for WAIT x Cycle Time seconds after receiving the other side s last disconnect This includes all unproto and connected packets along with connect requests The actual cycle time is 1 25 or 1 4 seconds CONNECT Connect message The MFJ 1278B monitors connect attempts received from other station s with a message containing the called station s callsign when idle To successfully monitor a connect attempt to someone else the called callsign must be at lea
358. o go back to the receive mode type CTRL R in converse mode to unkey the radio and you will return to the receive mode This will start the transmit receive cycle over Commercial RTTY Reception Commercial RTTY presents a special problem for amateurs and short wave listeners Several conditions must be met before you can get a decent printout You have to locate the frequency of a particular station get the schedule right pick the sideband set the baud rate set the frequency shift and finally unencrypt the text You can receive many of these stations using the 425 shift 50 baud and lower sideband during the daylight hours For this setup use MODE VB 50 Some military frequencies are unencoded as well as some of the UPI broadcasts A good source of frequencies is Popular Communications and Monitoring Times magazines MFJ 1278B MULTI MODE BASIC OPERATION AUTOMATIC SIGNAL ANALYSIS The Automatic Signal Analysis or ASA feature installed in the MFJ 1278B firmware can analyze received signals such as RTTY ASCII AMTOR mode b and HF Packet ASA will tell you the speed data bits and if the signal is inverted ASA automatically switches the MFJ 1278B to the correct mode once you accept the results of the signal analysis by typing OK and ENTER As you see ASA is extremely helpful when tuning across the amateur or the shortwave bands Let ASA help you determine what kind of signals you are listening to ASA OPERATION ASA is eff
359. o listen to If you want to listen only for packets from a limited list you should enter your selected list with LCALLS and set BUDLIST ON If you want to ignore packets from a limited list you should list the callsigns to ignore in LCALLS and set BUDLIST OFF If 96 or amp is entered into the LCALLS parameter then the LCALLS list clears LCOK ONIOFF Mode Packet Default ON Parameters ON The MFJ 1278B will send lower case characters to the computer or terminal OFF The MFJ 1278B will translate lower case characters to upper case If LCOK is OFF lower case characters will be translated to upper case before being output to the terminal This case translation is disabled in Transparent Mode Input characters and echoes are not case translated If your computer or terminal does not accept lower case characters it may react badly if the AAT ANTON 1 1 n na MFJ 1278B MULTI MODE OPERATIONAL COMMANDS Parameters ON The MFJ 1278B will translate the character immediately following the STREAMSWITCH character to upper case before processing it OFF The MFJ 1278B will process the character immediately following the STREAMSWITCH character as it is entered When operating multi connect the user must enter a stream identifier default A through J after the STREAMSWITCH character default to select a new logical stream to send data Normally the stream identifier must be in upper case or an error message will resu
360. o print in the middle of the picture you may force a lock on the picture and the printer will begin to print upon the force lock To force a lock you simply type the letter L while in the FAX standby receive mode The LOCK detect feature on the MFJ 1278B is effective for FAXMODE 3 For other FAXMODES you will want to force a LOCK at the beginning of the picture to insure proper printing If the FAX picture appears to be printed shifted to the right you can type the key to shift the picture to the left Each repetition of the key will shift the picture 1 10 to the left To shift the picture to the right use the gt key Each repetition of the gt key will shift the picture to the right 1 10 For example if you needed to shift the picture to the left 1 inch you would press the key ten times The picture can be shifted to the right or left at any time during printing If your picture is elongated horizontally or vertically you can correct this by setting the ASPECT ratio ASPECT is used to establish a reasonable aspect ratio between the horizontal and vertical presentation of FAX graphics ASPECT ratio can be set between 2 thru 8 with 2 being the optimum aspect ratio for weather FAX The default ASPECT ratio of the MFJ 1278B is 3 The ASPECT ratio can be set by using the command ASPECT followed by a number from 2 thru 8 If you find that your picture seems to be elongated horizontally you should decrease the value of as
361. o the Mailbox The 32K version has the same capability but with 32K RAM capacity At the end of the message press a Control Z and the ENTER key The message will be sent The users message will be seen on your mailbox station s screen then the mailbox will respond with the mailbox command prompt nn free n Mailbox B E H elp J K L M R S T Where nn is the bytes free indicator This tells the user how much ram space is available in your Mailbox Also nj is the indicator of the current memory bank in use by the Mailbox 4 There are two 2 different ways to kill messages The first is given in the example below A To kill a message in a particular slot type K CR Where the is the message number you want to kill The message must be one that is addressed to the remote user If the message is not addressed to the remote user then Easy Mail will respond with Cannot not yours If the message is addressed to the remote user then the Mailbox will respond with Message deleted nn free n Mailbox B E H elp J K L M R S T This is whether or not the message has an N or a Y flag attached to it Note that the remote users may only kill messages that are addressed them The originator can also kill the message The local SYSOP can kill any or all messages in the Mailbox MFJ 1278B MULTI MODE ADVANCED OPERATION B You can perform a Global Kill on a group of messages which are under the same c
362. o the terminal in RXBLOCK format OFF The MFJ 1278B will send data to the terminal in standard format The RXBLOCK command is designed for automated operations such as packet bulletin board stations It is intended to help such systems discriminate between data received from the connected station and MFJ 1278 generated messages Correct operation of RXBLOCK is dependent on the AWLEN parameter getting set to 8 bits since the character FF hex marks the beginning of a received data unit header When RXBLOCK is ON data from other stations will be sent from the MFJ 1278B in the following format SFF LO L1 PID DATA prefix length pid data The fields above are defined as follows prefix FF A character with all 8 bits set length LO The high order length of the data length and pid fields logically ORed with the value FO L1 The low order length of the data length and pid fields PID The Protocol IDentifier byte received for the following data field E E E 2 DATA Optional variable length data For best operation it is suggested that parameters like AUTOLF MFILTER etc be set OFF in order to prevent uncertainties in the size of the data field MFJ 1278B MULTI MODE OPERATIONAL COMMANDS RXBRIGHT n Mode FAX SSTV Default 4 Parameter n 0 9 specifying a certain set of TVBreak points The RXBRIGHT command is used to select a certain set of TVBreak values for use with the SSTV and Multi Level FAX m
363. oalsjcnc a s uA adm A OWA te ee aA MFJ 1278B MULTI MODE OPERATIONAL COMMANDS Parameters ON XON XOFF flow control is enabled OFF XON XOFF flow control is disabled and hardware flow control is enabled If XFLOW is ON the computer or terminal is assumed to respond to the MFJ 1278B Restart and Stop characters set by and XOFF If XFLOW is OFF the MFJ 1278B will communicate flow control commands via RTS XMITOK ON OFF Mode Packet Default ON Parameters ON Transmit functions are enabled OFF Transmit functions are disabled When XMITOK is OFF transmitting is inhibited All other functions of the board remain the same in other words the MFJ 1278B generates and sends packets as requested but does not key the radio PTT line You might use this command to insure that your MFJ 1278B does not transmit in your absence if you leave it operating to monitor packet activity This command can also be used for testing using loopback or direct wire connections when PTT operation is not relevant XOFF n Mode Default 13 Parameters n 0 to 7F specifying an ASCII character code This command selects the MFJ 1278B Stop character that is sent by the MFJ 1278B to the computer or terminal to stop input from that device You can enter the code in either hex or decimal This character would ordinarily be set to lt CTRL S gt for computer data transfers If you are operating y
364. oblem or give significant clues as to the probable area of the MFJ 1278B most suspect After the above inspection has been completed and apparent problems are dealt with it is time to proceed to more specific analysis Symptom TNC appears dead If the MFJ 1278B powers up with the PWR STA and CON LEDs lit followed by STA and CON extinguishing a second or so later the processor is working and the software is probably working correctly You should suspect the RS 232C serial port at this point Check all connections and verify the logic levels according to the terminal interface troubleshooting section in this chapter Oscillator and Reset Circuits If no LEDs wink during the reset cycle the problem may be more serious Check to see that the crystal oscillator is working and that an MI signal 154 kHz square wave 0 to 5 volts is coming from U22 pin 27 The crystal oscillator input to the processor U22 is pin 6 The input clock should be a possibly distorted square wave signal Verify that the clock input at pin 6 of U22 is running at the correct frequency near 4 9152 MHz Verify that the battery backed up RAM protection circuit composed of Q4 U14 and associated devices is going to 5 volts at U14 pin 6 after input power is applied This signal enables normal operation of U24 and U25 There should bea logical low on the output of U7 pin 12 coincident with the application of power and lasting for a few hundred milliseconds Wi
365. ode MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CHECK n Mode Packet Default 30 Parameters n 0 250 specifying the check time in 10 second intervals A value of 0 disables this feature This command sets a connection timeout If a link connection exists between the MFJ 1278B and another station and the other station disappears your MEJ 1278B could remain in the connected state indefinitely refusing connections from other stations This might happen if propagation changes unexpectedly or an intermediate digipeater station is turned off In order to prevent this sort of lockup the MFJ 1278B will try to clean up the link if the specified time elapses without any packets being heard from the other TNC The operation of this feature depends on the setting of AX25L2V2 If AX25L2V2 is ON the MFJ 1278B will send a check packet to verify the presence of the other station if no packets have been heard from it for n 10 seconds This frame contains no information but is interpreted by the receiving station s TNC as an inquiry as to whether it is still connected If the receiving TNC is still connected it sends an appropriate response packet If the TNC initiating the inquiry does not hear a response after RETRY 1 attempts it commences a disconnect sequence as if the DISCONNE command had been given If AX25L2V2 is OFF and the other station has not been heard for n 10 seconds the MFJ 1278B will not attempt an inquiry but will send a disco
366. ode B then wait for a call from another operator in Mode A Setting up for Mode B FEC Setup for Mode B FEC is the same as ARQ although a selective call is not required Mode B FEC Operations To receive Mode B FEC tune the FEC signal in so the center segments on the MFJ 1278B tuning indicator light When the MFJ 1278B detects the synchronization pattern either the CON or STA led will light The exact point in the transmission to which you tuned to determines if the CON or STA led lights When either the CON or STA led lights the received data will begin to display on the terminal screen Use Mode B FEC for calling CQ operating in round tables and for transmitting bulletins to more than one station at a time To transmit MODE B FEC type FEC followed by a carriage return at which time your transmitter will key up Now type CONVERSE or K to enter the data mode and you re on the air with FEC Anything entered from the keyboard once in the data mode is transmitted When you re done transmitting return to the AMTOR command mode a cmd with CTRL C In order to release the transmitter type R or QRT followed by a carriage return At this point again the MFJ 1278B will automatically attempt to synchronize to any mode B signal it hears Mode S SELCALL Mode S is exactly like Mode B EXCEPT that the broadcasting station can select one or a MFJ 1278B MULTI MODE BASIC OPERATION AMTOR Status LED Indicators The CON and STA LEDs h
367. odes The TVBreak sets within the RXBRIGHT command control the brightness and contrast of the received SSTV and Multi Level FAX pictures The smaller the RXBRIGHT number the darker the received picture The larger the RXBRIGHT number the brighter the received picture When the RXBRIGHT number set to 0 then the MFJ 1278B uses the current setting determined by the setting of the TVBreaks command The TVBreaks command may have been changed by the user to something other than the default The default TVBreak setting when RXBRIGHT is set to 0 is shown below 0 TVB 80 46 47 48 4C 4F 52 54 59 5C 5E 60 63 67 69 If the RXBRIGHT command is a non zero value 1 through 9 the MFJ 1278B uses the TVBreaks set that corresponds to the RXBRIGHT number A list of the TVBreaks settings within the RXBRIGHT command is shown below O TVB 80 46 47 48 4C 4F 52 54 59 5C 5E 60 63 67 69 80 48 4A 4C 4E 50 52 54 56 58 5A 5C 5E 60 62 80 49 4B 4D 4F 51 53 55 57 59 5B 5D 5F 61 63 80 4A 4C 4E 50 52 54 56 58 5A 5C 5E 60 62 64 80 4B 4D 4F 51 53 55 57 59 5B 5D 5F 61 63 65 80 4C 4E 50 52 54 56 58 5A 5C 5E 60 62 64 66 80 4E 50 52 54 56 58 5A 5C 5E 60 62 64 66 68 80 4F 51 53 55 57 59 5B 5D 5F 61 63 65 67 69 80 50 52 54 56 58 5A 5C 5E 60 62 64 66 68 6A TVB 80
368. of which format a FAX SSTV picture was copied under The number of graphics characters nnn following a FAX SSTV frame header depends on the FAXMODE TVMODE See horizontal density under the FAXMODE TVMODE command for more information PRINTER ON OFF Mode Default OFF The PRINTER command turns the parallel printer port ON and OFF If the printer is not connected to the built in printer port the computer will not lock up The message PRINTER NOT READY is given to the user PRINTTES Mode ALL Immediate Command DLEA usas etn AS eint toten ed ye m dio ml b roe ek asi n Deci aie a des edn nte b s e cani m A acne MFJ 1278B MULTI MODE OPERATIONAL COMMANDS The PROfmars command causes the MFJ 1278B to set itself up for MARS operations The MFJ 1278B sets the following parameters for MARS operation AUTOLF OFF CCITT OFF DIDDLE OFF LFADDALT OFF LFIGNORE OFF MARSMODE 01 UNSHIFT OFF RXLENOCR ON PTOver nnn 0 lt nn lt 255 Mode Pactor Default 19 Parameters nnn Where the n variable equals 0 lt n lt 255 The PTOver character designates the Pactor changeover character The PTOver command was addded in order to make the MFJ 1278B command set compatible with other Pactor controllers This character initiates a control direction change in the Pactor signal This character can be varied from 0 to 255 decimal for computers which may not support the default The default is CTRL Y A value of 0
369. ogram provided by the MFJ Starter Pack proceed to the Computer Baud Rate section in this chapter Follow the instruction provided by the program If you are not using a MFJ terminal program then proceed with the instruction for your type of computer Note Some terminal programs require the initialization of DCD before they receive any characters This is also true for different types of serial port cards such as the Apple Super Serial Card If this is the case place a jumper across pin 1 and 2 of JMP 1 The DCD LED the front panel will function normally indicating received packets Apple Macintosh There is an MFJ Starter Pack available for Macintosh the MFJ 1287B Included in the MFJ 1287B is a terminal program to allow compatibility between MFJ 1278B and the Macintosh Also included is a cable to connect the MFJ 1278B to the Macintosh In Table 2 3 you will find a list of parameters should want to use a terminal program such as MacTerm Compatibility 1200 baud VT100 7 bits character Table 2 3 MacTerm Parameters for MFJ 1278B Apple II For the Apple II family of computers with Apple or third party RS 232C serial cards you may use ASCII Express Pro Hayes Smartcom DataCapture 4 0 for the MFJ 1278B There are others that may be compatible with the MFJ 1278B but have not been tested MFJ 1278B MULTI MODE COMPUTER INTERFACING Commodore C64 C128 and VIC 20 The optional Starte
370. omatic 128 Identification station 127 iming frame acknowledge time for digipeated packets 132 Input Editing character deletion 49 Input editing character deletion 49 219 Input editing disabled in Transparent Mode 293 Input editing line cancellation 50 197 Input editing packet cancellation 121 198 Input editing pass character 265 Input editing redisplay line 50 274 Integrated circuits incorrect installation 332 Integrated circuits normal temperatures 332 Interfacing Radio 20 INTRODUCTION J J1 serial port connector 320 J2 radio port connector 20 J4 modem disconnect 318 328 JMP1 DCD override 15 JMP10 digital loopback 42 47 JMP2 clock speed selection 317 JMP4 watch dog timer override 319 JMP5 ROM memory size selection 318 JMP7 analog loopback 42 Jumper functions 322 K keying negative Grid Block 71 keying positive direct 71 Keywords AFTER and EVERY 174 190 264 Keywords ASYNC 223 Keywords CHARACTE 223 1 TX DES Y Tm ana MFJ 1278B MULTI MODE L LED normal power up display 333 Line Spacing packet text 130 Line wrapping 35 282 Link status messages 312 Logic lines troubleshooting 334 Lower case characters translation to upper case 238 M Macintosh serial port interfacing 6 Macintosh terminal program 11 memory buffers 38 memory buffers chaining 40 memory buffers loading of 39 memory buffers numbering of
371. on as well as causing it to perform specific functions such as connecting to another station to start a QSO You can enter a command to the MEJ 1278B whenever you see the command mode prompt cmd You will change parameters and issue instructions to the MFJ 1278B by typing commands composed of English like words or word abbreviations The English like words or word abbreviations refered to as keywords sometimes contain variables that are numbers or strings of characters chosen by the user You will probably never change some of these parameters however one of MFJ s goals is to allow each user maximum flexibility to adapt the MFJ 1278B to his environment ENTERING COMMANDS You may use either upper case capital letters or lower case small letters when you enter commands In order to have the MFJ 1278B accept a command you must finish command entry with a CR or carriage return character This will not be mentioned explicitly in the examples below Before you type the final CR of your command you can correct typing mistakes or cancel the line completely If any command is misspelled to the point where the MFJ 1278B does not understand it then an error message will occur See Chapter 4 for a discussion of input line editing This chapter will use UPPER CASE for commands and lower case for explanatory text In examples showing input typed by the user together with the responses of the MFJ 1278B the user s input will be sho
372. on between NRZ formatted data and NRZI formatted data is necessary because the AX 25 protocol specification requires NRZI operation while the SIO is only capable of NRZ Jumper JMP11 may be used to bypass the NRZ and NRZI conversion for use with external modems if required MFJ 1278B MULTI MODE HARDWARE Watch dog Timer Inverters U7c U7d U7e and Q10 and Q20 provide a watch dog timer on the transmit key line to ensure that the transmitter does not remain keyed for more than about 30 seconds should the TNC fails This allows you to leave a station such as a remote digipeater on the air and unattended without much chance of having a malfunction lock up the packet channel This also helps ensure compliance with FCC regulations regarding unattended station operation Jumper JMP4 is provided for testing purposes When JMP4 is installed timing capacitor C31 is shunted disabling the watch dog timer Modem U16 an XR2206 is a Frequency Shift Keying FSK modulator that generates an audio data signal for use by the radio transmitter Two tones are used one for each digital level and these tones may be calibrated via trimpots R77 R78 R105 R106 R119 R122 and R139 R138 in conjunction with the on board calibration support circuitry and software When the transmitter is not being keyed transistor Q9 is switched on thus preventing U16 from producing tones This allows you to leave a microphone connected to your packet transmitter for voice
373. on packet callsign text 254 lt CR inserting in text strings 265 lt LF gt followed by lt NULL gt 262 3 300 baud operation demodulator DCD filter 319 9 9600 baud operation 135 328 A Acknowledgment 45 ACKNOWLEDGMENT PRIORITY 153 Acknowledgment digipeated packets 132 Acknowledgment minimum delay 275 Acknowledgment of multiple packets 232 Acknowledgment retries before 276 Address routing information 44 Address setting with callsign 254 ADDRESS HDLC field 338 ALOCKCHAR 73 Analog loopback 305 Analog loopback full duplex operation 232 Apple Macintosh serial port interfacing 6 Apple Macintosh terminal program 11 ARCVCHAR 81 ASENDCHAR 81 Audio repeaters 188 auto speed tracking 72 Automatic operations beacons 130 Automatic operations connect 128 Automatic operations connect message transmission 128 205 Automatic operations connect refusal 128 Automatic operations data packetizing 135 Automatic operations data packetizing in Converse Mode 211 Automatic operations digipeating 128 220 Automatic operations disconnect 201 276 Automatic operations entry to data transfer mode 207 259 Automatic operations inclusion of send packet character in pack 212 MFJ 1278B MULTI MODE Automatic operations transmit operation 128 305 AUTOTRAC 72 AWLEN 278 Awlen 34 AX 25 Level 2 protocol 187 337 B Baud rate Radio 124 Baud rate Serial po
374. on where an ACK is delayed from being sent beyond the FRACK timer limitation In fact the FRACK timer becomes relatively meaningless in this context However in the current firmware release The FRACK timer is still active and must be set to a value that is long enough to allow time for DACI EN 1 ACKWATT ta avnira hafara ED ACK Thio tima unll danand an tha radin MFJ 1278B MULTI MODE ADVANCED OPERATION Enforcing a channel access delay for all stations on the channel for whom the packet that caused the queue was not intended amp who therefore aren t going to ACK it allows even ACKs from hidden terminals to get back to the expecting station This clears that traffic from the offered load list If the packet was indeed copied and ACKed further retrys of the same information will not be necessary New Parameters There are several new parameters that relate to this modification of the protocol They are as follows ACKPRIOR ONIOFF This enables prioritized acknowledgments if turned on If ACKprior is turned off and SLots see below is set to 0 this modification of the AX 25 protocol is effectively disabled The MFJ 1278B will behave like normal AX 25 protocol Being independent of each other the enabling and disabling of slotted channel access and Prioritized acknowledgments are the same So you could if you wished run normal AX 25 with slotted channel access or the new protocol without slotted channel access DEADTIME
375. one diode on the IF board The 270 Hz filter can then be installed in the normal narrow CW filter position making two bandwidths of narrow filter available for CW operation with all filters selectable from the front panel Cama af tha UE and manir aldar nanao ollas calantian af filtar indanandant af MFJ 1278B MULTI MODE ADVANCED OPERATION If the HF radio is to be dedicated to packet use the 500 Hz filter can be installed in place of the SSB filter This is possible on ANY radio designed for SSB and CW use It is important to use lower sideband rather than upper sideband if you are going to use a CW filter in the radio for packet operations The reason for this is simple The filter designed for CW operation is usually centered approximately 800 Hz away from the upper sideband suppressed carrier This is the carrier oscillator which is normally used as the BFO on CW This means that if the two carrier oscillators are 3 KHz apart the CW filter center will be near 2200 Hz below the lower sideband carrier This is the reason 2220 Hz was selected for the center frequency of the modem If you are going to use a narrow filter and serious HF operation is NOT recommended without one it will be necessary to take steps to be certain that the filter passband is centered over the modem center frequency If your radio has IF shift this is a simple matter The tuning indicator and DCD LED are used to give you an indication of fi
376. op command forwarding and reverse forwarding are performed from the Packet mailbox The Pactor Mailbox in the MFJ 1278B provides the sysop with about 32K of RAM for message storage The Pactor and Packet Mailboxes share the same 32K RAM The mailbox RAM is in addition to the system RAM However you can increase the RAM size to 128K or even an enormous 512K You can increase the RAM size by simply replacing the mailbox RAM chip on the MFJ 1278B motherboard The mailbox RAM is battery backed up just like the system RAM Additional RAM chips are available from MFJ Enterprises Inc and easily installed by the user The user can order the 128K RAM chip as the MFJ 45B or the 512K RAM chip as the MFJ 45C The number of slots and space available for each memory size are as follows of Slots Bytes Avail 32 000 99 128K 99 per bank 128 000 512K 99 per bank 512 000 Setting Up your Pactor Mailbox The new Pactor Mailbox is operative only while the MFJ 1278B is in the Pactor mode of operation The Pactor mailbox uses the callsign used during standard Pactor operations The user must set a few of the Pactor commands before operating the Pactor mailbox As we mentioned earlier there are a few functions that are performed only in the Packet mailbox The functions that are performed only in the Packet are the SYSop command forwarding and reverse forwarding We will go over the different commands while we talk about the Pactor s
377. or a Y Note that the remote users may only kill messages which are addressed them The originator can kill any message that he she originated The local SYSOP can kill any or all messages in the Mailbox b You can perform a Global Kill on a group of messages that are under the same callsign To perform a Global Kill on a group of messages the following conditions apply L All messages must have been read and the message flag must be a Y II The callsign contained in the MYcall must be the same as the callsign in the MYcall command If the above conditions are met then all the user must type K lt ENTER gt This will go out to Mailbox then the messages with the message flags set to Y and all of the proper callsigns will be killed The Mailbox will respond back to the remote user with all message numbers killed during the Global Kill process Also the Mailbox prompt will be given again The Mailbox will update the bytes free indicator when the messages are killed The local SYSOP cannot perform a Global Kill The SYSOP must individually kill any messages 5 The remote user or local SYSOP can List messages from the Mailbox In order to do this first the Mailbox prompt must be obtained by either a connection to the Mailbox or through the local SYSOP command Please type the following to List messages from the Mailbox L lt ENTER gt MFJ 1278B MULTI MODE BASIC OPERATION The Mailbox will respond with a list of currently used slo
378. ort that connects to your computer or terminal MFJ 1278B MULTI MODE HARDWARE Other integrated circuits are used for functions including clock oscillator baud rate generator memory space decoder power supply and voltage inverter clock recovery transmit watch dog timer and modem Refer to the schematic diagram while reading the following circuit descriptions DETAILED CIRCUIT DESCRIPTION Oscillator Components U10a U10b U10c R46 R47 R48 C24 C47 C51 and crystal Y1 provide an accurate crystal controlled oscillator for system timing Resistor R48 forces inverter U10a into its linear region and provides a load for crystal Y1 Capacitor C47 provides an adjustable reactive element to allow the oscillator s frequency to be precisely set this precision is not normally required Inverter U10c buffers the clock for additional stability before driving additional dividers Resistor R46 is used to bias HCT logic to the proper levels for best oscillator operation it is not necessary if U10 is an HC logic element Dividers and Baud rate Generator Components U10e U10f U4a U4b U1 U30 and U31 provide clock outputs derived from the oscillator Electronics switches within U30 and U31 provide all the terminal and RF baud rate signals under software command Inverter U10f provides buffering and isolation between the divide by two output of counter U4a and the capacitive load presented by the CPU U22 and the SIO U21 UIOfs input
379. ot occur Message saved The Message Saved occurs when a Mailbox message is actually stored after pressing the CTRL Z and ENTER This message also appears if the EX and ENTER Cannot not yours This message occurs when a remote user attempts to kill a message that is not his or he tries to read personal message by or for someone else The SYSOP can READ or KILL any message in the Mailbox system Mailbox full This message occurs when either all of the available slots are full or the actual message space is full The number of slots and message space for the different mailbox versions are as follows Memory size Slots Message Space Unexpanded 30 2 900 Bytes 32K 99 32 000 Bytes 128K 99 Bank 128 000 Bytes 5 2K 99 Bank 512 000 Bytes MFJ 1278B MULTI MODE SYSTEM MESSAGES Not found This message occurs when one attempts to read or kill a non existent message from an empty slot For example if the user issues the command R 30 to read the message in message slot 30 and there is no message in message slot 30 None found A parameterless Kill or Read command The NONE FOUND message occurs when the MFJ 1278B mailbox is unable to find any messages addressed to the user No mail The No Mail message occurs when a Read command with no slot designator is done but mail does not exist for the remote user COMMAND MODE ERROR MESSAGES If you make a mistake typing a command to the MFJ 1278B an error message will be printed
380. other packet station that is beyond your direct radio range If a third packet station is on the air and both you and the station you want to talk to are in range of this third station that station can relay your packets You set up the packet routing when you initiate the connection The MFJ 1278B will then automatically include the routing information in the packets it sends The diagram below shows Example 1 situation in which digipeating is useful AD7I N2WX K5FLU You are station KSFLU and you want to have a packet QSO with N2WX There is a mountain in the way and you are not in simplex range of each other However there is a station located on the ridge AD7I which is in range of both you and N2WX You direct the MFJ 1278B to set up a connection to N2WX using AD7I as an intermediate digipeater as follows cmd CONNECT N2WX VIA AD7I You can specify a routing list of up to eight intermediate stations Consider Example 2 below as a modification of Example 1 above N2WX V K5FLU KV7D NK6K AD7I has turned off his station but you can contact N2WX by going around the mountain through NK6K and KV7D This time you issue the connect command like this cmd CONNECT N2WX VIA NK6K KV7D You specify the digipeaters in the order you would encounter them going from your station to the station to which you wish to connect xr 2 24 1 gt ato s 3 a 2 as mm MFJ 1278B MULTI MODE BASIC OPERATION Unsucces
381. otice that on the air reports suggest that you are transmitting and receiving on significantly different frequencies after successfully completing the above alignment procedure it is possible that the radio needs realignment Many different transceivers for HF are capable of being misaligned due to reference oscillator crystal aging or careless alignment by amounts exceeding 500 Hz RIT inadvertently left on can also cause hard to detect problems in this area Reliable HF packet communications requires that the frequency error presented to the demodulator be below 30 Hz If several stations are to successfully share a single channel transmitter receiver offsets larger than this will be intolerable MFJ 1278B MULTI MODE APPENDIX B MODEM CALIBRATION MFJ 1278B Adjustment Location Map This is a map of the physical locations of the adjustment potentiometers on the MFJ 1278B circuit board They are shown as they appear when looking down on top of the board with the board oriented so that the rear panel connectors are to the left Information in the boxes is organized as shown below PART MODE PART MODE H L PART MODE H L CALSET FREQ CALSET FREQ CALSET DEMODULATOR MODULATOR R113 HP R106 HPL R77 VPH CALSET 32 2125 247 2200 240 R114 VB R122 VBL R105 HPH CALSET 32 2125 247 2295 229 RY ME R78 VPL R119 VBH CALSET 8 1200 438 2975 177 R115 CW R138 SSTV H R129 MCW NO CALSET SEE NOTE
382. ould appear This signal should appear somewhere in the middle of the rotation approx 10 turns Which turn on the pot where you find the spot that produces a stable square wave may vary from unit to unit There are only about 1 to 2 turns where the square ware will appear on the scope So turn the pot CW to where the square wave just appears and is stable Make note as to where slot on the screw is at Then rotate the pot CCW until the square wave just becomes unstable Make note as to how many turns you went CCW and turn the pot back CW half that many Now you are in the center of the demodulator h Adjust R115 so the square wave displayed has a 50 percent duty cycle Note that when R115 is adjusted properly the period of the square wave should be about 0 59 milliseconds The square wave will appear as shown below MFJ 1278B MULTI MODE APPENDIX B MODEM CALIBRATION NOTE If you have a square wave on the scope face but the tuning indicator is not near center you are on a false setting Adjust R115 so that the tuning indicator is near center and THEN set the square wave duty cycle 4 If MCW transceive operation with another station is desired do the above procedure to BOTH MFJ 1278s using an agreed upon frequency for Fc Then leave the modulator tone on the agreed on frequency with the demodulator Fc 5 Remove jumpers placed at JMP 4 and JMP 7 6 Remove the jmuper at JMP9 pins 1 and 2 Place it on JMP9 pins 2 and 3 7 Remove the two ju
383. our station in a Converse Mode and there is some chance that you might fill up the MFJ 1278B s buffers you might set this character to lt CTRL G gt 07 which rings a bell on aa ow Te MFJ 1278B MULTI MODE OPERATIONAL COMMANDS XOff nn Mode Pactor Default S Parameters nn 0 lt nn lt 25 This command determines the Flow Control STOP character The Pactor XOFF command is the same as the XOFF command in the standard MFJ 1278B command set For further information on the XOFF command please refer to the explanation of the XOFF command in Chapter 6 of the MFJ Data Controller Main Instruction Manual XOn nn Mode Pactor Default Parameters nn 0 lt nn lt 255 This command determines the Flow Control START character The Pactor XON command is the same as the command in the standard MFJ 1278B command set For further information on the Pactor XON command please refer the explanation of the XON command in Chapter 6 of the Data Controller Main Instruction Manual see discussion above for more on XON XOFF software flow control XON n Mode AII Default 11 Parameters n 0 to 7F specifying an ASCII character code This command selects the MFJ 1278B Restart character which is sent by the MFJ 1278B to the computer or terminal to restart input from that device You can enter the code in either hex or decimal This character would ordinarily be set to CTRL Q for computer data transfers If yo
384. ow the FAX frames to pass through without special handling each character in the frame is biased upward with the value 30 Hex so only characters of ASCII value 30 through 7F are sent to the terminal A few side effects of the special handling MFJ 1278B MULTI MODE BASIC OPERATION The number of graphics characters nnn following a FAX frame header depends on the FAXMODE See horizontal density under the FAXMODE command for more information Multi level FAX Picture Raw Data Format In FAX mode the MFJ 1278B can provide data thru the RS 232 port in raw data format With special terminal software which can support this data format you can display and save multi gray levels pictures The number of gray levels which the raw data format provides thru the RS 232 port is determined by the command TVBREAK Current TVBREAK is set to 16 levels of gray To invoke multi level FAX receiving under the cmd prompt type MULTIFAX ON ENTER then make sure that you are in the FAX mode by typing MODE FX ENTER Type K to enter CONVERSE mode then type L to start receiving raw FAX data Note that with MULTIFAX turned On you must type L to start receiving data Unlike the 2 level format which the MFJ 1278B firmware detects the beginning of a FAX picture and also signal the end of the FAX picture in multi level FAX the terminal program will establish synchronization and decide when to start and when to finish printing picture to the s
385. oxes This feature allows you to compose your mail on your TNC at your leisure and then Forward the resulting messages for eventual delivery Messages may be forwarded any one of three ways either manually by command or by automatic forward You can either forward messages hourly or by your local full service mailbox s reverse forward request Manual and hourly forwards may proceed through up to eight 8 digipeaters allowing the messages to be forwarded through ROSE switches Also NODE forwarding is can be done too thus allowing you to forward mail through NETROM THENET and KA NODE switches Please refer to the NODeforw command in this manual In order to conserve RAM space the SYSOP may specify that forwarded messages be killed upon successful forwarding However if conserving RAM is not a concern then forwarded messages will be flagged F This flag will appear in the message flag block Messages with F flags will be saved in the mailbox for the SYSOP s disposition All forwarding events are monitored on the screen in order to inform the SYSOP of the forwarding progress In order for a message to be eligible for the forwarding process two 2 conditions must be met 1 Messages must have N flags in the message flag block MFJ 1278B MULTI MODE ADVANCED OPERATION The command used to forward a message is FO AII forwards must be done in the stream cmd mode This command is by pressing a CTRL C while in the SYSOP mode Be
386. pect If the picture is elongated vertically you should increase the aspect value If you notice spaces in the printed picture you should set GRAPHLF to OFF The GRAPHLF command determines whether the MFJ 1278B will issue a line feed before the carriage return on every line of graphics The GRAPHLF command defaults to OFF For most printers GRAPHLF should be set to ON If the printed picture appears to be slanted to the left or to the right this indicates that the master CPU clock on the MFJ 1278B may not be in frequency with the transmitting signal To correct this problem you will need to remove the cover of the MEJ 1278B and adjust the ehita AAA ei MAT Thin Aann mat A Anil Ain MFJ 1278B MULTI MODE BASIC OPERATION Display FAX Picture on Computer Screen amp Save it to Disk The MFJ 1278B firmware does not support printing to your computer screen or allow you to save FAX pictures in disk files Printing of fax pictures to your computer screen and saving pictures to disk are a function of the computer software Any good terminal program has a save to disk routine In order to print the fax pictures to your screen you need special software for your particular computer that provides this feature For IBM PC and compatibles Macintosh Amiga and Commodore C64 128 computer users offers an optional Starter Pack that will allow you to receive SSTV FAX in near real time to your computer screen SSTV FAX pictur
387. possible as long as the terminal program can detect the end of the picture when the picture is being received When TVX is turned OFF SSTV picture format is determined by the setting of the TVMODE command For example if TVMODE is set to 5 36 seconds format the picture sent to the terminal will end at 36 seconds Which means that if you set the TVMODE too short you may not receive the whole picture TVX is automatically turned OFF when PRINTGRA is turned ON this sends SSTV picture being received to the built in printer port When SSTV pictures are sent to the printer port in 4 gray levels when PRINTGRA is set to ON TXDELAY n Mode Packet Default 33 Parameters n 0 120 specifying 10 ms intervals This value tells the MFJ 1278B how long to wait after keying up the transmitter before sending data Some startup time is required by all transmitters to put a signal on the air some need more some need less In general crystal controlled rigs with diode antenna switching do not need much time synthesized rigs need time for PLL lockup and rigs with mechanical T R relays will need time for physical relay movement The correct value for a particular rig should be determined by experimentation The proper setting of this value may also be affected by the requirements of the station you are communicating with MFJ 1278B MULTI MODE OPERATIONAL COMMANDS TXDelay n Mode Pactor Default 2 60ms Parameters n Actual Delay Time equals n
388. press any key on the keyboard Random Code Generator If you want to improve your CW copying proficiency you will find the CW Random Code Generator helpful The RANDOMCW command invokes the Random Code Generator Setting the RANDOMCW command to ON activates the Random Code Generator The Random Code Generator can generate Pseudo Ransom Code in two formats The two formats of Pseudo Random Code are NORMAL CW and FARNSWORTH CW The MFJ 1278B uses the setting of the FARnswor command to determine which format to send when RANDOMCW is ON To end CW random code generation type CONTROL C to return to command mode and then type RANDOMCW OFF lt ENTER gt CW random code speed is set by using the MSPEED command described above Many find training for CW tests with a FARNSWORTH method of code generation more valuable It teaches letter recognition at a speed fast enough to avoid the common learning plateau The learning plateau proves to be difficult for some people to get over This is because as their code speed increases they must re learn the sound of the characters To select the Farnsworth method of random code generation set the FARNSWOR command to ON before entering the RANDOMCW mode When the FARNSWOR command is ON the MFJ 1278B generates random code using standard 15 word per minute timing for all code elements When using the Farnsworth generation method the inter character spacing is increased to send the text at the slower s
389. r Pack for the C 64 C 128 and VIC 20 is available from MFJ Enterprises Inc or from any dealer of MFJ products Included in the Starter Pack is a cable to connect the MFJ 1278B TTL port to the user I O port on the Commodore computer Also included with the Starter Pack is a terminal program The terminal program allows compatibility between the MFJ 1278B and the Commodore computer To order specify MFJ 1282B for software on disk or MFJ 1283 for software on tape If you do not have the MFJ Starter Pack then you may use the BASIC communications program given in the Programmer s Reference Guide published by Commodore Use the program listing for true ASCII as these computers use a modified ASCII format internally You will probably want to run your MFJ 1278B at 300 baud on the serial port with these computers NOTE When using the BASIC communications program above you must first use the COMMODORE Key to shift to lower case before using this program Also line 200 should read For J 0 to 64 T 7c J 2J NEXT The information given on page 5 of this chapter is used to make a cable for use with the BASIC communications program mentioned above However do not use pin E connection for this program IBM PCjr The IBM PCjr has a built in terminal program in the BASIC cartridge Start this program by typing TERM Refer to your PCjr BASIC manual for details on this program For best results with PCjr do not run the MFJ 1278B serial port fast
390. r and link state of 6 41 all streams cw f 1 blank AMTOR Characters are sent as CW when ID 6 41 character are issued Pactor Determines the CWIDmode used when in 6 42 the Pactor mode n n SENDCH 0 f fi f Causes the MFJ 1278B to adopt the incoming CW speed as its transmit speed Packet Sets the time and date used by the MFJ 1278B ll CW Controls how MFJ 1278B transmits the 6 43 pending text in the CW buffer CWSPEEDM ONIOFF D T C N DAYTIME DAYUSA ONIOFF DDisc on Packet Determines the display format for the time and date CALL I S 1 This is the last resort disconnect for the Pactor mode DISCONNECT I command Initiates a standard Pactor disconnect 645 DISplay 1 Displays all Pactor commands while in 6 45 PEL a 6 44 6 45 6 45 MFJ 1278B MULTI MODE APPENDIX COMMAND SUMMARY r DEADTIME nnn 33 330Ms Packet DELETE DEFLTDLC i ISPLAY 24 AMTOR DWAIT Packet ON OFF on EAS ONIOFF off CW RTTY ASCII Eee quu es FAXNEG ONIOFF off FAX Determines the basic time interval used by 6 46 the slotting procedure Sets the delay between keying the 6 transmitter and transmitting AMTOR um Sets default DLC number for Host Mode Synchronization character sent by RTTY 6 47 the MFJ 1278B each time transmitter is is E
391. r determined by n INT 525000 F low 1 This tells the CPU what tone frequency you are trying to achieve f Command the MFJ 1278B into calibrate mode by typing CAL lt CR gt Command the MFJ 1278B to key the modem by typing K Select the MCW tone by pressing the space bar until a voltmeter connected to U16 pin 9 reads 5 volts This signal is more conveniently available at the collector of Q12 Adjust R139 carefully until both the CON and STA LEDs on the front panel of the MFJ 1278B are lit Remove the jumper placed at JMP 9 pins 1 and 2 and install at pins 2 and 3 Return the MFJ 1278B to command mode by typing MFJ 1278B MULTI MODE APPENDIX B MODEM CALIBRATION b Place a scope probe on the top pin of JMP10 the pin furthest from Q14 The oscilloscope will be used to indicate when the square wave that will appear at this point during the adjustment procedure approaches 50 percent duty cycle c Command the TNC into calibrate mode by typing CAL lt gt d Command the TNC to key the modem by typing K e Select the MCW tone by pressing the space bar until a voltmeter connected to U16 pin 9 reads 5 volts This signal is more conveniently available at the collector of Q12 f Turn R115 fully clockwise until a click can be heard from turning the pot This could be a little hard to hear g Now begin to rotate R115 CCW slowly Watch the scope while rotating R115 A stable square wave sh
392. r digipeater The reason is obvious There are few 2400 nodes at the present time However it should be pointed out that implementation of a 2400 node is just as easy as building and using a 1200 node To select 2400 packet operation under the CMD command prompt type MODE VP 2400 CR The MFJ 1278B changes its operating mode to 2400 bps packet The TURBO LED will MFJ 1278B MULTI MODE APPENDIX F 2400 BPS PACKET 2400 BPS Receive Audio Setting The 2400 modem employs automatic gain control AGC for its receive audio The receive audio level is pre set for proper 2400 operation and no adjustment is necessary in most cases If you set the receive audio of your radio properly for 1200 operation then in most cases will be suitable for the 2400 operation also No adjustment for the receiver audio on the 2400 modem board is needed 2400 BPS Transmit Audio Setting Transmit audio on the 2400 board is set by adjusting R38 next to T2 on the 2400 modem board Transmit audio for the 1278BT is pre set at the factory to match the audio level of the 1200 modem on the MFJ 1278B mother board Once the 1200 and the 2400 transmit audio are set to the same level then you may adjust the audio level going into your radio by using the Transmit Audio controls on the left side of the MFJ 1278B Note that these controls set the transmit audio levels for all the operation modes of the MFJ 1278B including the 2400 packet operation When adjusting
393. r the manual ID command or one of the initial CWIDMODE features selected by CWIDMODE bits 1 or 2 A fully automatic CW ID is achieved by setting CWIDMODE to 3 Reduced levels of automation are selected by other combinations The eighth mode is manual cwid Invoke manual CWID by issuing the ID command Also see IDTIME The CWIDMODE command in Pactor is very complex and provides several combinations of CWID Below is an example of how CWIDMODE functions Man Mode 1 is manual ID only Only 3 ISS IRS IRS IRS Auto Auto ID interval dependent on the ISS IDTIME setting ISR 4 ISS ISS If ISS does changeover and new ISS disconnects then the new ISS will ID 5 ISS ISS Auto If ISS does changeover then previous ISS ISS auto ID is Disabled only ISS IRS ISS Upon reciept of disconnect from ISS IRS and the disconnect appears on IRS screen the IRS will ID After ID from IRS the ISS will ID ISS IRS IRS IRS When ISS sends changeover new ISS ISS AUTO ID enabled Auto ID for previous ISS is disabled Disconnects are handled the same as Mode 6 MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CWSENDCH nnn Mode CW Default FF Parameter nnn 00 to FF specifying the CW xmit character This controls when the MFJ 1278B transmits the pending text in the CW buffer It is only effective for CW and MCW modes If this is left at the default of 000 the characters to be transmitted are left buffered and unsent until such time as either a SPACE
394. r values represent the lighter shade of gray The value 46 is the white and 69 is black and the values in between define the gray areas Sync is the first value at HEX 80 Sync value should not be changed when resetting the TVBREAK values TVBREAKS control the brightness and contrast of the SSTV images received on the MFJ 1278B computer screen and also the printer port SSTV pictures sent to the MFJ 1278B printer port are set to 4 gray levels With special terminal software which supports multi gray level SSTV you can receive color SSTV and 16 gray level B amp W SSTV If the picture you are receiving does not seem to have the right contrast or tint reset the TVBREAK values This can also be done by changing the setting of the RXBRIGHT command Please see the RXBRIGHT command in this chapter Note that if you choose to operate only 4 level SSTV such as printing to the MFJ 1278B printer port the MFJ 1278B will automatically select 4 TVBREAK values from the 16 TVBREAK values which you have selected TVHSYNC ON OFF Mode SSTV Default OFF When receiving SSTV pictures your MFJ 1278B will usually maintain correct synchronization with the picture as long as the transmitting station is keeping accurate time However some stations may attempt to use a tape recorder or some other unstable picture AA AA Tew anna nn nniernd mintan ie dA Aan craw etn han natti Ant aaner MFJ 1278B MULTI MODE OPERATIONAL COMMAND
395. r you delete You can display the corrected input line by typing the redisplay line character which is set by the command REDISPLA MFJ 1278B MULTI MODE OPERATIONAL COMMANDS BLP ON OFF Mode Packet Default OFF Parameters ON Puts the MFJ 1278B into Host Mode OFF Takes the MFJ 1278B out of Host Mode Setting the BLP command to ON puts the MFJ 1278B into Host Mode After you turn BLP ON and enter transparent mode the host code will run Once BLP is ON subsequent RESTARTS and power up cycles will be directly and silently into transparent mode and it will continue to do so until you turn BLP back OFF or the bbRAM fails In order to run the Host Mode code the following commands must be set up as stated CONMODE TRANS CONV You MUST set CONMODE to TRANS else the first time you re connected you ll lose the DLC connection This is actually putting the MFJ 1278B into Transparent mode PARITY 0 The Parity must be set to 0 for Host Mode operations AWLEN Set the AWLEN command for 8 bits MON If you have BLP ON and MON ON gt ALL lt packets data command beacons whatever will be sent to the host on BLP channel 0x71 If you re being inundated with countless frames when debugging you might want to turn monitor off to avoid the mess MYDLCNUM DEFLTDLC Effective only when non 0 MYDLCNUM this parm tells TNC what the DLC address is of the host ex MTHOST Default is 254 MFJ 1278B MULTI MODE OPERATIONAL COM
396. ral commands that set special character functions You can choose any character for this function by entering the ASCII character code for the key For example you can use a lt CTRL E gt to enter Command Mode by setting cmd COMMAND 5 was 03 The MFJ 1278B displays the previous value in hex and you can also enter character codes in hex if you prefer All of the special characters described below can be changed in the same way as COMMAND We have already mentioned that you can erase mis typed characters by typing the BACKSPACE character You can change this character with the command DELETE If you set DELETE ON you can erase characters by typing the lt DELETE gt character setting DELETE OFF returns to using lt BACKSPACE gt You will probably want to use the same key that your computer normally uses to rub out characters lt BACKSPACE gt is more commonly used than lt DELETE gt by personal computers If you are not sure whether your rubout key produces lt DELETE gt or lt BACKSPACE gt characters von can trv hath settinos af the command and see which warks MFJ 1278B MULTI MODE BASIC OPERATION If you make several mistakes in a line or if you change your mind you may want to cancel the whole line rather than rubbing out the characters one at a time You can cancel the line by typing CTRL X The MFJ 1278B will display a lt BACKSLASH gt followed by a lt ENTER gt If you are in Command Mode you will s
397. rd log with the MHCLEAR command xr 21 aut cut 4 4 1 4 11 toa MFJ 1278B MULTI MODE BASIC OPERATION Your First Packet QSO Although there are still a number of features you should be familiar with you are probably eager to get on the air and try out your new MFJ 1278B Arrange to have another packet operator get on the air to help you get started Make sure that your friend will be close enough to ensure solid copy with no FM popcorn noise It s best if you can get an experienced packet operator to help you get started If you are both beginners try to have both stations in the same room and operate on low power or into dummy loads The first step in starting packet radio operating is to remove the shorting jumper from Digital Loopback header JMP10 Connect your radio to the MFJ 1278B Turn on your computer the MFJ 1278B and your radio Be sure you have adjusted the MFJ 1278B and radio according to one of the methods described in Chapter 3 When the other station transmits the DCD LED on the MFJ 1278B should glow steadily for the duration of the transmission You can work through the remainder of the examples in this chapter while you try out the 1278 on the air Starting the QSO Once you have the MFJ 1278B connected to your radio you are ready to initiate a connect For the sake of example we will continue to use K5FLU in place of your call sign and we will use WBOQRP for your friend s call Make sure you ar
398. re retry limit exceeded A newline is added just before V xxxx Busy A newline is added just before ERMR sent A newline is added just before ERMR A newline is added just before Connect request xxxx This message is omitted The BBSMSGS command is primarily useful for host operation Primarily with WORLI and like bulletin board systems that require link status messages to begin in the first output column The connect request message is omitted during BBSMSGS mode This should be most MFJ 1278B MULTI MODE OPERATIONAL COMMANDS BEACON EVERYIAFTER n Mode Packet Default EVERY 0 Parameters n 0 250 specifying beacon timing in 10 second intervals A value of 0 disables the beacon EVERY Send beacon at regular intervals AFTER Send beacon once after the specified time interval with no packet activity This command enables the sending of beacons and causes the first beacon frame to be transmitted A beacon frame consists of the text specified by the BTEXT command in a packet addressed to BEACON and sent via the digipeat addresses This command enables beacon sending and causes the first beacon frame to be transmitted A beacon frame consists of the text specified by BTEXT in a packet addressed to BEACON and sent via the digipeat addresses specified by the UNPROTO command if any If the keyword EVERY is specified a beacon packet is sent every n 10 seconds This mode might be used to tr
399. re acknowledged for 100 baud The NO200 command works most effectively when both units are capable of NO200 operation Regardless of the setting of NO200 the TNC complies This ensures connectivity with non MFJ units NODEFORW node Mode Mailbox Default Parameters node via x up to 8 vias NODEFORW is an immediate command It is similar to the FORWARD command except that the NODEFORW parameter is the callsign via path to your NETROM THENET or KA node When your TNC establishes the connection to the node it sends the text in NODEPATH to establish a network link to the receiving BBS If all goes well the forwardee will send its sign on string and forwarding will commence To detect failure NODEFORW looks for two strings BUSY and RETR as node connection failure indications Upon finding BUSY or RETR the forward attempt is considered failed and the TNC disconnects from the node The command can contain the callsign of the node and up to 8 vias MFJ 1278B MULTI MODE OPERATIONAL COMMANDS NODEPATH text string Mode Mailbox Default Parameters text string specifying node connect string Enter the command the TNC will command the node connected by the NODEFORW command to link with the receiving BBS Example cmd NODEPATH KB4VOL cmd NODEFORW PSL5 This sequence first connects to the PSL5 node When connected the TNC sends the node connect command KB4VOL to establish a link with the receivi
400. re entered by inserting a carriage return ENTER after each command is typed Note also that carriage return may also be marked as ENTER on some computer keyboards Now try typing just the command by itself cmd MYCALL The MFJ 1278B will respond with MYCALL KSFLU You can see the current value of most parameters by typing the command that sets the parameter followed by just a ENTER This verifies that the MFJ 1278B accepted your callsign The next section describes the commands you will use to configure the MFJ 1278B for proper text display for your particular computer You may not use these commands again unless you change computers or terminal programs SERIAL PORT CONFIGURATION This section describes the commands you will use to set up the MEJ 1278B to work best with your computer These commands will determine how the computer or terminal and the MFJ 1278B communicate back and forth There are commands that determine how the MFJ 1278B displays data on your computer or terminal screen So let s start talking about Serial Port Configuration MFJ 1278B MULTI MODE BASIC OPERATION Parity and Word Length If you are using one of the optional MFJ Starter Packs then you should follow the instructions given by the terminal program documentation with the starter pack If you are not using one of the starter packs then you should use the following instructions to set the parity and word length for the MFJ 1278B
401. red The maximum number of packets which the MFJ 1278B will send before waiting for acknowledgment is specified by the command MAXFRAME This does not mean that the MFJ 1278B will wait until several packets have been entered before transmitting MAXFRAME in combination with the command PACLEN which sets the maximum number of characters in a packet determines how much information can be sent in a single transmission The best combination for efficient data transfer is determined partly by the channel quality and partly by the rate at which the terminal can process data For a 1200 baud terminal data rate you should start with a combination that produces about 300 characters outstanding at one time Radio Baud Rate The radio data transmission rate is software selectable for 300 baud and 1200 baud External modem if installed can also be selected thru software command Note that there is no relationship between terminal baud rate and radio baud rate In order to communicate with another packet station you must use the same radio baud rates The length E Lo 2 ais 2 ede tes at MFJ 1278B MULTI MODE ADVANCED OPERATION signals up to 9600 baud but an external modem is required for operation above 1200 baud An optional 2400 bps PSK modem board is available from MFJ Enterprises Inc This 2400 bps PSK modem board can be installed inside the MFJ 1278B Radio data rate of 2400 9600 is selectable with software command by the
402. relatively strong carrier from an AM broadcast transmission preferably ground wave signal tune the receiver so that the carrier falls near the center of the filter passband Choose a signal level near S 9 for this test If your rig has a built in calibration oscillator this is a good source for this signal Slowly and carefully tune the receiver so that the tone frequency is decreasing Find the point where the signal is reduced by 1 S UNIT from the peak value reached near the center of the filter passband Measure this tone frequency with the counter Record this value as Flow Slowly and carefully tune the receiver so that the tone frequency is increasing Find the point where the signal is reduced by 1 S UNIT from the peak value reached near the center of the filter passband Measure this tone frequency with the counter Record this value as F high Calculate the required modem center frequency as F low F high 2 Once the required center frequency has been determined the modem calibration can be carried out NOTE It is essential that the modulator tones be properly aligned FIRST as they will be used to align the demodulator center frequency Set the modulator tones to Fc MINUS 100 Hz for the low tone and Fc PLUS 100 Hz for the high tone using the procedure given in the owners manual Align the demodulator to the modulator tones using the built in demodulator alignment routine invoked with the RXCAL command as desc
403. rent line CANPAC Cancel current packet COMMAND Command Mode entry DELETE Character deletion MFILTER Characters to be filtered in monitored packets PASS Insert following special character REDISPLA Re display current line SENDPAC Send current packet START STOP User s flow control characters sent to MFJ 1278B XOFF XON MFJ 1278B flow control characters sent to to terminal The following commands enable display features which are active in Converse Mode Refer to the discussions of these commands for details on the operation of these characters in Converse Mode 8BITCONV Retain high order bit from serial port in converse mode AUTOLF Add lt LF gt after lt CR gt BKONDEL Echo after character deletion ECHO Automatic echo of serial input ESCAPE lt ESCAPE gt translation FLOW Type in flow control LCOK Lower case translation NUCR Null characters after lt CR gt NULF Null characters after lt LF gt NULLS Null count SCREENLN Automatic lt CR gt insertion Transparent Mode Packet radio is very well suited to the transfer of data between computers In some cases Converse Mode will work well for computer data transfer However files such as a CMD file on a CP M system a BASIC program or even a word processor text file may contain characters that conflict with special characters in Converse Mode Some of these files may utilize all eight bits of each byte rather than the seven bits required by ASCII codes If you transfer such
404. respond R79 23 Adjust R79 until the 10th LED from the LEFT on the tuning indicator is lit 24 Press the SPACE BAR the MFJ 1278B will respond Tauna D114 antl tha Lth T CN feam thaT DUOT ta it MFJ 1278B MULTI MODE APPENDIX B MODEM CALIBRATION NOTE If recalibrating the VB modem for Low Tone RTTY then remove the jumpers from JMP E F G and H and tune R114 until the 10th LED from the left is lit 26 Press the SPACE BAR The MFJ 1278B will display the CMD prompt This indicates the completion of the MFJ 1278B MODULATOR and DEMODULATOR CALIBRATION If there any problems or difficulties with this procedure feel free to contact our Technical Staff at 1 800 647 8324 and they will be more than happy to help you Calibration Method II The MFJ 1278B Modulator and Demodulator Calibration with CALSET The below procedure needs no test equipment and is accurate if done properly This procedure relies on the internal calibration routine that uses the STA and CON leds as calibration indicators Be sure to follow each step carefully If any problems arise please go back and check the preceeding step to make sure it works as specified Calibration Procedure Calibration Method II is a three 3 step process The three steps areas follows 1 Center the modulator tones over the required modem center frequency Fc 2 Align the demodulator center frequency 3 Align the tuning indicator NOTE ALL THREE STEPS SHOULD BE PERFORMED IN THE
405. ribed in the Appendix B section of this instruction manual MFJ 1278B MULTI MODE APPENDIX E CONVERTING TO TNC 2 CONVERTING THE 1278 TO LIKE TNC 2 With a simple modification as described in this section APPENDIX E the user can easily convert the MFJ 1278B to a like TNC 2 controller Once converted the MFJ 1278B can run programs such as NET ROM THE NET and other special firmware that have been developed for the TNC 2 The modification described below sets the MFJ 1278B into a like TNC 2 mode What this means is the MFJ 1278B will work like an MFJ 1270C 1274C TNC 2 The modification forces the MFJ 1278B to operate 1200 baud VHF packet and to select Radio Port 1 The modification also forces the terminal baud rate to 4800 baud The modification involves replacing IC U27 and U28 with pre programmed headers as shown in Figures E 1 and E 2 Firmware EPROM U23 will be replaced by an EPROM that contains programs such as NET ROM and THENET etc Modification of MFJ 1278B for Like TNC 2 operation involved making it to default 4800 baud for the terminal baud rate 1200 baud radio baud using VHF packet tones on Radio Port 1 The procedure is as follow 1 Remove power from the MFJ 1278 2 Construct Header U27 by connecting pins 9 12 16 and 19 to ground at pin 10 Connect pins 2 5 and 15 to 5 Volts at pin 20 See Figure E 1 below 20 19 18 17 16 15 14 13 12 a4 O BW YN
406. rintable Characters The setting of the MNONPRINT parameter determines whether monitored packets containing non printable characters i e characters other than ASCII CR LF BEL and not between 20 and 7e are monitored or simply discarded The default setting permits monitoring all information packets subject to LCALLS MONITOR MNONA X25 etc When MNONPRIN is OFF information packets containing one or more non printable characters are discarded You may find this command helpful when there are binary transfers on the channel that you d rather not monitor The MNONPRIN command has no effect on data received during connections Monitor ON OFF Mode Pactor Default ON The MONITOR command in the PACTOR command set is the same as the other modes When not connected and MONITOR is ON the TNC displays monitored data and connect attempts MONITOR ON OFF Mode Packet Default ON Parameters ON Monitoring of all packet activity is enabled OFF Monitoring of all packet activity is disabled If the MONITOR command is ON and the MFJ 1278B is not in Transparent Mode packets not addressed to your MFJ 1278B may be displayed The addresses in the packet are displayed along with the data portion of the packet e g N2WX gt WS5FD 3 I m ready to transfer the file now The calls are separated by a gt and the sub station ID field SSID is displayed if it is other than 0 The MALL BUDLIST and LCALLS commands determine which packets are
407. rioritized ACK protocol avoids the above problems by giving ACKs priority access to the channel It does this in such a way that even ACKs coming from hidden terminals are protected from collision The current protocol gives a limited version of this priority access only to digipeated frames Although it will be possible to support digipeating in a compatible with the new protocol fashion compatible digipeating support was not an objective that was addressed in this release Ack prioritization works with slotted channel access in the following way 1 Response frames ACKs are always sent immediately with no time delays unrelated to hardware limitations applied Ultimately not even DCD will be checked for sending an ACK However in this release DCD will still hold an ACK off the channel 2 Stations queued up to access the channel but waiting for a channel busy condition DCD true to clear will start a slotted access procedure only AFTER enough time for a response frame to clear the channel has transpired weather or not the response frame is detectable by the queued up station 3 Slot time windows are selected to be large enough that the local TNC will be able to unambiguously determine whether any other detectable station has selected any slot preceding the slot selected by the local TNC This is to prevent two TNCs which have selected adjacent slots from colliding As you can see under this protocol there will never be a conditi
408. rminal If the MFJ 1278B s buffers fill it will negate CTS signaling the terminal to stop sending data The MFJ 1278B will assert CTS when it is again ready to receive data from the terminal Thus data flow from the terminal to the MFJ 1278B is controlled by the use of the CTS line The CTS line is always asserted if software flow control is enabled in this direction MFJ 1278B MULTI MODE HARDWARE Some serial I O ports do not implement CTS DTR and DSR handshaking If these pins are not connected at the terminal end they will be pulled up and thus asserted by resistors at the MFJ 1278B end However a non standard serial connector may use some pins for other purposes such as supplying power to a peripheral device so be sure that your system pins of J1 whatsoever Note that reference to RS 232C compatibility or the presence of a DB 25 type connector does not guarantee that you have a full RS 232C serial port The MFJ 1278B supports most standard baud rates from 300 through 9600 The port supports standard parity options as well as 7 or 8 bit character lengths Setting these terminal parameters is discussed in Chapter 4 If you want to interface your MFJ 1278B with a device configured as DCE such as a telephone modem or another TNC a so called null modem cable may be constructed to interchange the data and handshake signals See for example Byte February 1981 page 198 MFJ 1278B MULTI MODE HARDWARE JUMPER FUNCTIONS The follo
409. rn conforms to the HDLC standard The AX 25 protocol adds two extensions to BLAP extended address fields and unnumbered information or UI frames BLAP limits addresses to eight bits while AX 25 uses from 112 to 560 bits containing the originator s call sign the destination call sign and an optional list of one to eight digipeater and simplex digital repeater call signs The AX 25 protocol uses the UI frames to send information bypassing the normal flow control and acknowledgment protocol The UI frame is not acknowledged and is transmitted at layer two without fear of disturbing higher layers The AX 25 protocol also uses UI frames for beacons frames automatic identification packets and for sending information frames when the MFJ 1278B is not connected to another TNC e g CQ and QSO activities The ARRL publication Amateur Packet Radio Link Layer Protocol AX 25 Version 2 0 shows the exact specification for the AX 25 protocol The TAPR implementation adheres to this standard for AX 25 version 2 0 The implementation of version 1 0 is almost identical to the TAPR TNC 1 version of AX 25 protocol in software releases 3 x This provides MFJ 1278B MULTI MODE PACKET RADIO PROTOCOL provided by the TRACE command Some texts including the AX 25 protocol specification list the bits in the order in which they are transmitted which is low order bit first The AX 25 protocol presents the control bytes in hexadecimal with x used to indicate fo
410. rnsworth method of transmission where the element dot and dash times are equivalent to 15 WPM but the character spacing of the slower speed is used MFJ 1278B MULTI MODE OPERATIONAL COMMANDS MSTAMP ON OFF Mode Packet Default OFF Parameters ON Monitored frames are time stamped OFF Monitored frames are not time stamped The MSTAMP command enables time stamping of monitored packets The date and time information is then available for use for automatic logging of packet activity or other computer applications The date and time are set initially by the DAYTIME command and the date format is determined by the DAYUSA command Setting MSTAMP ON increases the length of the address display and you may wish to set HEADERLN ON as well to display this information on a separate line MTIMEOUT n Mode Packet Default 30 Parameters n 0 250 specifying 10 sec intervals The MTIMEOUT command specifies the packet mailbox timeout in 10 second intervals Timeouts on the mailbox apply only to remote users the SYSOP can never time out The mailbox will timeout and discon nect after n 10 seconds of mailbox inactivity Note that the synchronous 10 second clock may cause the timeout to occur as much as 10 seconds before the calculated timeout time So if you want to set your Mailbox timeout to 5 minutes then you set the MTimeout command to 30 which would specify a time out of 300 seconds If the MTIMEOUT command is a non zero value the timeout is di
411. roves the reliability of packet radio connections on shared channels The greatest improvement is yielded when all stations in a network are so equipped and configured with the appropriate matching parameters SLOTTING improves channel efficiency by requiring each TNC to flip a many sided die whenever the channel goes from busy to not busy The result of the flip is the number of 10ms DEADTIME intervals the TNC waits before transmitting SLOTTING solves most of the problems that occur when there are two or more stations waiting to transmit when a third is already transmitting Before slotting the first two stations are definitely going to transmit at the same time guaranteeing a collision With slotting the first station will probably choose a slot different from the second If everyone is hearing everyone else collisions are very unlikely In conjunction with slotting the ACKNOWLEDGMENT PRIORITY feature helps improve channel utilization by assigning priority to acknowledgments AX 25 frame types S i e acknowledgments are never delayed by slotting The reason this works is because each TNC recognizes when another is transmitting It also recognizes the destination of each packet it hears If a TNC hears a packet not addressed to it it can assume that somewhere another TNC will send an acknowledgment Therefore on hearing packets for others a TNC will always wait at least one slot time in case the addressed TNC acknowledges And it
412. rs which need TTL signals such as the Commodore C 64 C 128 or the VIC 20 In order to use the MFJ 1278B with your computer the computer must have an RS 232C serial port or a TTL serial port Also a program which supports the serial or TTL port must be used The program will typically be called a modem program terminal emulator or communications program Since there are so many computers on the market today it is impractical for this chapter to provide detailed instructions for each computer Detailed information is given for some of the popular models available in the United States Also provided is general computer interfacing information Starter Packs MFJ Enterprises Inc offers Starter Packs for some of the most popular computers These Starter Packs contain a terminal program and a cable for connecting the MFJ 1278B to your computer The Starter Packs available are as follows MFJ 1282B Commodore VIC 20 C64 C128 in 5 1 4 diskette MFJ 1283 Commodore VIC 20 C64 on tape MFJ 1289 IBM PC amp compatibles in 5 1 4 diskette Supports color SSTV and 16 gray level FAX MFJ 1289M IBM PC amp compatibles in 3 1 2 diskette Supports color SSTV and 16 gray level FAX MFJ 1287B Macintosh in 3 1 2 diskette Supports color SSTV and 16 gray level FAX MFJ 1290 Amiga in 3 1 2 diskette Supports 8 levels SSTV and 8 levels FAX MFJ 1278B MULTI MODE COMPUTER INTERFACING Computer Interface with MFJ Starter Pack
413. rt 124 Baud rate serial port 17 315 321 336 Baud rate switch 317 Baud rate generator 317 bbRAM 118 316 bbRAM loaded with defaults 308 bbRAM protection circuit 318 bbRAM troubleshooting 333 Beacons sent as UI frames 339 Beacons setting address 301 Beacons unnecessary transmissions 190 binary file transfers 5 BUF command 38 Buffer 0 Repeating 40 Buffer sizes 344 BUFKEY 39 74 BUFTIME 40 Bulletin Board operations 5 Bulletin board systems automatic packet transmission 211 Bulletin board systems beacon message 193 Bulletin board systems compatibility with TNC 1 259 Bulletin board systems time stamping of connections 210 Bulletin board systems Transparent Mode 293 Bulletin board systems type in flow control 230 Busy signal sent as DM frames 342 C Cables troubleshooting 333 336 Calibration commands 196 Calibration formula for demodulator tones 196 Calibration formula for modulator tones 196 Calibration troubleshooting 334 Callsign parameter setting 254 MANUAL INDEX MFJ 1278B MULTI MODE MANUAL INDEX Clock NRZ to NRZI encoder 318 Clock speed selection 317 Collision avoidance 231 275 343 Collision detection 343 Command abbreviations 173 Command Defaults 173 Command list format 173 Command Mode 32 Command Mode entry character Transparent Mode 203 Command Mode lt NULL gt transmission 262 Command Mode automatic entry 121 26
414. ry characters default CTRL C within an interval CMDTIME of each other After a final CMDTIME interval in which no characters are typed you will see the cmd prompt If any characters are typed during this interval even Command Mode entry characters the escape will be aborted and all the Command Mode entry characters that have been typed will be sent as packet data If you set CMDTIME to zero you will not be able to escape from Transparent Mode using this second procedure FLOW CONTROL Whenever data is transferred to computers home computers or TNCs there is a chance that the data will be received faster than the computer can handle it Some programs try to deal with this by providing data buffers for storing incoming data until the program is ready for it However this merely postpones the problem since there is a limited amount of room in any buffer In order to prevent loss of data the computer must be able to make whatever is sending data stop sending and later tell it to resume sending If you are a home computer user you are probably already familiar with one type of flow control which allows you to stop the output from the computer while you read it and restart it when you are ready for more Data lossThe MFJ 1278B s input buffer may fill up in Command Mode if you try to type too long a command In Converse Mode the buffer may fill up for any of several reasons you mav be usine a faster serial port baud rate than the ra
415. s and Line Wrapping eese eene rennen nne 33 THE MFJ 1278B MULTI MODE MODEM eee eee eene eene 33 OPERATIONAL MODES entree e nro eS temer oe eee 35 Verifying Operation 8 35 Mode Switching With the MODE Command sese 35 Radio Port Switching tremere eet a 36 MEMORY BUFFERS Ripe iet e ee eq Ee EORR e 36 Loading the Memory Buffers sess 37 Transmitting the Memory Buffers sese 37 Butter Seral Numbers eni ende ete fe eeepc etii 37 Memory Repeat and Buffer Repeat Time 38 Chaining the Memory eene 38 TUNING INDICAT OR 5 5 etie rette p ER C E Er eripe ir r 39 PACKET OPERATION 5 RB oam Ue ct CR pete ERR 40 VHF Racket e RIED vhs eMe Iis eee 40 A Connecting and Disconnecting Exercise eseeeeeeeee 40 Di Sip atin gas iiir err HERPES ERR tonsa ine 42 Unsuccessful Connections sere 43 Monitoring Channel Activity eese eene eene 43 Your First Packet sese erepti 45 Starting the QSO cose diee e RO D eene terere Dra ates 45 Digipeating epe a enitn UM tente 46 Monitoring onthe Aif id cedet er iere tied HE SEP ER eek 47 Special Input Characters eene nennen nennen nenn
416. s are shown in bold face and received packets are shown underlined Commands and other special keywords are shown in upper case other text entered to the MFJ 1278B is shown in upper and lower case SPECIAL CHARACTERS The MFJ 1278B recognizes a number of special characters for input editing flow control and other control functions You can change any of these special characters to customize the MFJ 1278B to suit your applications your computer your whim Commands within the MFJ 1278B set these special characters These special character commands specify the ASCII character code for the desired character You can disable any special character feature by setting the character value to 0 The user can disable the input editing characters without no serious side effects You should use caution in disabling the flow control or Command Mode entry characters Also be careful not to set two special characters to the same value Various control characters are normally used for special characters The user would enter control characters by holding down the CONTROL key CTRL while typing another character For example to enter a Control C or lt CTRL C gt the user would hold down the CONTROL key CTRL and press the C key at the same time If your computer does not have a special control key you will have to consult your computer s documentation to see how to enter these characters If you will have difficulty entering control characters you can ch
417. s established OFF text message is not sent CMSG enables automatic sending of the message set by CTEXT whenever your MFJ 1278B accepts a connect request from another TNC For example if you have left your station running even though you do not want to operate just now you might want to set CMSG ON to let people know that you cannot talk when they connect to your MFJ 1278B When you are ready to operate you would set CMSG OFF CMSGDISC ON OFF Mode Packet Default OFF Parameters ON Automatic disconnect enabled OFF Automatic disconnect disabled This command controls whether the MFJ 1278B will initiate a disconnect sequence after it is connected to If CMSG is OFF or CTEXT has no connected text the MFJ 1278B initiates a disconnect immediately upon receiving information or acknowledgement frames from the other station If CMSG is ON end CTEXT contains some text information the MFJ 1278B initiates a disconnect after the packet containing connect text CTEXT is acknowledged This command may be useful to bulletin board operators or others with a need to send a short message confirm its receipt and disconnect NOTE Use this command with care If you find you re able to receive connects yet never get data it s possible CMSGDisc has been left on It s also possible is that RS 232 DCD is holding the terminal off See Chapter 5 for details on hardware flow control MFJ 1278B MULTI MODE OPERATIONAL COMMANDS COMMAN
418. s is in the Packet command set the other being in the Pactor command set Both of the MAILBOX commands must be ON If either of the MAILBOX commands is OFF then the Pactor mailbox will not function Your MFJ 1278B is ready for Pactor Mailbox operations As we mentioned earlier the SYSop command must be issued from the Packet mailbox You can access the SYSOP in La n 1 4 E 21 1 MFJ 1278B MULTI MODE BASIC OPERATION The MFJ 1278B will respond with the standard cmd prompt From the cmd prompt type SYSOP ENTER Your MFJ 1278B will respond with 2 1 1 Mailbox ready n free Mailbox B E H elp J K L M R S T You are now in the Packet mailbox as the SYSOP of the above command are available to you as the SYSop Please refer to the Easy Mail mailbox section in Chapter 5 of this manual for further information on the above command From this prompt you as the SYSop can Kill List Read Send messages in the mailbox You can also send private messages edit the messages headers bank switch the mailbox RAM General Overview This section will deal with the Pactor Mailbox in general We will take a look at the Pactor mailbox from mainly a remote user s stand point However lets take first things first You very well cannot operate the Mailbox without knowing the functions of the commands When remote user connects to the Pactor mailbox and issues the changeover your mailbox will present
419. sabled MFJ 1278B MULTI MODE OPERATIONAL COMMANDS MULTIFAX ON OFF Mode FAX Default OFF Parameters ON MFJ 1278B is set to transmit and receive FAX picture in raw data format OFF MFJ 1278B is set to transmit and receive FAX picture in 2 levels format When MULTIFAX is turned ON MFJ 1278B is set to transmit and receive multi level FAX pictures FAX Raw data format is sent to the RS 232 port during receiving and raw data is also expected from the terminal program for MFJ 1278B to transmit multi level FAX picture Also see PIXTONES Multi level FAX printing to the MFJ 1278B printer port or printing to the computer screen is not supported by the MFJ 1278B firmware A Special terminal program must be used for this operation for those who wish to write terminal program to support MULTIFAX more information is provided in the FAX Operation section of this manual When MULTIFAX is OFF the default setting MFJ 1278B will operate in standard 2 level FAX mode FAX data format is sent to the MFJ 1278B printer port when PRINTGRA is OFF IF PRINTGRA is ON MFJ 1278B sends only 2 level data the the RS 232 port Note that when MULTIFAX is turned ON the PRINTGRA command willl be ignored This means that under FAX mode with MULTIFAX turned ON the MFJ 1278B will start to send raw data to the terminal regardless of the setting of the PRINTGRA command MYCALL call n Mode Packet Default NOCALL 0 Parameters call Callsign of your MFJ 1278B n 0
420. sed to display all of the current AMTOR parameters type DISPLAY at the a cmd prompt The user must be in the AMTOR mode to obtain the cmd prompt DWAIT n Mode Packet Default 33 Parameters n 0 250 specifying default wait time in 10 ms intervals This value is used to avoid collisions with digipeated packets The MFJ 1278B will wait the default wait time after last hearing data on the channel before it begins its own keyup sequence unless the MFJ 1278B is waiting to transmit digipeated packets This value should be agreed on by all members of a local area when digipeaters are used in the area The best value will be determined by experimentation but will be a function of the keyup time TXDELAY of the digipeater stations This feature is intended to help alleviate the drastic reduction of throughput that occurs on a channel when digipeated packets suffer collisions It is necessary because digipeated packets are not retried by the digipeater but must be restarted by the originating station If all stations specify a default wait time and the right value of n is chosen the digipeater will capture the frequency every time it has data to send since digipeated packets are sent without this delay The DWAIT timer is defeated superseded when the command ACKPRIORITY is ON EAa ON OFF Mode Pactor Default ON Echo As Acknowledged When ON the TNC echos transmitted data to the terminal upon receipt of the remote s acknowledgement of
421. ser two 2 radio ports This allows for both FM and HF operation from either radio port Since the radio ports are independent of each other the user is not restricted to FM or HF operations The radio ports on the MFJ 1278B allow an FM radio and an HF radio to be connected at all times In fact you can have any combination of HF radios or VHF radios connected to the radio ports at any time The pin designations for both radio ports are exactly the same See Fig 3 1 for the radio port pin designations The radio ports on the MFJ 1278B are switched by using the RADio command We will discuss radio port switching in the next chapter Once the user obtains the proper microphone connector not provided use Fig 3 2 to wire the 5 pin DIN cable provided to the microphone connector If two radios are to be used with the MFJ 1278B you will need to wire two radio cables You may obtain the specific pin designations for your radio s microphone connector from your radio s manual Appendix A at the end of this Instruction Manual lists pin assignments for some of the most popular radios The accuracy of this information is not guaranteed You should verify this information with your radio manual Mic Audio Black Ground Green PTT Red Rec Audio Yellow Squelch Input White Cable Shell Bare Wire Cable Shell Fig 3 2 Radio Connector Pin Diagram Two 5 pin male DIN cables are provided with the MFJ 1278B These cables
422. sful Connections Sometimes you will initiate a connect sequence that can t be completed The station may not be on the air or it may not be within range of your station You may have even mis typed the other call sign If the MFJ 1278B does not get a response to its first connect packet it will try again You can control the number of attempts the MFJ 1278B will make with the command RETRY The default number of retry attempts is 10 If the MEJ 1278B does not get an answer after this number of transmissions it will give up and display the message retry count exceeded DISCONNECTED The retry count is also used once the QSO has started Each transmission sent to the other station is acknowledged or ACKed by the other station and vice versa The ACK means that the packet was received and that the CRC checksum indicated that it was received without errors This is the means by which packet radio can ensure error free communications Sometimes a packet will not be received correctly by the other station either because of accidental interference from another packet station a collision or because of other channel noise If the MFJ 1278B does not get an ACK soon enough it retransmits the packet and increments the retry count If the count set by RETRY is exceeded the MFJ 1278B will automatically disconnect and display the same message retry count exceeded DISCONNECTED The automatic disconnect feature keeps a MFJ 1278
423. sical symptoms Are any components discolored Does something smell burnt Do any of the parts seem excessively warm If you have never had your fingers on operating digital integrated circuits before you may erroneously conclude they are too hot when they are actually operating normally Take for instance the Z80 CPU and the Z80 SIO They generally are warm to the touch In general their normal temperature will be well below the boiling point of water but you may not want to keep your finger on them very long Step 3 Assembly Problems Carefully inspect the PC board and component installation Are any cold solder joints present Is a metal screw shorting to the board anywhere Are all ICs firmly seated in their sockets Are any IC leads tucked under the chip or otherwise bent in such a manner that they are not making proper contact with the IC socket Inspect the diodes and electrolytic capacitors for proper installation Are the diode cathodes pointing the correct way Are the negative ends of the electrolytic capacitors pointing the correct way MFJ 1278B MULTI MODE TROUBLESHOOTING Step 4 Cabling Problems Inspect the interconnection cabling Does it work on another TNC Has the radio and or terminal been successfully used on packet with this or another TNC Are all the connections tight Has the cable frayed or broken SPECIFIC SYMPTOMS While the steps described above may seem obvious careful inspection often will point to the pr
424. signal is used for transmitter activation The SIO will pull this output low when the MFJ 1278B wants to transmit otherwise it will remain high This pin is normally jumpered to pin 6 when the on board modem is used Pin 6 Transmitter Key Input This signal is an input to the on board modem It activates the PTT pin of the radio connector via the watch dog timer It should be left high and pulled low only when transmission is desired This pin is normally jumpered to pin 5 when the on board modem is used Pin 7 CONNECT Status Output This pin is an output from the SIO It is normally low and goes high only when the MFJ 1278B is in the connected error free mode with another packet station Its status is monitored via the CON LED Pin 8 Unacknowledged Packets Pending Status Output This pin is an output from the SIO It is normally low and goes high only when this MFJ 1278B has unacknowledged packets in its transmit buffer Its status is monitored via the STA LED Pin 9 CTS Input This pin is an input to the SIO It is high when the attached modem is not ready to accept data and low when the attached modem is ready to accept data The TNC will not attempt to send data when this pin is high This pin is normally jumpered to pin 10 when the on board modem is used Pin 10 Transmitter Key Input This pin is physically tied to pin 6 above It is used in conjunction with pin 9 above to allow the MFJ 1278B to use the on board modem whene
425. solutely essential for HF packet operation The tuning indicator makes it possible for the operator to reduce the modem to modem frequency error to near zero Reliable HF packet operation requires tuning errors of 30 Hz or less 6 Many of the stations currently operating HF packet do not have their radio bandwidth matched to the characteristics of a 300 baud 200 Hz shift FSK signal This causes a severe degradation in modem performance resulting in unnecessarily increased numbers of retries and drastic reduction in data throughput for the SHARED channel Serious HF packet operation should not be considered without a 500 Hz filter in the receiver IF An audio filter is NOT an acceptable substitute Squeezing the edges of SSB filters together with so called variable bandwidth tuning VBT or PBT to produce a 500 Hz bandpass is difficult to properly align and results in operation near the edges of the filters where the phase response and group delay characteristics are particularly poor So while this offers some marginal improvement over wide filters it is not a good substitute for a real 500 Hz filter In spite of the above factors HF packet communications can be a reliable and enjoyable mode The trick is to operate in a manner that allows you to avoid the problems mentioned above Your purchase of an MFJ 1278B has already helped you avoid the DCD and tuning indicator difficulties Configuring your radio bandwidth to match the spectral chara
426. st 4 characters in length and the signal be of sufficient quality that the 200 baud area be error free when received Unfortunately the callsign in the connect attempt packet unlike all other monitored data is subject to corruption the Pactor protocol did not provide for error free connect packets Therefore you may at times see a garbled callsign in a Connect message but it should be rare Remember this garbling affects only monitored connect attempt packets It does NOT affect ARQ or FEC data packets because they are error protected by a sophisticated CRC checking scheme SPEEDup SPEEDdown Speedup and speeddown When the MFJ 1278B is the receiving station or IRS and after four consecutive failures to receive a 200 baud packet the TNC requests a SPEEDDOWN to 100 baud A SPEEDUP occurs when the MFJ 1278B receives 10 error free 100 baud packets If NO200 is set to ON all SPEEDUP requests are inhibited Bad band conditions During poor band conditions links will be quicker by avoiding use of the 200 baud mode Setting NO200 to ON instructs the MFJ 1278B to avoid 200 baud operation in a compatible way AUTOMATIC ON LINE COMPRESSION Huffman coding Huffman coding offers somewhere between 2 1 and 4 1 compression on lower case German and English plain text In receiving modes conversion to 8 bit data is automatic On transmit the MFJ 1278B packetizes outgoing data and transparently selects the mode Huffman coding will be used if a a
427. ste ete Ste fon TVA oe MFJ 1278B MULTI MODE OPERATIONAL COMMANDS ID Mode Packet Immediate Command ID is an immediate command It will send a special identification packet ID can be used to force a final identification packet to be sent as a digipeater station is being taken off the air The identification packet will be sent only if the digipeater has transmitted since the last automatic identification An identification consists of an unsequenced I frame whose data field is your station identification The identification packet is addressed to the CQ address set by the UNPROTO command Your station identification is your callsign as setby MYCALL with R appended Id Mode Pactor Immediate Command The ID command is an immediate command that when used will invoke an immediate CWID to be sent The ID will be sent at 20 WPM and will consist of the station callsign IDTime nnn Mode Pactor Default 590 Parameters nnn 6 lt nnn lt 255 The IDTime parameter specifies the time interval between automatically generated CWID events The actual time yielded is equal to IDTIME 10 seconds The IDTime parameter is relevant only when bit 0 of the CWIDMODE parameter is set to 0 The default IDTime is 590 seconds K Converse Mode Pactor Immediate Command This command will put the MFJ 1278B into CONVERSE mode from the p cmd MFJ 1278B MULTI MODE OPERATIONAL COMMANDS KILONFWD ON OFF Mode Mailbox Default OFF Parameters ON
428. stics for the various methods of operation With your radio in the receive mode open the squelch control so that a steady hiss is present on a speaker Set the volume control to the minimum volume position The tuning indicator on the MFJ 1278B should drift off to one side of the display and become stationary It may drift enough to disappear off the end of the display Slowly advance the audio output level with the volume control until the tuning indicator springs to life and dances around a point near the middle of the display This is the absolute minimum audio level for marginal copy Continue to advance the volume control until there is approximately twice as much audio present at the receiver output This can be estimated by ear or measured with an oscilloscope or AC voltmeter This will be near the correct amount of audio for NBFM operation Levels higher than this will not degrade the modem performance as long as the receiver audio amplifier is capable of producing the chosen output level without distortion clipping MFJ 1278B MULTI MODE RADIO INTERFACING The bandwidth of the receiver audio will have an effect on modem sensitivity to false DCD Some receivers produce wideband audio that will NOT produce any false DCD activity regardless of the threshold control setting In this case set the DCD threshold control to its maximum clockwise rotation This will not effect modem performance Method 2 Accessory Jack or Interface Box Connec
429. sue a command Anything you type after this prompt will be interpreted as a command to the MFJ 1278B If a monitored packet has been displayed the prompt may not be visible even though you are in Command Mode You can type the redisplay line character set by REDISPLA to retype the prompt was Whenever you change the setting of one of the MFJ 1278B s parameters the previous value will be displayed This confirms that the MFJ 1278B properly interpreted your command and raminde von af what van have dana MFJ 1278B MULTI MODE SYSTEM MESSAGES too many packets outstanding This message would appear in response to a CONVERS or TRANS command under special circumstances If you have previously entered packet data filling the outgoing buffer in Converse Mode or Transparent Mode and then returned to Command Mode You will be allowed to enter one of these modes when some of the packets have been successfully transmitted Mailbox Messages Expected bank n x This message occurs when you try to switch to an extended Mailbox memory bank which does not exist For example trying switch to memory bank 8 using the 512K memory extension Memory bank 8 does not exist only banks 0 thru 7 are present You have new mail Upon accessing the mailbox this message will appear if there are any new messages addressed to you These will be the messages with the N message flag set Once the message is read and the Y message is set this message will n
430. t i m ze PEA External DN Speaker Speaker s 122 Connecter J2 MFJ 1278B 2 4 Fig 3 7 External Interface Box All Cables Should be as Short as Possible If you built the external interface box as in Fig 3 7 then follow this procedure to adjust R s 1 Install JMP J on the MFJ 1278B PC board 2 Temporarily solder a variable resistor in place of R s Fig 3 7 The maximum value of this resistor can be determined by experiment However a 500K resistor should be adequate most cases Connect your MFJ 1278B to the radio Connect the microphone to the radio or to the interface box if one is being used Connect the radio to a dummy load and listen to the transmission with another nearby radio Adjust R s for proper modulation as the next sections describe MFJ 1278B MULTI MODE RADIO INTERFACING Transmit Audio Level Adjustment for Interface Method II 1 Turn on the MFJ 1278B and computer and start your terminal program Enter the modem calibration procedure by typing CALIBRA Press the K key to key the transmitter then tap the space bar until the higher of the two tones is heard Pressing the K key again will unkey the transmitter After the transmitter has been keyed for a few seconds it will shut off automatically by the transmit watch dog circuit As you perform the adjustments below you will have to periodically
431. t Tone For example if you like to have the packet connect tone then leave JMP Z intact If you do not wish to hear the transmitted or received packet signal then disconnect JMP X to disable the transmitted audio and JMP Y for received audio MFJ 1278B MULTI MODE RADIO INTERFACING CW INSTALLATION The MFJ 1278B user can send and receive CW by using your computer keyboard However the MFJ 1278B expands CW operating fun by allowing you to connect an iambic paddle to the KEY input jack of the MFJ 1278B This feature allows you to use the MFJ 1278B as a CW memory keyer So now the user can operate CW from either the computer or an iambic paddle Connect the MFJ 1278B for CW operation as follows Keying Connection Connect a two conductor shielded cable from the Keying Output jack of the MFJ 1278B to the keying input of your radio The keying output jacks of the MFJ 1278B accept a standard RCA phono plug The keying output of the MFJ 1278B provides both the Direct or Grid Block type of keying output for your radio The default output setting for the MFJ 1278B is Direct type keying If your radio requires Grid Block type of keying you may set the keying output to Grid Block by moving the shorting jumper on JMP22 from positions 2 amp 3 to positions to 1 amp 2 See Appendix G at the end of this manual to locate JMP 22 on the MFJ 1278B mother board After properly connecting the keying cable you must determine what kind of keyin
432. t if power a outage occurs the MFJ 1278B will sign on when power is on again If AUTOBAUD is OFF and the terminal program baud rate does not match the MFJ 1278B then once the MFJ 1278B 15 turned off it will not sign on again If you reset the MFJ 1278B or the terminal program baud rate then the MFJ 1278B will sign on Once reset the MFJ 1278B will default AUTOBAUD to ON and it will sign on upon power up and with a few strikes of the return key The MFJ 1278B can be reset by removing JMP 5 on the main PC board of the MFJ 1278B The MFJ 1278B terminal baud rates of 300 and 19 200 is selectable by a jumper on JMP 18 on the mother board Please refer to Chart XX on page to locate JMP 18 For 300 baud set the shorting jumper to positions 2 3 and for 19 200 baud set the shorting jumper to positions 1 2 The factory setting for JMP18 is positions 1 2 MFJ 1278B MULTI MODE COMPUTER INTERFACING VERIFYING SERIAL PORT OPERATION Now that you have a terminal program and the connecting cable for attaching the MFJ 1278B to your computer you are ready to verify that the MFJ 1278B will communicate with your computer 1 Turn on your computer Load and run the terminal program 2 Setthe parameter of the terminal program as follow Word Length 8 bits Duplex Full Parity None Stop Bits 1 Baud Rate 300 1200 2400 4800 9600 or 19 200 3 Turn on your MFJ 1278B and note that the PWR STA and CON LEDs are lit 4 the MFJ 1278B termin
433. t on the display you should set ECHO ON If you see two copies of every character you type you should set ECHO OFF If you see the characters you type displayed correctly you have ECHO set correctly MFJ 1278B MULTI MODE OPERATIONAL COMMANDS ECho ON OFF Mode Pactor Default ON Parameter ON Characters received from the computer or terminal are echoed by the MFJ 1278B OFF Characters are not echoed The ECho command in Pactor performs the same function as in Packet mode except that echoing is deferred when EAA is ON as described above EPSON ON OFF Mode All Default ON Parameter ON Enables EPSON graphics mode to the MFJ 1278B printer port OFF Disables EPSON graphics mode to the MFJ 1278B printer port This parameter specifies whether there is an EPSON tm compatible or C Itoh 8510 P printer attached to the printer port of the MEJ 1278B If the printer connected to the MFJ 1278B is not an EPSON or C IToh 8510 P you should set EPSON to OFF ERrstrin cccc Mode Pactor Default where cccc is 1 to 5 characters in length The ERrstrin command designates the character string that is displayed when an unconnected packet is monitored out of sequence To clear the string set the first character to or amp ERUS ON OFF Mode Amtor Default ON AMTOR monitoring is protected to some extent from errors but not fully If ERUS is ON at times when the MFJ 1278B is receiving and detects the reception of errors the ASCII u
434. t the message The Subject column will contain a brief message title Note that the number of slots for an MFJ 1278B without memory expansion board is 30 For an MFJ 1278B with the memory expansion installed the maximum slots per memory bank is 99 tha M aillha e Lata all mannan ena tt nll tana tha MFJ 1278B MULTI MODE ADVANCED OPERATION 6 Anyone who accesses the Mailbox can read messages or that are addressed to him her Also a message that is a addressed to ALL such as bulletins can be read by anyone Messages can be read by two 2 different methods Below are the two methods A This method will allow the remote user local or remote SYSOP to read a group of messages This is only good for a group of messages with the same callsign as MYcall The set conditions of the Type or message flags have an effect on a read process They can be set to an N Y or an F To perform this type R CR B Messages can also be read individually by the slot number This is good for reading other messages like bulletins or messages addressed to ALL In order do an individual read type Ri CR Where is the slot number of the message that you wish to read The Mailbox will respond with the message from the slot specified messages read will be in the following format Slot tm To From Subject This is an example of a message from the Mailbox Where Slot column is the number of the slot that
435. t time If it is offered more than this to handle performance falls off sharply with increased offered load Currently the typical AX 25 simplex channels observed on the HAM bands tend to hover around 10 to as high as 18 percent throughput This is far below the 62 percent that is possible when the protocol is working right MFJ 1278B MULTI MODE ADVANCED OPERATION Packet Picture Transfer The MFJ 1278B gives you the unique ability to transmit and receive Packet Pictures Unlike the binary file transfer ability common to all packet controllers that lets you transmit and receive picture files MFJ 1278B lets you transmit and receive actual packet pictures directly You can also transmit and receive FAX SSTV and other graphics formats pictures with the MFJ 1278B in the VHF packet mode Packet pictures received are directed to and printed on the built in printer port on the MFJ 1278B Any EPSON or BM graphics compatible printer may be used Packet pictures can also be sent to the computer screen if special software such as the MFJ 1284 is used Printing Packet Pictures thru Built in Printer Port This routine is for users who do not have a special terminal program like MFJ MultiCom to receive high resolution Packet Pictures Packet picture data transmitted from the connecting packet station is received and data is sent directly to the printer attached to the MFJ 1278B without any intervening modification Therefore all data MUST
436. t to set FRACK to its worst case value for whatever baud rate you are using on the radio port This way you can make adjustments to PAClen without having to worry about interaction with the setting of FRACK The FRACK settings that should be used at least initially for BETA testing are as follows BAUD RATE FRACK SECONDS 1200 3 300 8 Note that these settings apply when everyone on the channel is running the new protocol This assumes that all stations on the channel have both DWait and RESPtime set to 0 If you are running the new protocol on a channel where some of the stations have long RESPtime delays those stations will not be able to successfully communicate with you after connecting If you wish to communicate with these stations you will have to set your FRACK timer to a number which is longer than the other stations RESPtime delay MFJ 1278B MULTI MODE ADVANCED OPERATION Initial Parameter Settings Summary The settings for use at 1200 baud on a VHF FM channel are ACKprior ON SLots 3 DEAdtime 33 ACKTime 13 RESPtime 0 If you require a nonzero value for this parameter in order to prevent ACKing individual packets in a MAXframe greater than 1 blast your DCD circuit is not working Please get it fixed DWait 0 DWait should be set to 0 even if there are digipeaters on the channel The new system will not degrade the performance of digipeaters on the channel because the ACKWAIT can be used by the DIGI MAXfr
437. t used in Converse Mode This command enables the periodic automatic sending of packets in Converse Mode This feature may be used for computer communications such as Bulletin Board operation when the full Transparent Mode features are not desired If CPACTIME is ON characters are packetized and transmitted periodically as they are in Transparent Mode but local editing and display features of Converse Mode are enabled and software flow control may be used For a discussion of how periodic packetizing works see the command PACTIME which controls the rate and mode of packet assembly You should set CR OFF in this mode since otherwise the send packet character will be inserted in the data being packetized even though it was not typed In order to include CR characters in transmitted packets set SENDPAC to a normally unused character e g lt CTRL P gt at which point TNC will treat CR as an ordinary character You can set CPACTIME ON for a mode of operation similar to full break in CW in which your text is transmitted soon after you type it but in short bursts of a few characters and the other station may break in at will Some operators find it easier to carry on a conversation in this mode since it eliminates the delays while long packets are being typed CR ON OFF Mode Packet Default ON Parameters ON The send packet character normally CR is appended to all packets sent in Converse Mode OFF The send pack
438. taining synchronization and end of picture detection of pictures In 8 gray levels the raw multi level data are packed two pixels per byte To enable ASCII transparency of the raw data the MFJ 1278B biases each byte with 30 On transmit you must likewise bias the outgoing data with 30H There are two exceptions If the actual data byte Before unbiasing is p or q then the 1200 Hz Syne tone is being received p means it was receivedin the first time position q the second After unbiasing bit 765 43 2 1 0 data x x a aa bbb x don t care a b first and second pixel groups MFJ 1278B MULTI MODE BASIC OPERATION Coding If prior to unbiasing the value of the data byte is an ASCII p q or r then the received byte is a sync byte Otherwise the received byte contains actual display information as described above The color level of each pixel contain in the data byte is given below 000 001 110 111 white lightest grey darkest grey black NOTE If the data byte is NOT a sync byte you must remove the 30H bias BEFORE extracting the pixel information For example if an ASCII 9 is received then the following steps should be taken 1 Remove bias 39H 30H 9H 2 Extract pixel information aaa 001 bbb 001 3 Display two pixels of lighest grey level If an ASCII p q or r is received then process the byte as a sync tone Saving SSTV Pictures to Disk When the PRINTGRA command of the MFJ 1278B is ON SSTV p
439. te amp time is yymmddhhmm where yy is the last two digits of the year mm is the two digit month code 01 12 dd is date 01 31 hh is the hour 00 23 and mm is the minutes after the hour 00 59 All these codes must be exactly two digits so that numbers from 0 to 9 must be entered with leading zeros The MFJ 1278B does not check thoroughly for the correct number of days in a month so you should use some judgment when you set the date The date amp time parameter is used by the commands CONSTAMP and MSTAMP to time stamp received and monitored messages Entries in the heard displayed by MHEARD are also time stamped if date amp time has been set The MFJ 1278B s time is updated continuously as long as it is powered up You must reset the date and time each time you turn on the MFJ 1278B If you don t do this the commands CONSTAMP and MSTAMP will not enable time stamping If you type DAYTIME without a parameter the MFJ 1278B will display the current date and time The format of the display is dd mm yy hh mm if DAYUSA is OFF and mm dd yy hh mm if DAYUSA is ON The format for entering date amp time is not affected For example cmd DAYTIME 8402291530 sets the date and time to February 29 1984 at 3 30 PM The display of the date and time with DAYUSA ON would be cmd DAYTIME 02 29 84 15 30 26 MFJ 1278B MULTI MODE OPERATIONAL COMMANDS DAYUSA ON OFF Mode Packet Default ON Parameters ON Date is displayed in the form
440. ter or waited PACTIME if CPACTIME enabled the packet can not be canceled even if it has not been transmitted Packet cancellation like other input editing features is disabled in Transparent Mode Cancel Display Output The cancel packet character also functions to cancel display output in Command Mode If you are in Command Mode and type the cancel packet character any characters that would be typed on the screen except echoed characters are thrown away by the MFJ 1278B Typing the cancel output character a second time restores normal output To see how this works try typing DISPLAY then type a CTRL Y The command list display will stop You won t see any response from the MFJ 1278B to commands Now type another lt CTRL Y and type DISPLAY again to see that the display is back to normal You can use the cancel display feature if you inadvertently do something that causes the MFJ 1278B to generate large amounts of output to the terminal such as giving the DISPLAY command or setting TRACE ON If you are in Converse Mode or Transparent Mode and want to cancel display output you must exit to Command Mode and then type the cancel packet character The default character for the CANPAC command is a CTRL Y MFJ 1278B MULTI MODE OPERATIONAL COMMANDS CBELL ON OFF Mode Packet Default OFF Parameters ON Connect bell enabled OFF Connect bell disabled This command is used to control whether an ASCII 07 or CTRL G BELL
441. ter indication Tuning Indicator Alignment This procedure adjusts the tuning indicator so that it correctly indicates when a signal is properly tuned in relation to the demodulator center frequency In order for the Tuning Indicator to be properly aligned the above calibration must be done properly otherwise you will align the Tuning Indicator improperly NOTE The tuning indicator should ONLY be adjusted in reference to the 300 baud 200 Hz shift modem used for HF packet and RTTY If adjusted for this modem it will indicate with sufficient accuracy for all other modes If you have not just finished aligning the modem as per the above instructions do so now Otherwise you may be aligning the tuning indicator to incorrect calibration settings Alignment Procedure 1 Install push on jumpers at JMP 4 and JMP 7 if they are not still in place from the MFJ 1278B MULTI MODE APPENDIX B MODEM CALIBRATION 3 Command the calibration routine to send 50 percent duty cycle square wave data from the modulator by typing RXCAL CR 4 While observing the LEDs in the tuning indicator adjust R212 in the tuning indicator area so that either the 10th or 11th led from the left or both are illuminated 5 Return the MFJ 1278B to command mode by typing 6 Remove jumpers at JMP 4 and JMP 7 This completes the tuning indicator alignment Now the modulator demodulator and tuning indicator are all aligned to the same center frequency If you n
442. terminal or computer off The next morning turn the computer on then type CTRL Q The MFJ 1278B will dump everything monitored during the night limited only by the amount of available RAM The MFJ 1278B can operate unattended for extended periods of time If you would like to have the MFJ 1278B operate as a digipeater but not connect with a station be sure to set DIGIPEAT ON and CONOK OFF This is probably most useful when setting up a dedicated digipeater in a remote location Packet Formatting The maximum length of a packet is determined by the command PACLEN If you type more than the maximum number of characters without entering a send packet character the MFJ 1278B will transmit a maximum length packet In Transparent Mode a packet will be sent if the maximum number of characters is entered before the delay conditions set by PACTIME force a packet to be sent Some MFJ 1278Bs may not be able to accept packets longer than 128 characters If you have set the send packet character to CR you probably want the CR to be included in the packet for display at the other end If you set the send packet character to a special non printing character you probably want the character to be treated as a command only The command CR controls whether the send packet character is to be echoed and included in the packet MFJ 1278B MULTI MODE ADVANCED OPERATION Commands Affecting Protocol This section describes some of the commands that aff
443. test is only valid if your printer is connected to the MFJ 1278B parallel port This test can not be performed if the printer is connected to the parallel port of the computer MFJ 1278B MULTI MODE RADIO INTERFACING RADIO INTERFACING Computer interfacing covered in the previous chapter is only half the interfacing task The other half is connecting your MFJ 1278B to your radios 1278 Radio Ports Interfacing the MFJ 1278B to your radios involves connecting the following signals at Radio Port 1 and Radio Port 2 The pin outs of Radio Port 1 and Radio Port 2 are shown in Fig 3 1 Pinl Microphone audio from the MFJ 1278B to your transmitter Pin2 Ground audio and PTT common Pin3 Push to talk to allow the MFJ 1278B to key your transmitter Pin4 Receive audio from your receiver to the MFJ 1278B Pin5 Squelch input optional to allow the MFJ 1278B to detect activity on a shared mode channel Fig 3 1 Radio Port 1 and Radio Port 2 Connector This chapter describes how to connect the MFJ 1278B to your radio and how to adjust the receive and transmit audio levels appropriately The interconnection needs to be well thought out to minimize pickup of stray audio and RF noise by the lines If possible you should set up your station with a monitor speaker and be able to operate on voice without disconnecting the MFJ 1278B MFJ 1278B MULTI MODE RADIO INTERFACING RADIO PORTS CONNECTION The MFJ 1278B gives the u
444. that occurs when the BBS user disconnects and unacknowledged packets remain U1 UNproto Mode Pactor Immediate Command Issuing the U1 command from the prompt initiates the 100 baud FEC The U1 mode is mainly used during poor band conditions The MFJ 1278B will request a SPEEDdown to the U1 mode depending on the number of error laden 200 baud information packets recieved ALSO SEE MAXDdown and NO200 U2 UNproto Mode Pactor Immediate Command Issuing the UZ command from the p cmd prompt will initiate the 200 baud FEC mode The U2 mode can also be used during good band condition where communications are real good The MFJ 1278B will request a SPEEDUP to the 200 baud depending on the number consecutive good 100 baud information packets it receives ALSO SEE MAXUP and NO200 UNPROTO calli Mode Packet Default CQ VIA call2 call3 call9 Parameters call Callsign to be placed in the TO address field call2 Optional digipeater call list up to eight calls This command is used to set the digipeat and destination address fields of packets sent in the unconnected unprotocol mode Unconnected packets are sent as unsequenced I frames with the destination and digipeat fields taken from calll through call9 options When no eL sect M d a TT emend E rr COT E MFJ 1278B MULTI MODE OPERATIONAL COMMANDS UNSHIFT ON OFF Mode RTTY Default ON In Baudot RTTY receive mode only UN
445. the CW receive functionality becomes degraded if not eliminated NOTE If the DEMODULATOR is not EXACTLY centered in the receiver s CW filter passband CW receive performance through a narrow filter will be degraded Also the demodulator will likely not be receiving on the transmitted signal frequency This note is for the HF direct keyed radio case NOT MCW via SSB transmitter microphone audio which is discouraged Since MCW operation is primarily intended to provide a means to transmit code practice and not for CW reception the demodulator center frequency may be set to a different frequency than the modulator without penalty in most cases Typically the modulator will be set to 700 Hz and the demodulator will be set to whatever frequency is dictated by the HF radio with which it is to be used The CW demodulator can be used without a narrow filter in the radio It will of course be subject to more noise and QRM in this case The tuning range for the demodulator will be VERY restricted even though the wide filter is used in the radio since the demodulator itself acts as a very narrow filter An oscilloscope will be required to adjust the demodulator to a 50 percent duty cycle square wave output The main difference when aligning the CW modem is that there will be only 1 continuous tone presented to the demodulator for this adjustment Tuning the CW modem is basically a 4 step procedure The steps should be followed in the order presented
446. the MFJ 1278B operations start from Mode and command changes packet connects graphics initialization to name just a few start from command mode Converse Mode This is where the MFJ 1278B accepts digital data data that transmitted or received is accepted from Converse Mode Converse Mode also permits terminal editing features such as character and line deletion input and output packet deletion along with redisplay input via special characters trapped by the MFJ 1278B Converse Mode provides escape to command mode via a special character or BREAK signal Optional use of packet completion timer as in Transparent mode Transparent Mode Just as with Converse Mode Transparent Mode is where the MFJ 1278B accepts digital data The MFJ 1278B transmits packets via the packet completion timer or buffer full only The MFJ 1278B also receives packets in Transparent Mode Transparent Mode does not have all the local editing features of Converse Mode Escape to command mode via specially timed character sequence or BREAK signal Power Required 12 volts DC at 500 mA GENERAL DESCRIPTION The MFJ 1278B is based on the Zilog Z80 family of microprocessor components Major electronic devices in the MFJ 1278B include a CPU Central Processing Unit for controlling the MFJ 1278B and a SIO Serial Input Output chip for providing serial interface ports to the on board modem that connects to your radio and to the RS 232C serial or TTL terminal p
447. the computer You can enable the use of PACTIME in Converse Mode with the command CPACTIME Monitor Functions The MFJ 1278B s protocol is designed for setting up circuits between two stations However it can also operate in a mode more suitable for a net or round table discussion with several participants although reliable reception of all transmissions by every station cannot be guaranteed This is done by enabling the monitor functions Most of the monitor functions are described in Chapter 4 Monitoring is enabled by the command MONITOR ON and separate monitor functions are individually enabled If connected packet QSOs are taking place on the frequency of your group conversation you may wish to ignore all connected packets while your group operates in unconnected mode The command MALL OFF causes the MFJ 1278B to ignore connected packets MFJ 1278B MULTI MODE ADVANCED OPERATION If you want to monitor stations selectively you can set up a list of up to eight callsigns with the command LCALLS The callsigns in this list are regarded as buddies i e the only stations you want to listen to if BUDLIST is ON Otherwise the stations in the list will be ignored and all other stations will be monitored You can operate a group conversation with some data integrity by having the stations connect in pairs and setting MALL ON and MCON ON This does not insure that every packet is received at every station but it does insure that a
448. the following prompt Mailbox Ready n free de callsign H elp K L R S The Pactor mailbox will automatically issue a changeover after it sends the proper response to the users commands The n free is the amount of RAM space available for messages The de callsign is the callsign of your Pactor mailbox that the mailbox sends back to the remote user So lets take a brief look at the command functions of the Pactor Mailbox commands The command functions are as follows Heelp The Help command displays the Pactor Mailbox help list to the remote user A brief description of the commands available to the remote user is given Below is an example of the Help list as seen by the remote user H This message K Kill msgs L List msgs R Read msgs S Send msg These are the basic commands however there are derivatives of the basic commands MFJ 1278B MULTI MODE BASIC OPERATION Kill Allows the remote user to kill messages that are addressed specifically to the user If the message is not addressed to the user then the mailbox will respond with not yours and present the user with the mailbox prompt Kil fH Allows the remote user kill a message in a particular slot nn Slot nn is a particular slot number from 1 to 99 Remote users may only kill messages that are addressed only to them or originated by them The local and remote SYSOP can kill any messages depending on the setting of the command REMsysop Please refer to the
449. the frame again If the packet address includes relay requests the time between retries will be adjusted to Retry interval n 2 m 1 where m is the number of intermediate relay stations When a retried packet is sent a random wait time is added to any other wait times in use This is to avoid lockups in which two TNCS repeatedly send packets which collide with each other Frack will also reduce timeouts with multiple digipeaters FULLDUP ON OFF Mode Packet Default OFF Parameters ON Full duplex mode is enabled OFF Full duplex mode is disabled When full duplex mode is disabled the MFJ 1278B makes use of the Data Carrier Detect signal from the modem to avoid collisions and acknowledges multiple packets in a single transmission with a single acknowledgment When full duplex mode is enabled the MFJ 1278B ignores the DCD signal and acknowledges packets individually The latter mode is useful for full duplex radio operation such as through OSCAR 10 It should not be used unless both your station and the station you are communicating with are full duplex stations You may find full duplex mode useful for some testing operations such as the analog or digital loopback tests FULLDUP should be ON during digital loopback tests MFJ 1278B MULTI MODE OPERATIONAL COMMANDS GRAPHLF ONIOFF Mode FAX SSTV Default OFF Parameters ON Graphics line feed issued before carriage return OFF Graphics lin feed not issued before carriage
450. the same data MFJ 1278B MULTI MODE OPERATIONAL COMMANDS EAS ON OFF Mode CW RTTY ASCII Default OFF Parameter ON Enables Real Time echoing of out going CW RTTY and ASCII text OFF Disables Real Time echoing of out going CW RTTY and ASCII text ECHO AS SENT is basically the same as the EAS in AMTOR but is a separate command from AMTOR This command must be set independently from the AMTOR EAS command When issued from the cmd prompt enables Real Time echoing of out going CW RTTY and ASCII text When EAS is ON and ECHO is OFF real time echoing of all transmitted CW RTTY and ASCII text is enabled EASIN ON OFF Mode AMTOR Default OFF EASIN controls whether the MFJ 1278B echos text that you have sent it for transmission at the instant it is sent Normally the MFJ 1278B is configured to echo as you type this is the default OFF state of this parameter Setting EASIN ON is useful for monitoring channel quality If you type a few characters and they quickly echo it usually means the link is quite good On the other hand if it is taking a long time before the characters echo then the link is not that good ECHO ON OFF Mode AII Default ON Parameters ON Characters received from the computer or terminal are echoed by the MFJ 1278B OFF Characters are not echoed This command controls local echoing by the MFJ 1278B when it is in Command or Converse Mode Local echoing is disabled in Transparent Mode If you don t see your inpu
451. the transmit audio level please note that the range of R38 on the 2400 board is pre set by CN 6 header The shorting jumper on CN 6 header sets range as follows CN 6 Jumper Position Transmit Audio Range no load no jumper 50 mV 60 mV p p 1 amp 2 default 100 mV 200 mV p p 2 amp 3 250 mV 3 V p p MFJ 1278B MULTI MODE APPENDIX JUMPER FUNCTIONS JUMPER FUNCTIONS AND LOCATIONS The MFJ 1278B mother board has many jumper connectors Each jumper connector has a special function The Jumper Function chart Table G 1 in this appendix will help in identifying each jumper function Figure G 1 will help in locating the jumper connectors easily For normal operation a shorting jumper must be placed on the following connectors JMP 5 JMP 8 JMP 9 pins 2 3 JMP 13 JMP 14 pins 1 2 JMP 16 pins 1 3 and pins 2 4 JMP 18 pins 1 2 JMP 19 outside pair one top one bottom JMP 22 pins 2 3 JMP 24 pins 1 2 JMP 26 pins 1 2 JMP E F G Also on the mode disconnect header J4 the following pins need jumpers pins 1 2 11 12 13 14 17 18 Table G 1 Jumper Function Function inl amp 2 in2 amp 3 FF Default in 1 amp 2 Default in2 amp 3 FF Default Enable Tx watch dog N Default FF Default Normal modem operation D N Default emodulator enabled Jumper JMP JMP2 as JMP4 Z JMP5 2 esl 7 JMP8 Z emodulator calibrate inl amp 2 alibrate U16 tones D JMP
452. ther station Should you wish to break in for some reason before the other station sends and you want to become the transmitter go to AMTOR command mode with CTRL C and type CHANGE This forces the remote ISS to revert to the IRS Then you can start transmitting data If the CPU oscillator of the MFJ 1278B is improperly set then you may experience a phasing problem or a loss of sync during ARQ operations The CPU oscillator is factory set at MFJ 1278B MULTI MODE BASIC OPERATION Monitoring Mode A ARQ The LISTEN command is useful for monitoring other people s ARQ contacts To use tune in a Mode A signal and type LISTEN Both the CON and STA leds will light until the station is synchronized at which time the MFJ 1278B will start to receive Since the monitoring of MODE signals is not error protected you may see occasional errors How well the MFJ 1278B receives Mode signals depends on the quality of the signal The quality of Mode A signals depends on how well the MFJ 1278B hears both sides of the QSO Band conditions also have an effect on Mode A signal quality The LISTEN mode is most useful for allowing amateurs to continue to self police their bands Mode B FEC Mode B FEC is a One transmitter many receivers mode Unlike packet or ARQ FEC does not establish a one on one link setup nor does it have a re transmission feature Mode B FEC is mainly used for calling CQ The amtor operator would first call CQ in M
453. thout this RESET signal the Z80 probably won t start up properly Digital Logic Lines Remember that all the logic circuits operate at standard TTL levels a low is less than 0 8 V and a high is greater than 2 4 volts and all digital inputs and outputs switch between these two levels Thus if you see logic signals switching between 0 and say 1 volt you can be sure there is a problem usually a short On the other hand do not mistake switching transients on digital logic lines for improper operation these show up as ringing and other distortions MFJ 1278B MULTI MODE TROUBLESHOOTING Verify that there is activity on the control bus READ and WRITE lines the 3 CHIP ENABLE lines on the memories U23 25 pins 20 the IOREQ line on U21 pin 36 and the INT line on pin 16 Each of these lines should show activity and if any line is quiet this is a sign of trouble Logic lines that show no activity may often be traced to a short on the pc board probably due to a solder splash or bridge Logic lines that look the same can be traced back to a short between two or more of the logic lines Shorted data or address lines are found with a DVM in point to point continuity check Address and data line shorts may also show up as lack of activity on the control bus lines especially the chip selects Check each of the 16 address and 8 data lines for activity Any lines showing a lack of activity are not operating properly If you s
454. three times to indicate that the MFJ 1278B has entered the KISS mode Now you may call up a TCP IP or another host program that can use KISS or SLIP If you find that the MFJ 1278B will not stay in KISS mode then you will need to deactivate the KISSDOG timer Deactivation of the KISSDOG is done by sending these three bytes to the TNC C0 FD C0 This sequence will keep the TNC in KISS mode until the MFJ 1278B is told to exit KISS properly Before enabling KISS make sure radio baud rate and terminal baud rate are set to the desired values The terminal s baud rate that s determined at sign on is the same that will be used for KISS Once the operating terminal parameters have been selected you may enter KISS mode operation If you are using the KA9Q TCP IP software package to return to normal AX 25 operation issue the command param ax0 255 Note that this command must be issued under the TCP IP net gt prompt and lower case letters must be used Once the MFJ 1278B receives the param 255 command turns KISS off and will revert back to ordinary AX 25 mode of operation When the MFJ 1278B is powered on again it will sign on to the AX 25 operation mode If you are not using the TCP IP software package you will need to send the three bytes C0 FF C0 to the MFJ 1278B to restore normal operation Once the MFJ 1278B receives the param 255 command it turns KISS off and will revert back to ordinary AX 25 mode of operation
455. time From this log the remote can determine band conditions or just see who has been around The log holds eleven 11 of the most recently stations Chat Mode The Chat mode feature in the MFJ 1278B Mailbox is similar to the standard TNC converse mode It enables the SYSOP to break onto a mailbox link and get one on one with mailbox user This is just like a regular Packet QSO This is good for discussing problems maybe with the link or with the mailbox in general Chat mode terminates any user or forwarding operation in progress The mailbox will stay in Chat mode until the SYSOP returns to command mode Page SYSOP MFJ 1278B MULTI MODE ADVANCED OPERATION The Mailbox has the capability to be remotely controlled A callsign can be specified by the SYSOP for this purpose This would be useful in the case where the SYSOP is out in the field It would allow him to control the mailbox and do most of the local SYSOP s duties such as killing messages reading editing message headers for forwarding purposes Mailbox CText This is a message dedicated to the Mailbox but is used when a connect is made to the MYMcall callsign It is limited to 120 characters in length If MCText is empty then no message will be sent Idle Timeout The Mailbox incorporates an idle timeout function This is to ensure that the mailbox is still accessible in the event of a remote user drop out during a connection or walks away from the TNC for too lo
456. time clock by setting the date and time with the command DAYTIME Once you have set the clock you can request the time by entering MFJ 1278B MULTI MODE ADVANCED OPERATION Multiple connection capability is a very powerful addition to the MFJ 1278B It is very useful for traffic net operation multi user bulletin boards path checking and so forth Multiple connection operation is not the same as multi way operation With multiple connect you may establish several point to point links with various stations Multi way which is not available would enable multiple stations to be simultaneously interconnected to each other with each station seeing all data passed from any station in the group error free Multiple connection operation is another step on the road to proper networking and networking should eventually allow multi way operation Setting the MFJ 1278B to Normal Operation The MFJ 1278B defaults the multi connection related commands to the following parameters CONPERM OFF STREAMCAII OFF STREAMDouBLe OFF STREAMSWitch USERS 1 This sets up the MFJ 1278B to act just like a normal TNC does that does not support multiple connections The key to obtaining this traditional operation is to set USERS 1 How do I Invoke Multi Connect If USERS is not 1 you are telling the MFJ 1278B to allow multiple connections to your stations from other stations In addition TRANSPARENT mode will operate differently in that inco
457. tion If your radio has an accessory jack with PTT transmit audio and receive audio signals the interconnection can be done through this jack shown in Fig 3 6 Radio MFJ 1278B 1 r Accessory Jack 2 R s Microphone Audio Mic lt VARY P is 1 Input V V VV RX Audio I RCVR gt 4 l PT sw gt 3 Ground 2 hd Fig 3 6 Accessory Jack Interface If your radio does not have an accessory jack and you don t wish to add a connector to your radio you may construct a separate external interface box This box will permit simultaneous connection of your MFJ 1278B and a microphone Figure 3 7 shows a schematic of an external interface box A microphone interface box similar to the one shown in Fig 3 7 is available from MFJ Enterprises Inc or from any dealer of MFJ products The Model No of the microphone interface box is MFJ 1272B Regardless of whether you use an accessory jack or an external interface box you should use shielded wire for all signal carrying leads The connectors and fittings on your radio will be the deciding factor as to what hardware you will need The user may also want to refer to mannoala af tha anninmant inualyrad in tha intarnannantinna far anma infarmatian MFJ 1278B MULTI MODE RADIO INTERFACING Interface Box Radio t Microphone Audio Microphone Epi l
458. tion of the MFJ 1278B for SSTV operation is the same as for the other modes of operation Installation of MFJ 1278B to your radio is described in Chapter 3 of this instruction manual You can use either Radio port for SSTV operation Printer Connection If you have a terminal program which supports SSTV picture printing to the computer screen then you should attach your printer to your computer printer port and not to the MFJ 1278B In this case turn the PRINTGRA command OFF IF you intend to receive the SSTV picture and send it to the printer that is attached to the MFJ 1278B parallel port then you should turn PRINTGRA command ON MFJ 1278B MULTI MODE BASIC OPERATION Receiving SSTV Pictures Note that if you are using one of the special terminal programs that supports color or multi gray levels SSTV operation you should follow the instructions given in its operating instruction manual to receive and transmit SSTV The SSTV operation procedure given in this instruction applies to the receiving of 4 level SSTV pictures with a EPSON graphic printer attacted to the MFJ 1278B printer port From command mode the MFJ 1278B can be set to SSTV mode by typing MODE TV ENTER Select the desired SSTV formats by using the TVMODE command To select the desired TVMODE type the following from the cmd prompt TVMODE n ENTER where n is the TV format 1 through 5 as listed in SSTV Format Table 4 9 For example for 8 5 Second TV format
459. to a smaller value Be sure to remove JMP or JMP L when connecting the MFJ 1278B to another type of radio m R X Microphone 05 AAA Input To Talk WVS Tronsmit T 4 IMFJ 1278B MFJ 1 278B Audio 5 Pin Radio External Din Port E Speaker Receive Audio i L FIG 3 3 HT Special Keying Circuit Left Rear Corner of the MFJ 1278B Radio Radio akae Port 2 Port 1 2 3 1 2 3 4 RAD 2 5 4 RAD 1 5 m R107 48141 cj c mms 77 VR 3 i A 020 A nn gt AGT lt R136 MFJ 1278B MULTI MODE RADIO INTERFACING RADIO INTERFACING METHODS The MFJ 1278B allows radio connection without any modifications to the radio or any signal balancing devices in the cables There are two types interfacing methods presented in this chapter Method 1 Direct Connection to Microphone and Speaker For Method 1 shown in Fig 3 5 the MFJ 1278B s audio is fed directly into the microphone connector or similarly connected auxiliary jack The output of the MFJ 1278B will be adjusted to give a proper modulation level The receiver audio will be taken from an earphone plug or speaker jack and fed directly to the MEJ 1278B The user can connect a monitor speaker to the SPEAKER jack of the MFJ 1278B This allows yo
460. to experiment with various DELAY times working towards the minimum delay Note that if you re completely unable to work anyone in MODE but you can work people in modes B and S it is possible that you are not using enough DELAY delay which is too short could result in data loss Try increasing it until MODE A works reliably MFJ 1278B MULTI MODE OPERATIONAL COMMANDS DELETE ON OFF Mode Packet Default OFF Parameters ON The delete character input editing character is DELETE 7F OFF The delete character input editing character is lt BACKSPACE gt 08 This command is used to change the input editing command for character deletion When this character is typed the last character from the input line is deleted How the TNC indicates the deletion is controlled by the BKONDEL command You can not use this character to delete past the beginning of a line although you can delete lt CR gt characters that have been entered in the text with the pass character To see a corrected display of the current line after you have deleted characters type the redisplay line character which is set by the REDISPLA command DEFLTDLC Mode Host Default 254 Parameters Effective only when non O MYDLCNUM this parm tells the TNC what the DLC address is of the host ex MTHOST Default is 254 DIDDLE ON OFF Mode ASCII RTTY Default ON During ASCII RTTY transmit the MFJ 1278B sends a non printing synchronization character DID
461. transmitted from that Navtex station If you exit the a cmd command prompt the preamble memory is erased Emergency messages are numbered 00 and will always be printed regardless of whether they have already been received NAVSTN Text Mode Navtex Default ALL To prevent your MFJ 1278B from receiving certain Navtex stations just type NAVSTN XXXXXXXXXXXXX where each X is the identifying letter of the station you want to receive Your list of stations to receive may contain up to 26 letters each representing a station For example if you want to receive only stations A C and P then you type NAVSTN Only signals from these three stations will be received by your MFJ 1278B If you want to prevent certain stations from being received leave then off the list Then those stations will not be received while others within the receiving area will lnc 42 22 RTA WORT AG OW U 212 Weeds 222d4 2 2N 42 llf 2041 eee MFJ 1278B MULTI MODE OPERATIONAL COMMANDS NAVMSG Mode Navtex Default ALL The NAVMSG command works like the NAVSTN command with the ALL parameter used to exclude all or to specify the type of messages to receive The types of Navtex messages currently are Navigational warnings Storm Warnings Reports of Ice Search Rescue Information Weather forecasts Pilot Service Messages DECCA System LORAN C Omega Systems SATNAV Systems STROM SAS K thru Z are not
462. ts in the following format Slot t m To From Subject Where Slot column is the number of the slot that the messages are in The number of message slots present in the standard 32K Mailbox is 99 The lower case t is the Type Flag block The lower case m is the Message Flag block The To column will contain the callsign of the person who the message is addressed to The From column will contain the callsign of the person who left the message The Subject column will contain a brief message title After the Mailbox lists all messages it will issue the Mailbox prompt nn free n Mailbox H elp L S The Pactor Mailbox will send an automatic changeover after it lists all mailbox messages After the automatic changeover is sent the mailbox will send a CTRL G character back to the remote user The CTRL G character will sound the computer bell in the user s computer 6 Anyone who accesses the Mailbox can read messages that are addressed to him or her Also a message which is a addressed to ALL such as bulletins are readable by anyone Messages are read by two 2 different methods Below are the two methods a This method will allow the remote user local or remote SYSOP to read a group of messages This is only good for a group of messages with the same callsign as MYcall The set conditions of the Type or message flags have an effect on a read process They can be set to an N Y F To perform this type R ENTER
463. tting of the new command REMsysop Please refer to the REMsysop for more detailed information L This command allows the remote user local or remote SYSOP to list all messages in the mailbox All of slots which are currently in use will be listed They all will have the slot number flag field the destination callsign originator callsign subject field Also the Mailbox command line will be on the next line M This allows the remote user local or remote SYSOP to change memory banks in the mailbox ram The current memory bank is indicated on the mailbox command line The bank will be inside a pair of which will be after the bytes free indicator Below is an example of a typical command line from the mailbox nn free n Mailbox B E H elp J K L M R S T gt Where n is the bank number The bank number will vary from 0 to 7 depending on the size of the expanded memory ram The bank numbers in relation to the RAM size are as follows MEMORY SIZE NUMBER OF BANKS 32K 0 128K 1 512 0 thru 7 NOTE There will be only one 1 number in the at anytime For example let s say that you are running a 128K mailbox and a remote user wants to access memory bank 1 First a connection to your mailbox must be made Once the Mailbox command line is obtained the user will type M0 CR This will be received by your Mailbox and then your Mailbox will send back a new Mailbox command line nn free 0 Mailbox B E H elp J
464. turned ON With the MULTIFAX and TVX set to OFF the MFJ 1278B transmits and receives 2 level FAX and 4 level SSTV regardless of the setting of the SLEVELS command The built in printer port on the MFJ 1278B does not support printing of 8 level data whether it is FAX or SSTV Special terminal program such as MultiCom M must be used to decode and display Multi level FAX and SSTV With SLEVELS set to OFF and MULTIFAX and TVX commands set to ON the MFI MFJ 1278B MULTI MODE OPERATIONAL COMMANDS 16LEVELS ON OFF Mode FAX SSTV Default ON Parameters ON The MFJ 1278B will transmit and receive FAX and SSTV in 16 gray levels OFF The MFJ 1278B will transmit and receive FAX and SSTV in 8 or 4 gray levels depending on how the MULTIFAX and SLEVELS commands are set In FAX and SSTV modes if 16LEVELS is ON and 8Levels is OFF the MFJ 1278B will receive and transmit FAX and SSTV data in 16 gray levels As in 8LEVELS the 16LEVELS command is effective only when the MULTIFAX command is turned ON If MULTIFAX is turned OFF the MFJ 1278B is set to transmit and receive in 2 level FAX and 4 level SSTV regardless of the setting of I1GLEVELS The built in printer port does not support printing of 16 level data A Special terminal program such as MFJ MultiCom must be used to decode and display the multi level FAX and SSTV data Note that turning 16Levels ON will not turn 8Levels OFF you must turn 8Levels OFF when setting the MFJ 1278B to operat
465. ty of TNCs including the MFJ 1278B are configured to automatically go to a new line whenever a carriage return is printed Also see AUTOLF parameter LFADDALT ON OFF Mode RTTY Default ON LFADDALT is very similar to the LFADD command above However this command applies ONLY to Baudot RTTY mode Baudot RTTY operation almost always requires that a line feed be sent along with a carriage return When LFADDALT is ON the MFJ 1278B will automatically insert the Baudot line feed whenever the user sends a carriage return There is one case where line feeds should not be automatically transmitted that is when sending complex radio teletype pictures Also see AUTOLF parameter LFIGNORE ON OFF Mode Packet Default OFF Parameters ON MFJ 1278B will ignore lt LF gt characters OFF MFJ 1278B will respond to lt LF gt characters This command controls whether MFJ 1278B responds to ASCII Lind Feed lt LF gt OA characters or ignores them in command and converse modes When turned on line feeds are totally ignored except in transparent mode MFJ 1278B MULTI MODE OPERATIONAL COMMANDS LISTEN Mode AMTOR Immediate Command LISTEN is used to begin monitoring someone else s Mode A connection You ll need to enter LISTEN to tell the MFJ 1278B to start synchronizing to the desired signal LISTENing to Mode A connections can be irritating if conditions are poor because there is no error correction afforded to stations which are
466. u driven making it easy to operate all modes offered by the MFJ 1278B Dedicated functions keys are programmed to operate most functions with a single key stroke Even though the MFJ Multicom programs offered for other computers may have features different from the IBM version they do offer features that will make operating the MFJ 1278B very fun and very easy This compact versatile controller employs the genuine TAPR TNC 2 AX 25 protocol packet firmware plus many added features to receive and transmit VHF packet HF packet AMTOR CW ASCII RTTY color FAX and color SSTV The new 16 gray level fax board built in the MFJ 1278B gives you the ability to receive and transmit color SSTV and multi gray level FAX pictures In addition MFJ 1278B lets you monitor the new and growing NAVTEX broadcasting system The MFJ 1278B also has a Contest Memory Keyer mode Also a feature which so many have asked about Pactor has been added to the operating modes The new Pactor mode gives the user operating features such as Digital Memory ARQ full On Line Data Compression FEC Unproto operation just to mention a few Also included with the PACTOR mode is a PACTOR Mailbox With the Pactor mode also comes the ability to monitor AMTOR ARQ connect requests The MFJ 1278B offers the most versatile mailbox available when compared to the mailbox in other controllers This mailbox allows a dedicated mailbox callsign so that the mailbox stays on while you operate pack
467. u are operating your station in Converse Mode and there is some chance that you might fill up the MFJ 1278B s buffers you might set this character to lt CTRL G gt 07 which rings a bell on many terminals MFJ 1278B MULTI MODE SYSTEM MESSAGES 1278 SYSTEM MESSAGES This chapter describes the messages your MFJ 1278B may produce and the circumstances under which they can appear PACKET MESSAGES xJ bbRAM LOAD WITH DEFAULTS MFJ Enterprises Inc Model MFJ 1278B AX 25 Level 2 Version 2 0 RELEASE X X X DATE 32K RAM Checksum XXX cmd This is the MFJ 1278B sign on message that appears when you turn your MFJ 1278B ON or when you issue the RESET command The MFJ 1278B updates the RELEASE number whenever the user changes the firmware The checksum is a hex number that you can compare with the correct checksum given for the firmware version you are using bbRAM loaded with defaults This message appears along with the sign on message above if the battery backed up RAM checksum verification fails at power on time causing the MFJ 1278B to load the default parameters from ROM This will be the case the first time you turn on your MFJ 1278B This message also appears if the MFJ 1278B loads the defaults in response to the RESET command If the user issues the RESET all parameters set by the user are lost cmd This is the Command Mode prompt When this prompt appears the MFJ 1278B is waiting for you to is
468. u to monitor the transmit and receive audio on the channel MFJ 1278B Radio im PIT le Mic esses 1 Audio Spkr kl t Gnd JS ERU SEES OEE me tq ma asd tibns zi RX Audio Fig 3 5 Method One Interconnect The transmit audio levels for both radio ports are factory preset at 250 mV p p to be compatible with the mic input of most radios However if the transmit audio is too low or distorted then adjust the appropriate output level control as stated in the section Use the following procedure to calibrate Transmit Audio Level Adjustment for Method I Interface 1 Connect your MFJ 1278B and radio as shown in Fig 3 5 Turn on MFJ 1278B and computer and start your terminal program Connect the radio to a dummy load and listen to the transmission with another nearby radio 2 Enter the modem calibration procedure by typing CALIBRA LTT ees AM te ie A ae a eee Ths ween thee Wea ese Teed nD Nene the doe eee thn MFJ 1278B MULTI MODE RADIO INTERFACING 3 With the MFJ 1278B keying the transmitter and transmitting the higher of the two tones adjust the transmit audio level as follows With a small flat tipped screwdriver adjust trimpot located on the left side of them MFJ 1278B R157 for radio 1 or R158 for radio 2 while you listen to the monitoring receiver Adjusting the trimpot CW increases the output while CCW decreases t
469. un delav in 10 6 10 6 10 6 10 6 11 T 6 15 6 15 MFJ 1278B MULTI MODE APPENDIX COMMAND SUMMARY ONIOFF ropes ONIOFF T m me ui 1 pf 30 ii Fc Determines the way the screen is updated when a character is deleted in the command mode Allows Host Mode operation 20 Specifies the text of the beacon packet 21 Determines if the packets listed in LCALLS are to be displayed Allows addressing of the ten user ASCH as ae memories buffer without using the gt CTRL T Used to transmit buffer 0 when it is a non zero value at the set interval Causes the MFJ 1278B to transmit when it receives a lt CR gt o vole N N SEDE the count t setting for use by the calibration routing Changes the cancel line input editing command character Changes the cancel packet input editing command character Sends a bell tone through the computer or terminal speaker when a packet connection is made Sends a bell through the computer terminal speaker when a Pactor connect is established Determines whether U S standard or the internationally recognized character set is used Switches from receiver to transmitter in 6 28 AMTOR mode A ARQ Allows SYSOP to break onto the mailbox s connected link Enables the automatic idle link disconnect feature for AX 25 L2V1 connections Sends a bell tone to the computer or terminal when a Pactor changeover is done
470. ur bits that depend on the acknowledge functions the packet is performing Usually x is a frame number Frame numbers fit into three bits and are used to ensure that frames are received in order and that no frames are missed Since only three bits are available the frame number is counted module 8 This is why the MAXFRAME parameter has a ceiling of 7 no more than seven frames can be in flight transmitted but unacknowledged at one time A short description of the use of the frames is given after the table Table 10 1 AX 25 Control Codes Abbry Receive Ready Unnumbered Information D isconnected mode Connect request Disconnect request U nnumbered Acknowledge Any frame ending in an even number including A C and E is an information frame Below is a short explanation of the different types of frames associated with the AX 25 protocol I This and UI frames are the only frame types containing user data The control byte contains this frame s number and the number of the next frame expected to be received from the other end of the link RR The RR frame is usually used to acknowledge receipt of an I frame The RR function can also be performed by sending an I frame with an updated expected next frame number field MFJ 1278B MULTI MODE PACKET RADIO PROTOCOL RNR The RNR frame is used when the buffer space on the receiving side is full REJ Used to request retransmission of frames starting from x
471. ur connect request was rejected by a DM packet busy signal from the other station The MFJ 1278B will reject a connect request if CONOK is OFF or if it is already connected to another station or the connect request is from a station with a totally blank callsign frmr frame just sent FRMR sent xxxxxx The MFJ 1278B is connected and a protocol error has occurred The MFJ 1278B has sent a special FRMR packet to attempt to re synchronize frame numbers with the MFJ 1278B on the other end The string xxxxxx is replaced with the hex codes for the three bytes sent in the information part of the FRMR frame This message will not appear if your MFJ 1278B is in Transparent Mode MFJ 1278B MULTI MODE SYSTEM MESSAGES FRMR rcvd This message is followed by a display of the FRMR packet received in the trace display format This format is explained in the TRACE command entry This message will not appear if your MFJ 1278B is in Transparent Mode T INKOUTOFORDER possible dataloss opt daytime stamp This message indicates failure of a CONPERMed One or more packet nodes in the link have failed The time of failure may be appended to this error message if the stamping mode is on MFJ 1278B MULTI MODE HARDWARE HARDWARE This chapter details the specifications and the functional description of the MFJ 1278B hardware design 1278 SPECIFICATIONS Processor CMOS Z 80A Clocks Processor master clock input frequency 4 9
472. ur personal packet pictures bulletin board Graphics that you create with certain paint software such as QSL cards drawings and pictures can be saved and transmitted to the nannnantina ealrat atatinn with Alaa iato namantad with dieitinmaen Ah an tha MFJ 1278B MULTI MODE ADVANCED OPERATION DETAILED HF PACKET OPERATION Here we will go into further detail on the HF Packet mode of operation We will discuss modem center frequency HF tuning indicator etc So without any further delay lets get into HF Packet operation Radio Setup for HF Packet Operation Setting up your Radio interface will follow exactly the same procedure as for VHF NBFM operation with the exception that you will probably not need to set the modem output level This is because linear mode radios typically have a transmit audio level control on the front panel and an indicator that tells you when you have set the level correctly You will adjust the audio level just as you would for SSB operation If you are using an auxiliary audio input connector such as an accessory port MAY need to adjust the transmit audio level from the MFJ 1278B modulator This is because many auxiliary audio inputs are intended for phone patch audio These levels are typically much higher than microphone levels If you do adjust the output level of the MFJ 1278B to a relatively high value for this type of application do not operate the MFJ 1278B with a VHF NBFM radio unl
473. use the same printer control codes that your printer uses Typically EPSON format codes will be used The PKTPIX command provides a method for the MFJ 1278B to print packet pictures other graphics format data transmitted by another station in the VHF packet mode When you set PKTPIX your MFJ 1278B becomes ready to print graphics data Using PKTPIX Packet picture printing to the MFJ 1278B printer port requires you to first establish a packet connection with the station who is going to send the picture Note that you won t be able to call up PKTPIX until the connection is made You must have the printer powered and selected before MFJ 1278B will let you use the PKTPIX command Once these conditions are met all data received over the packet link are sent directly to the printer You can exit PKTPIX by using the escape to cmd mode sequence for TRANSPARENT connections Press CTRL C three times within one CMDTIME increment default or asynchronous BREAK Packet Picture transfer to the computer screen Packet pictures can also be received and displayed on the computer screen in real time To achieve this a special terminal program must be used The MFJ Starter Pack for IBM and compatible computer includes terminal program MultiCom that allows you to transmit and receive SVGA VGA EGA or CGA pictures in real time and display them on the screen Multicom can transfer binary files in additional to picture files It also allow you to set up yo
474. uspect problems with address or data lines try removing all the memory chips Each address and data line will now show a distinct pattern The address lines should be possibly distorted square waves whose periods increase by a factor of two on successive lines as you step line by line from AO to A15 If you decide to use an ohmmeter to check for shorted lines use a low voltage low current test instrument Most Modern DVMs are fine for this If in doubt remove any ICs connected to the lines you are measuring If you suspect a short check the high density areas of the PC board for the problem In most cases the short will be found there It is very unlikely that the PC board itself will have a short Symptom Modem won t calibrate or key transmitter Troubleshooting improper calibration amounts to checking for proper signals at U21 and following up any improper signal If the calibration signal is present but you cannot successfully calibrate the frequency you may have an out of spec frequency determining component Check the values of the appropriate passive components Also check the placement of jumpers As a last resort check the signal frequency with a frequency counter Note that due to frequency jitter while calibrating the demodulator the STA and CON LEDs may blink somewhat even when the 1700 Hz demodulator frequency is correct Calibration of the demodulator and the modulator tones are discuss in the Appendix chapter If the tra
475. ver the transmitter is activated Pin 11 Transmitter Clock 16x Input This pin is tied to the NRZ to NRZI converter which expects a clock signal at 16 times the desired radio port data rate e g 4800 Hz for 300 baud This pin is normally jumpered to pin 12 when the on board modem is used Pin 12 Transmitter Clock 16x Output Thina nin io trad ta tha radia hand rata onntoh naturel Tt a alanl at timana tha MFJ 1278B MULTI MODE HARDWARE Pin 13 Receive Clock Input This pin is tied to the SIO receive clock input pin It expects a clock at the desired data rate 1200 Hz for 1200 baud of the proper phase relationship to the received data This pin is normally jumpered to pin 14 when the on board modem is used Pin 14 Receive Clock Output This pin is the received data clock signal derived from the NRZI to NRZ state machine This pin is normally jumpered to pin 13 when the on board modem is used Pin 15 MFJ 1278B Ground Reference This pin ties to the MFJ 1278B digital ground system at the SIO Pin 16 Turbo LED output This pin is used to connect the Turbo LED on the mother board to the external modem board When this pin is high 5Vdc the Turbo LED will light Pin 17 Receive Data Input This pin is the received data input to the NRZI to NRZ state machine This pin is normally jumpered to pin 18 when the on board modem is used Pin 18 Receive Data Output This pin provides receive data from the on board mode
476. virtually no chance of an undetected bad frame using this method This satisfies the level two task of bad data detection The MFJ 1278B uses the Zilog 8440 SIO communication chip The Zilog 8440 operates in conjunction with a two chip state machine that is used to recover the data clock The transmitted data is encoded in NRZI form that encodes a 0 data bit as a transition in the encoded bit stream and a 1 data bit as no transition The data encoding in conjunction with the bit stuffing ensures that no more than five 1 s occur in a row except when FLAG bytes are being transmitted guarantees that a logic level transition occurs at least once every 5 bit times These frequent transitions allow the receiver to synchronize its clock with the transmitter Other chips that are compatible with the SIO and the state machine are the Western Digital 1933 1935 the Intel 8273 used on the VADCG and Ashby TNCs and the Zilog 8530 used on the Xerox 820 FAD adapter While the AX 25 protocol uses the HDLC format supplied by the communications chip there are several other Layer Two concerns The other Layer Two concerns being duplicate frame detection connection and disconnection of the Level Two layers on a different TNCs and buffer overrun avoidance The AX 25 protocol solves these problems as described below AX 25 LEVEL TWO The foundation for the AX 25 protocol is the Balanced Link Access Procedure or BLAP of the CCITT X 25 standard BLAP in tu
477. volts but less than 5 25 volts A TTL low or 0 is less than 0 8 volts but greater than 0 4 volts DO NOT connect an RS 232C level modem directly to J4 NOTE The modem disconnect is similar but not identical to that used in TNC 1 Be very careful about interfacing an external modem using the same cabling you may have prepared for use with TNC 1 For users that require pin out information on the modem disconnect header J4 MFJ provides the following pin out infromation The connector pin outs are as follows Pin 1 Carrier Detect Input This pin tells the SIO radio port that a valid data carrier has been detected It should be pulled high when no carrier is detected and low when a carrier is present This line must be implemented unless the software release notes indicate otherwise It is normally jumpered to pin 2 when the on board modem is used Pin 2 Carrier Detect Output This pin is an output from the the on board modem and satisfies the requirements outlined for pin 1 above It is normally jumpered to pin 1 when the on board modem is used Pin 3 SIO Special Interrupt Input This signal is routed to the radio port DCD input pin on SIO U21 This signal is normally used during modem calibration It may also be used for other purposes if so these functions will be listed in the software release notes This pin is normally jumpered to pin 4 when the on board modem is used MFJ 1278B MULTI MODE HARDWARE Pin 5 SIO RTS Output This
478. w Tone RTTY Mod JMPH N default Disable Low Tone RTTY Mod Enable Low Tone RTTY Mod X audio has flat response F default X audio 6db oct pre emphasized teens i di eee tl MPK JMPK 4 JOJO 2 2 2 4 TX audio loopback to PTT default for Radio Port 2 TX audio loopback to PTT FF default for Radio Port 1 Analog audio loopback FF default for Radio Port 1 JMPX N default peaker Transmit Tone Enable i SpeakerTransmit Tone Disable JMPY ON default Speaker Receive Tone Enable ATT CEE OE a a EA TRESS LT P ee il TEMERE EE MPx O Z o ips MFJ 1278B MULTI MODE HARDWARE NOTE When JMP23 is shorted it will RESET the MFJ 1278B This means that all parameters will be reset to the default values This is the same as removing the bbRAM battery except it is much quicker xa offers an optional Real time clock module MFJ 43 that can be installed on the MFJ 1278B mother board This clock keep the MFJ 1278B clock running all the time You will not have to reset the clock everytime you turn the MFJ 1278B on When these jumpers JMP E JMP F JMP JMP are removed the MFJ 1278B will operate European RTTY tone when the VB modem is selected four jumpers must be removed to operate European RTTY PARALLEL PRINTER PORT PIN FUNCTION J12 The MFJ 1278B provides the user with a built in Parall
479. want Memory Buffer 0 to repeat every 5 seconds under CMD command prompt type BUFTIME 15 ENTER Memory buffer 0 will repeat every 5 seconds To stop memory buffer from repeating set BUFTIME TO 0 If BUFTIME is a non zero value the MFJ 1278B will automatically release the PTT line and revert to the receive mode between repeats This allows you to monitor the frequency possibly for a reply message If uninterrupted during the pre set delay time then the MFJ 1278B will continuously repeat buffer 0 until BUFTIME is set to non zero value Chaining the Memory Buffers Chaining of the ten memory buffers in order is possible This enables the transmitting of the buffers in any order For example you may transmit memory buffers 0 2 and 5 respectively in one transmission To achieve this you should program the message in memory buffers as follows from the cmd prompt type CMD BUF0 XXXXXXXXXXX XXXXX CTRL T 2 ENTER CMD BUF2 XXXXXXXXXXX XXXXX CTRL T 5 ENTER CMD BUF5 XXXXXXXXXXX XXXXX ENTER Where XXXX is the desired text you wish to program into the memory buffers In the examnle ahave the CTRI T 2 does not mean von tune C TRI T 2 Tt means von hold MFJ 1278B MULTI MODE BASIC OPERATION Note If BUFTIME is a non zero value MFJ 1278B will automatically release the PTT line and revert to the receive mode between repeats This allows you to monitor the frequency for any replies to your message If the MF
480. whether or not the MFJ 1278B uses a highly efficient square wave signal in place of flags during the transmitter delay TXDELAY period When TXDIDDLE is ON you may select even smaller TXDELAY intervals because the square wave presents four times as many transitions as TXDIDDLE OFF does for your connectees receive synchronization TXDIDDLE is defaulted to the OFF setting to reflect that the function is inactive However there are a number of TNCs on the market which claim to be AX 25 compatible but do not recognize valid AX 25 packets preceded by the TXDIDDLE keyup technique You may recognize the need to set TXDIDDLE OFF if it appears that the station you re working is unable to successfully receive your packets despite your adequate signal This failure of some TNCs to receive TXDIDDLEd packets may be a result of some software carrier detect schemes All and derivative TNCs utilizing hardware generated carrier detect receive both TXDIDDLEd and non TXDIDDLEd packets with equal efficiency Note that when TXDIDDLE is OFF TXDELAYC is irrelevant Therefore the actual TXDELAY yielded when TXDIDDLE is OFF is equal to TXDELAY 100ms plus any AXDELAY time MFJ 1278B MULTI MODE OPERATIONAL COMMANDS TXFLOW ON OFF Mode Default OFF Parameters ON Software flow control can be enabled for the MFJ 1278B in Transparent Mode OFF Software flow control is disabled for the MFJ 1278B in Transparent Mode If TXFLOW is ON the setting of
481. while in link setup state is not checked MCON ON OFF Mode Packet Default ON Parameters ON Monitor mode remains active when MFJ 1278B 15 connected OFF Monitor mode is off while the MFJ 1278B 15 connected If MCON is ON the MONITOR command will enable monitoring while your MFJ 1278B is connected to another TNC If MCON is OFF the display of monitored packets is suspended when a connect occurs and is resumed when the TNC is disconnected If you want to see all packets displayed when you are not connected but have such display suppressed when you connect to another station you should set MCON OFF MFJ 1278B MULTI MODE OPERATIONAL COMMANDS MCTEXT text Mode Mailbox Default Text Any combination of characters and spaces up to 120 characters in length The MCTEXT command works like CTEXT except that MCTEXT is sent only when the mailbox MYMcall is connected to There is no express equivalent to the CMSG ON OFF command If MCText is empty no string is sent If the is message longer than 120 characters an error message will be given and the command is ignored The command string can be cleared by typing the command and then entering the sign where the text would normally be entered Also the RESET command will empty the MCText command For example you might want to set your MCText to Welcome to the Mailbox I m not here right now but feel free to use the system Enjoy MEND cccc Mode AMTOR Default nnnn Parameters
482. wing table lists the function of each jumper on the MFJ 1278B For normal operation a shorting jumper must be placed on the following connectors JMP 5 JMP 8 JMP 9 pins 2 3 JMP 13 JMP 14 pins 1 2 JMP 16 pins 1 3 and pins 2 4 JMP 18 pins 1 2 JMP 19 outside pair one top one bottom JMP 22 pins 2 3 JMP 24 pins 1 2 JMP 26 pins 1 2 JMP E F G H Also on the mode disconnect header J4 the following pins need jumpers pins 1 2 11 12 13 14 17 18 Table 8 1 Jumper Function Pin 1 amp 2 IDCD RS 232C stays on Pin 2 amp 3 IDCD RS 232C stays off OFF default DCD reflects connect status in 1 amp 2 default 4 92 MHz CPU clock in2 amp 3 2 46 MHz CPU clock N disable Tx watch dog FF default enable Tx watch dog JMP5 N default ithium battery connected Lithium battery disconnected d O 9 lalz Iolo lelo lglg 2 9 JMP7 analog loopback mode JMP8 N default emodulator enabled PF demodulator calibrate analog loopback mode FF default JMP9 inl amp 2 calibrate U16 tones Pin2 amp 3 default JMP10 digital loopback mode FF default EFT IGHT default transmit data NRZI O el MFJ 1278B MULTI MODE HARDWARE Table 8 1 Jumper Function Cont Jumper Position Function JMP16 Pinl amp 2 Without multi gray levels Pin1 amp 3 default With multi gray levels Pin 2 amp 4 default With multi gray levels 2400 baud ext modem clock P
483. with another packet transmission and since there may be other stations on the channel the receiving station may not be able to acknowledge the received packet immediately The time lapse before the originating station re transmits the packet is set by the command FRACK frame acknowledge time The maximum number of re transmissions before the originating station terminates the connection is set by the command RETRY The maximum number of transmissions of a packet is RETRY 1 since the initial transmission does not count as a re transmission Setting RETRY to 0 specifies an infinite number of retries The frame acknowledge time is automatically corrected for the additional time required for digipeating The time interval before MFJ 1278B re transmits an unacknowledged packet is Retry interval FRACK 2 n 1 in seconds where n is the number of digipeaters in use for this connection Acknowledgments of digipeated packets are made from end to end and digipeaters do not acknowledge the packets they relay If there are several intermediate relays the chance of either the original packet or the acknowledgment to be lost increases drastically To reduce this problem an automatic wait time can be imposed on any station not transmitting a digipeated packet Stations waiting for a clear channel to transmit packets wait for this time interval after the channel clears before transmitting This wait does not apply if the station will be transmitting one
484. wn in bold face Whenever the MFJ 1278B accepts a command that changes a value it will display the previous value For example if you type XFLOW OFF the MFJ 1278B will respond with XFLOW was ON MFJ 1278B MULTI MODE OPERATIONAL COMMANDS This reminds you of what you have done and indicates that the value has been successfully changed If you type something the MFJ 1278B can t understand you will get an error message If you type an unrecognized command you will see the message EH If you get a command name correct but the arguments are wrong you will see the message 7BAD complete list of error messages appears at the end of this chapter For example cmd ASDFASDF This is not a command EH This response indicates MFJ 1278B did not understand the command cmd BEA CON EThis is a valid command however a parameter was left out This response indicates a bad command Maybe the command was a valid command but parameter is missing Command List The commands are listed alphabetically and each command entry contains several sections as follows COMMAND NAME The boldface command name at the top of the entry is the word you will type to have the MFJ 1278B execute this command In this section the command names have some of the characters underlined These underlined characters form the minimum abbreviation required so that the MFJ 1278B still understands your command Of course you may type out the entire
485. y 316 318 Random wait 231 Real time clock error message 310 Real time clock setting 216 MFJ 1278B MULTI MODE MANUAL INDEX RS 232C 4 RS 232C signals Clear To Send 15 125 RS 232C signals Data Carrier Detect 15 RS 232C signals Data Set Ready 15 RS 232C signals Data Terminal Ready 125 RS 232C signals Frame Ground 13 RS 232C signals Request to Send 15 RS 232C signals Signal Ground 15 RS 232C signals Transmit Data 13 RS 232C baud rate 17 RS 232C handshaking 320 RS 232C negative power supply 320 RS 232C signal levels 10 RS 232C signals 13 RS 232C troubleshooting 335 S SABM frames 342 SABM frames monitored 247 Sanyo MBC 55X 6 Send packet character 283 Send packet character automatic inclusion in packet 212 Send packet character set to CR 130 Serial port 316 318 serial port adapter card 6 Serial port baud rate switch 317 serial port connector 5 Serial port problems baud rate 336 Serial port problems data signals 335 336 Serial port problems handshaking signals 335 Serial port problems parity 336 Serial port problems won t accept data 336 serial port signals 5 Serial port baud rate 17 321 Serial port hardware handshaking 13 Serial port jumpers for auxiliary signals 10 Serial port non standard 321 Serial port parity 264 Serial port signals 13 336 Serial port troubleshooting 335 Serial port word length 187 MFJ 1278B MULTI M
486. y the person to whom the message is addressed can read or kill it The SYSOP can also read the private messages When a private message is listed a P flag is shown in the Message Type flag block The P flag can also be inserted by the originator or the SYSOP through the Edit command This command allows the remote user to page the SYSOP When the T command is invoked from the remote user the following message appears on the SYSOP s computer screen and it also is sent back to the remote user s screen Paging SYSOP any key aborts The Mailbox will page the SYSOP by ringing the SYSOP s terminal bell 30 times If the SYSOP is at his or her terminal the asterisk character will appear on the screen every time the terminal bell CTRL G rings If the SYSOP does not answer the Mailbox will send the message back to the user saying no answer Below is an example of a typical screen Paging SYSOP any key aborts he oh oe fe of k speso k ok oh 2k ok 2k k k kN answer MFJ 1278B MULTI MODE ADVANCED OPERATION Mailbox Operation This section will depict the use of the Easy Mail mailbox from a remote users point of view We will discuss the different prompts and messages given by Easy Mail and what they mean So without any further delay lets get started 1 The remote user must first establish a connection to your Mailbox station 2 If your Mailbox is ON then it will answer the remote user back with the Mailbox prompt

Epson MFJ-1278B User's Manual

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