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analog acquisition uni analyzes circuit data

1. 7400 TTL 74LS168N 85 LM BLOBACZ 55 M7BLOBACZ QT C Vott en Pan Pee 74 5 169N Hrs cMyacizacz s SOLDER TAIL P Now Cap Vot 10 D pri i 100 fena 7400N 4d Has UN 2t ien TA uM7RLISACZ i DIP SOCKETS A ma pend 1 500 5 5 8 7461N 4B 3 on r f 9 45 lt 740 74LS174 13 00 3 7906C T 38 e single beam x p 500 6 4 48 7 22 50 J2N i ES 3 M S12CT 138 v 5 S ac i 5 6 6 7403N agf 74LS178N dps Ems c Low profile E 3 500 5 6 49 5 5 6 7404N 50 74 5 190N 2 00 50 a m s YOUR CHOICE TIN OR GOLO i p e 4 x Di 3405N ggh 74L51910 1 t BSF LM79LOSACZ 1 38 juliyu sa our INE gels misy n ebb nashyepa Weruswa nonne Pew ow vw pt sad 8 49 w SU A 3406 n 92N 2 5B 1 93 479L12ACZ 38 M Nor 7 3 nf 500 75 8 49 25 ist s Pay 206 83 13a MHC 48 TIN PLATED SOLDER TAIL Mim 288 Mwromchas Tin n VOTE o Tar pi 500 75 6 43 B 675 b 6 28 KN 74 S195AN 593 Ld 38 amio c Rated Amb ent Temp oc ot 25 227 1950 18250 50 br
2. channel is determined by the box s channel selector not by the VCR s or TV receiver s channel selector As a result you will not be able to preset the VCR to successively record pro grams on more than one channel though you can set it to record two or more programs on the same channel If you do preset your VCR to record a desired program there is the dan ger that someone may come along and change the selected channel on the cable box leaving you with a pro gram you did not want to record The obvious solution to this probelm is to record from the cable ahead of the cable box Shown in Figs 3 4 and 5 are in creasingly complex hookup arrange ments that yield increasingly greater flexibility Of course there are other possible hookup arrangements you can use However the ones illustrat ed here are relatively simple and in expensive to implement With the arrangement shown in Fig 3 the VCR and TV receiver must always be set to channel 3 You select the channel to be recorded or viewed with the channel selector on the cable box The major advantage of this arrangement is its simplicity Its disadvantages are when record ing you can view only the channel be ing recorded and you cannot preset the VCR to record two or more dif ferent channels during your absence With the slightly more sophisticat ed arrangement shown in Fig 4 an A B switch and a signal splitter in crease your options The advantag
3. RB PB 10K see text Schematic diagram of power supply display circuit ICSC and ICSD causing its output to latch in a low state K to energize and ALARM LED2 to light The relay RESET switch S Z is operated to reset the flip flop If a piezoelectric buzzer isn t used a 10 000 ohm resistor must be in stalled at R9 in Fig 3 You can have either PBI or R9 not both The four BCD lines from the re ceiver decoder go to the Fig 3 cir cuit via miniconnector pins 4 through 7 These lines carry a num ber between 1 and 9 that indicates which of the 10 channels the decoder is tuned to has been activated These four lines go to quad storage latch IC3 and then on to 7C2 Say You Saw It In Modern Electronics see text POWER SUPPLY DISPLAY PARTS LIST a Semiconductors D1 D2 1N4001 rectifier diode D3 D4 1N914 switching diode DIS1 10 LED array Panasonic No LN10204P IC1 7805 5 volt regulator IC2 74LS42 TTL decoder IC3 74LS75 TTL quad latch IC4 CM7555 timer ICS5 74LS03 quad NAND gate LED1 LED2 Light emitting diode RECT1 DB101 or similar bridge rectifier Capacitors C1 thru C4 0 01 yF ceramic disc C5 470 uF 16 volt axial lead electro lytic C6 0 1 4F ceramic disc C7 1 uF 50 volt axial lead electro lytic Each of the 10 output lines from IC2 is sequentially held low causing one of the 10 LEDs in DISI to light at a time As long as the ou
4. vg a 9 2 EM GCV oz v 3520 8312235 252 SESS LESE ERT 96 MODERN ELECTRONICS November 1986 ADVERTISERS ll Readers can obtain free information on ll panies as well as for some editorially Il mentioned products Simply circle the INDEX RS Page 9 AMC Sales Corp 4 25 AINE Bi eorr M 37 13 Access Software Inc 79 Advanced Microcomputer 94 48 B amp K Dynascan Corp 67 12 Bodex Corp 79 CFD Enterprises Inc 94 C O M B 91 171 Cleveland Institute of Elec 214 Command Productions Li 50 CompuCover 89 14 Cook s Institute 67 18 Deco Industries 94 Dick Smith Electronics 92 25 Digi Key Corp 93 29 Floppy Disk Services Inc 15 63 Fordham Cov IV 45 Greentree Computer Supplies 5 76 Heath Cox oep oes OLENTO 29 46 J amp W Electronics 89 49 Jan CASES us comes 4 58 MCM Electronics 75 McGee Radio 94 44 Megatronics T 716 NRI Schools 8 11 fj 47 Omnitron Electronics o Pacific Cable Co Inc 7 Portasol Mail Engrg 94 Protecto mam vs 48 49 138 RCA UU A UR 8 Cov IIl 24 Radio S
5. 05 7 ClocieC dard K Mn apium amina ala B AS Dad nt m 25 Power Strip 6 Outlets _ 5 Game Cards a oud uid Sada POE bw cee wee 15 Power Strip w Surge Protector 6 OE LONG ce ui E C mmc cam m m sau 65 Power Pad w Surge Protector 18 AT2MBMTF 127 Printer Switch Box 20 FLOPPY DISK DRIVES Bulk Diskettes a 39 Teac Look Alike 68 Drom WNTItET we mua vr reep S d 160 i TeSe360_ esso ose res E fol oO Kos 86 Printers sensu rri oma NA ARI Ca w a Call Teac 1 2 MB ate vous we ana aie el Ela t Beane 110 j Chinon 360 n n 78 Chinon 1 2 MB 110 k EUJMSH sans oe smerter ack ont ere gaan 78 LIMITED OFFER HARD DRIVES amp CONTROLLERS 1 XT System 640K w 2 Floppy Disk Drives nae Keyboard amp Amber Monitor for 2 We will assemble Systems to your Configura tions for ONLY 5 00 for Components purchas ed from us gt 20MB Seagate 68 MS 295 30 MB Seagate 40 MS 598 20 MB Seagate ST238 w Adaptec Controller 480 CIRCLE 28 ON FREE INFORMATION CARD 9V battery 24 5V dc from Ji computer m existing AMPLIFIER CIRCUITRY 1 Power switch Amplifier circuit board Eat mo tede i Fig 1 Modification circuit consists of r
6. NOTE All cables are 752 quired are signal splitters to distri bute the r f signals as needed and A B switches like those used with video games and home computers to selectively route the signals to either of two destinations These items are commonly available from local elec tronics parts distributors like Radio Shack and video equipment stores When shopping for components for VCR installation avoid the bar gain basement variety Particularly avoid cables that have thin inner con ductors that tend to bend and break off very easily From here on we will assume that your TV receiver and VCR are ca ble ready allowing you to receive all nonscrambled channels without requiring the decoder box supplied by the cable company If this is not the case in your particular setup simply change all references to all nonpremium channels to chan nels 2 through 13 The Hookups Let s now examine specific VCR hookups using splitters and A B switches and assuming either an out side antenna or a cable feed that can deliver both premium scrambled and nonpremium channels e Outside Antenna No Cable This simplest of hookups is illustrat To TV antenna terminals Fig 3 This simple VCR TV cable hookup s channel selection is governed by the cable box s channel selector Say You Saw It In Modern Electronics November 1986 MODERN ELECTRONICS 35 Input ae
7. 22 95 ET or FIREBIRD Features on line clock dialing from COLOSSUS cuess p e 22 95 keyboard capture and display high ELITE 64 D oos ees 22 95 FRANKIE GOES TO HOLLYWOOD D 12 95 resolution characters and much more 547r er OF BRITAIN BATTLE OF MIDWAY D 9 95 Includes exclusive easy to use program for iw JIMA FAULKLANDS D eene 9 95 u down loa in to rinter an i k TALKING TEACHER D 24 98 dri xc Best i DEA List 99 00 SALE LAG Cc rives n U S A LIS CARD WARE D 7 95 29 95 HEART WARE D on amp comm enn opp mtem su 4 aam 7 95 PARTY WARE D 9 95 WARE WITH ALL KIT DY oe gi n nc ana ma 9 95 1200 BAUD MODEM JINGLE DISK D ls 4 95 7 9 9 5 HOLIDAY PRINT PAPER D P uvm 198 UB LOOIC FLIGHT SIMULATOR H D 31 95 List 199 JET D ee I erp Immer 26 95 AE D pe eoep qu Po e m usa mar ame features as the above modem along BASEBALL D nem roses mem coo rdi A tree 31 95 with C 128 mode and 1200 Baud speed List f s s 199 00 SALE 79 95 ROADWAR 2000 D 23 95 BATTLE OF ANTIETAM D 31 95 GETTYSBURG ie esee c inr a cmt nie aste 35 95 SOF 5 WW ARE MECH BRIGADE D 11 eio m mamap peso 34 35 95 NAM D el e 23 95 ACCESS US AMAT CUDE Lisa ad u nmn dua
8. Fig 2 Digital section supplies the 25 input and output lines required by the 2764 you to program 2764 EPROMs with a Commodore 64 computer With the Programmer plugged into the C 64 s User Port you key into the computer a software routine that allows 2764s to be read and programmed Addi tionally the Programmer allows the contents of an EPROM to be read and saved to disk These functions can be performed either from the di rect mode or under program control About the Circuit The 2764 EPROM Programmer con sists of a power supply Fig 1 and a digital section Fig 2 The power supply develops and delivers to the EPROM being programmed the 22 volts required to actually accomplish the programming Power for the EPROM Program mer is obtained from the 9 volts ac available at pins 10 and 11 of the C 64 s User Port as shown in Fig 1 This 9 volts ac enters the Program mer and is rectified by DZ and D2 and filtered by C to produce about 11 volts dc Timer JC then gener ates a roughly 50 kHz square wave that is fed to the base of and turns on and off Q1 Coil L and capacitor C3 in the collector circuit of Q7 cause a waveform consisting of a series of positive going peaks of about 50 volts amplitude to charge C5 to about 30 volts This 30 volts is then regulated to 22 volts by D7 and is de livered on demand to the EPROM plugged into the programmer When the Programmer needs the programming voltage Q2 conduct
9. T MA MM ihig W N NS a pnt i ELIT TT iini ia WM YU MW i ior S j je path i j ba 4 N QNS MI T i 462 s za Nod aL LU i i N FI a aE A L II ja ae i a d zm Margy Ei 4 NS e TNR ft Dos nid Hi Af rw 244 my e 7M oe ane s EE ae sia Fa MES A a LJ ZW A 10 Channel Wireless Home Security System A flexible highly effective wireless security system with the economy of hard wired devices By Dan Becker rate it isn t necessarily a better Hence the system not only alerts you x alarm Because it eliminates unsight to an emergency condition it even ly wires and the time consuming task tells you its location variety of security alarm ofrunningthem throughout a house Transmit receive range is up to A systems are available to the however it s the system of choice for 150 feet so you can use the system to home owner The simplest many home owners who can afford it monitor entrances windows your and least expensive are little more Our 10 Channel Wireless Home car etc Depending on the types of than a relay with hard wired sensor Security System offers an inexpen sensors you use to trip the transmit switches the most elaborate and sive approach to the radio type sys ters you can monitor for fire very expensive feature a micropro tem used in the m
10. lI Fig 5 Components placement orientation diagram November 1986 MODERN ELECTRONICS 25 A d s mw a s NW K uw m M a p s OPSoR Ee E B d gd oe G m a P wm P ME b 4 xd S dag pom m B A m s a m g MOTO l 9 mam ow ou Fig 6 AAU in its final form with LEDs labeled for easy identification tance of about 1 and trim away 1 4 of insulation from each Tightly twist together the fine wires in each conductor and sparingly tin with solder Pass the cable through its hole in the rear of the Unibox and tie a knot in it about 3 from the end in side the box Now prepare the interface cable This five conductor cable can be as long as needed but a practical length is between 3 and 10 ft Prepare both ends by cutting away 1 of outer insulation Separate the conductors and trim 4 of insulation from each Tightly twist together the fine wires of each conductor and sparing ly tin with solder Pass one end of the cable through the remaining hole in the rear panel and tie a knot about 4 from the end inside the box Connect and solder the wires com ing from the INPUT 1 through INPUT 4 jacks on the front panel to the appro priate pads on the circuit board Then do the same for the 12 volt dc and interface cables Make all con nections to the bottom of the board see Fig 6 If you decide to use a different type of enclosure than the Unibox you might
11. 22 Flashing Green LED T 13 4 4276 030 w 1 19 23 Flashing Red LED T 13 4 276 036 1 19 Digital Logic Probe and Pulser Speed Up Testing Pulser 17 27 Logic Probe The fast way to test TTL LS and CMOS digital circuits Color coded LEDs indicate high low or pulsed logic states up to 10 MHz Simultaneous tone output frees your eyes for faster testing 36 leads with clips provide power from circuit under test With instructions 22 303 16 95 28 Logic Pulser DEAD the P pul a and probe make an effective diagnostic team for testing today s digital circuits Produces single 5 us pulse or a continuous 5 Hz pulse train at the push of a button Overload protected Power Supply Components e 6 40 Volt 1 Amp Schottky Barrier Diodes 276 1165 Pkg of 2 99 7 LM317T Voltage Regulator Adjustable from 1 2 to 27 VDC output Heatsink such as our 276 1367 is required for maximum current rating of 1 5 amps TO 220 case With pinout and specs 276 1778 _ 1 99 8 1000 uF Electrolytic Capacitor 50 WVDC Perfect for filtering 272 1047 1 99 9 Power Transformer 120 VAC primary 12 6 VAC center tapped secondary is rated 1 2 amps For chassis or PC board mounting 273 1352 j Assortment Bargains i sf ar 13 48 13 100 Disc Capacitors Includes NPOs Hi Qs N 750s Mylar and ceramics 272 801 Set 1 98 14 a Watt Carbon Film Resistors 5 tolerance Jumbo 500 pi
12. Educational TV in the form of a video tape that documents various uses of bar code data in a manufactur ing environment has been introduced by Intermec Corp Lynnwood WA Titled Introduction to Bar Code Applications a VHS 1 2 cassette costs 25 COMMUNITY COMPUTER SERVICE A free open access community computer information service has been started for the Cleveland metropolitan area It s arranged like an electronic city with a post office for electronic mail a schoolhouse for use by Cleveland area public and private schools and a hospital and courthouse where medical dental and legal questions can be asked with answers by teams of quali fied professionals There s also a government house where area residents many contact their elected representatives and a public square with a podium where users can give electronic speeches Credit Tom Grundner an assistant professor at Case Western Reserve University for conceiving the system and a 50 000 donation from AT amp T s Information System Division as well as individuals and organizations in the Cleveland area who volunteer skills and time Users can access the system with a computer and modem dialing 216 368 3888 to read any thing they wish To place material on the computer and have electronic mail privileges however one simply needs to fill out a form send it to CWRU University Communication 1 Adelbert Hall Cleveland OH 44106 and get an ID number and pa
13. INTERFACE CARDS KO Ls cs cue vin wa Heit BUDS aa Mag acidao dis 55 41 oo AM MERE 65 gt Monochrome Adapter gt o Mono Graphic Printer sees 60 MONITORS bean eal he CT 6040 Herc Comp seee ee 65 Samsung Amber 2280000 ees 68 Color Graphic Display 44 Samsung Green n e 65 Color Graphic Printer 55 Belton Tilt amp Swivel oen 85 EGA CardS 190 Mitsubishi RGB n n 230 EXPANSION CARDS TVM RGB Green Amber T 0 Qa 275 XT Disk Controller 1 Port 25 EGA Mitsubishi cnn 395 Q XT Disk Controller 2 Ports 27 OTHERS AT Floppy Disk Controller 60 SO EAKEl a Gorane Ba ca Lar ade dri d M SG ea DI a o 1 4 RS232 1Port b ent nna 21 Disk Storage 100 vans s lt eer mmt 7 RS 232 2 POortSy epu pig Dre Fees krg kala a ae 29 Keyboard Drawer 1 30 x Parallel Card o6 6n 14 Modum Internal feet e a n m 121 Multi lO us sa ces mm sq aac REP sya r 71 Logi Mouse ra ous emn era 77 1 O Plus Card 65 JOUSHEK zz Gale wank a weas easel Aeon 16 384K MTF O R 0 ee n 74 Printer Stand Big zii re ns poss 6m e 8 640K Ram O Ki g a EPA pia ce aa aeu w 38 Printer Stand Small
14. P4532 39 333 2882 20820 S 1N5401 3 Amp OQPIV Plaste 30 270 7400 71000 CET 3A MLS160N 16 NES32 n b i eii pras ERI 4 Dp M06 Finse 3 Amp 200PIV Pesis 31 283 2820 22050 R S405 rp perio 1009 ro 2 OK Q n ws 10 CAPACITORS Cai No P4533 a7 4 37 3279 23 490 TALSTEON 1 10 NESSSN 65 i Compatinie NMOS 8 Br 1NS4 4 3 Amp 4Q0PIV Plase 33 237 26 40 23100 Paga 56 AB 321 3624 380 MESES NESSSN 20 Micropracessor 40Dg 339 1N9406 3 mp GO0PIV Plasnc 35 375 28 00 24500 10 Wart Reamtor Aasortmant panty TNENT oris ONLY P4535 88 S2 172 4056 29500 AE M NESEEN 164 pot gB CMOS INSAQ 3 Amp BOOPIV Plast 4 360 3200 28000 myo 2eachot aii stend rd vetues ACTORS 3Q95 Passe 82 SB 532 4578 3300 UA ZaN 64 Microprocessai 40 Da 3 Amp 10Q0P V Pias 50 450 4000 168 Iota pcs P4537 10 66 The Digi Key volume discount and service charges ace wmple to apply Most items soid by DigeKey may be combined for a volume discount Items that are not digtountabie are identified by the s SERVICE CHARGES VOLUME DISCOUNT ND folowing the part number After writing your order total all of the discountable tems and appty the appropnate discount To this subtotal add the non discountable stems Then add the charge We pay all shipping and insurance to addresses in the U S 4 Canada and Menco when check or money order accompanies order Digi Key only ships Orders within the continental U S Alaska 0 00 9 83 Add 2 00 0 00 989 99
15. YOUR ONE STOP SOURCE OF ELECTRONICS INFORMATION ICD 08559 EC THE MAGAZINE FOR ELECTRONIC 5 T ji quet eO P og Acquistign Unit p 22 a SE rv s ce y 8 lt O n C 3 a E lt i v r 5 a O oz gt m Z Ox 5 uc 2 gt C cc lt r 2 E ew gt gt w gt Daoa lt ONJ Bulk Rate N ordPertfe m Permit No 79 Apple II GS a Chaac EPR U S Postage Paid S Currentahlaas irina Gordonsville VA 22942 Electronic amp Cor NOVEMBER 1986 1 95 CANADA 2 50 KENWOOD pacesetter in Amateur radio e Sec ME POWER i ee A OFF VOICE TIMER DIM MODE KEY ge s d Nt THE high performance receiver is here from the leader in communica tions technology the Kenwood R 5000 This all band all mode receiver has superior interference reduction circuits and has been designed with the highest perform ance standards in mind Listen to foreign music news and com mentary Tune in local police fire aircraft weather and other public service channels with the VC 20 VHF converter All this excitement and more is yours with a Kenwood receiver Exclusive Kenwood DynaMix system ensures an honest 102 dB dynamic range 14 MHz 500 Hz bandwidth 50 kHz spacing 150 kHz 30 MHz in 30 bands e All modes Digital VFOs tune in 50 Hz 500 Hz or 5 kHz steps 10 memory channels e Programmable scanning
16. ples and observing the rough results that counts here According to the Manual a 1 bit sample is taken at about every 72 microseconds and there s some quantization noise A knowledge of programming isn t required to quickly learn about electronics and how mechanical con trivances are controlled by a compu ter With a knowledge of BASIC however you can modify or create your own control programs For those who are advanced in this area there s a programmer s reference section with technical specifications advanced commands and a memory map at the back of the manual Free information on interfacing compo nent data sheets and a schematic are Offered too to purchasers We were favorably impressed by the Workshop It fulfilled its prom ise of providing an educational tour of electronics and mechanics in an animated fun way According to the distributor there are enhancement modules that include two Robotics modules a scope enhancement mod ule a thermodynamics module a switching and relay module and a speech digitization enhancement module among others ME Art Salsberg CIRCLE 27 ON FREE INFORMATION CARD lt amp 2 N uJ lt X n ul s L lt E 2 3 ui ba wd z 2 8 t amp z lt G v sse t 3 7 SO 23st SON pee 52235 lt lt saD FEELER E w a TLP vm Sz dX oO ism zafe2 PS pm eet stessc E s gt se EES BEEZ ES iz TLEER S lt sia 9 25953 Eas Q
17. ways start with a small pilot bit and work up with successively larger bits until the hole is the appropriate size It is important that you use protec tive soft plastic jaws or blocks of wood when holding the work in a vise Note too that the word carefully is used a number of times in the text By this we mean that you should work slowlv and gently to prevent damaging the parts being modified holds the piston in the cylinder may be secured differently than for the pump shown in the photos which is crimped on tightly You want to re move that cap without distorting it or the cylinder To do this first try by gently tapping around the edge of the cap with a small hammer and punch It may be necessary to care fully cut a slot in the edge of the cap with a hacksaw making sure not to cut into the cylinder Remove the piston fro the cylinder Fig 1 and slide the cap off the pushrod Then remove the rubber O ring from the piston and set it aside in a safe place so it won t be dam aged Notice that the simple valving arrangement consists of the two cut outs on the O ring groove To give the pump its vacuum action you have to reverse the piston on its rod On the pump shown in the photos in this article the plastic piston was molded onto the end of the rod It is possible though to remove it with out damage Drill into the center of the top of the piston with a bit the same size as the p
18. Dual 24 hour digital Clocks with timer e 3 built in IF filters CW fiiter All mode squeich noise blanker RF optional e attenuator AGC switch S meter e 100 120 220 240 VAC operation e Record phone Jacks e Muling terminals e VC 10 optional VH F converter 108 174 MHz Listen Up usa cw FM L STEP HF vHF NB1 DOWN ETT T UP Nn n SELECTIVITY SQL 9 NOTCH AUTO 4 r RESET NB 9 iFSHIFT AF RF Aa f A B EA A j m 4 10 RF e 1 10 720 3 du d8 HOUR MINUTE A B FLOCK NB2 NOTCH ae Lithium battery backs up memories all functions remain intact even after lithium cell expires Optional DCK 2 allows DC operation Store mode frequency antenna selection Accurate to 10 ppm over a wide temperature range Optional filters further enhance selectivity Dual noise blankers built in Specifications and prices are subject to change without notice or obligation e VC 20 VHF converter for 108 174 MHz operation e YK 88A 1 6 kHz AM filter e YK 885 2 4 kHz SSB filter e YK 88SN 1 8 kHz narrow SSB filter e YK 88C 500 Hz CW filter YK 88CN 270 Hz narrow filter e DCK 2 DC power cable e HS 5 HS 6 HS 7 headphones e MB 430 mobile bracket e SP 430 external speaker e VS 1 VS 2 voice synthesizer e F 232C IC 10 computer interface More information on the R 5000 and R 2000 is available from Authorized
19. It was great for studying at home for preparing the test EP Tampa FL Get Started Immediately Thousands of high paying jobs are waiting for ambitious people who have an FCC license So mail us the coupon below and well rush you complete information FREE by return mail dien dU per y rir Saa d COMMAND PRODUCTIONS j FCC LICENSE TRAINING Dept 201 Custom House POB 2223 San Francisco CA 94126 Please rush FREE DETAILS immediately j Name s mex s see a Ea Address oe State Zip November 1986 MODERN ELECTRONICS 1 ICS NOVEMBER 1986 LX 22 30 33 34 38 52 16 18 72 80 84 THE MAGAZINE FOR ELECTRONICS amp COMPUTER ENTHUSIASTS VOLUME 3 NUMBER 11 FEATURES An Analog Acquisition Unit Lets a computer store compare plot and analyze data from circuits By Eugene Weber amp Wayne Slugocki The Optical Isolator Part 1 Exploring the various types of optical couplers and their applications By Ralph Tenny Automatic Telephone Ringer Silencer By Rich Vettel VCR Hookups With Cable Boxes VCR connection arrangements most user manuals failto address By Cass R Lewart A 10 Channel Wireless Home Security System Wireless security system has the economy of hard wired devices By Dan Becker An EPROM Programmer For the Com modore C 64 Computer driven plug in board inexpensively pro grams 2764 EPROMs By Paul Renton Sup
20. You could leave it out in strong sunlight for a week or you could buy a special high intensity short wave length EPROM eraser at a cost of 80 or more Many hackers felt this was too high a price to pay for just an occasion al erasure JKL components has just introduced a brand new BF727 UV2 miniature ultra violet lamp that sells for only 5 Its spec trum has been optomized specifically for erasing EPROMs A drawing of this lamp is shown in Fig 1 its simple 110 volt ac drive circuit in Fig 2 Ultraviolet light comes out the side of the lamp between the two parallel plates The Fig 2 driver circuit is basically a voltage doubler and current limiter The lamp fires at 300 volts and runs at an ex ternally limited operating current of 1 milliampere Be sure to use very high quality 350 volt capacitors if you build this circuit There are some gotchas The intensity of the BF727 UV2 is far lower than the 80 erasers The good news is that you don t have to be quite as careful with your visual interlocks as you did with the higher intensity lamps Keep in mind that high intensity UV light can easily cause permanent blindness For this rea son I still would not recommend looking directly at the JKL lamp except for the briefest possible time The bad news is that it takes overnight to erase an EPROM And that s running at higher than normal current with a concentrating reflector Still you can easily build a small snap o
21. a second picture on any of the VCR s TV channels The window first appears about size in the lower right cor ner but it can be moved to any other corner and can be blown up to fill the screen as desired New digital technology is respon sible for the picture within picture feature It lets the viewer freeze the live picture on the broadcast Digital LC Bridge Heath s Model IT 2240 kit is re ported to be a laboratory accurate digital LC bridge that measures ca pacitance inductance and their asso ciated dissipation loss factors Measuring range is from less than 1 pF to 2 000 F and 1 H to 2 000 H with a rated accuracy of 0 5 each in eight user selectable ranges Resolution is 0 1 pF 01 H on the lowest ranges Dissipative factor range is from 0 000 to 1 999 3 0 channel and enhances special effects to provide virtually noise free pic tures On top of this the digital cir cuitry can give the picture a mo saic or a mottled oil painting ap pearance like that used in profession al music videos A scene transition stabilizer minimizes picture breakup in pause Standard features include remote programming with on screen dis play delayed start express record ing VHS HQ circuitry for compati bility with other VHS machines fre quency synthesized 119 channel tun ing automatic program tuner 4 event l year timer automatic re wind and a full function wireless re
22. and has a fixed skimpy margin of one line between headers and text But WordPerfect s other first class features are all there from footnotes and endnotes to automatic timed backups temporary exit to DOS password file se curity and the ability to undo not just one but any of your last three deletions Its screen display is still the cleanest in the business with easy toggling to hide or edit formatting commands Compared to the world s other word processing superpower Microsoft Word 3 0 WordPerfect uses the PC s function Ctrl Shift and Alt keys instead of mne monic menus despite excellent docu mentation the function key template isa must It lacks Word s fancy mixing of fonts and typestyles and can t show right justification on screen though unlike Word it shows page breaks automatical ly But it s an equally smooth superb word processor combined with the best spelling checker and thesaurus I ve seen a 115 000 word dictionary loads of spelling or synonym suggestions fast and intuitive to use Bad spelling sloppy footnotes and chronic poverty are endemic on Ameri ca s campuses Student WordPerfect is a laudable affordable answer to those 84 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics The Practical Multifunction 1200 memory modem and more problems even if it undercuts a Word Perfect Corp executive s quip in 7nfo World that if b
23. ital Scale lets you closely a monitor your weight with electronic precision And it s battery operated so it s safe t use right out of he shower 6 Add a video entertainment cen Mp ter to your bedroom Cur 19 ciagonal L stereo TV kit gives you an extra sharp color corrected picture with full stereo sound and convenient viewing that you can ccr trol from your bed Comes in a simulated walnut cabinet that complements your room Send NOW for your FREE Heathkit Cata_og Send to Heath Company Dept 079 472 Benton Fartor Michigan 49022 I Name MM CIRCLE 76 ON FREE INFORMATION CARD III Address n M CHES a RES e Zipes A subsidiary of Zenith Electronics Corporation CL 789A Technology The Optical Isolator cary In this first of a two section focus on optical isolators our emphasis is on the various types of optical couplers available to experimenters and hobbyists their technical characteristics and typical applications In the second half which will appear next month will be construction details for building an in expensive and versatile tester that can be used in conjuction with a dual channel oscilloscope and a digital multimeter to test all types of optical iso lators in dual inline packages low voltage zener diodes and 9 volt batteries Exploring Optical Couplers By Ralph Tenny ptical couplers o
24. or ALERT the various LEDs of DISI according to location such as FRONT DOOR KITCHEN WIN DOW GARAGE etc in Fig 12 and S1 RESET Calibration and Installation Starting with the receiver system place it within about 3 feet of a TV receiver turned on and tuned to channel 2 Plug the projects s wall transformer into an ac outlet and note that the POWER LED immedi ately comes on and that all 10 LEDs in DIS light for a few seconds and then shut off After this the array s LEDs will turn on and off sequen tially in scanner like fashion Use a small screwdriver to adjust the tuning slug in 77 Caution the tuning slug is very fragile so work carefully With the slug about half Say You Saw It In Modern Electronics way Out begin slowly turning it clockwise while monitoring the TV picture Lines of interference should appear Continue clockwise adjust ment until most or all of the lines fade out and a light snow remains indicating that the r f detector is op erating in the correct frequency range Connect an audio amplifier to testpoint TP1 and GND on the re ceiver decoder board see Fig 7 Turn up the volume to about half way and listen for the hissing noise that indicates correct receiver opera tion If a TV station is broadcasting on channel 2 you can detect the video portion of the signal by back ing 77 s slug about halfway out until you hear a harsh buzzing sound To calibrate the transmitter s star
25. the circuit re turns to scanning You can use the relay to control a siren or and a lamp or floodlights Additionally you can use channel 1 as a wireless remote reset switch that allows you to pass through a security zone without setting off the alarm The Transmitters All transmitters in the system are iden tical except that each is tuned to a different tone code that makes it uni que and immediately identifiable The transmitters Fig 1 operate on November 1986 MODERN ELECTRONICS 39 aS er er eer m rru s DOJ B B E r 4 T T R TY c Transmitter Componeni Values CLELIA C3 lu F Channel Frequencs Numher Hz 4 ADU 670 TER 3 MN 2 44 at RUE OO 7 407 dE TRIAR X LR RIS hae 54 0047 IP 1 att th 49 890 MHz and are crystal con trolled for stability They are basical ly amplitude modulated oscillators with Q2 dc biased by R8 R9 and R10 Capacitor C operates as a short circuit at 49 MHz which places Q2inacommon base configuration thus maximizing stability and prevent ing unwanted spurious oscillations Because the crystal is in series with the emitter of Q2 emitter current is very sinusoidal and free of a strong second harmonic Capacitors C8 and C9 make up a voltage divider that feeds a small
26. 10 00 25 00 Add 0 75 100 00 249 99 Less 10 Hawaii Canada and Mexico WHEN ORDERING BY PHONE CALL 1 800 344 4539 AK cali 218 681 6874 BY MAIL SEND YOUR ORDER TO OIGI KEY P O Box 677 Thief River Falls Mit 56701 4 25 00 449 99 Add 0 50 250 00 3499 99 Less 15 00 Add 0 25 500 00 4 999 99 Les3 20 You may pay by check money order Master Charge VISA or C O D DIGI KEY GUARANTEE Any parts or products purchased from Dige Key that prove to be defective wil be replaced or rel 50 g pr apeta 1000 amp Up No Charge 1000 amp Up Less 25 ed if returned within 90 days trom receip1 with a copy of your invoice PRICES SUBJECT TO CHANGE WITHOUT NOTICE CIRCLE 25 ON FREE INFORMATION CARD 12v PORTABLE VIDEO LIGHT OWNERS TAKE CONTROL STOP BLINDING your subjects Get the right fill in light for close ups CONTROL light intensity power from 30 to 10076 on 12vdc lights up to 100 WATTS e SAVE MONEY DRASTICALLY extends bulb life e RUN up to 2 times LONGER per charge from any NI CAD or LEAD ACID power pack Real time BATTERY ANALYZER know pack status can EXTEND operating lifetime 69 95 4 2 50 shipping KIT ONLY 49 95 2 50 shipping MasterCard amp VISA accepted CFD ENTERPRISES INC BOX 10998 374 USA 1 800 531 5255 Vass an TX 1 800 252 9146 J Ext 1822 LOCAL 512 440 9422 Brot be SPEAKER CATALOGHOMO Sy 1001 bargains in
27. 12 CL rd 1 uF O4 KR 224Q RS LOK OUT Fig 5 A programmable timer circuit built around the XR 2240 chip 74 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics S P T s sel T lays When all the outputs of the second XR 2240 are connected to the output bus the delay becomes 65 536T There fore if T is 5 minutes at 65 546T the delay is 327 680 minutes 5 461 3 hours or 227 6 days Referring to Fig 6 note that the timer section of the second XR 2240 is not con nected only the binary counter portion of the chip is used The timer section of the first XR 2240 is connected in the astable mode so that the timer is auto matically reset after a timing cycle is complete These repetitious timing pulses are then applied to the binary counter in the second XR 2240 The circuit in Fig 6 is based on one giv en in Exar s application literature I add ed R4 and configured the circuit for astable operation For additional infor mation on using this versatile chip see Exar s XR 2240 application note Commercial Digital Timers A crystal controlled timebase having a digital readout is required for ultra preci sion timing applications Of course many such devices are available as com mercial devices While it is possible for the experimenter to design and build such a timebase it s usually much more con venient and considerably less expensi
28. 1560 West Woods Cross UT 84087 each Workshop model contains a computer interface unit motors sensors snap together me chanical parts software and proj ect experiment instructions in a 136 page spriral bound manual The Model MB230 workshop model we examined which included an interface for a Commodore C 64 or C 128 computer costs 129 95 Similar Workshops are available for Atari 8 bit computers 139 95 with Apple Amiga Atari ST and IBM versions expected to be avail able soon At the heart of the system is a B100 interface that plugs into the C 64 s user port Powered by six AA bat teries it has switch selections for set ting up motors to be powered on or off and switches for choosing me ter scope infrared sensor and au dio applications A variety of input and output jacks are included Eight LEDs are incorporated to provide activity information A floppy disk contains the Robot ic Operating System R O S which uses the BASIC language while ad ding 25 special commands to make computer control more powerful such as FLIP reverse a motor s di rection TMR for setting up an in terrupt timing interval and other extraordinary commands not com mon to BASIC The mechanical parts about 50 of them are rugged snap together Cap sela plastic components two of MOTOR 1 LEADS OCTAGONAL N T CONNECTOR VOLTMETER CABLE N2LEADS d MOTOR USED AS GENERATOR Here s
29. 362 2105 Associate in Applied Science Degree in Electronics Let us get you started today Just call toll free 1 800 321 2155 in Ohio 1 800 362 2105 or mail in CIRCLE NO 171 ON FREE INFORMATION CARD start first with CIE aggm 55 OS Why CIE Because we re the leader in teaching 1 World Headquarters electronics through independent study Consider this n 1 Cleveland Institute of Electronics Inc We teach over 25 000 students from all over the I 1776 East 17th Street Cleveland Ohio 44114 United States and In over 70 foreign countries And O Please send your independent study catalog we ve been doing it for over 50 years helping For your convenience CIE will try to have a representative thousands of men and women get started in 1 contact you there is no obligation electronics careers We offer flexible training to meet your needs p Fuga You can Start at the beginner level or if you already Address m mu Apt know something about electronics you may want to DN start at a higher level But wherever you start you d SER ZR can go as far as you like You can even earn your I Age Area Code Phone No I i I I I I I I I By Eugene Weber amp Wayne Slugocki ne of the more interesting uses for a personal comput er is to have it store com pare plot and analyze data from your electronic experiments and cir cuits Such data is usually put into the compute
30. 62 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics i Fig 7 Many types of marking pens and Teflon tips can be adapted for use in the basic Super Solder Sucker Two examples are shown here steel pipe plug available at any hard ware store can be run into the coup ling to cut enough thread to get the hose barb started It s not elegant but it works Next screw in the x XA N P T hose barb available from automotive suppliers using a sealant like RTV Permatex or Teflon tape on the thread The hose barb is made of soft brass so even if it s cross threaded it will conform to the new threads Don t over tighten Tighten only enough to hold the barb securely Now thoroughly clean the bore of the cvlinder of all metal chips and other debris You don t want to damage the rubber O ring Smear a petroleum jelly around the circum ference of the piston and slide it into the cylinder Slide the end cap over the piston rod and tap it gently onto the cvlinder using a block of wood BILL OF MATERIALS foot operated bicycle tire pump 2 4 x 4 hose barbs for tubing with 4 x 27 N P T threads 1 2 hose clamp with worm gear A hose clamp with worm gear 6 ft silicone rubber tubing Aero trend extra large or similar see text Desoldering iron Radio Shack Cat No 64 2060 or similar see text Small size CO cartridge see te
31. 92316 PROJECTION TV Convert your TV to project 7 Foot picture Results comparable to 2 500 projectors Total cost less than 30 00 Plans and 8 Lens 21 95 Illus trated information FREE Macrocoma MC Washington Crossing Pennsylvania 18977 Creditcard orders 24 hours 215 736 3979 Dealer Inquiries 215 736 2880 DISCOUNT CATY Converters Decorders and Video Accessories Free information Easy View P O Box 221C Arlington Heights Illinois 60006 312 952 8504 Ask for Rudy Valentine CABLE TV DESCRAMBLERS All brands available WE WON T BE UNDER SOLD Dealer inquiries welcome We ship C O D S For catalog send 3 00 to Consum er Video Corp P O Box 913 Clifton Park NY 12065 518 783 5636 M F 9am 5pm EST CABLE TV CONVERTERS amp EQUIP MENT Plans and parts Build or buy SEND SASE C amp D ELECTRONICS P O Box 1402 Dept ME Hope AR 71801 92 MODERN ELECTRONICS November 1986 YCR REPAIR Tech tips Complete issue all brands Send 7 95 to Cotton 4207 97th Ave E Parrish FL 33564 STRANGE Stuff Plans kits items Build Sa tellite Dish 69 Descramblers bugs adult toys Informational photo package 3 Re fundable Dirijo Corporation Box 212 M Lowell NC 28098 WORLDS best channel 3 notch filter 19 95 Dealer inquiries invited Crosley G Box 840 Champlain N Y 12919 ELECTRONICS VOICE BAND SPECTRUM NETWORK DISTORTION ANALYZER module swe
32. Brands ELECTRI FIED DISCOUNTERS 996 Orange Ave P O Box 151 West Haven CT 06516 MC VISA 203 937 0106 Say You Saw It In Modern Electronics m m mm m Bu AK Puerto Rico 218 681 6674 Teiex 62827914 FAX 218 681 3380 TWX 9103508982 DIGI KEY CORP JODES DIAMOND TOOL UNGAR ES CW INDUSTRIES AMDEK G E IGAR e YAGEO J W MILLER LUXO 3C CHEMICALS ARIES PLESSEY DISC CAPACITORS TANTALUM CAPACITORS neea Mmmm NATIONAL SEMICONDUCTOR PANASON VISA OK MACHINE EWC INC INTERSIL AD ew 256K wass EAC INC J W MILLER AAVID ENGINEI amp E F JOHNSON ATLANTIC SEMICONDUC E INTEGRATED CIRCUITS INTEGRATED CIRCUITS T 262 144 x 1 DRAM 150NS 5 70 1 39 95 9 Factory Firsts i 1 c SOCKETS
33. C4 100 pF 35 volt electrolytic Resistors 4 watt 5 tolerance R1 2 200 ohms R2 R4 10 000 ohms R3 220 ohms R5 470 ohms Miscellaneous K1 5 volt spst relay L1 100 4H coil SO1 28 pin zero insertion force IC socket Printed circuit board female 24 contact 12 contacts on each side to tunately for the home programmer there is a single type of EPROM that is widely used in computers and many other digital circuits and systems It is the 8K by 8 bit 2764 EPROM that in most cases is the only type you need consider Presented here is a low cost EPROM Programmer that allows From IC3 Q2 2N2222 D6 1N4001 conform with the C 64 s User Port arrangement card edge connector with 0 156 contact spacing sockets or Molex Soldercons for all ICs see text solder etc Note The following items are available from Paul Renton P O Box 1525 Mer cer Island WA 98040 complete kit in cluding pc board ZIF socket and all com ponents but not IC sockets and software on disk for 34 00 double sided pc board for 12 50 software on disk for 5 00 Washington residents please add state sales tax Fig 1 Power supply section delivers 22 volts to program the 2764 EPROM 52 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics IC2 74LS273 Serial Ta Parallel Converter led 74L5373 C cpan an Address Generator 5V To user port
34. CIRCLE 9 ON FREE INFORMATION CARD II EDITORIAL NENNEN Breaking The Bell Connection There are three apparent results from the breaking up of AT amp T higher consumer prices more ad vanced telephone equipment and long distance phone service competi tors such as MCI and SPRINT The first higher consumer prices for local service might have people wondering about the benefits of breaking up Ma Bell Shouldn t such costs go down instead of up Well yes and no Part of the answer has to do with the introduction of techno logically advanced equipment but in a way you might not imagine AT amp T before divestiture was able to get depreciation of its equip ment stretched out to as long as 40 years With such a wonderful cost re covery deal it paid to keep existing equipment running instead of up grading Great for AT amp T s then subsidiary Western Electric which made electromechanical relays I suppose but certainly such archaic equipment imposed limitations on communications advances that end users could enjoy Without the long term equipment depreciation deal and competition all over the place the change to solid state switching and other new tech nologies increase costs which in turn caused our local phone rates to rise The truth is though that the present rates are not terribly outrage ous It s just that earlier rates were so nice and low As proof of this phone service costs since the AT amp T
35. Information Readers can obtain free information on products advertised by certain companies as well as for some editorially mentioned products Simply circle the appropriate number printed below an advertisement onto the Modern Electronics Free Infor mation Service card bound into this is sue After filling in your name and ad dress just mail the postpaid card Your re quest will be forwarded directly to the ad vertiser with a mailing label prepared by our reader service department to ensure speedy response 86 MODERN ELECTRONICS November 1986 space by creating a master menu rather than many batch files this is space wasting silliness You can edit your PATH statement to undo Le Menu s damage then delete the duplicated files but it s a chore caused by poor design Otherwise Le Menu works well is priced right and packs some likable fea tures such as file encryption Minus the cutesy names I d recommend it for most office environments ME Names and Addresses Chambers International Corp 5499 N Federal Hwy Suite A Boca Raton FL 3343 305 991 0444 Practical Peripherals Inc 31245 La Baya Drive Westlake Village CA 91362 E18 991 8200 Popular Programs Inc 135 Lake St Suite 180 Kirkland WA 98033 Hartel Software 1275 Fort Union Blvd Midvale UT 84047 801 566 5544 Say You Saw It In Modern Electronics Give a a gift that lasts all year MODERN I Now you
36. SHOP D THEATRE EUROPE D DESIGNWARE V 1 l BODY TRANSPARENT D 26 95 included FREE Disk or Tape List 89 00 EUROPEAN NATIONS amp LOCATIONS D 19 95 SALE 39 95 STATES AND TRAITS D 19 95 ELECTRONIC ARTS HEART OF AFRICA D e s ei eee RE LE i d Re 9 95 VOICE COMMAND ONE ON ONE D soo venim women m te 9 95 PINBALL CONTRUCTION D 9 95 MODULE MUSIC CONSTRUCTION D 9 95 RACING DESTRUCTION D 0 2000 00 00 ee eee ees 9 95 MARBLE MADNESS D 24 95 CHESSMASTER D Z Pun 91 as Eb lo D ges boats 26 95 e List 80 EXER Dis Ee cel 26 95 HUGE fon san anh tan As massa ee 22 95 The VCM is a speech recognition device that ON N nod lets you give commands to your C 64 with MILLIONAIRE D eese 16 98 your voice List 79 95 SALE 39 95 ld D s saam c reme cec oF gp s 16 95 SUPER AUTO DIAL MODEM CHAMPIONSHIP WRESTLING D 23 95 FAST LOAD Q ieeee re remm Ires 22 95 MOVIE MONSTER D 13 95 WINTER GAMES D 23 95 e List 99 WORLD GAMES D 825222 duca c b cac E nll oi 24 95 WORLD KARATE D n 17 95 Easier to use than dialing your telephone WORLD S GREATEST FOOTBALL D
37. TBn wna wrap un 106 1030 10200 ANASDNIC L er 7A 48N 38 bike 3 50 t50 1 02 DP8307N 6008 CBI40 40 pin wee wrap bn 142 1390 13800 P s S SERIES 3 i 4 7AHCI5S N 113 i DPBR3OSN 500 Mounture Akure Electrolytic Capacitors 4 4 141508 2 03 C GOLD INLAY WIRE WRAP min B JAMCISBN 113 160 63 10N d wacrownapaw Goki 22 47 40 Taan 73 JAHCIBON 183 133 rig OPON sm na Description 1 10 100 Axial Radial 33 52 45 M D 7AMCI IN 163 145 e oranin 588 cgi08 B pn wire wrap gold s sm 5700 m ape ML S BM JAHCIB2N 16 200 1 18 INSBOISLN 67 50 E C14 Tapn wre was god 79 780 70 u OC 10 9 y 300 58 m 74155N 73 MHCIB3N 163 2 00 77 INSBOQSN 11 750BCS156 16 pint wrap god 85 840 8300 22 63 18 155 1283 05 900 PA ON sa HC164N 158 175 166 INSBOQIN 6 9638 Co Isp wre wrap god 99 980 9700 33 53 20 188 1404 17 931 15 i 204 7415 75 74MC165N 245 95 165 INS80398 1110 50 C9120 20pn wwo wrap gokt 119 ItBO 11700 47 63 21 1 1448 14 115 955 0 50 xz 21 74180N 358 745 114N JMHCYMN 125 1 70 413 coim 2 ya 2 100 83 22 183 1522 133 5 0 5 2 50 IGAN 90 745133N JHCUEN 12 1 BB Il a Oi ua mee d Be ha 1 Matal Flim Values in Ohma 100 to 00M ZO 63 28 234 1953 21 178 1480 022 0 2 50 74163N sa 4S 34N JAMC SNN 203 i3 344 INSA2S5N 938 4 C9124 pn wwe wap goc 139 1380 137001 How To Order Toke any standard resestor value ie 330 63 29 246 2048 2 9 1695 3 5 R 770 2250 74164N sal 4sissN 25 4MCi9N 150 d ioo SP 8F 382 2500 C928 28n wro
38. a copy As always this is your column and you can get technical help by calling or writ ing per the Need Help box We are way behind on answering letters right now so you ll get the best response with a tele phone call NEED HELP Phone or write vour Hardware Hacker ques tions directly to Don Lancaster Synergetics Box 809 Thatcher AZ 85552 602 428 4073 I November 1986 MODERN ELECTRONICS 83 Say You Saw It In Modern Electronics E PPC PAPERS ill First Impressions Student WordPerfect Multifunction Modem Le Menu By Eric Grevstad I was about to write a column about dol drums dog days it s August as I write and the computer industry being in a slump lots of me too products endless Enhanced Graphics Adapters IBM with nothing to show lately but modest price cuts and the portless PC Convertible But it looks like things are perking up for fall with at least three nice trends worth talk ing about Trend One There are rumors about IBM s finally using its manufacturing might to teach the low cost clones a les son in other words doing what Tandy did July 30 by introducing the 1000 EX at 799 ignoring Epson and Leading Edge to take on the discount houses like PC s Limited Have you seen the EX It s a One piece unit like a Color Computer with the keyboard of a Tandy 1000 and the side mounted drive and limited ex pansion room of an Apple IIc it has 256K RAM runs
39. and Energy x Voltage Regulators and Meters x Fundamentals of Communications Theory Introduction to Transmitters Six Step Trouble Shooting x CW and FM Reception Rules and Regulations WE PLUS 30 MORE COMPREHENSIVE LESSONS Our Guarantee We are the only FCC course publisher in America to offer you a full money back guarantee Say You Saw It In Modern Electronics Be anFCC LICENSED ELECTRONIC TECHNICIAN GUARANTEED PASS You get your FCC License or money refunded No need to quit your job or go to school No Previous Experience Necessary Our proven course is designed so even beginners can start fast Step by step you start with the very basics and continue lesson bylessonata pace tnat coincides with your lifestyle The course is written in everyday language complete with photos diagrams and drawings that make it simple and easy to understand Here s what you ll get 40 audio cassette lessons Featuring information covering the answers to FCC exam questions Test answer solutions To assure your self of no surprises at exam time FCC Math Problem Solutions work book Simple solutions to FCC exam math problems PLUS Two in depth Electronics Home Study Course Training Manuals Read What Others Are Saying Yes got my FCC license also got a pay increase and am now studying for the Radar Endorsement JC Hope AK The questions were almost identical to those on the FCC exam
40. auus Aes 38 98 ACTION PACK D ouad Ims Tn aa al De 14 95 WAW HIP a D eene mnm nnne pe B LEADER BOARD D rnm ya s b ues nint 23 95 eme ehh hane hh hederae eren nn COURSES FOR LEADER BOARD D 13 95 HAYDEN MACH S C Ro SS Ars ren SUE Ie en care 19 98 SARGON H D 9 95 MACH 128 O msani 38 VAM SAT VERBAL D manens ua i dar c2 sas ao Daun 14 95 TENTH FRAME D 723985 SAT MATH D nnn R6 14 95 ACCOLADE od peli TEST D ad nr a3 a sas t bcd 1979 ausi 14 98 ACE OF A ill wa puma onim awaopia gt pan 18 DAM BUEFER zD sitter gi WP Te ACCOUNTANT INC C128 D 86 95 ACCOLADE FOOTBALL D X Q 19 94 DESK MANAGER D siwiw s RS Uode x BAS QE ARA RARE NEP os mimi sive 24 95 FIGHT NIGHT D sse 18 95 EDO ib ILI eg PARDBADI D nons etta 12 4 ma se nis 18 9s MODEL DIET D sso 6666 LAW OF THE WEST D cee oe ccm n ye eee nee 18 988 TRIO C64 D im sa i ionima enn 32 95 KILLED UNTIL DEAD D 19 95 PER LIF um COSMI eee eee s WU sU s s sum aX Bie SUPER HUEY II D eR 14 95 TER C x cer da me parengna pi TALLADEGA D erm Ped LW en gis 12 95 LER C rer wa pasan o cte MI pe e BEYOND FORBIDDEN FOREST D 14 95 B UP amp ADD EM O Siren w espa 5 nm ial pti EET en Add 3 00 for shipping handling
41. cable boxes that have built in decod ers for premium pay TV channels We will address this deficiency here by presenting a few basic VCR hookups that may solve your cable VCR TV receiver dilemma Each hookup arrangement introduced is explained in detail including its rela tive merits and disadvantages If you follow the instructions given here there should be no reason why you can t take full advantage of your VCR s capabilities Our emphasis here is on using your VCR with a ca ble box that has pay TV decoding ca pabilities rather than on complex Input from antenna Or vhf uhf tuner channel selector 7 d Video tape unit x Fig 1 Simplified block diagram of the typical videocassette recorder video systems that contain a multi plicity of signal sources and more than one TV receiver or VCR VCR Basics To better understand the hookups detailed here you should be familiar with some VCR basics Figure 1 illus trates the simplified block diagram of the typical videocassette recorder The built in vhf uhf tuner and chan nel selecting mechanism duplicate those in your TV receiver This sec tion is followed by a video audio system of circuits that terminate in the video tape unit The latter is the electromechanical tape transport that actually moves the tape and reads the program information from it via its tape heads In the play mode the tape unit feeds a signal to the r f
42. can WE out every month and learn LECTRONICS the latest innovations in consumer electronics and personal computers what s new how products and circuits work and what leading authorities think of them Stereo Video Home amp Car Electronics Test Instruments Circuitry amp Devices Servicing Personal Computers Communications Construction Projects n every issue authors lucidly explain how exciting new electronics ideas are applied issue forthright buying counsel present complete plans to build electronic devices to enhance products even unique ones that are not yet being sold in the marketplace MODERN ELECTRONICS 76 North Broadway Hicksville NY 11801 Please send me Modern Electronics for _ 2 Years 1 Year Name Street City State Zip 2Years 24issues 31 000 1Year i2issues 16 97 1 Charge My Order To Payment Enclosed My account number is C MasterCard sii D VISA Piet reer 1421 3 we lt lt so 0 VENE wr A Great Gift Idea Send the following gift subscription to my friend at my expense Happy Holidays From Name Street City State Zip 2Years 24issues 31 00 1Year 12issues 16 97 Charge the above order o Payment Enclosed My account number is DESCRAMBLER PARTS We stock the exact parts PC Board and A C Adaptor
43. computer all sharing the same TV receiver split ters and A B switches are no longer practical In such a case use of a video selector box with inputs and switching for multiple sources is the only practical way to go The only real disadvantage to this arrange ment as compared to the alterna tive jungle of cables splitters and A B switches is an occasional ghost caused by impedance mis match SURPRISE You don t have to be a licensed ham to join ARRL and receive QST every month Join the over 10 000 radio enthusiasts who are un licensed ARRL ASSOCIATE MEMBERS and receive QST every month It s jam packed with articles and columns on ham DX VHF UHF Making Waves for young hams radio clubs emergency com munications antennas and simple build it yourself projects up through the cutting edge of communi cations technology We hope to have you as a member Prov State O Yes Sign me up as an ARRL member Send me 12 big issues of QST and my membership certificate Enclosed is 25 33 outside of the US O Please send me information on how to become a licensed radio amateur _ Bank No Expires Expires The American Radio Relay League 225 Main St Newington CT 06111 USA CIRCLE 23 ON FREE INFORMATION CARD November 1986 MODERN ELECTRONICS 37 JI hi ji W js dk ee lt RES Soo ees Z i M pu hit Mii t um www m
44. described above The circuit closes a relay after the countdown is completed Momentarily pressing the reset switch interrupts the SCR relay circuit thereby switching off the SCR The circuit works even though the signal applied to the SCR s gate is a series of pulses since the SCR switches on in response to the first pulse The timers with which I have used the circuit in Fig 7 were fairly easy to open for connection of output leads Keep in mind though that opening and modify ing a commercial device may void the manufacturer s warranty You should also use care when opening and modify ing a timer to avoid damaging its plastic case or circuits Since such devices use CMOS circuits you must follow stan dard CMOS handling and soldering safe ty precautions Both timers that I modified for use with the circuit in Fig 7 were equipped with a standard circular piezoelectric sound source or alerter The alerter in the Westbend unit was attached to the inside of the unit s back panel and connected to the circuit board by means of a pair of St CLosE TO ACTUATE SCR DRIVER SEE TEXT S 2 NORMALLY CLOSED PUSH BUTTON OPEN TO RESET Di S1 ingia RED 6 21 TO TIMERS lt 7 PIEZO BUZZER Re S LEADS So 1ook I BaacK color coded wire leads I used a battery powered soldering iron to remove the leads from the circuit board I then wrapped the bare ends of two lengths of wrapping wire around
45. each buzzer lead and carefully resoldered them to their re spective terminals on the circuit board After threading the leads through a small hole bored in the back panel of the timer I replaced the panel The alerter disk in the KMC timer was also attached to the inside of the back panel but electrical connection to the alerter was made by means of two small springs soldered to the circuit board and pressed against the alerter when the back panel was in place A printed circuit land led from one of the springs to one of the battery terminals I soldered one length of wrapping wire to that terminal and a second wire to the second spring termin al I then threaded both wires around an indentation in the circuit board adjacent to the clock timer slide switch and out through a hole bored in the back panel Be sure to use as little heat and solder as necessary when making these connec tions Too much solder may cause solder bridges to adjacent pc lands Too much heat will cause the lands to separate from the board The spring terminals are espe lt lt TO t G ea Rome A g ee O DEVICE ar Lb RELAY RADIO SHACK 225 004 n Q vour BATTERY A 7 see c SEE TEXT Re OPTIONAL GATE RESISTOR Fig 7 An SCR relay output interface for digital timers 76 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics cially delicate since too much heat will cause
46. in Fig 4 Its internal structure contains a LED emitter whose energy is di 32 MODERN ELECTRONICS November 1986 Reading plane Fig 4 Internal and package details of a typical reflective sensor rected at a slight angle out through a slot in the device s housing Any re flective substance that appears at the LED beam s focal point is reflected at an incident angle back through the slot onto the photosensitive surface of and turns on the internal transis tor Figure 3 shows this device being used to signal when a ticket has been placed into a ticket printer An interrupter module is similar in size to the reflector module but is shaped like a C with the LED emitter and transistor output device in opposite jaws Transparent plastic windows in each jaw allow the LED s radiation to reach the transis Fig 5 An interrupter module detects the edge of a printer s carriage Say You Saw It In Modern Electronics ks Te Automatic Telephone Ringer Silencer tor s photosensitive surface Be iween the jaws is a narrow open slot through which thin items like cards can pass Figure 5 shows the interrupter module at the sensing edge of a print er carriage The printer also has an interrupter module that looks through the spokes of a serrated wheel Each wheel spoke causes a pulse signal to be generated by the in terrupter module These pulses are counted by a microprocessor to com pute carria
47. inspection The measurements mentioned on the labe are those required by section 15 118 which states a The r f carrier and modulation products shall be mairtained within the band 29 82 49 90 MHz 5 The power input to the devic2 measured at the battery or the power line ezminals shall not exceed 100 mill November 1986 MODERN ELECTRONICS 45 watts under any cond tion of modu lction o The antenna shall be a single ek ment meter or less ir length perma nantl mounted on the enclosure con taining the devicz B The device shall with the exces tion Df the microphone be completely self contained with the antenna perm anenzly attached to the enclosure con taining the devize Tie microphoae may De external o the cevice provided it is permanently attached to the enclo sure with a cable not onger than 1 5 meters e Harmonic emissions shall be sup pressed at lezst 2X dB below the level 5f the unmodulated carrier If you build and tune the transmitter as detailed in this article it will comply with the FCC rules If you should ce c de to build more thaa five transm t ters you must make the measuremerts detaded in section 15 118 and file an ap plication for certificaticn Consult Vol ume II of the FCC Rules and Reguk tions available zt many libraries for more informatica As of September of this year the FCC charges a fee for cer tific tion Fig 4 Actual size etching an
48. is on the up stroke You will find that you can control the speed of the flow with your foot while simply lifting your foot from the pump gives a nice smooth wooosh In Closing The Super Solder Sucker described here offers an inexpensive alterna tive to the 250 and more commer cial vacuum desoldering tools It may not have the elegance of a vari able speed electrically operated vacuum pump but manual foot pumping is a small price to pay when you consider that the Super Solder Sucker costs less than a tenth of the commercial desoldering workstation Say You Saw It In Modern Electronics Analog Acquisition Unit from page 26 Fig 8 Calibrating circuit for AAU tal A followed by a carriage return from computer to AAU This should cause LEDI to flash After a delay of 240 ms the AAU should return 00 HEX followed by a carriage return to the computer Only the capital letters A through H are recognized by the AAU The letters A through D instruct the AAU to sample INPUT 1 through INPUT 4 in that order The ASCII string re turned to the computer will be a two digit hex number between 00 and FF If the letters A through H are re ceived by the AAU INPUT through INPUT 4 will be sampled as before only now the value returned to the computer will be in the form of a three digit decimal number between 000 and 255 The actual value re turned depends on the voltage on the sampled AAU input In this
49. lar Energy much more Free catalog Gil Elec tronics Dept 9 P O Box 1628 Soquel CA 95073 PICTURE Flyer lists quality electronic sur plus at low prices Since 1970 Send for the last 3 issues Star Tronics Box 683 McMinnville OR 97128 FREE flyer on parts Semiconductor and Tube Material B E Since 1954 Bigelow Elec tronics Box 125 Bluffton OH 45817 COMPUTERS TI 99 4A Software Hardware bargains Hard to find items Huge selection Fast Ser vice Free Catalog TYNAMIC Box 690 Hicksville NY 11801 T1 99 4A Discount Software Free Catalog from Microbiz Hawaii P O Box 1108 Pearl City HI 96782 CLONE Kits Modems Hard Drive Kits Disk Drives Diskettes Printers Memory ICs Dis tributor Pricing To End Users and Dealers Free Shipping For Catalog Call 800 833 2600 in Ohio 513 531 8866 BASIC Computers 10 lesson correspondence course 39 50 Certificate Details free AMERICAN TECHNICAL INSTITUTE Box 201 Cedar Mountain NC 28718 FINAL Closeout of New Surplus MS DOS Software and manuals 10 Off with this ad Free Catalog Gil Electronics Dept 8 P O Box 1628 Soquel CA 95073 COMMUNICA TIONS COMMUNICATIONS PLANS BOOKS KITS AM FM broadcasting licensed unli censed 1750 Meter transceivers ham CB amplifiers surveillance bugs more FREE catalog PAN COM Box 130 ME1 1 Para dise CA 95969 ATTENTION CB ERS HAMS SWL S SEND FOR FREE DISCOUNT CATALOG AMA TEUR COMMU
50. must be isolated from the switch ing system Bilateral FET optical isolators have a linear resistance range from 100 ohms to beyond 10 000 ohms and a 60 volt peak to peak signal handling capability Unit cost is about 4 which is a bargain consid ering the versatility of the device e Light Activated SCR Shown in Fig ID is the schematic package re presentation of the optical isolator with light activated SCR output This device shares the normal char acteristics of any discrete silicon controlled rectifier Its gate lead is usually connected to the cathode through a resistor to improve immu nity to noise With a 300 mA current capability the LASCR optical isolator provides remote switching control for relays lamps and other low to medium power devices For the average LASCR device that can be used with 117 volt ac circuits one can expect to pay just a bit more than 1 e Triac With a triac output stage Fig IE isolated control of low power lamps and other ac loads is possible using digital logic circuits The most common use for triac out put is for triggering higher power triacs since the same digital logic circuits can now control thousands of watts of power This type of de vice retails for about 1 50 e Schmitt Trigger Shown in Fig 1F is the logic package representation for the Schmitt trigger output opti cal isolator A Schmitt trigger is a special logic element that rejects noisy input signals
51. ohm 75 ohm and UHF RGB cable 19 95 Add 14 50 shipping IList 399 00 SALE 239 95 List 129 95 SALE 49 95 14 RGB amp COMPOSITE COLOR MONITOR 239 95 iis s Must be used to get 80 columns in color with PROTECTO We Love Our Customers 22292 N Pepper Rd Barrington Illinois 60010 312 382 5244 to order November 1986 MODERN ELECTRONICS 49 A 10 Channel Wireless Home Security qu i si 1 Gail iic vada ha mally open r fay switch Fig 10 Wiring guide for power supply display board and any type of hookup wire for the leads that go to 7 the piezoelectric buzzer if itis to be used and the Nor mally Open Relay Switch pads For RFC on the receiver board wind 14 turns of 28 gauge magnet wire on a No FT 23 42 toroid core Fig 11 If display array and discrete LEDs are to protrude through front panel mount them on the rear of the board Observe proper orientations Both RFC and RFC2 on the power supply board are wound on the same No FT 23 43 toroid core To pre pare this double RFC twist together two 6 lengths of 30 gauge magnet wire about 30 twists an wind five turns of thetwisted pair on the toroid 50 MODERN ELECTRONICS November 1986 form Be sure to start and end with the same conductor for each RFC as shown in Fig 2 when installing the assembly Don t cross connect the windings If you wish to have the wireless pass through
52. or write to AMERICAN RADIO RELAY LEAGUE noo cos 0611 This space donated by this publication in cooperation with the American Radio Relay League PRODUCT EVALUATIONS The Multibotics Workshop from page 18 We then quickly snapped together plastic devices to make a sort of vehi cle with a moving propeller and pro ceeded to control its movement across a carpeted floor Each motor requires use of a color coded pair of leads Red for Motor 1 White for Motor 2 and Blue for Motor 3 an ex panded Model MB330 has three mo tors in the kit instead of two and nearly twice the components and projects for 199 95 The sensors too are attached in pairs for both transmitter and receiver use The in terface s LEDs illustrated the action of pulses during a motor speed ex periment After switching the interface to Scope Meter we loaded the oscillo scope program A color scope ap peared on screen graticule and all Good use is made of the computer s function keys for toggling data in creasing and decreasing graticule di visions etc There s easy toggling for Time Div Volts Div real time and stored display Triggering Slope for instance Moreover trace and border colors can be changed and the trace can be moved for center ing purposes One shouldn t expect hi fi sound from the digitally recorded and played back sound It s noisy but turning down the tone control takes care of this It s learning the princi
53. puter via the latter s serial port Power up the system and send a capi Continued on page 91 Say You Saw It In Modern Electronics b A IBM PC AT Compa ihle Make your home into something special That s exactly what your home will 7 Transform your warns you when the inside temperature of be when you fill it with Heathkit elec rec rcom into a your freezer rises too high Prevent water trenic products products that make haven for hebby damage with our Food Ajarm that warns your life easier and mcre enjoyable fun Put our Deluxe 3 you ol water that s where it shouldnt be Within our diverse line are kit and QRP CW Transceiverin this room and en 10 P assembled products sure to enhance joy superb HAM radio operation that ex e Make your each rcom in your home cells in performance and features It offers coming and going easier than ever Your garage door will open with incredible 1 3 Give your workbench ease and dependability with our Deluxe 1 Make your entryway expandable trar smission and reception more secure and easy touse C Pabilities with the Keyless Doorlock a gem Youll never again be locked out a touch of profession Garage Door Opener Easy to install this because of lost or forgotten keys 33 alism with this oscillo opener is durable and includes a handy B All it takes is a simple fingertip scope Whether you re a security lig
54. ready for programming To program an EPROM first place the data that is to be trans ferred to it in memory in your com puter with the first byte at location 24576 and each successive byte in consecutive memory locations coun ting up from there When this is done type SYS49158 to have the Say You Saw It In Modern Electronics software begin programming the EPROM verifying each byte pro grammed as it attempts to program it Programming a 2764 usually takes 30 seconds to 2 minutes to accom plish If there is an error the pro gramming will halt and the message VERIFY ERROR will appear on the computer s screen to indicate that the computer could not verify that a byte was properly pro grammed This is usually due to in complete erasure of the EPROM Upon successful completion of programming no message is dis played other than the usual READY The EPROM can now be removed from the ZIF socket Keep in mind that EPROMs have transparent windows in their cases to provide access for erasing pro grammed data If this window is not covered over so that no light can get through accidental erasure of pro grammed data can result It is esti mated that a one week exposure to direct sunlight will begin the erasure process To eliminate the possibility of accidental erasure from occur ring it is important that you cover the window of all your programmed EPROMs with some opaque mater ial An excellent choice for th
55. remove it use an automotive type hose clamp of appropriate size to secure the cap Replace the pushrod end in its an choring hole and the securing nut The pump is now finished Adding the Frills The Deluxe Version There are two ways to go with the business end of the tool A solder collecting chamber with a Teflon tip using your present soldering iron as the heat source is the simple and in expensive approach The deluxe ver sion uses a Radio Shack desoldering iron modified for use with the pump The basic device is simply the bar rel of a marking pen with a Teflon Tip on one end and an internal filter screen I used a Marksalot marker that has a writing end that was the perfect size for the tubing connection and the Teflon tip from my retired Sold a vac snapped into the other end a perfect fit Many other types of marking pens and Teflon tips can be adapted for the application as you can see in Fig 7 It is a little messy dismantling the pen even if it is dried out So before you begin put some newspaper down Pull the felt tip out with pli ers Usually there is a snap fit cap in the other end Pry this out without damaging it The ink wicking should now slide right out When assem bling your unit be sure to push a piece of metal screening into the bar rel of the pen to prevent pices of sold er from getting into the pump Small circular pieces of copper screen are available at tobacco stores Dependi
56. resistor ratios and currents can cause problems when lots of accuracy is needed Instead we ve shown an R 2R network that needs only two re sistor values and lets each switch always handle the same current We have also summed the analog current to the virtual DIGITAL INPUTS 5 6 74HC04 10K ANALOG OUTPUT 0 5 V gt Fig 4 A neuron like D A converter that uses R 2R summing ground of a CMOS inverter connected as an op amp rather than trying tosum out put voltage This gives a faster settling time and a lower output impedance In real world D A converters you us ually use input latches and clock them at a specified rate Let s throw some more terms at you A monotonic D A converter guarantees that each successive digital value will pro duce a progressively higher output volt age This can become sticky in high reso lution converters that must work over a wide temperature range A De glitched converter has some steps taken to make sure that there are no unacceptable output spikes following a change of digital input This becomes NAMES AND NUMBERS A C E Marlin P Jones SGS Box 46199 Box 12685 1000 East Bell Road Baton Rouge LA 70895 Lake Park FL 33403 Phoenix AZ 85022 504 291 3449 305 848 8236 602 867 6100 Analog Devices Mouser Electronics Solarjack 2 Technology Way 11433 Woodside Avenue 102 West Eighth Street Norwood MA 02062 Santee CA 92701 Saford AZ 85546 617 329 4
57. s r uiaaIHq syo kFF November 1986 MODERN ELECTRONICS 31 Say You Saw It In Modern Electronics sory that tests alltypes of optical iso lator including their CTRs Isolation ratios for most optical couplers will be typically 1 500 volts minimum However optical isola tors with up to 5 000 volts of isola tion are available Ratings are ex pressed for dc voltages or peak to peak ac voltages or the sum of both Bilateral FET devices are rated for isolation voltage maximum and minimum resistance output FET off and on respectively and turn on and turn off times Important char acteristics of LASCR optical isola tors are output current capability and voltage isolation Triac devices do not offer a wide variety of choices except with regard to higher voltage isolation Their output is suitable for driving most power triacs Schmitt trigger units are rated according to turn on current less is better with 1 6 mA being about typical and maximum data rate When choosing an optical isolator for a particular application select one with at least 25 excess capabil ity more if you can afford it Related Devices Two types of industrial sensors use the same type of technology as the optical isolator These are interrupt er modules and reflective sensors Shown in Fig 2 is a reflective sensor that gives some idea of size Figure 3 shows the sensor in use A sketch of this sensor is shown
58. simpler and cheaper than the A D converters we looked at last month The three most important parameters of a D A converter are its cost its resolu tion and its settling time The resolution of a D A converter is the number of out put steps you get In turn this is related to the number of input bits the converter can handle For instance an 8 bit con verter will give 256 output levels a 12 bit converter will give 4096 levels and a 16 bit converter will give 65 536 different output levels Settling time is the time it takes for a change in the input digital code to produce an output that is very near the final desired analog level Let s look at some circuits Figure 3 is a very simple 4 bit manual D A converter The 1 2 4and 8 switches are respectively summed with their 80K 40K 20K and 10K resistance values pro ducing an output voltage with 16 discrete steps Note that the larger resistance val ues provide lower current increments As the switches are flipped the output will go to the level set by the switch com binations Since there are four switches this is a 4 bit converter There are 16 pos sible combinations for the four switches so we get 16 possible output levels from 0 to 5 volts Intermediate levels will be 0 333 volt each Thus level 1 will be a third of a volt level 2 will be two thirds and so on Let s add some improvements in our neuron like D A converter shown in Fig 4 Those 1 2 4 8
59. to tackle all computers NRI QS MFF makes sure that you ll get the training you McGraw Hill Continuing Education Center need to maintain troubleshoot and service computers Learn at home in spare time With NRI training you ll learn at home on your own time That means your preparation for a new career or 3939 Wisconsin Avenue NW part time job doesn t have to interfere with your current Washington DC 20016 m We ll Give You Tomorrow en job You ll learn at your own pace in the comfort and convenience of your own home No classroom pressures no rigid night school schedules You re always backed up by the NRI staff and especially your NRI instructor who will IBM is a Registered Trademark of International Business Machines Corporation NEW PRODUCTS Ill For more information on products described please circle the appropri ate number on the Free Information Card bound into this issue or write to the manufacturer Tektronix 995 50 MHz Dual Channel Oscilloscope With its new 995 Model 2225 two channel 50 MHz portable oscillo scope Tektronix sets its sights on the lower end general purpose instru ment market Primary among this scope s features are a rated sensitiv ity of 500 microvolts alternate mag nification auto trigger mode and high low frequency trigger filtering Alternate magnification allows the user to view both magnified and un magnified sweeps simultaneously and
60. wrap goid 169 1680 18700 1691 end aad en X fie 1 89KX this m the Dig Kev 470 83 23 278 215 23 19 18 047 50 a 33 BR 24165N 102 74 139 SolaMCiN 135 15 5 go 314 325 C9 40 pn wen wrap sod 229 2280 227 009 psn number 1000 63 49 420 3500 3 308 2582 68 u 78 1 Ex 24168N 1 13 745 138N J4HC221N 305 170 50 MM58167AN 18 00 Pricing 1 1000 2200 63 60 913 3275 h 456 3795 0 50 45 184 32 2 63 81 694 7S 53 50 67 578 4800 auus Under JAHCAMON 310 Ju 5 9 Awaiy4AN13 78 Silicon Transistors 1 4 Watt wo 3 mo i ciii be Lv n 36 88 2 22 5 726 6050 14173N 1331 JAHC24 N 3 0 aj 204 M5m 53 For large quantities and paces es low as 08 15 M cai 6800 3 27 10 87 9058 113 968 9082 33 amp OB 8400 74Y74N 88 745 5 N 74HC242N 2 45 1 QR 1 5 Dig Key t5 17 1977 15 13 109 4 K 1 32 010 241758 BB 24S163N 150 j4HC243N 245 atag NSN 2251 iGEKEY H 909 63 IS U UH i Pe s 5 2748 229 00 14 76N 120 asi N 1 BOB 7aHHCZ4AN 3 10 32 2 o amp NSCBOON Part No m 00 19 1A Wan Mate Tin Assorimsate 22 1B 15 1283 13 106 894 68 30 33 2746 290 MITIN 1 WSN 1 2 00 124 RSX1 5 each of valuas 100 to 97 62 v2 ss z Ma Zeiss Te ee 780 eso MEO UN z 14FC245N 3 45 124 2N3055 202 16 380 151 20 1344 00 480 total pce 47 id 21 177 14 78 4 18 9 30 IT JAGON TE FASIGIN 379p 7AHC2SIN 1130 45286 133 124 A D amp D A 253904 Z 220 89 7325 peu m Pa m gt 24 200 1865 17 139 1154 CAT NO F K 41 74S162N 2 888
61. 0 system Instructions take you through Getting Started About Electronics and About Mechanics before presenting actual projects We did bump into a prob lem at the onset however but it was easily solved There was a poor elec trical connection on one of the plugs that terminate each lead in the 10 conductor 10 ft ribbon cable This was discovered when we couldn t ac tivate one of the motors from the computer s keyboard The motor is encapsulated in a clear plastic ball with input jacks at different ends After correcting the problem with a touch of solder everything else went along smoothly The motor turned changed direction slowed up and speeded up in selected increments all controlled by keyboard input Continued on page 96 Say You Saw It In Modern Electronics P ER HORIZONS EXPAND YOUR CAR 2222222222 x i Rm mori up poOM _ Nun oy a MET PESOS The CIE Microprocessor Trairer helos you to learn how circuits with microprocessors function in computers START WITH CIE the handy reply coupon or card below to Cleveland Institute of Electronics Microprocessor Technology Satellite Communications 1776 East 17th Street Cleveland Ohio 44114 Robotics Wherever you want to go in electronics Check box for G I Bill bulletin on Educational Benefits Ll Veteran Active Duty MAIL TODAY Just call toll free 1 800 321 2155 in Ohio 1 800
62. 1 80 88 53 5 2 3 7491N 2 t3 74S02N Le ecole 88 Ke 77 Steg i Minin MO cpanawisach pori niay on quid aech ets 365 total pea P4410 GBpl 500 1338 10035 4 3 94 4HC10 OF L 75 TEXA NTS A 3 39 Bet m Lee MHCTIZN 56 aa CORO 4 13 H WINETRUME SGOATETY RS250 5 cach of the standard values n sariwa 1 1 99 90 24411 8 of 500 17 58 131 36 1 7495N 0 1 SON J4RC113N w 953 COP49eN 538 TIN PLATED WIRE WRAP w 200 Miccsmohas Ti 13 16 20 24 mc through 910K 360 For Complots Space on Physical Size and Electrical 68 j3 g PT Ps FHCIN 270 z200 cOP4S9N 538 Pen a Caxcrpian 1 0 100 Yorn Cherscteristica consulit your FREE DIGI KEY Catalog al 74107N a JASON 74HCI 5N 30 Uim 96 CP8212N 375 C8108 8 pim wre wrap 1 38 ASSORTMERT OF 18 23 0 74109N 3 24s 0N JAHC126N 208 5 132 panen 3 0 US 000 wre wrap m S 49 4800 POPULAR VALUES CAT NO 180 dd 74121N B DSTI JA C13N 6B T 2 4af Drazan aso CRUS 160m mre wrap tin 8 560 S500 PANASONIC QUALITY DH KIT T 74123N 00 74S 5N JAMC138N 138 2 aaj Ora22 CB11B 1B pin wwe wrap tin 59 670 68500 2 74HC139N 123 n 193 DPS226N 350 C8120 20 ow wire wrap tin 76 50 74 00 x ONLY 4 3 74125N 78 74520N J4HC 18 ggf 098228N 803 3 310 DISC A 3 95 2 31 74132N m 745228 HEAT yi 9s G iipnvece wrap no 5 29 9100 CAPACITORS Yo 033 3 7A141N 163 245308 HHCTSTN 13 E Se orgaan BOOK CHI 24 pan wire weap bn 9 890 8800 J 47 74145N 130 lets ep 156 agaj DPE3MBN 463 Chiz8
63. 2 22 192 219 3 1 221 160 145 38 169 188 141 239 193 32 22 192 169 184 141 239 133 32 22 192 230 38 208 2 230 33 105 39 201 112 208 213 169 161 141 239 193 32 02 0192 193571 221 169 0 145 su 109 189 141 239 193 32 22 192 169 185 141 230 4103 Be lo 102 0030 2036 2080224 30 39 155 39 201 128 208 213 169 196 141 239 193 32 22 192 169 184 141 239 193 32 22 192 689 96 32 230 192 123 237 93 208 1 96 152 28 39 139 227 36 120 169 186 141 239 193 32 22 192 169 1541 141 939 93 7 32 7122 105 I6s5 40 155 38 169 96 133 39 169 0 141 238 193 169 255 141 3 221 160 0 177 38 141 t 22 169 240 141 239 153 0133 22 190 169 208 141 239 193 32 22 192 32 240 133 189 240 141 239 193 32 22 192 169 O 141 3 221 169 224 141 259 195 32 22 192 160 0 123 1 22l 259 38 240 13 235 238 193 173 238 193 201 16 208 185 169 7 1 0141 257 195 2265 1522 9192 159 252 141 239 193 32 22 192 169 240 141 239 193 32 22 192 230 938 208 2 239 38 7165 739 1201551199 0402 53 196 2557 195 163 0 141 238 193 169 255 141 3 221 150 0 177 38 141 1 2215 169 2415 14i 239 193 32 22 192 169 209 141 239 193 82 0720 52 7395 940 401093 1 59 299 115010 2935 193 73 5 022 0199 08990 141249 2001 59 225 141 239 193 32 22 192 160 0 173 1 221 209 38 240 18 238 238 19
64. 286 oval pcs ol 2 Ies T d 2 parating Temperature Renga 40 ta 85 C MLSZN P 3 Ml Part No t n am m o 00 7 Don 9m BUD 290 1000 35 96 B 5380 2 7354 5532 Capacity Range 01uF to 1 OuF 8 amp 0 790 z TIP135 13 9 go 84 00 77000 M ASWI Seach of values 2K to 2 OMO 928 06 2200 35 61 1377 11471 166 1 77 1180 A Ep a 14 96 47 98 ND 15 12 s7 1 218 O 806 49 1397 s gt TIP29C 7B 3 63 DO 577 50 255 total pcs E 5 1 39 i7 n amp 3 Heyn ann wd ac ja MN JALS30N a5 V An 5 63 22908 NO 15 12 57 12 21500 806 aG 39 75 M v pgoc 78 35 63 00 77 50 2 watt Reamtor Assortments 04 amp 16 T 5A 12 63 i3 108 8 34 et wed adeo oet j JALSENN An ix GEL IMS npn m 7 Teac 75 700 55000 l asw Geach of values 472 10 580 29 96 50 18 154 1283 73 09 B9 ingutation Resistance 25CI 1000 0 uF 7ALS37N 53 p sitet 15 64K DRAM 1508 2 95 1 THPEIC 75 700 60 00 55000 255 total pcs T 4 14 VB qi 108 BSE Vonses Costhcieor DCI Negro bie SEN ss M ida NEC Memory Chips Missis 7 700 500 550008 neon wach of vakon B20 107 5KQ sane f 3 S 18 154 2283 ta 11S 5852 Aging Rate Negigine 1 pi to t 7 50 21 17 14 77 4 1 978 Mataitis i MESAN zu IZioake 0 nce vee 2 2KQ to 2 OMO 2 gt 209 Ds SLE Le Leod Spastg 200 200 86 ot v to 7 50 28 234 1953 22 1 1539 i MSN 44 1 13 ias uno Description Price 3 AMP SILICON RECTIFIERS 33 t 22 2 243 23 190 3157 Sel Hesling Yes 8 E Otac zu Dynamic RAM b 3 2
65. 3 173 238 193 201 16 208 185 169 1 141 237 193 76 197 192 169 252 141 239 193 32 20250195 169 248 14d 2395 1935232 22 155 230 38 208 2 230 39 165 39 201 128 210 53 720 13 193 1069 0 141 297 105 Jo 197 152 0 O 0 173 233 193 201 15 208 9 162 50 32 0 194 202 208 250 96 160 208 136 208 253 96 162 0 189 26 194 240 41 142 103 194 32 22 231 174 103 03040 232 76 9 194 147 17 17 70 73 76 69 78 65 77 69 32 84 79 32 83 65 36 69 32 65 83 32 763 312 739 42 20 329 95 165 163 5 162 3 160 5 32 186 255 162 0 189 0 2 240 4 232 76 Gs 194 133 162 0 160 9 39 189 255 169 0 133 38 169 96 133 39 169 38 162 0 160 128 32 216 255 96 0 58 MODERN ELECTRONICS November 1986 Port slot on the C 64 power up your computer and key in Program 1 Save a copy of this program on disk and then run the program This pro gram creates a machine language program that resides in the machine language space of memory locations 49152 through 57344 After running Program 1 key in Program 2 which creates an all ma chine language version of the pro gram that can be directly loaded into the correct memory space by typing LOAD EPROM 8 When us ing Program 2 be sure to add the 1 to your LOAD command You operate the Programmer with the SYS command which calls a ma chine language routine The first command to use is SYS
66. 3 3 a a na 4 1 mila al 1 BOS7N a 2 BE acean ACM LMICLN 245 3 44 MJE37 9 910 7800 71600 ated Ambient Temp m e 22 z Lr E2154 250 18 27 228 895 7055 BOBEN 83 4 939 24HCOGBN 23M oi amp N e 2 48 MJE521 amp amp 805 60 IZ SOM Gparsting Tam 33 25g M Vor pi 3 108 aH D 2 1 ip Range BEC to IFC 47 2 18 154 126 13 108 894 EIM 150 18 29 249 207 16653 N 4 buco d ipei E PN a Bi 2 ae E ia zy JAHCAKON LMGUIN n x MJET22 Bos 900 BAZ EO Dimension i 6 3 5 1 14 B n 6s 39 c EM mx io ee oe 7 EL LS MM gt M 9 9510 730 NEO Lee E 22 1 122 01 25 74LS00 TTL 378 74HCA040N 175 CMQTIN 75 90 I noc aero 45 n m 2 200 s v im netz mo n y rs 39 zs 3 798 vaca DAS N LMA17K 5 05 90 uie m ns MPF102 956 525 5 D 17 5 28 2 2 73 1442 t2394 250 39 4f 344 2865 15785 Par Price 3758 74HCa060N SALMAZ 38 90 nee dup s2222 23 220 890 1 25 menman d 0s s 100 2 33 278 23 190 1577 4 E474 290 0 43 388 3065 27585 74LS00N 45 2 63 1 SBLM3I7MP 1 51 gf DSN 25 mesra z 220 1890 173 25 5 Meu Once Fin Values in Ohma 0 47 to 1 OM 220 2 M 375 40 342 28 5 j Eze 250 5 4 402 3345 306 OST sasicaop N MALI x MABSAN 126 hes 330 22 5 42 52 445 3708 28808 250 68 52 443 359 33233 74LS01N 50 909 OS How Yo Order T dard valua ii s 1 5 7 so 74HC4075N LM3171 1 83 DS49N 125 MPSz9074 23 220 189 173 26 tO MS qk Sanc MN land 470 25 58 i9 64 532 45 3 E294 2560 amp 58 494 11 3 37013 ue so 744C4078N MIIAN 188 s MPS3563 28 2 28 625 200 e
67. 367N 125 2 Ra 33 6 2 17 146919 99 153 250 015 1 164 1368 12308 74198N 188124S S2N 2380 74HCIBN 1 25 H 1 1o ADC ICON 90 2Ns457 67 630 sa 495 06 2 6 a 200 166 16 13 nm E83 2800 018 19 84 3368 12308 741998 88 745240N 288 HEITIN 360 Mes 96 AOC311CCN 13 75 g2PU01A 45 420 3600 33000 100 6 28 234 1989 21 178 4 E2273 250 022 9 16 1368 12308 4251N 29 pas2eN 2 OBB cazan 360 ux 107 ADCIYICENIS 63 q2PU10 4 420 3 0 2000 220 amp 33 778 2315 24 206 10 t22723 250 027 39 oga 3388 12306 m 2 16 2121 097 6 297 4 69 E27K 2 09 15 164 368 2308 uM B cupo T lt 1a apoyo e stra s i5 sm mu wo sig ee sie RS ES m 5 lu ue n 74357N ag 325p 4HCSIIN 360i Fac x i go pacosoot CNS 38 a2pustA sco gt Dmm 0 10WI 13 STI 1x0 60 Sog 4245 50 42 3508 E243 250 04 i9 0184 03268 1300 74358N ga 163i aHCsuN n Gop l Da COBO7 CN2 08 MJE172 67 630 5AQ0 9500 3 1723 ZW ces 2200 16 92 785 8539 87 748 21 E23 290 oa 2 185 1543 13983 FCN 96 138 58208 ZW 4 8093N 78 163 rc A DACOBOBLCN2 80 ll 6182 665 900 5285 3300 16 316 391 8262 117 1001 gias E2008 250 a 22 85 154 13863 s 74HCse4N asai irsch 276 208 Wan IW 16 157 1340 1 57 1343 11187 E2822 250 082 22 185 01543 138 a a vob HcSanM 3 Le 2 3 44 MJ EMA 89 v 54 00 495 00 4700 16 57 1340 11168 157 1343 11187 E H BOS6N Es T rr aof LEG j 44 MJE370 7 ce sme 5e Working Vonago 350V XXV 6800 6 199 1700 14163 gh zo 9 B I4 wn un LM1OCLN 4 33
68. 40 2500 Palio 680p 500 90 6 3 j 7AL S266N 65 BC29N 350 C9ROB B 0 3 1 20 p 92 51 86 M MN test bem 20 jg mmara2a 2000 mea iR DOR ree m uiu ne E NUM De M 3 51 96 T 39 7438N sg 4tS280N 110 LM349N 179 CN C986 47 45008 3 2Wer 2 36 1600 pane o cop 500 00 84 3 a3 7 2 p x 35 15 N Sarre saf 24LS290N 1 IE m TEBE 7 o c38 gold ap 5200 vr large quenbres un M cat Dy Kov Pails 1800 pt 500 31 84 3 22 Sy JAA AN 1 SOR 4LS299N 15 5 LMOBOT 517 C9620 gt rad gold 53 570 1 8 Watt Carbon Film Assortments P 1500 p 8 33 an E 74425 6B 74L5296N 1 CMOS gt C9822 22 pin solder tari goid 590 00 nsu S each of the 73 standard veluas in senos 09 90 fF 2200 pt 00 E 5 de 2445N e E i Fer Pnce 38 f M359 220 C9824 24 pin solder ai gol 720 70 00 10 12 1 5 1 8 22 etc through 1 0M 3300 pf 00 58 68 7446N 1 25 74 S359N 34HCUON en 7n C928 28 pe saider iau gori 73 79 3 00 355 vous pcs i 94206 3 00 pt 100 58 3 oo 1 276 2370 19750 1 3447N 25 7ALSS6SN 74H CO2N 6B Ux 3 30 A C9840 40 pin solder tad gold 112 9 90 g7 ETT te 72 s 0630 P42 6300 p 100 70 00 45 00 T 455 300 325 0X 325 00 TASON ss 74L5366N 74HCO4N 68 4 26 7 5 each of the 72 standard valuas in ser PAX Olut 25 s 483 352 10 5 a380 11500 373500 7451N 4g 74L5367N 744 COBN 68 120 1 38 11 13 18 20 24 etc through 910K PAXG 22uf 25 68 591 3a 32 a 35350 74538 55 HUSSEN 74HC10N 68 125 Le EAN WIRE WRAP 1360 tora pes f Jut 25 82 53 1C Lag
69. 42 transformer 2 May require 75 300 2 transformer Videorassetre Fig 2 Simplest VCR hookup is to an outside antenna which allows you to re cord and view different channels simultaneously but not to decode premium scrambled cable channels This usually lights up in the VCR posi tion When it is in the TV position the VCR s output is directly connect ed to its input such that the outside antenna or cable box that feeds the TV signal into the video system by passes the VCR s circuits altogether With the TV VCR switch in the VCR position the VCR s output is con nected to the internal r f modulator When this is done your TV receiver must be on and be tuned to the select ed modulator output channel for the program to be viewed In every mode but play the TV VCR switch is automatically set to Input from cable INPUT a OUTPUT the TV position It is also automatic ally set to the TV position whenever the VCR is switched off so that you can view your TV programs in the normal manner as though there is no VCR in the system Finally you can manually switch between TV and VCR whenever the VCR is powered up allowing you to view one channel while recording another Components Needed To be able to make the connections suggested here you need short about 2 ft coaxial cables with F type plugs on both ends Also re INPUT OUTPUT T de E e EE m Vid ncamsefte recorder F
70. 49152 which initializes the programming hard ware This must be done before you insert an EPROM in SO1 To read an EPROM load in the software and type SYS49152 The Programmer will then be ready to program or read an EPROM Now insert an EPROM into SO make sure it is oriented so that pin 1 is near the sockets lever and type SYS49155 The contents of the EPROM will then be read from the EPROM and be moved into the com puter s memory This takes about 10 to 15 seconds Memory space used for this data begins at location 24576 and extends to location 32767 6000 to 7FFF in hexidecimal You can examine the contents of the EPROM by PEEKing these locations To save data loaded into the com puter from a 2764 EPROM type SYS49161 You will be asked for a filename for the program Data saved this way can be loaded by typ ing LOAD filename gt 8 1 It will load back into the computer in the same memory space that is 24576 through 32767 Before programming a 2764 the EPROM must be erased to set all memory location bits to logic 1 You do this by exposing the EPROM to ultraviolet light Once erased the Say You Saw It In Modern Electronics The finished project Program 2 Creates Machine Language Version of Program 1 REM MAKEML MAKES ML FOR EPROM BAS OPEN 5 8 5 0 EPROM P w PRINT 5 CHRS 0 CHR 192 FORT 49152 TO 49768 PRINT 5 CHRS PEEK T NEXT CLOSE5 READY EPROM is
71. 5 1 000 swan 2 29 2400 0 0000 f gt i 22 15 io js 12 o0 rem oss 15 33 3590 Po A 1 10 Wan 35 320 2700 10000 18000 33 100 24 200 1865 Y 138 so f pas2s 0 082 18 163 1403 10210 ULN20D4 146 ON Kev m Price Nos waqa acewshen and pipes on kets ss MED GO CAM Dep Nay RE Do g x Hs SEE P4526 01 18 168 1449 10540 PALSTAN TOA286A 270 ert No cription Each Watt Resietor Assortmen te A EE AME P4526 0 12 20 181 15 62 173 66 J4LS139N TDA 1023 2860 baragHC 8 Bu Micros 15 75 rn 24 Wo 4 3656 3030 2 2 Microcompute a inp 1575 ep 0 j 100 45 38 3212 3 84527 15 24 221 900 3820 TALIBIN us Pen E D874B8HD amp B M roCcOomp 1er 40 Dip 18 56 053 i 210 8106 one 0 309 to 0 319 sae 100 54 462 3849 41 re 5A a D8749F C High Pertormance Single Chip ane 100 74 629 85243 57 A 0 18 24 22 1900 13820 MLSISIN _ 150 ae ss B Ba Microcomputer Dn 856 R2208 4 gach of waves 1 09 109 12 927 96 DD 108 926 7718 3 P4529 22 27 242 3083 5150 DBORSA e BON C 96 tot 130 1110 925 25 1 f PA Sisa bes TDAI 64 x Was a S NUN phasi a 33 Deecripson Pkg 1 10 100 1 000 TE atl 470 MO 16i i546 TAG DE PAR 2 ape gs n9 L P CrODIDC 8330 p 3 RS305 van oi valves 109 to919 sz db 100 318 2208 2262 pasa 033 33 100 2579 1760 J LS157N 88 LM339N D8086D 16 Bii Micraprocesso 40 Dip 16 86 N54 Am PIN 7 i 000 100 318 27 09 225 72 x 7ALSISAN 75 SG3524N 28 peoga Hi Performance B Bii IASAD VADE n Muere E IS 96 total pce
72. 70 4 50 36 304 2533 24 208 1703 WYdc 50v 74LS5AN 45 sc MALSSSN 45 pE 129 D41416C 15 Dynamic RAM Dp 279 1 100 Nc 1 100 100 amp 4 189 Jb 308 5 6749 D43254C 20 Dynamic RAM 18 D p 6 19 0 50 61 518 4315 52 445 3 V 5EA 2 PTS Duet M Em om Bury 5 t l Te 1574N 56 1 16703 16 384 x 1 Bii Sunc gt or El 34 ke ap isa so TDA1515U 360 i AS ES AA JACS75N Fri N MOS Ram AEDS 17 00 a 125 1071 8927 131 6 3283 Pan Na uf 1 10 10 oo 9 OF TDAU 1 76 am Oy 2200 50 199 1700 14183 iode 2 7ALS7SN 56 oec 3 Simic RAM 24 Dio 194 3 2 ana w j JaLST8N O 2 TDA1015U 153 Da6 2 State RAM 24 Dio ato 034 i 107 04 3 1 tsa 0283 13 112 332 P4509 9 90 3 789 sa 74 SRIAN 98 ri TD21520u 5af D4361C 0 Siane RAM 20e 4500 F 22 R3 H ra n ees us P4510 0 0056 n 9 788 54 74 S85 8 151 D4364C 201 Stc RAM D 7 2 18 12 83 1 52 JAL SWN Sa is cae 362 D2764C EPROM One Tima pikes Ue Description Pkg O 700 3000 10 0008 Dperaing Temp Range BC to TPC 13 E 30 EE MAINE es Eos 0 01 91 LES 15799 7ALSSON 75 4 53 wesesN 3 69 Programmabie 28D 405 18400 50 Prv 4 8G 700 6000 815008 X Coeticent QM 1 ei x O BE qe eg 4253 Peta 012 1 a B09 5890 JALSS3N uc 3 0278402 EPROM Unra vote 184002 100 PIV DO4 80 7 00 6000 54000 amp Coe 300 PPM C gt 6 B 23 n z2 167 65 0 015 s 847 660 AUS TO ss 4809 PCE2100N 5 aS Erasable 28 Dio 4 95 f 1N4003 200 PiV DO4 BO 7 50 64 00 5e 00 Dimenson t 20 48 0 n 63 y 312 2804 27 224 1
73. 700 619 449 4477 602 428 1092 AESAR Newark Flectronics Speleonics Box 1087 4801 M Ravenswood Bax 5283 Seabrook NH 03874 Chicago IL 60640 Bloomington IN 47402 800 343 1990 312 784 5100 812 339 7305 Intersil Popular Communications Texas Instruments 10600 Ridgeview Court 76 North Broadway Box 22502 Cupertino CA 95014 Hicksville NY 11801 Dallas TX 75265 408 996 5000 516 681 2922 800 232 3200 JKL Components 13343 Paxton Street Pacoima CA 91331 800 421 7244 82 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics very important in video applications where any glitches at all will produce hor rible screen results An essential first step at de glitching a high speed D A con verter is to make sure the turn on and turn off times of the input latches are identical This is not trivial A second method of de glitching is to catch the an alog output only at known data valid times and hold this result until the next known data valid time Normally a D A converter is driven from a precision voltage reference ra ther than from the power supply This prevents any glitches in the supply from getting into the output In general Schottky TTL circuits make very poor D A converters since they sit there mut tering to themselves rather than satu rating to ground or the positive supply as does CMOS Some D A converters will let you in put any voltage you want and
74. 74H C2 3N 115 asz 245 ae A each of values to 220 0 29 246 248 23 192 159 34182N 1 1517451638 78b4MHC2S7N 113 men s Fn Price 283906 2 220 WP U325 480 total pos M s LN Sis SZ 209 LIO JUN peg opi dey dela s54 5 241B4N 3 639 74517aN 1789 74 iC258N 2 25 300 4 13 ocosoaL CNT 75 2N4124 a 22 19500 W5 s 0 44 372 397 W 29 2469 em 34185N 3 EHA 24S 175N 4 s 3544 0 R8XJ Ssachof values COKQ 109 76KQ izn 1 z Pea d H rf gt J4HC2GSN 95 y 30 9C0804LCN5 00 f 2N4126 24 22 19 178 7 1480 total pcs 000 55 16 3882 342 284 74190N vos f 248 181N 508 74HCZBON 4 B0 t aai 3 44 DCOBOSLCNS 63 B 28407 23 220 1890 173 26 2200 0 78 563 5528 0 593 4342 Metallized Polyester Capacitors 7488 108 E 04S 182N 2 74AHC2SSN 50A 1 88 33 ADCONSCCNS B 2N4403 2 220 1B 90 172 25 REXA 2 vaias DK 1697 6KQ 29 95 19 39 8 c 3 v D az JAISON 198 JAS TEON 3 HASN r 23 C CNS S8 M aav 33 315 2700 24750 aat 6800 10 155 1326 11052 1 54 1320 10940 DOREY worming Main SE UP Fen Pak DE 7A194N vobasses 225 rice ess ein 285087 24 220 9000 18 00 Peso ee ee MAKE Le 10000 710 199 1700 14163 Parina Vete pf l n dm 10 ee ET E e 1 2 34 135 2N5089 3 29 200 22000 10 6 18 1S 1283 3 i108 894 03 25 Q Ig 16 1368 12308 74196 7asieN 238 4MCOBSN 2 g3 DCOBS3CCN 525 z 15 2 123 290 o2 19 16 1368 1208 831 4Dc101cCN22 so 278210 2 22 18390 17325 2 y Ste JE 5 3m 015 5 74197N 1 20 48 196N 2 35 4HC
75. 860 Pacis 0018 u 191 B75 6370 Sea as PCEZV10N 8 39 0271280 15 384 r 8 Brt 1N4004 400 PIY DO BO 7 68 00 588 7 37 63 B3 ai 3762 38 318 2845 3022 1 74LS109N 5E n NESQ9O0N 248 N MOS UY EPROM 28 Dip 720 iM 600 Piy DO4110 5900 74 00 6250 5 Wirewound Rectangular Resistors 5 Watt Values 100 63 56 476 X64 SQ 324 3827 P4517 22 2 1 06 8 16 LU 7ALS112N 58 DB NESSON 2218 02712803 EPROM One Time IN4006 BOO PIV DO41 0 50 8000 66100 0300 to 2 0KQ 10 Watt Values 102 to 3 02 zm amp 76 B50 5414 78 661 5502 freie 027 i2 11 985 70 74 31 13N 58 P bie 28 D 09 154207 1000 PIV 0O 4 50 1200 10000 71000 Order 330 amp 32 78 6555 Ba 653 5 ve oN NESSIN 234 rog ammatle m t a 5 DIT 2 fp E 2 JALS THAN 58 1 ess D272561 EPROM IUlIra Violet 1M4148 Umm fas DO4 60 00 2958 211268 ow Jo Ordenar Take any stans a siw POE T Shand F 370 63 105 B34 7452 899 823 0019 B oM 1 UG gta EAS B esse add WS for 5 watt o add WID for 10 wert le 1 1 165 43R P4520 0 039 13 24 107 77 30 4 S122N 75 NESOAAN 245 Erasable 28 Op 12 amp 3 Swe Diode x 1000 63 64 1399 11655 66 14 803 s NESOASN 245 OF7C64D 75 EPROM Ultra Viatel 7 SWS tor 7 BQ S watt thu is the Digi Koy pan number i 2300 63 267 223 185 39 P462 047 5 132 03 890 2 in 2 tuit 4 Z LAE Du ASIN 68 NEAN 187 Erasable 28 Dip 3 AMP SILICON RECTIFIERS Pricing ow w wo x joe io dg 15 1283 13 gao 542 oo 6 132 0229 9920 Msn ib MEM NEC Microprocessor Chips 1 000 37
76. Additionally it tolerates slow rising input signals and switches reliably with them a feature not possible with ordinary logic devices Isolation of high speed digital sig nals a 1 MHz data rate is typical is the most popular use for the Schmitt trigger optical isolator High speed capability in any optical isolator is always premium priced hence Schmitt trigger optical isolators will usually cost about 4 apiece Technical Details From the designer s point of view the two most important technical specifications of an optical isolator are current transfer ratio commonly abbreviated CTR and voltage isola tion In transistor output optical iso lators current transfer ratio is the ra tio of the output current developed by the transistor to the drive current needed by the internal LED to pro duce the output current The optical isolators discussed above have a 20 CTR which means that 10 mA of LED drive current will develop 2 mA of output current from the transistor For about a 209 increase in price you can obtain optical isolators with 100 CTR in which input and out put current are equal Where the slower speed of a Darlington device is acceptable CTRs of 500 output current is five times input current can be had for about the same price as the better single transistor optical isolators The Opto Tester article that will appear next month will contain details on construction of an acces a r s
77. C fence m I 4 channel analog multiplexer ITT Table 1 Baud Rate Options Baud Rate Jumper 1 Jumper 2 J1 J2 300 1 200 4 800 9 600 keeps the microcomputer chip s in ternal oscillator operating at a stable 4 000 MHz Jumpers J and J2 permit selec tion of the proper baud rate for com munication with the computer Ta ble 1 lists the available baud rate As shown in Fig 3 power for the AAU is supplied via a 12 volt ac plug in transformer The positive voltage is rectified by D1 filtered by Cl and C2 and regulated by IC3 The negative supply consists of rectifier D2 and filters capacitors C3 and C4 with regulation supplied by zener di ode D3 Power on indication is sup plied by LEDS Construction Owing to the relatively low compo nent count and the fact that there is nothing critical about parts layout Say You Saw It In Modern Electronics MODERN BU MODERN ics November 1986 Accumulator Index register Oscillator and timer Condition CPU contro register Stack pointer Program counter 3775 x 8 EPROM 191x 8 bootstrap ROM Fig 1 Internal details of the Motorola MC68705 microcomputer chip the AAU can be assembled using just about any wiring technique Even so a printed circuit board is recom mended You can fabricate your own board using the actual size etching and drilling guide given in Fig 4 or you can purchase a ready to wire bo
78. CORN ole 1986 Dick Smith Catalog enclose 4 to cover shipping NOmB oun ss ad T eee uu j Address c MEM IE x l bith i City n nn T Zip c Mu ua p m m p goma Eng DICK SMITH ELECTRONICS INC P O Box 2249 Redwood City CA 94063 EVERYTHING FOR THE ELECTRONIC S ENTHUSIAST FIDEO CABLE and SUBSCRIPTION TY secret manual Build your own DESCRAMBLERS converters Instructions schematics for Sine wave Inband Outband Gated Sync Pulse SSAVI HBO Showtime Cinemax UHF etc Send 8 95 to CABLETRONICS Box 30502R Bethesda MD 20814 SATELLITE DESCRAMBLING Latest methods of digital scrambling of the audio in satellite television transmissions Covers sampling rates pseudo random data genera tion and decoding 10 95 Design manual for constructing PARABOLIC SATELLITE DISH ANTENNA 9 95 CABLETRON ICS Box 30502 Bethesda MD 20814 ALL New 6th Edition 100 pages Schematics and instructions for all major cable and satel lite systems including Orion Videocipher Fantasy Extasy New sections on bypasses how illegal decoders are detected MDS Hand book 9 95 Product catalog 2 CABLE TV Secrets the outlaw publication the Cable Companies tried to Ban HBO Movie Channel Showtime Descramblers Converters etc Suppliers List Included 8 95 Cable Facts Box 711 ME Pataskala OH 43062 FREE VHS Tape Rewinder Forwarder for Details Send S A S E To EPC M 1027 South Spruce Bloomington CA
79. HACK 27S 004 Qi 182222 St PERMITS MANUAL CONTROL OF AERATOR Fig 2 A bait well aerator timer driver All that s required to use this circuit to control a bait well aerator is to connect the normally open relay terminals be tween the aerator and the boat battery The timer itself can also be powered by the boat battery Of course the timer should be installed in a weatherproof housing It should also be equipped with a delay controller in the form of a poten CSSS PiN 2 tiometer RD and a power switch A se lector switch can be included to permit various dealy intervals to be conveniently selected Alternatively the output and reset pins can be hard wired to give a fixed on off cycle For instance con necting the reset pin 15 to pin 9 and the input of the relay driver to pin 6 will close the relay one clock interval for each eight Oo uU 11 mus EE uc lt M M T Fig 3 The timing diagram for the bait well aerator timer in Fig 2 Say You Saw It In Modern Electronics November 1986 MODERN ELECTRONICS 73 ELECTRONICS NOTEBOOK clock pulses see the timing diagram in Fig 3 for details Incidentally be sure to connect a 0 1 F capacitor across the supply leads of this circuit C2 in Fig 1 The capacitor should be placed close to the circuit Oth erwise the circuit may fail to function properly without t
80. II command on pin 13 This command is generated by the com puter with which the AAU is being used and is coupled into C2 through Q2 Transistor Q2 shifts the signal level from that used for standard RS 22 MODERN ELECTRONICS November 1986 An Analog Acquisition Unit Lets a computer store compare plot and analyze data from your experiments and circuits 232 transmission to the 0 to 5 volt level required by 7C2 Upon receiving a valid command from the computer C2 samples one of the AAU s four analog inputs shown along the left side of Fig 2 Quad op amp Cl buffers the analog iputs and shifts the O to 1 volt input levels to the 0 to 5 4 volt levels required by IC2 Gain in each input channel is individually adjust able by R2 R6 R10 and R14 After IC2samplesaninput it con verts the analog voltage on that input into an 8 bit binary number This number is then converted to its deci mal or hex value the format depend ing on the instruction command re ceived from the computer Then C2 outputs this number in a serial ASCII format data string at pin 14 Thereafter Q7 converts C2 s 0 to 5 volt level to the 5 volts required for RS 232 data transmission to the computer Light emitting diodes LEDI through LED4 indicate which of the analog inputs is being sampled and are under direct control of the C2 microcomputer Crystal XTAL Say You Saw It In Modern Electronics Cmm TZ register Port
81. INT TOTAL Name Address City State Zip Phone Number Cashier s Check Money Order COD Mastercard Acct Exp Date Signature Q q Z z rd4 OQ Tt Z TI O FOR OUR RECORDS DECLARATION OF AUTHORIZED USE the undersigned do hereby declare under penalty ot perjury thatall products purchased now and in the future will only be used on cable TV systems with proper authorization from local officials or cable company officials in accordance with all applicable federal and state laws LOWEST Dated Signed PRICES Pacific Cable Company Inc WHERE 7325 RESEDA BLVD DEPT 20 RESEDA CA 91335 818 716 5914 No Collect CN e 818 716 5140 S C E N T z C A T L E N T A U N T S Say You Saw It In Modern Electronics November 1986 MODERN ELECTRONICS 7 MEL G i m B9 NnODOY S e 000 practical transistor circuit et wmae GESOEN and analysis With NRI training at home you can And you can start by actually building your own 16 bit IBM compatible computer You can create your own bright high paying future as an NRI trained computer service technician The govern ment now reports that computer service and repair is the fastest growing career field The biggest growth in jobs between now and 1995 according to Department of Labor estimates will occur in the computer service and repair business where demand for trained technic
82. INTPUTS Fig 5 A simple microprocessor driven D A converter circuit cludes the circuit board and two chips needed for a 4 amp 5 to 40 volt dc step down switching regulator You still have to wind your own coil though Two distributor catalogs came from Newark a complete old line electron ics distributor and from Mouser with mostly foreign components at outstand ing prices A surplus catalog that came from Marlin Jones offers super cheap pricing on ultrasonics lasers digital dis plays robotics steppers and such From Texas Instruments came a new LSI Logic Data Book Intriguing new de vices include a memory mapper barrel shifter read back latches shaft encoder interfaces and nearly 200 pages of appli cation notes Finally from AESAR came another catalog of exotic metals and elements at exotic prices For some strange reason none of these exotic metals houses offer 6 inch plutonium spheres I guess it s be cause this particular product would give you an unfair advantage in lawn bowling Where can I learn the fundamentals of machine language programming Check into my Micro Cookbook Vol umes I and II Whilethey are particularly useful for the 6502 microprocessor things are presented in such a way as to apply to any 8 or 16 bit microprocessor of your choice I have a few copies in stock if you want one of them I also have expanded and revised my free stuff list so be sure to get
83. Kenwood Dealers KENWOOD TRIO KENWOOD COMMUNICATIONS 1111 West Walnut Street Compton California 90220 CIRCLE 4 ON READER SERVICE CARD A WEEK PARI S ND MORE UP TO 800 Universities use our Training Aids No costly school No commuting to class The Original Home Study course prepares you for the FCC Commercial Radio Telephone License This valuable license is your ticket to thousands of exciting jobs in Communications Radio TV Radar Microwave Computers Avonics and more You don t need a college degree to qualify but you do need an FCC License FCC License Home Study Course It s a whole new way of preparing for the govern ment FCC license examination The classroom is your home The method 40comprehensivelessons on audio cassette tapes plus five simple step by step training manuals all make up this complete self paced learning program The First Self Study Course of it s Kind Many text books on electronics don t explain how to easily answer questions on actual FCC exams They usually just gloss over the subject Our FCC LICENSE HOME STUDY COURSE was developed to provide you with clear pictorial examples simple step by step solutions and reliable answers to FCC exam questions FCC License Course Outline Matter Energy and Electricity x Concepts of Alternating Current x Inductive and Capacitive Reactance x Characteristics of Matter
84. NICATIONS 2317 VANCE JACKSON SAN ANTONIO TEXAS 78213 512 733 0334 Q amp A Element 6 Radiotelegraph 11 95 1 50 PH and Element 3 Radiotelephone 13 95 1 50 PH duplicates from my out of print FCC license handbooks Ed Noll Box 75 Chalfont PA 18914 VOICE DISGUISER FM Transmitter Tele phone Transmitter and More Catalog 1 00 Refundable XANDI Box 25647 C Tempe AZ 85282 LINEAR PARTS TUBES TRANSISTORS MRF454 16 MRF455 12 MRF477 11 MRF492 18 Catalog RFPC Box 700 San Marcos CA 92069 619 744 0728 INVENTORS INVENTORS Have idea for product or in vention don t know what to do Call AIM we present idea s to manufacturers Tol Free 1 800 225 5800 94 MODERN ELECTRONICS November 1986 PICKS UP A WHISPER 50 FEET AWAY The model WAT 50 miniature FM tranmitter uses a 4 stage circuit NOT to be confused with a simple wire less microphone Simply snap the unit on top of a 9V battery and you can hear every sound in an entire house up to 1 mile away Use with any FM radio Tunes to any frequency from 70mhz 130mhz Easy to assemble kit includes al parts and instructions Only 29 98 tax incl The WIRELESS TELEPHONE TRANSMITTER model WTT 20 is only about the size of a dime yet transmits both sides of a telephone conversation to any FM radio with crystal clarity Completely automatic Uses power from the telephone line itself never needs a battery Up to mile ran
85. ST SixPak and Hayes Smartmodem 1200B but Practi cal s 154 fee for adding 512K memory is definitely greedy You can buy the RAM chips yourself for under 60 Waiter I ll Have DOS I was all set to ridicule Bartel Software s Le Menu It s the only hard disk organiz er named for a frozen dinner the manual has photos of disks on china plates and Bartel s press kit is a howler it follows the common practice of reprinting a re view of an earlier version but with every thing negative over half the review blacked out with Magic Marker But once I tested the current version 2 5 I found Le Menu isn t so laugh able It may not be the greatest DOS shell around but it does a good job of integra ting two functions many programs for either one of which cost more than its 59 95 If you have a crowded hard disk or manage an office XT or AT for inex perienced users Le Menu is worth a look Le Menu s first function as its name implies is to set up a program selection system similar to that of Delta Technol ogy s Direct Access Started from an AUTOEXEC BAT file it presents users with a custom menu of 26 choices such as Lotus 1 2 3 or Database Pro gram pressing one key the desired let November 1986 MODERN ELECTRONICS 85 Say You Saw It In Modern Electronics PC PAPERS Menu requires a correct filename as in the menu setup procedure is it 123 COM or 123 EXE it will quickly s
86. Saw It In Modern Electronics audio frequencies and thus amplifies the audio modulation Capacitor C6 couples the detected audio signal into op amp IC1 which provides about 10 dB of gain Be cause a Single ended power supply is used see Fig 3 C1 is dc biased to 2 5 volts by R5 R6 and C5 Other wise the input signal would be recti fied The amplified audio is fed to tone decoder C2 which outputs a logic 0 when the audio tone for which it is tuned appears at the input Because each transmitter uses a different audio frequency to modu late its carrier IC2 must be tuned to each of the 10 possible different frequencies To accomplish this 10 different capacitors C72 through C21 are sequentially connected to ground As each capacitor is grounded it s placed in series with frequency determining resistor R70 A clock signal generated by C3 determines the rate at which C72 through C2 are scanned and goes to BCD counter C4 whose outputs drive 1 of 10 BCD decoder JCS Since IC4 continuously counts up from O to 9 IC5 continually grounds C12 through C21 causing C2 to se lect each capacitor in succession The Power Supply Display The four BCD output lines from IC4 the output from IC2 and the November 1986 MODERN ELECTRONICS 41 psf 1OLEDy S array j IC2 74LS42 D3 1N814 5V O 1uF Fig 3 power buses go to the power sup ply display subsection shown in Fig 3 Ac line po
87. Stereo TV Decoder MODEL V 622 TY Say You Saw It In Modern Electronics design features and contains a selection table that lists model numbers and enclo sure dimensions For a free copy write to Formax 1120 Federal Rd Brook field CT 06804 Equipment Protection Catalog Hi Tech Equipment Protection amp Interfer ence Control from Electronic Special ists contains 40 pages that describe unin terruptible power supplies line condi tioners modem protectors equipment isolators spike suppressor filter devices and ac power interrupters Included are tutorials that describe various problems and the corrective action that can be taken Catalog 861 is available free by writing to Electronic Specialists Inc 171 S Main St Natick MA 01760 Wireless Selection Guide A booklet that attempts to demystify wireless for sound centractors and end users is available from Nady Systems The User s Guide to Selecting a Wireless System sets forth a series of objective and subjective tests for evaluating wireless systems on the market Some tests are technical others are not but taken together they can pro vide a practical guide for selecting the correct wireless system for a given appli cation For a free copy write to Nady Systems Inc 1145 65 St Oakland CA 94608 Capacitor Guide A new Quick Guide to Paper and Film Capacitors from Sprague provides an easy refere
88. The 10 Channel Wireless Home Se curity System described here pro vides the convenience of wireless op eration with the basic economy of a hard wired system Its ability to in form you of the location of an at tempted break in or other emergency situation is a benefit that most hard wired systems do not offer ME November 1986 MODERN ELECTRONICS 51 Project An EPROM Proerammer For the Commodore 64 Computer driven plug in board inexpensively programs popular 2764 EPROMS with the C 64 computer By Paul Renton rogramming EPROMs often P requires dedicated and ex sive hardware The home user who wants to program just a few EPROMS can build a device that can be controlled by a computer but if he wants to program a large variety D1 1N4001 Semiconductors D1 D2 D3 D5 D6 1N4001 diode D4 1N148 diode D7 1N4748 or similar 22 volt zener diode IC1 555 timer IC2 74L S273 octal flip flop IC3 74L 58373 octal latch IC4 CD4040 12 bit binary counter Q1 Q2 2N2222 npn transistor Capacitors C1 220 pF 25 volt electrolytic C2 0 001 4F disc C3 C5 0 1 4F disc of different types of EPROMS the cost of the increasingly more expen sive hardware would negate any monetary advantages to be gained by going this route However program ming hardware that handles a very limited variety of EPROMS greatly simplifies the requirements and dramatically reduces the cost For PARTS LIST
89. WI for want or add a WZ for2 wart te M ig 25 B4 718 e 70 5878 gt 10 4 2aLS03N 45 L 90 75450N 90 15KW for 1 BKQ 1 wand tha ia the Dig Key pert NN N UR 11 305 i E206 250 10 amp 535 4S 406 7ALSOAN Fc petite iWGISN 315 90 75451N 68 fl Mes3666 2 22 890 7326 number ZA G I 3 M a og Ga Pez c 12 c se 485 sw MIZ E 25 T t1 t 66 7 k 7 7ALSOSN 4 38 Mica veg i 75A52N a8 MPS3538A 23 22 18 90 173 25 Pricing i 100 800 1000 4700 189 700 M ed 1 Hj PM i A pene 7ALS06N 2 LMWSCK 3038 75493N 86 f west 2 229 B 17325 27 35 i8 i54 E2226 290 22 03 6885 7308 85308 dep 7 Ba Duca 2a MNA ADR 88 f ops 3642 z 25 9 maj Usa o 00 40 D TED Qs 3 8 5 12 1 92 348 a Eo m JALS10N an 1 r3 LM73IBCK 303 EM MPS91S z 2 2250 206 25 2 Watt 18 85 1050 A750 87 BO a H eoe 12 d 19 des AEN CAT NO 95 PALSIIN 3 50 261g MEST 96 p N PSA13 33 am 20 24750 fF 0 rae aus ena pen s om 27 M M cas Do 22 35 24 200 16 3 16 333 vatuES E KIT 54 HESIAN 4 ty 26 MR CT se TEDAN i hi TIP112 108 10 15 8700 79 0 Y Watt Resistor Aasortmente R 3 28 239 19 21 178 14 amp 4LS13N 60 AZN y Ey 47 35 R 27 23 21 190 157 SALE AN LM322 od 112 1050 90 00 as E RS1Qi beso ES 47Q to SEQ s 100 35 a 36 X 924 208 3 pee aa v SERIES M e x 4116 200 nsec 16 384x1 D Ram ics 101 Bas rio 74250 R8204 Seach of value 620 107 SKO uem o S SE GS se Saks 6 Price Per Pak Ot P O
90. YOU ORDER OUR PRICES MAY BE LOWER COMMODORE 128 COMPUTER 289 00 This powerful 128K computer has three modes One for C 64 software one for C 128 software and one for CP M business software List 399 00 SALE 289 00 340K 1571 COMMODORE DISK DRIVE 259 00 Double sided single disk drive for the C 128 allows you to use the C 128 mode plus CPM mode 17 times faster than the 1541 and runs all the 1541 formats List 349 00 SALE 259 00 amp AND WE OFFER SPECIAL SYSTEM DEALS BIG BLUE PRINTER 39 95 List 199 00 This is the affordable printer you have been waiting for This 81 5 letter size 80 column thermal printer features upper and lower case underline graphics word processing and much more List 199 00 SALE 39 95 PREMIUM QUALITY 150 170 CPS COMSTAR AERO 160 PRINTER 199 00 States programs and more at 100 characters per PRINTER TYPEWRITER COMBINATION 199 95 Las Superb letter quality daisy wheel printer typewriter combination just a flick of the switch to interchange Extra large carriage typewriter keyboard automatic margin control compact lightweight drop in cassette ribbon 90 day warranty Centronics Parrallel Interface is built in List 299 00 SALE 199 95 10 COMSTAR 1000 PRINTER 179 95 This is one of the best values in the United today Print letters documents second or 20 cps in Near Letter quality mode Some f
91. ac line making it easy to accurately measure current drawn by a device death knell for clamp on current probes which are much more costly They are still as useful as ever for measuring current that greatly ex ceeds 10 amps and for checking out an integrated electrical device say a clock timer that s part of a refrigera tor s innards which has separate leads all without touching a live wire But to quickly and accurately measure current drawn by the whole unit up to 10 amperes steady power consumption nothing beats this lit tle low cost device since you needn t uncover a separate wire as you d have to with a clamp type probe The meter we used a 149 Fluke Model 23 portable is a neat DMM unto itself It has recessed inputs to accept shrouded banana plugs na turally and its internal fuses include high overload protection and a fused 0 36 ohm fusible resistor 10 amp range The latter provides interrupt protection to 100 00 amps says the manufacturer while a 430V MOV metal oxide varistor in series with a spark gap gives volt ohm protec tion Among its generous features are autoranging auto zero auto po larity an audible beeper for continu ity and diode tests and an appropri ate easy to use rotary dial Additionally the DMM has a 31 segment analog bar graph display for easier reading of fluctuating signals and for zero adjustments as well as large bold LCD numeric readouts Another useful
92. acts completes the battery s positive line to the amplifi er circuit board Thereafter any audio signal that the computer gen erates delivered to the input of the mini amplifier through a separate INPUT jack will be heard through the speaker Powering down the computer re moves the 5 volts dc from the com Say You Saw It In Modern Electronics i LT TAIWAN COMPUTER TRADE CENTER 7220 NW 58th Street 2215 N Broadway Miami FL 33166 Los Angeles CA 90031 305 477 2600 213 222 9680 e 213 224 8610 800 342 2332 MANUFACTURER S REPRESENTATIVE DIRECT IMPORTERS OF IBM PC XT COMPATIBLES FACTORY PRICES TO DISTRIBUTORS DEALERS Prices Are For Quantities of 50 MOTHER BOARDS Western Digital Controller 101 W O BIOS amp MEMORY AT Floppy amp Hard Disk Controller w Cable 200 Regular640K ne 87 POWER SUPPLIES XTTurbo4 77 8 MHZ 2 Layers 96 135W o ees 50 XT Turbo 4 Layers eee 125 150 oun casa nae uw yama map w w w P eee 55 fh XTTurbo4 77 10 MHZ oon 125 OU s S aye 90 AT 6 8MHZ MI 450 KEYBOARDS AT Turbo 10 MHZ 450 K7S 5150 eee tod nara doa d 40 CASES IO DO gjar Aa nV KA ROC i RD 55 XT Flip Top or Slide oann eee eee eee 27 BOSON aa cxeraibecemimica 44 46m iene een 50 pes AT For XT 2 een cee e n 50 5160 XT AT aus eu napa rum m E ERA 50 4
93. al Possibly you might know how this type of CoCo II can be changed I hope to use this com puter for my electronic organ service business Herbert O Karnes Gorham ME Sorry you cannot use the article di rectly to upgrade your CoCo II but it was clearly stated that the upgrades were for the latest version the model Radio Shack was selling at a bargain price You have an older Say You Saw It In Modern Electronics W LETTERS kk version from your description I would say the first of many CoCo II models If as you say there is no empty socket your CoCo most likely already has Extended BASIC What you need is a retrofit kit and instructions specifically for your model It is possible that the kit is still available from the source in the article Author LOWEST PRICE YES DS DD 39C BULK 514 DISC GD3 DS DD 59 BOXED 51 4 DISC GD2 HIGHEST QUALITY YES WE GOT AN OFFER TOO GOOD TO REFUSE A new supplier offered us the best price imaginable Thanks to them our new GD 3 disk is one of the lowest priced DS DD disk in the country but is still certified error free at more than 25 above indus try standards They come with lots of labels and tabs and have Tyvex sleeves not paper that creates static and lint Sorry no quantity discounts at this low price Packed 100 per box GENERIC DOESN T MEAN JUNK Our GD 2 disks are the best quality disks we sell Their error free ce
94. amount of the r f out put back into the emitter of Q2 In ductor L and capacitors C8 and C9 tune the circuit to resonance Capa citor C7 bypasses BJ at 49 MHz Audio oscillator Q7 modulates r f stage Q2 and is dc biased by R4 through R7 so that Q operates as a common emitter amplifier Capaci tor C4 connects the emitter to ground for ac signals to maximize gain The Q stage has an open loop gain of 1 to maintain oscillation Since Q s gain is directly propor tional to the dc emitter current the value of bias resistor R4 must be chosen to provide unity gain at the selected frequency see Transmitter Component Values table for the values of this resistor and other fre quency determining components To adjust the percentage of modu lation the value of R4 can be varied by or 5 000 ohms Trimmer R7 RI R3 ikilohms ae Pao n PIE 2 I mr rt fat Pal JA p E pug PB C permits fine tuning of the operating frequency The audio output of Q is coupled by C5 to the base of Q2 to modulate the dc bias level and r f amplitude This is readily accom plished because Q2 operates as a common emitter amplifier at audio frequencies Transistor Q3 is a power MOS FET that provides connection to a normally closed security switch This external security switch connects the gate to ground thus biasing off Q3 Should this switch open R711 for ward biases Q3 and applies battery power to the transmit
95. an example of how to connect Multibotics Workshop s components as D MOTOR s Ti R Ap TRANSMISSION part of a Motor Efficiency Test experiment which contain tiny motors Other parts include speed reducers to slow speed while increasing torque a worm gear to change drive direction a transmission to extend a motor shaft s length an axle four wheels and tires connectors couplers a 10 ft remote operation cable two pair of infrared sensors coax cables with phono plugs and so on Accompanying the equipment which requires one to also have a Commodore C 64 or C 128 compu ter a video monitor or TV set and a disk drive is the especially fine proj ect experimenter s manual cited earlier It contains 50 well illustrated and documented projects experi ments to interact with real world objects that are computer con trolled For example the Workshop enables you to easily build a gyro Scope and a generator experiment with joysticks light color check battery voltage up to 3 6V higher with a shunt resistor measure rpm and speed build a counter burglar alarm a car that can be controlled to go forward reverse left right brake slow down speed up digital 18 MODERN ELECTRONICS November 1986 speech recording and playback with the addition of an audio amplifier that has an auxiliary input and a host of other applications In Use It was easy to get started with the MB23
96. an rest assured that your sleep will not be interrupted As always no modification should be made to telephone company property Rich Vettel To preserve your copies of A choice of handsome and durable library cases or binders for your copies of MODERN ELECTRONICS Both sytles bound in green library fabric stamped in gold leaf Cases Each case holds 12 issues Price per case 7 95 three for 21 95 six for 39 95 Binders Each binder holds 12 issues Issues open flat Price per binder 9 95 three for 27 95 six for 52 95 Canadian and foreign requests should also include an additional 2 50 per item for shipping costs a n ue HD 8 a O a s e Fp m i To Jesse Jones Industries Since 1843 P O Box 5120 Dept MOD Philadelphia PA 19141 I enclose my check or money order for MODERN ELECTRONICS Please Print Please send me O Files Binders Name Address City State Zip Please allow approximately 4 weeks for delivery Say You Saw It In Modern Electronics November 1986 MODERN ELECTRONICS 33 VCR Hookups With Cable Boxes VCR connection arrangements most user manuals fail to address By Cass R Lewart T he modern videocassette re corder is a marvelous enter tainment appliance But most operating manuals that accom pany VCRs fail to give extended in formation on how to connect them into a system especially ones with
97. ance MODERN ELECTRONICS MART Classified Commercial Rates 90 per word 15 word minimum 13 50 prepaid Word count includes name and address ZIP code and abbreviation each count as one word P O Box number and telephone number count as two words each Indicate free cate gory heading A special heading is available for a 6 surcharge First word only is set boldface caps at no charge Add 20 for additional boldface words Mart Display Rates 1 x 1 col 120 2 x 1 col 230 3 x 1 col 330 Prepayment discount 5 for 6 issues 10 for 12 issues prepaid at once All advertisers with PO Box addresses must supply permanent address and telephone number Copy is subject to publisher approval Mailing Information Copy must be received by the publisher by the 20th of the third month preceding the cover date Send Advertising material with check or money order to Modern Electronics Classified Department 76 N Broadway Hicksville NY 11801 HIGH PAY HIGH TECH EXCITING CAREERS Electronic Hydraulic amp Robotic Skills Taught Call or Write for FREE BROCHURE TODAY Ask About Our Correspondence Course 713 690 0405 UNDERWATER VEHICLE TRAINING CENTER 10046 Chickasaw Houston TX 77041 CIRCLE 20 ON FREE INFORMATION CARD Pa press Got tre r DCE SMITH ELECCTICOINIC eR fired Cy 1 ic Tap Tel ria enthuses Ire cota sect On alone Awol fhe pice elmgidmisiori Serv for your ct py TOR CDIV Please spa
98. and insurance Illinois residents please add 6 sales tax Add 6 00 for CANADA PUERTO RICO HAWAII ALASKA APO FPO orders All orders must be in U S Dollars WE DO NOT EXPORT TO OTHER COUNTRIES EXCEPT CANADA Enclose Cashier Check Money Order or Personal Check Allow 14 days for delivery 2 to 7 days for phone orders doy express moil Prices amp Availability subject to change without notice Hardware shipplng prices vary according ta weight Please call for amount VISA MASTER CARD C O D to us via United Parcel C O D on phone orders only 48 MODERN ELECTRONICS November 1986 SUPER VALUES PROTECTO ENPERPRIZES A y A Ave BEST SERVICE IN THE U S A 90 DAY REPLACEMENT WARRANTY ONE DAY EXPRESS MAIL 15 DAY FREE TRIAL OVER 500 PROGRAMS A CUSTOMER LIST OF OVER 3 000 000 LARGEST IN THE U S A CALL FOR FREE CATALOG WITH 2 00 OFF COUPON SPECIAL BONUS COUPON We pack a special software discount coupon with every Commodore 64 Computer Disk Drive Printer or Monitor we sell This coupon allows you to SAVE OVER 250 off sale prices EXAMPLES PROFESSIONAL SOFTWAF COMMODORE 64 Name List Sale Coupon Paper Clip 59 95 34 95 29 95 Consultant 59 95 34 95 29 95 Leader Board 39 95 22 95 21 95 The Print Shop 44 95 27 95 25 95 Bop N Wrestle 39 95 19 95 18 95 Super Huey 19 95 12 95 11 95 Voice Command Modul
99. ant channel recall Automatic fine tuning THE RABBIT MODEL TR 7000 m up 59 95 6 11 69 95 1 5 IT S LIKE HAVING A VCR IN EVERY ROOM 66 CHANNELS AUTOMATIC FINE TUNING A B SWITCH OPTION CAPABILI E MASTER CARD BI VISA CIRCLE 47 ON FREE INFORMATION CARD 68 MODERN ELECTRONICS November 1986 EXTRA HAND REMOTES REM 400 29 TEKNICA CORDLESS CONTROL 40 CHANNEL The other guide Videocassette Selec tor is a colorful leaflet that describes the unique features and recommended uses of the company s four videocassette categories For free copies of these guides write to Maxell Corp of Amer ica Video Products Div 60 Oxford Dr Moonachie NJ 07074 LED Lamp Catalog Dialight has a 12 page catalog that describes the com pany s complete range of LED lamps It gives information on T 134 T 1 and T 34 LEDs and rectangular and special shape LED lamps Charts list peak wave length typical forward voltage luminos ity test conditions and LED color lens for each device Dimensioned drawings and a list of Dialight representatives in the U S and Canada are included For a free copy write to Dialight Corp 203 Harrison Pl Brooklyn NY 11237 Aluminum Enclosures Brochure Now available from Formax is a colorful 4 page brochure that discusses the com pany s complete line of aluminum instru ment and control enclosures It details Universal MTS
100. ard from the source given in the Note at the end of the Parts List Note that this board has been de signed to fit inside a popular Series 200 Unibox enclosure PARTS LIST Semiconductors D1 D2 1N4001 rectifier diode D3 1N5232 or similar 5 6 volt zener diode D4 D5 1N4148 switching diode IC1 LM324 quad op amp IC2 MC68705R3 microcomputer Motorola LEDI thru LED4 Red light emitting diode LEDS5 Green light emitting diode Q1 2N4403 or similar pnp transistor Q2 2N4401 or similar npn transistor Capacitors C1 C3 220 F electrolytic C2 C4 C5 C6 C7 22 uF 16 volt ra dial lead electrolytic C8 27 pF ceramic disc Resistors 4 watt o tolerance RI RA4 R5 R8 R9 RI12 RI3 R16 10 000 ohms 16 volt radial lead R3 R7 R11 R15 33 000 ohms R17 560 ohms R18 R21 1 000 ohms R19 R26 430 ohms R20 R22 thru R25 4 500 ohms R2 R6 R10 R14 20 000 ohm upright pc type potentiometer Miscellaneous XTAL 4 00 MHz HC 18 crystal Printed circuit board 12 volt ac plug in transformer sockets for ICs input connectors 5 conductor cable hookup wire solder etc Note The following items are available from GTC Industries P O Box 443 Hinsdale IL 60522 Programmed MC68705 microcomputer chip for 29 95 etched and drilled pc board for 12 50 kit of all parts not including enclosure for 69 00 Add 2 50 P amp H for each or der Illinois residents please add state sales tax N
101. at either the usual 4 77 or 7 16 MHz and should hit the educa tion market like a hurricane The regular 1000 becomes the SX with the faster CPU five instead of three 10 inch slots and space for 640K on the motherboard Between Radio Shack and Asian im ports the day of the corner store clone has dawned Looks like you ve had it Commodore Trend Two While 8088 based PCs plunge toward 500 and the high end market looks to 80386 dream machines the 80286 is finding its place in the mid dle the 1 500 AT compatible just as the 286 s multi tasking memory addressing DOS 5 0 begins to look like more than a rumor Tandy calls its trim new 3000 HL 1 699 an XT compatible mainly for the sake of keeping the original 3000 HD the titular head of the line smaller firms are selling 8 MHz machines cheap to make way for 10 and 12 MHz speed sters It s cruel to those of us who are still making payments on two year old XT clones but you can t stop progress Trend Three Come to think of it all my trends add up to products being built more efficiently and sold at lower prices Dear Mom and Dad I know you ve heard this before but please TTE money There s this new student named Denise in my history class and we send v dispatch v 1 direct 1 address expedition guide B forward haste refer C issue speed route D route swiftness E send 2 mail F transmit 5 bulletin ship item 2G
102. ates seconds the desired time delay can be programmed only in hours and minutes Instead of the 10 dig Serving you the highest quality at very affordable prices Our credentials are impeccable friendly service superb quality affordab prices and quick delivery All of these thincs can be found in our latest catalog And weve reserved a copy especialy for you To receive sours simply call TOLL FREE 1 800 543 4330 In Ohio 1 800 7 2 4315 In Hawaii or Alaska 1 800 858 1849 858 E Congress Park Drive e Centerville Oh 45459 MCM ELECTRONICS A PREMIER Company Source No ME 17 CIRCLE 58 ON FREE INFORMATION CARD ELECTRONICS NOTEBOOK H TO 1S V 12 Ci Cz SEE TEXT O1 RL 4K 14 N Rie 20K amp T P m V X ui 8 Dn pc 150K SUY gem Fig 6 Cascaded XR 2240s give extra long time delays it keyboard of the previous timer this unit has single hour and minute keys that must be repetitively pressed to set the de sired interval Miniature countdown timers identical or similar to the two described above are available at department and discount stores and Radio Shack Some apparent ly identical timers have different mark ings or even names Prices for digital timers can vary widely so be sure to shop around for the best deal Figure 7 shows a simple SCR output interface that I have used with the two digital countdown timers
103. backup option solder 8 lengths of hookup wire to the pads labeled 12 VDC Mount S in its hole and the termi nal strip on the enclosure Then use 1 4 spacers and 4 40 x V4 machine Say You Saw It In Modern Electronics U UB UN ws an audio tone might also be heard but not clearly indicating that the transmitter is working Use the 450 Hz transmitter to make the following adjustment Place the transmitter about 15 feet from the receiver and adjust 77 s pepa Pa m Sa slug until you hear a tone coming 597 Los EE fromtheamplifier s speaker Adjust TE EE ere for best signal Once tuned check to make sure that each transmitter causes the receiver s relay to latch y uni gi po k a Nar Rh s T LE TP SRA A AZ S 7068 yas i Virga Mundi EIER ved aa LU a Fy fei TE j LI fy thf UN wo veste reet pH VE id UU PEDE ce ye ut t i eh bg forte Mees 4 7 pass erre EGER d T J y if i Wiican E ae Veneri rey ee eee i Fig 12 A suggested front panel layout Jor the TL system hardware to mount the pc board as semblies Plug the ribbon cable onto the connector on the power supply board and route the antenna wire through its hole Connect and solder the wires to SJ PB and the termi nal strip Label LED POWER and LED2 ALARM
104. breakup have risen only about half as much as did the Consumer Price Index The new smaller Bell regional op erations actually subsidize local phone service believe it or not The tinier Bells like its earlier parent have to offer phone service to every 4 MODERN ELECTRONICS November 1986 one while competitors can pick and choose areas Meanwhile the new Bells there are seven regional ones are acquiring and starting a host of new busi nesses And making plenty of mis takes too that come out of profits Some have computer retail stores equipment leasing companies soft ware publishing companies real es tate operations credit companies and so on It s nice to be able to do this out of profits But what happens when profits dwindle as they might as tough competitors force phone service prices down After all MCTI s sales per employee doubles that of AT amp T s Furthermore non Bell fiber optic cable systems that are moving ahead provide long dis tance hookups while bypassing local ones This has the makings of hitting the Bells where it hurts and where they re getting the profits to take care of in the red operations like lo cal service and trying to become re tail entrepreneurs in a hostile unfa miliar world We ve all gone through some bad times with the phone companies and equipment makers since the Justice Department put an end to a benign monopoly Much equipment made by new competitors was p
105. ching a bait well pump on and off The circuit in Fig 2 is a simple relay driver that easily controls the aera tor To use this circuit with the timer in Fig 1 requires a slight modification to thetimer When the output is taken from the reset pin as in Fig 1 the output changes state for only an instant before the 4017 is reset Therefore for the cir cuit to drive a relay it s necessary to reset the 4017 when the count advances to the first level after the desired level For ex ample assume you want the circuit to close the relay once for every four clock pulses from the 555 The input of the re lay driver in Fig 2 would then be con nected to pin 7 of the 4017 and the reset input pin 15 to pin 10 the next output Figure 3 is a timing diagram that sum marizes the operation of the circuit in Fig 1 when operated in this fashion Note that the reset input can be connect ed to ground to give a count of nine clock intervals This is possible because the output and reset are not tied together as in Fig 1 Therefore depending on the connections selected from the timing dia gram the clock interval can be multiplied by from 1 to 9 In each case the relay will remain actuated for only a single 555 tim ing cycle OO POT RESET PIN TO Pin a A a 7 7 1o 10 t a 5 o q Ir GN D CLOCK HER ee SE S ea ng SU ae a Q TO 12 Vv Di LN 914 TO OUTPUT PIN 12 V SL O ACRATOR RELAY RADIO S
106. computing can use up batteries at an alarming rate The simple modifica tion described here neatly solves both potential problems Modification Circuit Shown in Fig 1 is the modifying cir cuitry needed to automatically con trol the mini amplifier which con nects in series with the amplifier s positive battery supply line Once connected as shown the amplifier s 4 s M AM MSIE A sm a mm Nm a x w s m Wo w x k Na ia ww 1 Fata s acm OON ra 7 1 ww i hh NE w a a WW k R Y a JE JE eee m E Fre P power switch is always left in the on position and the volume con trol 1s adjusted to a desired listening level Thereafter all that need be done is to apply and remove power from the circuit This is accom plished with relay KZ Power to energize KI comes from any convenient 5 volt dc point available at any of the computer s ports This 5 volt line is available at pin 5 of the joystick ports and pin 9 of the cartridge port on the Radio Shack Color Computer and at pin 7 of the joystick ports pin 2 of the User Port and pins 2 and B of the cas 64 MODERN ELECTRONICS November 1986 m 8 n m CN s j Fal a grs F P sette port of the Commodore 64 computer Whenever the computer is turned on this 5 volts dc is automatically delivered to K s coil through the PI J1 mini phone plug jack pair Closing K s cont
107. connected in its astable mode with a timing cycle gov erned by R and C1 Each count pulse from the 555 advances the count from the 4017 so that active outputs go high in se quence while inactive outputs remain low By connecting the reset input of the 4017 to one of the outputs the counter will reset itself to O after the respective number of count pulses In short the 4017 permits the timing period of the 555 to be multiplied by from 1 to 10 This circuit permits a variety of on off cycles of the pump to be selected The pulse interval from the 555 determines how long the aeration pump will remain on per cycle The 4017 output to which the reset input is connected determines the time between aeration cycles For ex ample if R is adjusted so that the 555 emits a pulse every two minutes and the reset input is connected to pin 5 output 6 the pump will switch on for 2 minutes every 14 minutes output 6 is the seventh count state 2 x 7 14 Incidentally though the Fig 1 circuit includes provisions for counts of 0 and 9 in practice these outputs are not usable when the circuit is connected as shown The 0 output never becomes high and the 9 output always remains low Fortunate ly as revealed below a practical version of the circuit salvages the 9 output r c s a 72 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics The circuit in Fig 1 doesn t include a means for swit
108. converters and descramblers Low prices quality merchandise we ship C O D Send 2 00 for catalog Cabletronics Unlimited P O Box 266 M S Weymouth Mass 02190 CPI 871 6500 BEAUTIFUL Island FEE desire correspon dence friendship marriage Photos details Palm Box 816 Belton SC 29627 Say You Saw It In Modern Electronics Andy is a Ham Radio operator and he s naving the time of his life talking to new and old friends in this country and around the world You can do it too Join Andy as he communi cates with the world Enjoy the many unique and exclusive amateur bands the millions of fre quencies that Hams are allcwed to use Choose the frequency and time of day that are just right to talk to anywhere you wish Only Amateur Ra dio operators get this kind of freedom of choice And if it s friends you re looking to meet and talk and you can to i TE Nes with Amateur Radio is the hobby for you The world is waiting for you If you d like to be part of the fun if you d like to feel the excitement we can help you We ve got all the information you ll need to get your Ham license Let us help you join more than a millicn other Hams around the world and here at home Who are we We re the American Radio Relay League a non profit representative organ izaticn of Amateur Radio operators For information on becoming a Ham operator circle number 110 on the reader service card
109. coupling e Calibrated 18 step tirrebase with x10 magnifier X Y oper ation e Bright sharp rectangular CRT with P31 phosphor e Front panel trace rotation contro e Tilt stand and soft handle e Selectable slope e Built in calibration source e Compact low profile design For immediate delivery contact your local B amp K PRECISION distributor or call B amp K PRECISION today D DYNASCAN PNG MA CORPORATION 6460 West Cortland Street Chicago Illinois 60635 e 312 889 9087 internationalSales 6460W Cortland St Zhicago lllinais60635 e ConadianSales AtiasEiectronics Ontario CIRCLE 48 ON FREE INFORMATION CARD South and Central Americcn Sotes Empire Exporters Plainview NY 11803 Engineer s Mini Notebook Optoelec tronics Circuits by Forrest M Mims III Radio Shack Soft cover 48 pages 1 49 Modern Electronics columnist For rest Mims has generated another fine lit tle volume for experimenters This one focuses on working with optoelectronic devices Its informal format consisting of hand printed text with hand drawn il lustrations and schematics is logically arranged according to category These include light sensors lightwave commu nications optoelectronic logic and source sensor pairs This arrangement makes it easy for the user to quickly look up needed information Text is kept to a minimum with em phasis on easy to understand and use drawings Hence the book is meant to be used by readers ranging f
110. d suitable en closure to house both receiver de coder and power supply display boards sockets for ICs 4 40 ma chine hardware hookup wire sol der etc Note The following items are available from Dan Becker 101 Highland Dr Chapel Hill NC 27514 compleie transmitter kit No SS 10 TR minus enclosure and external security switch es for 17 95 plus 2 00 P amp H specify chan nel desired complete receiver kit No SS 10 RC including all components in Receiver Decoder and Power Supply Display Parts Lists but not including piz zoelectric buzzer and enclosure for 69 95 plus 4 50 P amp H inductor kit containing r f transformer and three RFCs for 9 95 PPD COMPLIANCE WITH FCC RULES The receiver in the W r2less Security System described in this article can be home built without you having to ob tain special permission from the Fed 2ral emmunizations Commission and without violation of the FEC Rules and Rezulations You can bu ld up to five transmitters without obtaining permis sion from the FCC provided you com ply with the requirements set forth in sect ors 15 133 and 15 119 which re quire tie following To each transmifter vcu build you must ettach a signed and dated label thet reads I nave constructed this de vice o7 my own use I have tested it and certify that it complies with the applica bleregualtionsof FCC Rules Part 15 A copy of my measurements is in my pos Sessior and is available fos
111. d drilling guide for transmitter pc board have a metal panel that will accom modate the transmitter circuit board and 9 volt battery Using the board as a template position it inside the enclosure and mark the case for the two mounting holes Then mark the hole locations for the antenna wire sensor wires and access for RJ and L1 Use a 2 bit to drill the antenna hole and a bit for all other holes Prepare as many enclosures as you will be using transmitters Decide how many transmitters you are going to have in your system and the audio tone frequencies you wish to use then wire each board ex actly as shown in Fig 7 using the ap propriate values for R7 through R4 and C through C3 from the trans mitter Component Values table in each case Wire only one transmitter board at a time to avoid confusion In stall all components except the tran sistors which mount X above the board s surface flush with the board Note that most resistors on this board and many on the other two boards in the system mount vertical ly Make sure the electrolytic capaci tors are properly polarized and that basing is correct for the transistors before soldering them into place If Fig 6 Actual size etching and drilling guide for power supply display board you plan to use a normally closed sensor install C70 between ground and point A For a normally open sensor omit Q3 and solder a jumper wire between the drain D and sou
112. ded and leadless SMD packages The tips are shaped for use on most popular size 1206 chip components SOT 23 tran sistors and SOIC packages Incorporated into the soldering iron is a Posi Ground feature that is claimed to ensure less than 2 milli volts of leakage to comply with MIL Specs making it safe to use on volt age sensitive components A self compensating heating element main tains tip temperature at 750 degrees Fahrenheit Adapters are also in November 1986 MODERN ELECTRONICS 13 tal lockout antenna positioning pro gramming up to 30 channels block system technology full function IR remote controller composite video input and i f loop through for TI fil ters and the ability to accommodate either matrix or discrete stereo trans mission modes Using a 950 to 1450 MHz block input frequency this block conver sion receiver also features dual input switching that eliminates a need for external relays or switching splitters It accommodates either two C band LNBs or one C and one Ku band LNB and is compatible with all Drake LNBs and BDC24 block downconverter About 1 500 CIRCLE 34 ON FREE INFORMATION CARD cluded for using the SMD tips with other soldering irons and worksta tions The kit comes in a handy clear plastic case CIRCLE 35 ON FREE INFORMATION CARD NEW PRODUCTS Car Radio With Cassette Changer Alpine s Model 7375 car radio sys tem features a trunk mo
113. dering iron are shown in Fig 8 Put the small hose clamp around the neck of the CO cartridge and slidethis over the tube as far as possi Fig 9 The assembled modified desoldering tool 90 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics ble without contacting the barrel of theiron You want the tube to extend into the cylinder a bit to prevent sol der from getting back onto the tip Tighten the hose clamp just enough to secure the connection Clip off the extra bit of the clamp with a pair of diagonal cutters as close to the worm gear as possible The assem bled modified desoldering iron is shown in Fig 9 If you don t have the facilities to perform the maching operations de scribed here are having difficulty obtaining the required parts or just prefer assembling the Super Solder Sucker from a kit see the note at the end of the Bill of Materials You will find listed there a number of kits and individual parts that are available to suit any need To take full advantage of the in creased suction power remove the replaceable tip and drill it out to 4 Remove any burrs with a file and re assemble Finally connect the pump to the iron with the silicone rubber hose about 6 feet is a good length In using the Super Solder Sucker put the iron s orfice right over the lead protruding through the circuit board Allow the solder to liquify and then pump Remember the suc tion
114. e 79 95 39 95 34 95 Nine Princes in Amber 32 95 20 95 19 95 Super Bowl Sunday 35 00 19 95 17 95 Flip and File Disk Filer 24 95 14 95 12 95 Pro Joystick 19 95 12 95 10 00 Party Ware 19 95 14 95 9 95 Dust Cover 895 5 95 3 95 Financial Planner 49 95 29 95 25 95 Hardball 29 95 17 95 16 95 C64 Troubleshoot amp 24 95 12 95 10 95 Repair Guide See over 100 coupon items in our catalog Write or Call for sample Special Software Coupon PHONE ORDERS 8 a m 8 p m C S T Weekdays 9 a m 12 noon C S T Saturdays 312 382 5244 THE PROTECTO WARRANTY All Protecto s products carry a minimum 90 day warranty If anything fails within 90 days from the date of purchase simply send your product Service prepaid We will IMMEDIATELY send you a replacement at no charge via United Parcel Service prepaid This warranty proves once again that We Love Our Customers Say You Saw It In Modern Electronics JUR 5919515 P ZH 312 382 5244 TO ORDER COMMODORE 64 COMPUTER 99 e 00 299 You pay only 99 00 for the Commodore 64 when you purchase a Pocket Writer 64 word processor for only 39 95 List 299 00 SALE 99 00 1541 DISK DRIVE 1 79 e 00 List 249 To run all that software and add to the prestige of your system you l want the 1541 cisk drive Runs all of the 3 000 plus pieces of software for the Commodore 64 List 249 00 SALE 179 00 CALL BEFORE
115. e as a terminal DTE mode wire the con nector as shown in Fig 7A Alterna tively if your computer s serial port operates as a host system DCE mode wire the connector as in Fig 7B Check your manual to determine the configuration of your comput er s serial port If your computer fails to commu 26 MODERN ELECTRONICS November 1986 Table 2 Communication Protocol see Table 1 none baud rate parity data bits stop bits handshake DB 25 DB 25 DCE MODE DTE MODE Data out Data in Ground Fig 7 Connector wiring details for DTE and DCE modes nicate with the AAU try reversing the wires to pins 2 and 3 of the serial connector Many computers also re quire that pins 6 and 20 of the serial port be connected together with a jumper wire You must also set your computer s RS 232 serial I O communication protocol as shown in Table 2 Be sure that the baud rate matches that selected by installing the appropriate Jl and or J2 jumpers on the AAU s circuit board On power up the program in C2 s EPROM initiates a self test At com pletion of this test the four red LEDs LEDI through LED4 will flash and TEST OK will be trans mitted out of the serial data output connection Verification of data transmission can be obtained with an oscilloscope connected to the data output point while observing the screen for a series of pulses after self test has run Connect the AAU to your com
116. e i 8 25 50 7 43 Pact dq Description 10 109 CO eer BIA 155C 3 we rv s f n x MUN A 8 75 50 165 08 B pin solder tad br 3 115 50 um M I B pt 500 n 410N 48 FN 75 C8914 14 pur tail ty 1 45 12 imensior 3 B6 B 50 edo M 31 AIIN 74L5221N 145 a 63 251 k NS Me 82 ot 5 5 74 241N 145 2114 3 3 B if gt 1 90 17 R a ms EA 4 i n MLS2GN 4 Ur i03 MM2114N L 350 Cg922 2 yr tall on 25 225 2100 5 Carbon Film Resator Values in Ohma 1012 47M 44 220 of 500 saei 4 LS 1 UF r 14 4 rir E eem ot lt P 14 f j ps m 74L8244N 50 74C947N 0125 1 38 3 03 MM2137N 17 50 CB924 24 pin solder tall nn 28 2 50 24 008 How To Order Take sny siandard resistor value e P4106 270 pt 500 63 4 fi x 34235 xal LSA to aoc9eN 100 83 bs MM27 60 Ce928 solde ad lin R 29 27 00l 3 2 end add n E tor 1 8 wart ors CO for 1 4 wan P4106 330 pf 500 63 5 EA 62 3 7425N zai 751825 N 78 acco6N 1 00 2 Vs gg MM27160 5 98 C8940 40 pin poide gd nn a 4 20 39 00 or an H for 1 2 wan the 320 for 3 20 4 wan thee cayo 3890 of 500 ea ba bi 7 M Jg y D urnber L 5 A 10 00 74265 53 455459 784 anCs7N 95 158 5 rgia 13i GOLD INLAY SOLDER TAIL see 2 here eee fh OO SOY Pt pu P4108 20 pt 500 a0 2 7427N 53 74LS267N 75 BOCSBN 100 I x 6 28200 19 amio UC Pricing 200 000 P4109 560 600 90 0 3 n 225 7430N an 4L S258N 78 22C 19N 453 EA i qoe M ee297N Baa Peru Descepuon 10 1008 iawer 15 8
117. e output will then be low so long as any of the selected outputs is low This makes possible any multiple of the timer frequency up to 255T For exam ple wiring together outputs 3 6 and 7 would give an output of 100T 4T 32T 64T 100T Figure 5 shows how to usethe XR 2240 in its monostable single cycle mode TRIGGER L Reser JL BINARY COUNTER Fig 4 Internal details of Exar s XR 2240 programmable timer counter chip The time constant of the timer portion of the chip is determined by R7 and C1 Mo mentarily closing S begins the timing cy cle The binary counter then counts the pulses from the timer A particular tim ing interval is selected by connecting the timer s reset input to one or more of the outputs via R4 When the programmed count is reached the timer automatically resets The XR 2240 can be reset at any time during a timing cycle Once a timing cycle has begun any subsequent trigger pulses or closures of S are ignored To operate the timer in its astable repetitive cycle mode the reset input is disconnected Though the circuit in Fig 4 uses a switch to initiate a timing cycle an exter nal control signal can also be used The external trigger signal should have an amplitude of at least 1 5 volts and a dura tion of at least several microseconds Figure 6 shows one way to cascade two XR 2240 timers to achieve ultra long de 4 TO 1S V R1 LM PUSH TO START if
118. e relay Connect and sol der them to the contact posts on the relay Connect and solder appropri ate lengths of wire from the lugs on the newly installed POWER jack to the coil pins on the relay Cut a two conductor cable for the relay s 5 volt dc line to the length needed to go from the computer port you plan on using to the location where the amplifier will normally be Terminate one end of the cable with the connector required for the com puter port you are using and connect and solder a miniature phone plug at the other end Plug the 5 volt power cable into the amplifier and computer Similar ly plug an audio cable from the com puter s audio output to the amplifi er s input Turn on the amplifie by rotating the thumbwheel VOLUME control on its right side past the click and adjust volume for about half way up Connect a dc voltmeter set to read 5 or 10 volts across the relay s coil EARN YOUR Now turn on your computer you should hear at least some electrical B S E E noise from the amplifier s speaker D EGREE and the meter should read between 3 5 and 5 volts dc If you have a pro THROUGH HOME STUDY gram that generates sound use a Our New and Highly Effective Advanced Place demonstration program from the ment Program for experienced Electronic Tech nicians grants credit for previous Schooling and computer user s manual to generate Professional Experience and can greatly re duce the time required to complete Prog
119. earch all directories to help you find it You can t jump directly from one subdirectory to x sx Directory Desserts lt lt lt PERFECT Directory Filename Ext Size Date T ima Disk Statistics another without going from list to tree 1 gt i EE s 2u z ram a and back but Le Menu makes up for that PARERT DIRECTORY Logged Disk ith juable b i CONVERT EXE 39536 H4 24 85 15 87 Global Files with a valuable bonus it can encrypt CURSOR COM 1451 84 24 86 15 87 Total Disk Space 18 584 064 and decrypt files with a password of your LETTER FiL 153 BHB8 83 Bb 28 58 Space Used 7 583 872 choice LEX WP 2986589 89 19 85 15 55 Space Available 3 8BB 192 i i T PRINTER EXE 39872 HB4 24 Bb 15 87 Directory Space 1 243 638 Another main menu choice DOS PHINTOUT 1897 H 23 8Bb 19 4z Marked Files Space 61 821 Appetizers brings a dedicated menu of SPELL EXE 44720 89 19 85 15 54 Number of Files 18 I TH WP 216663 89 19 85 11 45 Harked Files DOS functions from making directories ur COH 1960 87 15 86 23 39 to running BACKUP DISKCOPY or HP EXE 192008 87 28 86 16 84 Press Pglip or PgDn for EDLIN or executing a program or a E Ji 25 8b 11 21 Top or Bottom of Windos sta sae deeem ui 11 22 dust d fcire short batch file typed on the spot It s HPFONT _FIL 7158 87715766 23 49 Tii to Execute here that Le Menu strikes me and the UPHELP FIL 49897 4 24 B6 15 07 P
120. eatures are dot addressable graphics adjustable tractor and friction feed margin settings pica elite condensed italics super amp subscript underline bold and double strike List 349 00 SALE 12 88 COLUMN MONITOR Super High Resolution green screen monitor 80 columns x 24 lines easy to read plus speaker for audio sound included Fantastic value List 129 00 SALE 79 95 x The Comstar Aero 160 gives you a 10 carriage 150 170 CPS 9x9 dot matrix with double strike capability for 18x18 dot matrix near letter quality high resolution bit image 120x144 dot matrix underline back spacing left and right margin setting true lower descenders with super and subscripts prints standard block graphics and special characters It gives you print quality and features found on printers costing twice as much Centronics Parrallel Interface List 499 00 SALE 199 00 13 COLOR MONITOR 139 95 This premium quality monitor comes with speaker and audio hook up High lines front panel controls and much more Can also be used with VCR One year warranty List 329 00 SALE 139 95 ATTENTION COMPUTER CLUBS DEALERS Wo offer big volume discounts CALL TODAY Say You Saw It In Modern Electronics TV TUNER 49 95 This tuner has dual UHF VHF selector switches mute automatic fine tuning and computer TV selector switches Hook it up between your computer and monitor Inputs included for 300
121. ece set has 54 popular values from 10 ohms to 10 megohms 271 312 Set 7 95 15 Inductors 30 piece assortment may include RF IF and video peaking coils ae small chokes and trans formers toroids 273 16 1 98 Unique Sounders 25 26 24 Tri Sound Siren Wiring options permit three dif ferent outputs Requires 3 VDC 4273 072 5 95 5 Electronic Chime Pleasant ding dong aape erates from 6 to 18 VDC 273 071 95 26 UMC 3482 Melody Synthesizer IC ASA grammed with t2 popular tunes including Happy Birth day Oh My Darling Home Sweet Home SIUE on1 5 VDC 16 pin DIP with data 276 1797 2 99 76 Function Soiar Scientific Calculator Never Needs 2995 Batteries Radio Shack EC 4018 is powered by room light Features nine physical constants 10 digit man tissa and 2 digit exponent memory random number generator Uses true alge braic logic Fold up case 565 982 One of our most popular models check the features Selectable 12 24 hour display huge 1 8 digits snooze control 24 hour alarm hi lo brightness super Styling Battery backup preserves accuracy if AC power fails E Touch Tone Decoder DTMF Receiver in One 18 Pin DIP SSI 202 ideal for any remote control circuitry use a standard touch tone phone as the controller Features built in switched capacitor filters no input filtering is re quired Provides selectable hexadecimal or binar
122. ectronics Radie fhaek Parts Plaee EXCLUSIVE VALUES AT THE SHACK NEAR YOU Builder s Helpers e 21 4 Clips Open to 7 16 Screwdriver terminals 5 red black 270 347 Pea Tu iret Set of 10 1 59 2 Antenna Insulators Strong ideal for antenna and guy wire installation 4270 1518 Pkg of 2 69 3 Plug In Board With Ground Plane Masked on both Sides to prevent solder bridges Has 2066 indexed solder ringed holes 41 2x 511 4e component area Fits 44 position socket 276 188 2 2 4 99 4 44 Position Socket 4276 1551 20 2 99 5 PCB Standoffs 25 32 high all metal hex studs hold PC boards in place 4276395 Set of 4 99c wir Testing Needs by 12 10 Solid Bus Wire 50 feet of pretinned 24 gauge x wire on a plastic Spool 4278 1341 11 Magnet Wire 3 spool set includes 40 ft of 22 rU i0 I y 75 ft of 26 ga 200 ft of 30 ga 4278 1345 4 4 12 Set of 10 Test Cables 14 long with insulated clip J each end 278 1156 3 79 Hobby Lamp Values 20 lt o X7 22 gs 20 12 Volt Flashing Lamps One each yellow red green 4 wire leads 272 1097 Pkg of 3 99c 21 Colored Mini Lamps Ideal for doll houses mode trains and cars One each yo red green 6 Volt 272 4098_ een Pkg of 3 69 12 Volt 272 1099 _ Pkg of 3 69
123. ed for more information on the other under ground radio the one that involves pi racy broadcasts satellite unscrambling and such This is one area I just haven t gotten into very much but I hear there is a magazine called A C E that is pub lished by the Association of Clandestine Radio Enthusiasts There s also our sister publication Popular Communications that gives lots more details on this sort of thing Finally there apparently is a satellite descramb ling hotline available at 305 771 0575 And now for this month s feature at tractions What s the word on the new Apple H GS In a word fantastic Publishing deadlines being what they are I have only had a limited amount of hands on time on this machine so far What you have here is a drop it in board swap for an Apple Ile that instantly up grades the computer to full 16 bit 65C816 based computing power while maintaining nearly full compatability with most existing Apple software You still have lots of slots like in a IIe Like in a IIc all of the stuff that used to need slots is now on board including two ser ial interfaces a real time clock video firmware the mouse interface Apple talk and support for as many as 128 disk drives each of which can potentially handle media up to 4 gigabytes in size You ll find three operating modes There s the slow emulation mode that Fig 1 JKL s new BF727 ultraviolet la
124. elay miniature phone jack plug and length of cable to computer s 5 volt dc power supply Relay s contacts wire in series with amplifier s positive battery supply line PARTS LISTt J Miniature phone jack K1 S5 volt spst relay Radio Shack Cat No 275 232 or 275 004 see text P1 Miniature phone plug Misc Radio Shack or similar battery powered mini audio amplifier two conductor cable hookup wire sol der etc Ew pert Fig 2i Mounting details for relay and jack puter s ports With no power coming to KI s coil the relay deenergizes This causes the contacts to open and break the positive battery line auto matically disabling the mini amplifi er s circuit board To avoid overloading and possibly damaging the computer s power sup ply a low power relay must be used The relay specified in the Parts List n eR su os reed type relay in place 66 MODERN ELECTRONICS November 1986 General purpose cement anchors requires less than 20 mA of energiz ing current from the computer s 5 volt supply Mechanical Details Opening the mini amplifier s enclo sure you ll observe the 9 volt bat tery compartment at the bottom There is sufficient room inside the enclosure to accommodate the relay and miniature phone jack for the 5 volt line from the computer on the right wall as shown in Fig 2 The first step is to test fit the relay inside the enclosure at the upp
125. electronics Save up to 50 call toll free 1 800 346 2433 for ordering only Order by VISA MC AMX No COD s Missouri Alaska Hawaii call 1 816 842 5092 or write McGee Radio 1901 McGee St K C MO 64108 Postage for catalog 1 00 7 MILLION TUBES Includes all current ob solete antique hard to find receiving transmitting indus OWEST trial radio TV types PRICES Major brands in stock Unity Electronics Dept M P O Box 213 Elizabeth N J 07206 PORTASOL MAIL OFFER Soldering Iron Order your Portasol now Safe butane powered no open flame e Adjustable from 10 60W power e Compact only 7 long e Fach unit comes with 2 4mm tip e Extra tips available at 7 50 each Choose 1 2 2 4 3 2 or 4 8mm Send check or money order for 29 95 plus 2 00 shipping and handling VA res add 4 lato Portasol Mail Offer Fairfax VA 22032 Phone Orders Call 703 323 8000 Quantity Discounts Available Weomomomene Portable Butane vm 4358 Harvester Farm Lane e SPECTRUM Analyzer Receiver Kits 60 Send SASE for details Science Workshop Box 393ME Bethpage N Y 11714 LASERS and Nightvision surplus components FREE catalog M J NEAL COMPANY 6672 Mallard Ct Orient OH 43146 RECONDITIONED Test Equipment 1 25 for catalog Walter s 2697 Nickel San Pablo CA 94806 415 724 0587 HARDWARE Software Surplus Parts So
126. ent side Hold the wire steady until the solder solidifies Then clip the wire close to the solder I o Q Qa Q P O59 O Q D Q Q o o9 o o 99 O O WA 118 c n am Cc 2a mu 3 d PF CE T WH pe e uk xp EN AL JiM teH L on both sides of the board Repeat this procedure for the remaining jumpers Make sure that all soldered connections are smooth and shiny After you have installed all jump ers mount the relay so that about 4 of each pin is visible between it and the top of the board Solder the relay pins to the pads on both sides of the board Solder the relay pins to the pads on both sides of the board Note from here on except for the card edge connector solder refers to connections on both sides of the board Wire the board exactly as shown in Fig 5 paying careful atten tion to the orientations and polariza tion of the electrolytic capacitors transistors and diodes Q gt 9 o 1 s 6 O M 99 t R4 D6 E s Numbered contacts are on component side lettered contacts are on solder side Fig 5 Wiring guide for the pc board Say You Saw It In Modern Electronics Mount the transistors so that 4 of each lead is visible between them and the top of the board and solder them into place Then mount a long pin ZIF socket in the SO location spac ing it about 4 above the surface of the board so that you have access for solder
127. eps sine wave generator and a high Q bandpass notch filter for 200 to 5000 Hertz eight times a second Outputs magnitude sweep and sync voltages to oscilloscope computer or other device Add case and use as test instrument or as sensing or imput device for robot or alarm system 50 PPD Also FAST A D CONVER TERS and SOUND ENHANCERS FOR MU SICIANS Send business size SASE for de tails DIPAC Associates 645 Executive Cen ter Drive 204 West Palm Beach FL 33401 TOP QUALITY imported domestic kits sur plus discount electronics computer compo nents Free catalog TEKTRASONIX 80 50 Baxter Ave Suite 120 Elmhurst NY 11373 EXPERIMENT with Fiber Optics Send your voice over a beam of light via an optical fiber Complete kit 39 95 includes microphone speaker fiber pcb s and all parts Easily as sembled Complete plans package only 5 95 Send to FIBER SCIENCES P O Box 5355 Chatsworth CA 91313 5355 CA Residents add 6 5 SPEECH Synthesizer PC board With in structions Implements Radio Shack speech chips 13 Jeffrey Brown 19 Hatherly Brighton MA 02135 SEE IN COMPLETE DARKNESS with amazing new infra red night viewers Kit 189 Factory assembled 295 Super long range model 750 Dealers Wanted Catalog 1 Crosley G Box 840 Champlain NY 12919 514 739 9328 LOWEST POSSIBLE PRICES ANYWHERE FULL WARRANTY Most Audio Brands C D s Car Products Computers Hardware Software Most Video
128. er right and place the miniature phone jack far enough below it to ensure that there will be no interference be tween the two and the speaker Mark the location of the jack on the enclo sure and then remove the relay and jack Carefully drill an appropriately sized hole at the marked location Make sure you do not damage the speaker or the amplifier circuit After mounting the jack in the hole examine the relay If you are using the reed type shown note that it has four wire pins that all point in the same direction identifying the front of the relay With the pins fac ing upward and the end with the three pins facing toward you liberal ly coat the right side of the plastic end pieces with general purpose ce ment and press into place on the wall of the enclosure as shown When the cement has fully set in terrupt the red wire between the bat tery connector and amplifier circuit board You can cut through the ex isting wire and add a short length of hookup wire to each cut end insulat ing the connections when you are fin ished Alternatively you can dis mount the circuit board by removing the threaded rings from the attached jacks a single board screw and de solder the wire from its pad The lat ter is preferable because you will then need to add only one wire in the hole from which the wire was just desoldered Say You Saw It In Modern Electronics Makethe power wireslong enough to reach th
129. er Solder Sucker Desoldering Tool Modified bicycle tire pump performs like profes sional vacuum desoldering workstation at a fraction of the cost By Brian O Toole Sound For Video Monitors Modified external audio amplifier restores sound when using a video monitor with a home computer By Ralph Tenny PRODUCT EVALUATIONS John Fluke s New Development A 12 Current Measuring Accessory By Art Salsberg The Multibotics Workshop A Computer Interactive Construction Set By Art Salsberg COLUMNS Electronics Notebook Custom Timer Circuits By Forrest M Mims III Hardware Hacker Author answers readers questions By Don Lancaster PC Papers Student WordPerfect Multifunction Modem Le Menu By Eric Grevstad DEPARTMENTS Editorial By Art Salsberg Letters Modern Electronics News New Products Books amp Literature Advertisers Index 2 MODERN ELECTRONICS November 1986 EDITORIAL STAFF Art Salsberg Editor in Chief Alexander W Burawa Managing Editor Dorothy Kehrwieder Production Manager Elizabeth Ryan Art Director Barbara Scully Artist Pat Le Blanc Florence Martin Phototypographers Hal Keith Illustrator Bruce Morgan Photographer Joseph Desposito Leonard Feldman Eric Grevstad Glenn Hauser Don Lancaster Forrest Mims HI Stan Prentiss Contributing Editors BUSINESS STAFF Richard A Ross Publisher Art Salsberg Associate Publisher Dorothy Kehrwieder 1 General Manager Fra
130. es of this arrangement are its relative simplicity and the ability while re cording to view the same channel or any other nonpremium channel Dis advantages are twofold the channel to be recorded must be set with the cable box s channel selector which eliminates the possibility of preset ting the VCR to record different channels during your absence and you cannot view a premium channel while another is being recorded While the hookup arrangement Say You Saw It In Modern Electronics detailed in Fig 5 may look compli cated it is really relatively simple Even so it provides adequate flexi bility and is not too prone to errors With A B switch No 1 set to NOR MAL the VCR is independent of the cable box s setting allowing you to view any channel selectable with the cable box s decoder Only when you record a premium scrambled chan nel with A B switch No 1 set to PREMIUM are you restricted to view ing the same channel as you are re cording A B switch No 2 allows you to select between viewing a cable program or the prerecorded output from the VCR Substantial flexibility is the major advantage of the Fig 5 hookup ar rangement The major disadvantage of this scheme of course is that when recording a premium channel only that channel can be viewed If your video system has sources of video signals other than an outside antenna and or cable such as a videodisc player electronic game console or a home
131. ew TANDY 1000 SX New TANDY 3000 HL 599 1299 And call us now for latest pricing on all acces sories and limited quantity close out items TANDY 1000 TANDY 1200 2 Disk System 10 Megabyte 869 TANDY 3000 1 2 Meg Floppy Drive 512K 1969 20 Meg Hard Disk 512K 2689 We carry the full line of Tandy computers and sell Tandy Okidata Star Micronics and NEC printers SHIPPING FREE UPS Only All Prices cash and subject to change TRS 80 is a trademark of Tandy Corporation Not Responsibie for Typographicai Errors Jo 0 gt q010 1 7 224 East Main Street Marlboro MA 01752 617 485 5115 Hours M F 10 9PM Sat10 5PM CIRCLE 12 ON FREE INFORMATION CARD November 1986 MODERN ELECTRONICS 79 CIRCLE 13 ON FREE INFORMATION CARD Say You Saw It In Modern Electronics W HARDWARE HACKER sss The Apple II GS solar pumps low cost EPROM erasing D A conversion more By Don Lancaster Be sure to get yourself a copy of the August 8 1986 issue of Science maga zine You ll find a major paper here on neuron computing by J J Hopefield and D W Tank Thisis bound to become one of the key horses mouth source docu ments of this exciting new field that we looked at a few columns back Speaking of other publications it seems I got the phone number wrong twice for Speleonics Hopefully it is correct in this month s Names and Num bers box Quite a few of you have ask
132. feature is the 23 s Touch Hold button that locks in a displayed reading when the button is pressed enabling the tester to con centrate on where he s touching the probes The DMM goes through a Fluke s 3 2 digit Model 23 also fea tures an analog bargraph display two second self test when turned on emitting a chirping sound to show that everything s okay The beep sounds to indicate continuity too so you don t even have to look at the display Ensconced in a rugged yellow color case that measures 1 12 x 2 95 x 6 55 and weighing only 3 4 b the Model 23 also comes with a protective holster case in which it can be set in The holster provides a belt hook for convenient carrying pur poses Both DMM and the line current adapter performed admirably inde pendently and together Again we tip our hats to Fluke for introducing the 12 current adapter It s certainly an innovative accessory Art Salsberg CIRCLE 26 ON FREE INFORMATION CARD E REEL une ee ano s enm sn mrz a s Say You Saw It In Modern Electronics November 1986 MODERN ELECTRONICS 17 eee PRODUCT EVALUATIONS The Multibotics Workshop A Computer Interactive Construction Set The Multibotics Workshop line of kits is designed to teach principles of computer controlled electro mech anical operation through experi ments with hardware and software Distributed by Access Software Inc 2561 So
133. for DMMs and a high ac curacy semiconductor probe for use with DMM s For a free copy of The ABCs of Thermometers write to John Fluke Mfg Co Inc P O Box C9090 Dept ME Everett WA 98206 To preserve your copies of LU THE MAGAZINE FOR ELECTRONICS amp COMPUTER ENTHUSIASTS A choice of handsome and durable library cases or binders for your copies of MODERN ELECTRONICS Both sytles bound in green library fabric stamped in gold leaf Cases Each case holds 12 issues Price per case 7 95 three for 21 95 six for 39 95 Binders Each binder holds 12 issues Issues open flat Price per binder 9 95 three for 27 95 six for 52 95 Canadian and foreign requests should also include an additional 2 50 per item for shipping costs Say You Saw It In Modern Electronics l un zy B s lt qu i 23 a ra S 3 t9 4 3 9Qz lt amp D dar X gt 5 2 8 zu i ZS 5 E amp ES E m g 6 n BS 3 gm 82 gx d 6 is EVE x o 20 5 g a 9 5 E S 33 iiri November 1986 MODERN ELECTRONICS 71 By Forrest M Mims III Not long ago my son and I accompanied my father on a fishing trip The bait well of my father s boat was well stocked with small fish he had caught with a cast net and out on the lake it was necessary to pe riodically
134. for an article published in Radio Elec tronics Magazine Feb 1984 on building your own CABLE TV DESCRAMBLER 701 PARTS PACKAGE 29 95 includes all the original resistors capacitors diodes transistors integrated circuits coils and IF transformers 702 PC BOARD 12 95 Original etched amp drilled silk screened PG Board used in the article 704 AC ADAPTOR 14 volts DC 285MA Both 701 amp 702 39 00 701 702 amp 704 49 00 12 95 FREE Reprint of Radio Electronics Article on Building Your Own Cable TV Descrambier with any purchase Add 2 50 Shipping amp Handling 4 50 for Canadian Orders ORDER TOLL FREE 1 800 227 8529 Visa MasterCard or C O D JeW ELECTROMICS ICC P O Box 800Z Mansfield MA 02048 CIRCLE 46 ON FREE INFORMATION CARD Macintosh Monitor amp Keyboard Macintosh Pius Keyboard with Mac Bottom Image Writer Image Writer ll External Drive 5 95 IBM PC or XT or AT IBM Pro Printer Epson C Itoh Okidata Over 3000 covers to choose from You name it We got it Anti Static different colors ORDER LINE 1 800 874 6391 WB FLORIDA ORDER LINE l 1 800 342 9008 Dealer Inquiries Invited Customer Service 904 243 5793 Telex 469783 j LF 4 CompuCover P 0 Box 310 Dept D Mary Esther FL 32569 CIRCLE 50 ON FREE INFORMATION CARD Solder Sucker from page 63 Fig 8 Add on elements for the desoldering tool incl
135. from INPUT Fig 4 This more elaborate arrangement has a signal splitter and an A B switch that permit recording on one channel f kes recorder NS NOTE All cables are 7582 D DIRECT A B switch OUTPUT CHANNEL 3 or 4 To TV antenna terminals while viewing another Recording channel selection is made with the cable box s channel selector ed in Fig 2 With this arrangement you select the channel to be recorded with the VCR s channel selector You can then view the same channel as that being recorded or by setting the VCR s TV VCR switch to TV and your TV receiver s channel selector as needed any other TV channel can be viewed In the playback mode your TV receiver must be tuned to the selected r f modulator s output channel Throughout this article TV re ceiver and VCR channel selection can be accomplished with the indi vidual unit s remote controller if it has this capability When using the VCR s remote controller the TV VCR switch can beinthe VCR position and the TV receiver can be tuned to Input from cable Fig 5 This full feature VCR TV cable hookup arrangement gives substantial flexibility Its only real disadvantage the output channel to which the VCR s modulator is set so that you can view the same channel as that be ing recorded by the VCR All connections in all hookup ar rangements illustrated in this article must be made with 75 ohm coaxial cables with F ty
136. ge Tunes from 70mhz 130mhz Easy to assemble kit includes all parts and instructions On ly 29 98 tax incl Call or send MO VISA MC for Immediate delivery Single kit orders include 1 50 S amp H FREE SHIPPING on orders of 2 or more All orders shipped by U S Mail COD add 4 00 Personal checks allow 21 days DECO INDUSTRIES BOX 607 BEDFORD HILLS NY 10507 914 232 3878 CIRCLE 18 ON FREE INFORMATION CARD SUBSCRIBE TODAY I MODERN IELECTRONICS FREE CATALOG OF APPLE IBM amp COMMODORE ACCESSORIES CALL 404 922 0742 OR WRITE ADVANCED MICROCOMPUTER 2054 SIGMAN ROAD CONYERS GA 30207 PAY TV and Satellite Descrambling ALL New 6th Edition 100 pages Schematics and instructions for all major cable and satellite sys tems including Orion Videocipher Fantasy Ex tasy New sections on bypasses how illegal decod ers are detected MDS Handbook 9 95 Product catalog 2 SH JIKI ELECTRONICS CORP 1327 P Niagara Straal Niagara Falls NY 14303 EDO 3 716 284 2163 INVENTORS INVENTORS Can you profit from your idea Call AMERICAN INVENTORS COR PORATION for free information Over a de cade of service 1 800 338 5656 In Massachu setts or Canada call 413 568 3753 MUSIC EASY TO PLAY Easy to learn Electronic Or gan Uses standard typewriter keyboard Kits table top floor models Send 1 00 for bro chure SYNTHESON 1850 Rominger Rd Winston Salem NC 27107 CABLE TY CABLE TV
137. ge speed and position and uses this data to print characters with precisely controlled spacing The reflective module has two other common uses besides detecting paper in a printer If a narrow re flective stripe is attached to a rotat ing shaft and the sensor is placed the proper distance from the stripe a pulse will be generated for each revo lution of the shaft Counting these pulses reveals how many revolutions are made over a given period of time Adding a time measurement can then give speed in rpm In some punched card readers a bank of eight reflective sensors are used to detect data holes punched in the cards Reflective sensors can also be used in home security systems Window and door sensors are usual ly magnet relay devices that can be defeated relatively easily Replacing these with reflective sensors that re quire critical alignment of reflective tabs greatly adds to the effectiveness of the system An intruder must work within a 4 margin to defeat the sensor assuming he is aware such a sensor is being used in the system From the foregoing it should be obvious that the optical isolator in its many guises is an important and exciting component to use in elec tronic circuits It is also one of the best buys in electronic devices on the market With a firm understanding of optical isolators you can design circuits and systems that would otherwise be impossible without them Have you ever wished that
138. hard ware a printed circuit board is re commended Also recommended is the use of sockets for all ICs A zero insertion force socket is almost a must for SO1 since repeated inser tions and removals of EPROMs from an ordinary socket can rapidly fatigue the socket pins and more im portantly damage the EPROMS You can fabricate the pc board us ing the actual size etching and drill ing guide given in Fig 4 or purchase a ready to wire board from the source given in the Note at the end of the Parts List Before you begin wir ing any components to this double ec600000 co 000000000 odoY o 00000 Fig 4 Actual size etching and drilling guide for the double sided pc board 56 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics Fs s u w asna a T RP ME sided board install and solder into place the tiny wires that bridge the conductors on both sides of the board These are all shown circled in Fig 5 There are 60 such jumpers makinzg this the most tedious part of assembly Use bare 22 gauge solid hookup wire for the Jumpers Feed one end of a 12 or longer wire into a hole from the component side of the board and solder it to its copper pad on the noncomponent solder side leaving about a 4 stub pro truding from the solder Flip over the board and solder the wire to the pad on the compon
139. hasten news 3 dispatch H quicken publication issue I speed 4 broadcast 3 J achieve relay K conclude transmit L finish dispatch n 4M alacrity N celerity 1 Replace Word 2 View Doc 3 Look Up Word 4 Clear Column B You can see it happening with staple items like modems and multifunction boards You can find good software at a fraction of list price although for a limited audience You can spot a transi tion from introductory paragraphs to product reviews Student Financial Aid If you re not a college student or parent or pal of one you can skip this section the product must be purchased from a college bookstore or ordered with a pho tocopy of student ID or a professor s or registrar s letter If you qualify how ever Chambers International Corp has a great weapon against the onslaught of campus Macintoshes Student WordPer fect a version of Satellite Software s 495 word processor for just 75 Chambers promises 85 percent of WordPerfect 4 1 s power for 15 percent of its price I d peg it at 75 percent power Student WordPerfect has no mail merge macros math and sort functions or mul tiple column or split screen editing and can t generate an index or table of con tents For nuisance value it s also copy protected installable and uninstallable onto two floppies or preferably a hard Student WordPerfect includes a good fine first rate thesaurus disk
140. he while performing hands on experiments and demonstrations that LI AONI wana T E evs w ss pa 35 oe 7 f e i f f IAINING ORGA NIZER gt lg g v 4 4 Ji p 7 Ei career servicing computers fine tune your computer skills And you also get over 1 000 answer questions give you guidance and be available for worth of software including WordStar and CalcStar special help if you need it Learn to service today s computers Let others worry about computers taking their jobs As you train with your Sanyo you ll gain the With NRI training you ll soon have computers making knowledge you need to become a computer prcfes good paying jobs for you sional You ll learn to program in BASIC and machine Send for free NRI catalog language You ll use utility programs to check out the Send the post paid reply card today for operation of the Sanyo s 8088 microprocessor the NRI s 100 page catalog that gives all same chip used in the IBM PC You ll learn how to the facts about computer training plus debug programs and write your own new software career training in Robotics Data Com Most importantly you ll understand the prin munications TV Video Servicing and many ciples common to all computers Only a person 4 other fields If some other ambitious person who fully understands all the fundamentals can 4 beat you to the card write to NRI at the address below hope to be able
141. hgsck 3 Shojiki Electronics Corp 94 17 Synergetics 79 28 Taiwan Computer 65 4 Trio Kenwood Cov Il 20 Underwater Vehicles Training 592 Unity Electronics 94 D Free Product Information a x products advertised by the above com appropriate number printed below an advertisement onto the Modern Elec tronics Free Information Service card bound into this issue After filling in your name and address just mail the postpaid card Your request will be for warded directly to the advertiser with a mailing label prepared by our reader service department to ensure speedy re sponse Say You Saw It In Modern Electronics Y m s 7 Aina Sap Pr HO IC AULAS OUI C M HOURS ra QS SARS HAS Reliable Semiconductors Re3 acement aii solidstate replacements In the world of semiconductor replacements no one outper forms RCA s engineering excel lence We re in the business of manufacturing semiconductors SO ycu can depend on our reliability Our new expanded RCA SK Guide to Reliable Replacement Semiconductors lists more than 2 900 SK and KH types that replace over 214 000 industry types And forthe first time QMOS logic devices and an extensive line of RF types are included The new RCA SK Replace ment Guide SKG202E It s the only solid state replacement s
142. his capacitor especial ly if theleads to the battery are morethan a foot or so long Also be sure to include S1 so that the aerator can be controlled manually should the timer circuit mal function XR 2240 Programmable Timer The timer counter concept in Fig 1 has been integrated onto a single chip by Ex ar Integrated Systems Inc 750 Palomar Ave Sunnyvale CA 94088 One such chip is the XR 2240 Programmable Tim er Counter This chip provides much more programmability than the 555 4017 pair used in the previous circuit Depend ing on the values of the external timing capacitor and resistor this chip can pro vide delays of from microseconds to sev eral days Exar claims two XR 2240s can be cascaded to provide a time delay of up to three years Figure 4 is a simplified block diagram of the XR 2240 The timer portion of the chip is functionally equivalent to a stan dard 555 timer The output from the tim er is fed directly into the input of an 8 bit binary counter The eight counter out puts provide these escalating power of 2 multiples of the timer frequency T 2T 4T 8T 16T 32T 64T and 128T The output is normally high After SZ is closed the output goes low and remains low during the programmed time delay It then returns to the high state Since the counter outputs are open col lectors they can be connected to a com mon pull up resistor in any desired com bination in a wired OR output configu ration Th
143. ht entry of a four digit code anc service technician or a hobbyist you ll love j f the Key ess Doorlock unlocks your door the wide range of measurement capability You ll find fun and excitement with IF add ans in our laboratory grade Dual Trace 10 MHz or ee ee dimension to your ME Oscilloscope zives cu bled living room with 9 Add rax maliry gt vour ovn Comput to the utility room enjoy your home more than you ever dreamed possible r4 sembled our products will help you erized Weather and save mcpne toe 9 lt Station This Digital Wezther Station Avcid expens oec y displays up to the minute temperature spoilage with ou F eezer wir d ar d barometric pressure readings along w th time and date 3 Give your kitchen a unique blend of style and eff ciency with our Digital Wall Clock This 1 easy to uild kit keeps time wit 1 quartz crystal accuracy And wit its simulated oak wood grain finish cabinet you ll have a timepiece that fits nto alrrost eny decor 4 Put your den to greater use with this Ala m that Computer Do word processing personal accour ting and moze when you run exciting IBM compat ble sofware cn your fasi and powerful HS 241 And yo can buil it yourself in just a few hours 5 ring the latest ang in cigital tech nology to vour atarocm This Dig i
144. ians will actually double during the next 10 years There is still plenty of room for you to get in on the action f you get the proper traming now Total computer systems training only from NRI If you really want to leam how to work on com puters you have to get inside one And only NRI takes you inside a computer as powerful and advanced as the Sanyo MBC 550 series As part of your training you ll build this Sanyo which experts have hailed as the most intriguing of all the new IBM compatibles Computer critics say The Sanyo even surpasses the IBM PC in computing speed and graphics quality This hands on experience is backed up with training in programming circuit design and peripherals 4 Only NRI gives you such in depth total systems training Move up to a high paying E The kind of understanding built only through experience Even if you ve never had any previous training in elec tronics you can succeed with NRI training You ll start with the basics rapidly building on the fundamentals of elec tronics until you master such advanced concepts as digital logic microprocessor design and computer memory You ll build and test advanced electronic circuits using the exclusive NRI Discovery Lab and professional Digital Multimeter yy both of which are yours to keep You ll assemble Sanyo s intelligent keyboard install the power supply and disk drive and interface the high resolution monitor all t
145. ice activated to push button control on remote unit e Programmable digital alarm clock lets you schedule daily tasks at a set time e Rechargeable battery included runs up to 3 hours at a time Recharger incl e Factory new first quality product 90 Day Limited Factory Warranty Mfr List 399 95 1 49 Liquidation Price item H 1736 7000 862 Ship handling 8 00 Credit card customers can order byr phone 24 hours a day 7d k VISA ays a wee Y s Toll Free 1 800 328 0609 Sales outside the 48 contiguous states are subject to special conditions Please call or write to inquire ub umb b en en SOR cubo s o emp emp s um en emp uum C O M B Direct Marketing Corp Item H 1736 1405 Xenium Lane N or helo MN 55441 4494 Send Hearoid Robot s Item H 1736 7000 862 at 149 each plus 8 each for ship handling Minnesota residents add 6 sales tax Sorry no C O D orders DO My check or money order is enclosed No delays in processing orders paid by check Charge O VISA O MasterCard O American Express Acct No x LX D PLEASE PRINT CLEARLY Name Address City State Phone Sign Here C O M EB pirect Marketing Corp Authorized Liquidator 1405 Xenium Lane North Minneapolis Minnesola 55441 4494 November 1986 MODERN ELECTRONICS 91 Put Your Electronic Skills to Work in ROBOTICS N BECOME A ROBOT VEHICLE PILOT TECH Financial Ald Placemant Assist
146. ing it into place Do the same for the relay Unless a double sided pc board has plated through holes you can not use standard IC sockets for IC1 through IC4 You can of course in stall the ICs directly on the board and solder their pins to the pads However if you wish to socket your ICs you can do so with the aid of Molex Soldercons which do give sol dering access on both sides of the board If you are socketing the ICs install only the sockets not the ICs themselves at this time Once the above components have been soldered into place you can in stall the diodes resistors capacitor and coil It is not necessary to solder any lead to a copper pad on the top of the board that has no trace leading from it When this has been done carefully inspect the board for poor soldered connections and solder bridges the latter especially between the closely spaced pads around the IC or socket pins Finish construction by soldering the edge connector to the board To do this line up the connector s sol der lugs with the copper lands at the edge of the board and tack solder one lug at either end to the land on the component side of the board Make sure the back of the connector is flush against the edge of the board and solder the remaining lugs to the lands on the component side Then flip over the board and carefully bend the connector lugs so that they touch the copper lands on the bot tom side of the boa
147. is are floppy disk write protect tabs A couple of precautions should be taken when using the EPROM Pro grammer One is never insert and EPROM in the ZIF socket until the software is loaded into your compu ter and you have typed SYS49152 If you do when the hardware powers up it will be in an uncertain state the programming voltage from the Programmer might be applied to pin l at SO damaging the EPROM The second precaution to observe is never remove an EPROM from the programming socket once program ming has begun and has not run its course Wait until the programming cycle has run to completion before removing the EPROM The 2764 EPROM Programmer described here provides a low cost alternative to dedicated stand alone programmers If you are like many C 64 owners and users who have pro gressed beyond simple running or prepackaged programs and games to writing your own you will find this Programmer well worth the time ef fort and cost to build and use ME November 1986 MODERN ELECTRONICS 59 Project Super Solder Sucker Desoldering Tool Built around an inexpensive bicycle tire pump this vacuum type desoldering tool emulates costly commercial desoldering workstations at a fraction of their cost By Brian O Toole ow many times have you attempted to desolder a component from a print ed circuit board only to damage the component or and the board If you re like most of u
148. ith a multiple tap surge protector that has a computer system 640K of RAM and a hard disk drive plugged into it along with other devices With two telephone answering machines on the meter displayed 0 03A Turning on the computer increased the reading to 0 7A initially which settled to 0 69A Switching on a dot matrix printer rasied this to 0 86A reaching 1 19A when operating while adding an electric typewriter boosted the reading to 1 03A Setting up for measuring current was therefore a snap All made possi ble with a 12 accessory The accessory can be used with any multimeter that has a LOA ac range and recessed inputs to accom modate shrouded banana plugs Not all multimeters are designed this way of course Some meter brands have safety recessed inputs that re quire shrouded female plugs In such a case the plug leads can be easily changed taking care that spliced connections are sound and properly insulated Fluke of course designed the plugs to mate with their instru ments Be sure too that the acces sory is not used on lower than 10A ranges especially since turn on cur rent is often many times greater than normal running current This accessory does not spell the Say You Saw It In Modern Electronics TO LOAD 2 GROUND E RECEPTACLE LINE 120V 77 FOR DEVICE TO120V TO BE MEASURED RECEPTACLE f Z A break in LCA 10 receptacle places an ammeter in series with 120V
149. man n pA TASAN 55 JAHCUN 68 1 25 LA papaqa m DIP SOCKETS 1 4 Watt Carbon Flim Assortments PAX OF 25 89 7 G 5 a ND 7458N 25 419374N 175 HCN 23 Zaf Ssnan 825 Pa lut 26 1 1537 1153 3 74 ON 35 74LS670N 7AHC20N 6a 38 4 71 4S475AN 825 R8125 5 each of the 73 standard values m series 99 90 x 336 7a tg 74LS96N 3 14 C27N 68 20 2 75 748570N am Standard profile 10 12 1 5 18 2 2 atc through 0M NPO NPO NPO NPG MPO NPO NFO NPO 90 HMHN sa 9 LS96N 2 13 74HC30N 68 a rwessnN o im E NET 365 total pcs PaO 0p 500 VOR I BB 7475N Ta 81LS97N If FHCIN 68 63 2f issn 98 Contacta eccommodate 48228 5 sch of the 72 standard values In sees 98 80 P4402 150 HO 6 97 52 31 S DS 7476N 5g 81 S98 3 pHCON 125 Tem 2 15 74S573N 7855 0157 through 021 rec 1 3 16 2 0 2 4 etc through 910K p a IB pt 500 Bi 6 52 31 X bees HEIN A 130 EA Or round dual inima leads 380 total pcs 44 22 pt 300 B 89 amp 2 t7 60 74H5N 96 TML 133 2 Wire wrap posta held to true position of 015 pro Pa406 Wot 500 Lg GE 66 7 68 6 70 34B6N 60 J4MC 5N 95 17 151 Micro viding a true position of 020 on boards for etfi Uz Nor Carbon ett Carbon Pm Arimen 0440 39 pt 500 8 89 86 7489N 375 MMETON 5 ert cient momen y wrapping RS1 amp 5 m at the por vag velues oe pur 0990 fpu jo 500 BO BB 53 E A ndan 7490N 609 74S90 B YOUR CHOICE N OR GOLD 0 1 2 5 5 2 erc Ihrough 1 0 P4ADO 56 pt 500 1
150. modulator In other modes record search etc the video audio strip directly feeds the incoming signal to the r f modu Video Audio i f and detector stages RECORD A STOP i PLAY Function switch rf modulator output on TV channel 3 or 4 lator The output signal from the r f modulator is preset by the user to TV channel 3 or 4 The specific channel assignment to which the modulator is set depends on the TV broadcast channels available in a given locality For example if in your locality a sig nal is being broadcast on channel 4 you would set the VCR s output switch to channel 3 to obviate inter ference with the channel 4 signal and vice versa If you closely examine Fig 1 you will note that the typical VCR has all the circuitry a typical TV receiver has with the exception of the final video stages and the picture tube Conse quently the VCR is completely inde pendent of the TV receiver in terms of its recording capabilities This means that you do not have to have your TV receiver on to be able to re cord a program One important operating control on all VCRs is the TV VCR switch TV Output to TV receiver VERO TV VCR switch 34 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics Z To TV antenna terminals From outdoor antenna See note 1 w See note 2 recorder NOTES 1 May require 300 75
151. mote controller 700 CIRCLE 31 ON FREE INFORMATION CARD on all ranges Stray capacitance on the lower ranges is nulled out with a front panel control A 4 terminal Kelvin connector and an accessory cable make it possible for the instrument to accommodate any size component Connectors on the rear panel allow an external 0 to 10 volts dc to be fed in for batch test ing and provide an output that can be used to drive a plotter for charting capacitance voltage curves All in puts and connectors are overvoltage protected ae Se IA mU Re ECCO e ae ee amr T a fa eee eee ee ITA GRECE VR 12 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics Measurement results appear in a 31 decade LED display that fea tures automatic decimal point loca tion The instrument measures 12 5 D x 10 W x 3 75 H and weighs 6 5 Ibs 269 95 CIRCLE 32 ON FREE INFORMATION CARD Notebook Computer With 4 Color Plotter Printer Sharp Electronics new PC 2500 por table notebook computer offers on the go users built in business soft ware and a register tape width 4 color plotter printer It features a QWERTY style keyboard with eight special function keys a 150 x 32 dot graphics or 24 character x 4 line text LCD screen cassette interface and serial I O port The built in color plotter printer provides hard copy text and graphics in black red blue and green The built in business
152. mp for inexpensive EPROM erasing tries to behave exactly like the earlier II or IIc There s a fast emulation mode that speeds up Applesoft programs by a factor of 2 5 times Finally there is the new native mode that gives full 16 bit computing power complete with desk tops toolboxes windows Quickdraw graphics tools and more There are major improvements in the existing graphics plus two new full color graphics modes that are every bit as good as anything available elsewhere An op tional sound card instantly converts the II GS into an absolutely stunning studio quality music speech or special sound effects synthesizer Up to 32 fully poly phonic oscillators can be combined in as many as eight stereo channels all with their own private 64K RAM memory While there is only 256K of main RAM on board a plug in socket lets you easily and cheaply expand to 4 mega bytes of directly addressable RAM You can also add another 4 megabytes per slot 2 2 ufd 350 volts 110 VAC ok 1 2 watt Fig 2 An ac line operated EPROM eraser built around the BF727 UV lamp 80 MODERN ELECTRONICS November 1986 1N4005 1N4005 of slot based RAM to bring memory total beyond 32 megabytes The expan sion socket just needs RAM chips since all of the refresh and address multiplex ing is handled by the main board in the computer ROM is also expandable There are lots of new features too The ne
153. n eraser and actually erase an EPROM while it is still in the original circuit This is something the larger erasers cannot handle at all Let us know the best design you come up with for a clip on eraser Any new breakthroughs in solar energy Jim Allen of the Solarjack company has come up with a genuine breakthrough in solar energy economics And he has done so with a product that has been thor oughly field tested Windmills have traditionally been used in remote areas of the arid south west for pumping water for livestock and game But windmills are costly to service and they perform poorly because of er ratic winds and dropping water tables On the other hand solar powered pumps have simply been too expensive to use in these locations Why Because each solar array had to drive a costly inverter and a bank of expensive and hard to maintain batteries Worse yet the efficiency of the inversion and storage processes gets SO low that you lose all the way around Jim got to thinking that solar energy would make a lot more sense if you could throw away the inverter and the batter ies getting rid of both their cost and their inefficiency Now in a water pumping operation you have one goal and one goal only You want to put as much water into the tank as you can and do so as ef ficiently as possible So Jim reasoned that he would design the pump to fit the sunshine rather than using inverters and batteries t
154. n arrangement consists of two transistors The emitter of the input transistor drives the base of the output transistor Two effects result from use of the Darlington arrangement The first is that much lower LED drive current is needed to turn on the Darlington output device with a given load The second is that the Darlington stage has a much slower response time than the single transistor output de vice Response time refers to the per iod beginning when a drive current pulse is fed to the LED in the opto isolator and ending when the output device switches on A good transistor will typically switch on in 3 to 5 mi croseconds while a Darlington ar rangement of similar quality will re quire about 50 microseconds In terms of cost you can obtain the single transistor optoisolator for just slightly less than 1 e Bilateral FETs Shownin Fig 1C is the schematic representation of the bilateral FET output optical isola tor in its 6 pin DIP package with pin out information The bilateral FET output stage is symmetrical so that it is not polarity sensitive This is one of the more recent developments in optical coupler technology Two types of applications dictated development of the bilateral FET op tical isolator One was the need for a remote variable resistor in automatic gain and similar applications The other was the need for an isolated switch to turn on off power Dar lington transistors and other devices that
155. n the rod Make sure to keep the valve cutout side down during this operation Work slowly and careful ly to avoid distorting the plastic and tap the piston until it is flush with the end of the rod Fig 5 If the piston slides onto the rod freely you need secure only the bottom side by drill ntly tap the piston onto the push ing a 1 2 hole crosswise through the rod and pushing a 7 roll pin avail able at automotive suppliers through it Alternately you can use a cotter pin or a piece of finishing nail Make sure that the hole is located high enough so that the screw will tighten the piston onto the pin with out any play Use a flat washer of sufficient size with the screw to clamp the piston onto the rod Clean all metal chips and debris from the piston assembly reinstall the rubber O ring and set the assembly aside The threads in the coupling of the cylinder of the pump shown being modified here were of a different size than the standard American pipe thread N P T However it is very close to 4 x 27 N P T 4 N P T is a nominal size the actual size is closer to 4 diameter Hold the cylinder by hand square ly on the workbench gripping it in a vise can distort it Run a 4 x 27 N P T tap into the coupling with out drilling it and cut enough thread to screw in the hose barb Fig 6 In lieu of a pipe tap a 4 cast iron or Fig 6 Cutting the threads into which the hose barb screws
156. nce to more than 100 different Sprague com mercial and military paper and film capa citor lines It contains tables and graphs that reflect changes and upgrades tables of performance characteristics and appli cations information and graphs that show operating characteristics for var ious dielectric materials Guide No ASP 420K is available from Sprague Electric Co P O Box 9102 Mansfield MA 02048 9012 TI Filter Brochure Microwave Filters has a new brochure that describes filters that suppress terrestrial interference in more than 400 satellite TV receivers Fo cusing on three filter lines the brochure contains a list of receivers and compati ble filters If a particular receiver is not listed a form can be completed and re turned for a filter recommendation In formation on how to identify inteference and select and install filters is also pro vided For a free copy write to Micro wave Filter Co Inc 6743 Kinne St E Syracuse NY 13057 Temperature Measurement Brochure A brochure that explains the theory behind thermometers focusing on how thermo couples can be used and how to reduce measurement error is available from Fluke A section on refrigerator work and the types of temperature measure ments that can pinpoint trouble spots is included Also included are a glossary of terms commonly used in thermometry a thermocouple guide and a listing of Fluke digital thermometers a thermo couple adapter
157. nector on the board itself To prepare the receiver end shorten lines 4 through 7 by 2 and solder the conductors in the appropriate holes in the board Use a 24 length of stranded insu lated hookup wire for the antenna November 1986 MODERN ELECTRONICS 47 E C 128 DOUBLE SIDED DISKS 44 ea 100 Certified 5 4 floppy disks Lifetime Warranty automatic lint cleaning liner included 1 Box of 10 4 90 List 1 99 ea SALE 44 ea VOICE SYNTHESIZER 39 95 is ss Just plug it in and you can program words and sentences adjust volume and pitch make talking adventure games sound action games and customized talkies PLUS 19 95 value TEXT TO SPEECH program BCI PRO GOLF BY TOM WEISKOPF D MR TESTER D PRINTERS LIB t D a0 0 aim ota aaa a ispay R s cee 8 PRINTERS LIB 2 D cenar rmm v 8 DATABASE MGR PLUS FOR C128 D 14 TASK FORCE D as axe ka me comb te eee e 4 BRODERSUND Po o a O oa n s 3609 wo 99 Pom Boo 3 9 o P 9 9 o o a n WHERE iS CARMEN SAN DIEGO D GRAPHICS LiB HOLIDAY ED D DATA EAST COMMANDO D 5 e ahhh rra nnn 22 KARATE CHAMP D nes 22 KUNG FU MASTER D Y 22 DATA SOFT BAKER STREET D ee ee ee MERCENARY D NEVER ENDING STORY D MIND PURSUIT D VIDEO TITLE
158. ned off The lithium bat tery installs on the motherboard with a Velcro adhesive strip 27 50 CIRCLE 38 ON FREE INFORMATION CARD 14 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics COMPUTING POWER FROM FLOPPY DISK SERVICES Xj turbo systems 150 watt supplies add on d ves m 4 XWV A extemal drive cases mono cjapter ocioptors AT rails ntroil ars i WD controlier PRICES AND SPECS SUBJECT TO CHANGE WITHOUT NOTICE aaa ha RN n w Hoppy Disk Services has been supplying sto age systems tothe hobby and professior al Corm puter community for 7 years now You can buy with confidence from a supplier that isin for tha long haul Whether you neec advice or echnical help our staff 6 here t gt serve YOU Complete line of drive enclosures The Service in Floppy Disk Services stands for the confidence you ll have in dealing with us We do not make you wait when a problem comes up We will be there to heip and more import antly support and guide you In the unlikely event we cannot answer your questions a staff member will return a call to you in a timely and profes sional manner with the answer Warranty is q term that sometimes is taken for granted At Floppy Cisk Services we support one of the strongest war ranty policies in the bus iness Our policy is to replace any equipment found to be defective in any way duri
159. ng on the Teflon tip used make sure the orifice in the tip is at least 4 in diameter to take advan tage of the extra suction power Drill it out if necessary A stand can be made by driving an appropriately sized nail through a piece of 4 ply wood It also acts as a cleaning tool There are two types of tubing that Continued on page 90 November 1986 MODERN ELECTRONICS 63 Project sound For Video Monitors Modified external audio amplifier restores sound when using a video monitor with a home computer By Ralph Tenny _ W any Atari Commodore k Radio Shack and other home computer owners have upgraded their displays from TV receivers to video monitors to im prove video quality for word pro cessing and other applications If an economy monitor has no built in au dio circuit the sound portion of pro grams is lost of course hamstring ing certain programs Fortunately it is possible to use the computer s audio output to drive a separate amplifer speaker system to restore the sound The inexpensive battery powered mini amplifier from Radio Shack shown in the lead photo can solve the sound problem with some easy modifications The mini amplifier cited can be used as is if you wish However its combination power switch volume control requires that sound level be set every time you turn on the ampli fier s power Also forgetting to turn off the switch when you are finished
160. ng the war ranty period Its as simple cs that No waiting for the merchandise to be sent back to the factory If we find a problem other than abuse we simply ship a new unit back to you CIRCLE 29 ON FREE INFORMATION CARD The XT clone system pic tured above is our Super System VII XT clone It contains a turbo pro cessor a 20mb hard disk formatted RLL to 31mb 640K RAM two 360K flop pies 1 AT 1 2 mb drive mono amber monitor par port ser port c ock and AT type keyboard You might expect to pay thousands for this system but Floppy L isk Services inc will supply it ready to run with a 1 year war ranty Call for latest quotes on your custom system needs II PRODUCT EVALUATIONS John Fluke s New Development A 12 Current Measuring Accessory E ow adt Fa el ay 4 a V ae De pe a F Tuke S yr cost Line CETERI Adapter i is Show wn wn plugged into a model 23 DMM while the other end has devices to be tested plugged in and the accessory in turn is plugged directly into a 120 V ac wall socket John Fluke Manufacturing Com pany has introduced a wonderful multimeter accessory that s priced at only 12 It enables a multimeter to read ac current of most 120 volt ap pliances without having to cut into or separate any wire leads The line current adapter model LCA 10 is so simple it s a wonder that no one ever developed it earlier Resembling a heavy duty yellow electrical extensi
161. nk V Fuzia 1 Controller Arlene Caggiano Accounting Cheryl Chomicki Subscriber Services SALES OFFICES Modern Electronics 76 North Broadway Hicksville NY 11801 516 681 2922 Eastern Advertising Representative Herb Pressman 76 North Broadway Hicksville NY 11801 516 681 2922 Midwest amp West Advertising Representative Market Media Associates 1150 Wilmette Ave Wilmette IL 60091 312 251 2541 Ted Rickard Kevin Sullivan Offices 76 North Broadway Hicksville NY 11801 Tel aphone 516 681 2922 Modern Electronics ISSN 0748 9889 is published monthly by Modern Electronics Inc Application to mail at second class rates pending at Hicksville NY and other points Subscription prices payable in US Dollars only Domestic one year 16 97 two years 31 00 three years 45 00 Canada Mexico one year 19 00 two years 35 00 three years 51 00 Foreign one year 21 00 two years 39 00 three years 57 00 Foreign Air Mail one year 74 00 two years 145 00 three years 216 00 Entire contents copyright 1986 by Modern Electronics Inc Modern Electronics or Modern Electronics Inc as sumes no responsibility for unsolicited manuscripts Al low six weeks for delivery of first issue and for change of address Printed in the United States of America Postmaster Please send change of address notice to Modern Electronics Inc 76 North Broadway Hicks ville NY 11801 Say You Saw It In Modern El
162. nsmitter decoder and power supply display boards exactly as shown It s a good idea to use sockets for all ICs except JC in the power supply Again note that many resis tors mount vertically Make certain that all components are properly ori ented before soldering their leads or pins to the board Also note that the test point and ground on the receiv er decoder board consist of insula ted hookup wire with the tops looped over to retain ferrite beads FB and FB2 Don t forget to install insulated jumper wires on the receiver decod er and bare jumper wires on the pow COM NC NO Antenna Sensor switches Fig 7 Wiring guide for transmitter Say You Saw It In Modern Electronics A A Insulated jumper Fig 9 Wiring guide for receiver decoder board er supply display boards at all indi cated locations If you want the LEDs that make up DISI on the power supply dis play board to protrude through the front panel of your enclosure mount the display array LED and LED2 on the foil side of the board as in Fig 11 Make sure the discrete LEDs are at the same height as the LED ar ray and that they and D S2 are prop erly polarized Use a 7 conductor ribbon cable with an 8 pin connector at the pow er supply end to link the receiver decoder and power supply display boards The power supply end can be terminated in a miniature 8 pin con nector or be soldered directly to the board Install a mating con
163. nt spooler whose software takes 17K of DOS mem ory The spooler is a cute pop up pro gram that creates up to three print queues serial printers require redirection of LPT output with the DOS MODE com mand other Practical software includes an effective autodialer a crummy little communications program and the small est 752 byte driver I ve foundto create a 360K RAM disk The Multifunction 1200 s slot saving is its main attraction but Popular Pro grams Pop Up DeskSet and TeleComm regularly 129 95 are a bundled bonus TeleComm though limited to dinky phone directories three voice and three data numbers hides behind your favor ite application to dial other numbers from the screen or keyboard giving sur prisingly full powered communications except for the lack of an answer mode DeskSet usually takes more memory than Borland s SideKick but provides your choice of separately loaded acces sories and the accessories are of superi or quality such as a sophisticated finan cial calculator and a notepad that s a full fledged word processor Pop Up DOS offers internal commands like Delete and Rename from within an application Pop Up Anything lets you temporarily leave an application to run an external command or another program My only complaint about the Practical board is its price 395 with no memory That s not too bad considering its bun dled software and the cost and need for two slots of say an A
164. o make the sunshine fit the pump What he came up with is a new variable displacement pump mechanism When the sun is shining brightly the pump makes long strokes and lifts lots of water When the sun shines a little the pump makes short strokes and lifts less water At night the pump makes zero strokes and does not lift anything What about clouds Jim put a hefty flywheel on the pump so it can coast through brief cloudy periods A small simple and very efficient CMOS micro controller monitors flywheel speed and every now and then adjusts pump dis placement to exactly match the available energy coming in from up there A small secondary motor with a worm screw drive is used to adjust the stroke Thanks to the flywheel the pump runs at an optimum and nearly constant speed so long as any power at all is com ing out of the panel I am particularly proud of all this be cause Jim is one of my students And he N s m U rc November 1986 MODERN ELECTRONICS 81 Say You Saw It In Modern Electronics HARDWARE HACKER is successfully doing some extremely high tech things in a distinctly low tech part of the country Give him a call if you want any more details How do D A converters work D A or digital to analog converters convert digital numbers into nearly con tinuously varying output signals In gen eral D A converters are a lot
165. ometer see Table Miscellaneous B1 9 volt battery Cx 620 Antenna 9V L1 0 3 4H variable inductor TOKO 10K Series XTAL 49 890 MHz series resonant crystal Printed circuit board snap connec tor for B1 stranded 22 gauge hook up wire machine hardware solder etc Note For components and kit availabili ty see Note at end of Power Supply Display Parts List Fig 1 All transmitters in the system are identical varying in their tone coding by varying values of frequency determining parts in the Q1 audio oscillator alarm and can simultaneously turn on a lamp and or siren When assembled as outlined here the Wireless Home Security System complies with the FCC Rules and Regulations part 15 subpart D for the experimental 49 MHz band Though other devices share this band including toy walkie talkies the narrow bandwidth rapid scan ning technique employed makes the decoder reasonably immune to voice modulated transmissions SSS Say You Saw It In Modern Electronics The receiver decoder sequentially monitors 10 channels in scanner like fashion When a transmitter is ac tive the decoding circuit locks on and sounds a buzzer and turns on an LED that corresponds to the loca tion of the active transmitter In ad dition an ALARM LED turns on and a relay s contacts lock close to indi cate that the system has been tripped After a few seconds
166. on cord the 5 ft long accessory has a combination three prong plug and receptacle at one end and white and black leads terminated in banana plugs at the other end To use the accessory sim ply set a multimeter to its 10 ampere ac range and plug the leads into the meter s appropriate inputs E NM E d rz 22222 es A Then the electrical device whose current drain is to be measured is plugged into the adapter s receptacle while the three prong plug at the same end is plugged into a 120 V ac outlet This places the meter s cur rent shunt in series with the 120V ac live wire Turning on the device which may be a toaster refrigerator air condi tioner computer etc enables the multimeter to display turn on surge current normal current or standby current without any muss or fuss The plug receptacle is rated at 15A 125V ac with maximum con tinuous current of 10A ac It can withstand 20A ac safely for 30 sec onds according to the manufacturer I tried the adapter out with an old 16 MODERN ELECTRONICS November 1986 window air conditioner to learn how much current it was drawing using a new Fluke Model 23 digital multime ter Pressing High on the two speed unit caused OL overload to be displayed on the DMM which quickly changed to 8 5 Thus the compressor s initial surge exceeded 10 amps while the running current was 8 5 amps I followed the same quick procedure w
167. oorly made private line connections often dropped out in the middle of a con versation or were unintelligible and so on But things are improving It s not as nice and neat as in the old days but certainly more exciting a Say You Saw It In Modern Electronics e Several errors crept into my Digi tal Measuring System article Au gust 1986 In Fig 1 J2 should be numbered in ascending order from top to bottom and a shorting link with the legend typical should bridge Rz In the Panel Meter Parts List change the transistor number from 2N2222 to 2N2907A shown correct in Fig 1 and the manufac turer name to Bourns for R4 and R5 In the Technical Specifications Table change the accuracy at 25 C entry to read 0 1 1 count Finally reverse the J2 num bering in Fig 6 Charles R Ball Snellville GA Yours was a very welcome article on upgrading the CoCo II to 64K RAM Extended BASIC and the 64 column video output in September 1986 s Modern Electronics I care fully opened my CoCo II but the layout was nothing like your illustra tions The eight 16K RAMs are across the front of the motherboard in a Single line There appear to be no pads marked 64K RAM and every socket is filled This model is possibly an early one that doesn t have the shield over the RAM but I don t recall whether or not Extended BASIC was mentioned although the 64K RAM was listed in the manu
168. option install diode D3 as shown in Fig 3 Now Kl will reset whenever the transmitter for channel 1 is activiated allowing you to pass through a monitored en trance without tripping the alarm The wired receiver decoder and power supply display boards are shown in the lead photo Select an enclosure for the receiver system that is large enough to accom modate the receiver decoder and power supply display boards with out crowding as well as the backup battery option if you plan on using it and installing it internally Drill holes for mounting the receiver de coder and power supply display boards receiver on the bottom pan el power supply on the top panel the antenna and transformer cable in different sides and the LEDs and the SI RESET switch Line the hole through which the wall trans former cable is to enter the enclosure with a rubber grommet Cut a slot for viewing the LED dis play Then drill mounting holes for a 2 contact screw type terminal strip on the rear wall and for the piezo electric buzzer if you decide to use it on the front or one of the side walls of the enclosure The wires from the relay s contacts go to the terminal strip If your wall transformer has a con nector on it cut it off and prepare the cable for soldering Pass the ca ble through the grommet and tie a knot in it about 6 from the prepared end Solder the conductors to the pads labeled 12 vAC If you plan on using the battery
169. ore costly setups smoke frost flood and any of a host cessor controlled receiver and digi Though it doesn t employ micropro of other physical conditions for tally encoded radio transmitters cessor control each of its 10 trans which there are sensors available Though the latter can be very elabo mitters has its own unique code The system can activate an audible 38 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics NOTE See text and transmitter R5 component values table 33K C1 C2 C3 see note see note see note R2 R8 see note 4 7K E C6 R10 MS iw Ri 0 0014F 7T AM see note i see note l E ib is Luss P y C10 R11 V see text 10M d A C10 B3170 NC z 0 01uF ai w see text S Lj TRANSMITTER PARTS LIST Semiconductors Resistors 4 watt Q1 2N22224A npn transistor Q2 2N918 npn transistor Q3 BS170 PMOS switch Capacitors C1 C2 C3 Low voltage metalized film see Table C4 C5 10 4F 16 volt electrolytic C6 0 001 yF ceramic disc C7 0 002 4F ceramic disc C8 200 pF high Q ceramic disc C9 24 pF high Q ceramic disc C10 90 01 4F ceramic disc 5 R7 R9 1K 10K Q2 2N918 R2 R3 R4 1 tolerance see Table R5 33 200 ohms 1 tolerance R6 R7 1 000 ohms 5 tolerance R8 4 700 ohms 5 tolerance R9 10 000 ohms 5 tolerance R10 620 ohms 5 tolerance R11 10 megohms 5 tolerance R1 Trimmer potenti
170. ors di odes LEDs and transistors are prop erly oriented before soldering their leads into place Keep the crystal s leads as short as possible Install the jumper wires indenti fied in Fig 5 with the letter J with no suffix number but do not install the Jl and J2 jumpers just yet Con Data in AW Data out arcud G5 Wr U one 3 X R21 s R20 nect and solder 1 to 2 lengths of hookup wire to the INPUT 1 through INPUT 4 holes preferably using black wires for the grounds holes nearest the edge of the board and red wires for the signal lines If you have decided to use the Series 200 Unibox as the AAU s en closure mount all LEDs directly on and spaced about 1 4 above the sur face of the board In this case tem porarily mount the board in the bot tom half of the enclosure shell and carefully mark the locations for the holes to be drilled for the LEDs on the top half of the shell the front panel INPUT 1 through INPUT 4 jacks and the rear panel accesses for the 12 volt ac line and interface cable all in the bottom half of the shell Re move the circuit board and drill ap propriate size holes Mount the INPUT jacks in the front panel holes Cut off and dis card the plug at the end of the 12 volt ac plug in transformer s cable Sepa rate the cable s conductors for a dis amp R26 4 LEDS D5 mae i nae aes R25 R24 N
171. ource you need For a copy see your RCA SK Distributor Or mail a check or money order for 3 25 to RCA Distributor and Special Products Division Box 597 Woodbury New Jersey 08096 2088 res Solid State a CIRCLE NO 138 ON FREE INFORMATION CARD s x MINI METER MAX SPECS Small enough to fit in your shirt pocket a e x g 0 5 DC accuracy luc ZA g 6 Functions 19 Ranges p sod DC Voltage 0 1 mV to xi t 1000 V DC Current 0 1 uA Y m aw p i m to 2A Resistance 0 1 ohm Model to 2 M ohm e Diode Test DVM 630 e Battery Test 8 Measures approx 5 x 23A x 7 in Model CC 30 Deluxe 300 hour battery life Zippered Carrying Case s4 50 8 Automatic zero adjust m Low battery indication m Test leads included SCOPE HAND HELD DIGITAL A CAPACITANCE JM AA MULTIMETERS PNE OE l ji A a Be an dU EM il 0 5 DC Accuracy MV C oM ES I Md ade n ya Highest Quality j _ Kun TA mr mHinest eu Perlormance eT Lowest Prices Model DVM 634 Model DVM 638 75 7095 Model DCM 602 48 S9 P Model DVM 636 7 functions 32 ranges unctions ranges 69 95 Transistor measurement Includes logic level detector 62 75 ce Included audible visual continuity 3 Digit Capacitance Meter capacitance and conductance 8 functions 37 ranges 8 ranges with full scale values to 2000 uF measurement Capacitance measurement FEATURES Broad tes
172. ovember 1986 MODERN ELECTRONICS 23 BV 1v NI 1x81 835 ui eq 1x81 aas jno eje 02 9 1x92 aas JOPIBUUOD Sc 8Q Fig 2 Overall schematic of Analog Acquisition Unit without power supply Atv d dzz do de LA O tZEW1 191 310N WLP ML 301 D vu SZ OLY 2121 l CN e L 301 ue Ely JEE 02 GLY rly YOt ZLY ZA 9121 n 3 T IZH YOt S JEE XOZ OLH OPtNZ FER a VO oz YOL e E Jd4z aol o S0 892W 39 29 a MOL Mie XOZ E 9H YOt pH 58 YOt mii 8PLvNL va 0c cH Say You Saw It In Modern Electronics 24 MODERN ELECTRONICS November 1986 D1 1N4001 C1 D3 1N5232 Fig 3 This power supply for the Fig 2 circuit uses 12 volt ac transformer Though not essential fcr proper project operation sockets are rec ommended for JC and IC2 If you do decide to use them install the sockets first on the board and care fully solder their pins to the copper pads Make sure that you do not cre ate solder bridges between the close ly spaced pads Then proceed to in stalling the remaining components exactly as shown in Fig 5 starting with the resistors and diodes and Fig 4 Actual size etching and drilling guide Say You Saw It In Modern Electronics working up to the largest size com ponents Do not install C7 and IC2 until directed to do so Make sure that the electrolytic capacit
173. paration 80 dB alternate channel selectivity and 60 dB S N The control unit mea sures 7 W x 2 H x 13 4 D while the trunk unit is 13 W x 5 H x 91 4 D CIRCLE 36 ON FREE INFORMATION CARD meter illuminated X and K band short range signal indicators that tell the driver which kind of ra dar is being received another indica tor that lights when correct radar sig nals are being received and a high way city control that adjusts filter ing and sensitivity to prevent false alarms Upon power up the Road Alert goes into a test mode to inform the driver if the system is working pro perly A three position switch per mits selection of audible visible or both types of alerts A variable audi ble alarm indicates signal strength and radar intensity photoelectric sensor automatically adjusts the brightness of the front panel displays for daylight and night driving condi tions M i eee E E e K om LL S a i Ul qe Paria 7 a r The detector measures 4 25 x 2 72 x 0 75 making it small enough to mount on a visor or on a dashboard It comes with all mount ing hardware and cables 199 95 CIRCLE 37 ON FREE INFORMATION CARD Replacement RTC Battery International Battery Corp s Rese da CA Tadiran battery is a replace ment for spent batteries in the real time clocks RTCs in IBM PC AT and compatible computers to main tain the integrity of data when ac power is tur
174. pe connectors on both ends If your TV receiver or outside antenna use standard 300 ohm twin lead you will also need 75 300 ohm transformers to match im pedance and to make the required connections e Cable With Premium Chan nels The cable company supplies its subscribers with a channel selector box that contains the decoder circuit ry required to unscramble the pay TV channels The output of this box A B switch 1 Videota NOTE All cables are 7582 PREMIUM I switch 2 INPUT OUTPUT SXNN recorder is usually on TV channel 3 Both your TV receiver and your VCR must be tuned to channel 3 when connected to the output of the cable box However if your VCR or TV receiver are connected directly to the cable ahead of the box you should be able to view and record all nonpremium channels by selecting them with your VCR or receiver channel selector or via their respec tive remote controllers All methods that allow you to view one channel while recording another simultaneously are based on the con cept that the VCR or TV receiver are connected directly to the cable ahead of the cable box When a program is recorded through the cable box the choice of gt 4 To TV antenna terminals MEL MEME CM uui ue RE is that when recording a premium scrambled channel only that channel can be viewed 36 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics
175. pifies the optoisolator family of devices Note that this is a 6 pin IC like device A LED is a common element in virtually all types of optoisolators Most optoisolators use a single gal lium arsenide LED and all use a plas tic device for light coupling The 30 MODERN ELECTRONICS November 1986 coupler conducts the LED s output radiation which can be visible light or invisible infrared radiation to the photosensitive surface of the out put device Figure 1 s output device is a pho totransistor which is shown with the traditional transistor symbol This transistor s functional base lead is frequently not used Instead the transistor is turned on by the beam from the LED through the light coupler The same principle applies Say You Saw It In Modern Electronics with whatever output device is used intheoptoisolator Each type of out put device beyond the basic transis tor has its own specific characteris tics and was designed to meet one or more specific application needs that previous optical isolators could not handle Advanced Output Devices Other output devices that are avail able include Darlington transistors bilateral FETs light activated sili con controlled rectifiers LASCRs triacs and Schmitt triggers e Darlington Transistor Shown in Fig 1B is the schematic representa tion of the optical coupler with a Dar lington transistor output Note that the Darlingto
176. project 1 volt is full scale which is equal to 255 in decimal or FF in hex Use the circuit shown in Fig 8 to calibrate the Analog Acquisition Unit With the calibration circuit connected to the INPUT 1 of the AAU adjust RV for a meter indica tion of 0 5 volt Then adjust R2 until the AAU returns a 127 when a capital E is transmitted by the host comput er Repeat for INPUTS 2 3 and 4 ad justing R6 R10 and R14 respective ly as you did R2 for INPUT 1 You are now ready to input analog data directly into your computer Since the parameters of temperature humidity force pressure position and many others can easily be con verted to an analog voltage the uses to which you can put your computer with the aid of the Analog Acquisi tion Unit are limited by only your in genuity Amazing Hearoid talks and serves you remote Control Unit Batteries not incl REMOTE CONTROLLED HEAROID ROBOT Great Fun For Everyone Liquidation due to famous Japanese manu facturer discontinuing this model Loads of fun as Hearoid delights the family by serving them carrying objects in hand or on a removable tray Amaze and impress friends as Hearoid serves them and guides them on a talk tour of home built in cassette recorder e Remote microphone lets you converse with guests through robot e Hearoid obeys 12 voice commands Performs programmed routines up to 45 minutes long Switch from vo
177. r tability is not an issue try dusting off your home computer and writing custom timer programs The best thing about do it yourself computer timers is that you can dress them up with all kinds of alarms graphics and special functions that would be extremely difficult to in corporate in a hard wired timer circuit Best of all you can modify a computer ized timer simply by changing a few lines of the program NEW FROM DON LANCASTER HANDS ON BOOKS CMOS Cookbook 14 50 TTL Cookbook 12 50 TV Typewriter Cookbook 12 50 Active Filter Cookbook 14 50 Micro Cookbook vol 15 50 Micro Cookbook vol Il 15 50 Enhancing your Apple vol 15 50 Enhancing your Apple vol Il 15 50 Applewriter Cookbook 19 50 Apple Assembly Cookbook 21 50 Incredible Secret Money Machine 7 50 Postscript Ref Man Adobe 22 50 Postscript Cookbook Adobe 16 50 UNLOCKED SOFTWARE Absolute Reset lle amp fic 19 50 Applewriter Laserwriter Utilities 49 50 Laserwriter Demo Pack FREE Appie Ram Card Disassembly Script 24 50 Appleworks Disassembly Script CALL Enhance vol Companion Disk 19 50 Enhance vol I Companion Disk 19 50 Assembly CB Companion Disk 19 50 Applewriter CB DOS Comp Disk 24 50 Applewriter CB ProDOS C Disk 24 50 FREE VOICE HELPLINE VISA MC SYNERGETICS Box 809 ME Thatcher AZ 85552 602 428 4073 CIRCLE 17 ON FREE INFORMATION CARD Call us now for details and to order these exciting new TANDY computers New TANDY 1000 EX N
178. r opto isolators as they are com monly called have been available in one form or another for more than 25 years The earliest such devices consisted of a light bulb and a light sensitive sensor both housed inside a container with a tube to cou ple them together The sensor was usually a photoconductor like a light dependent resistor and the bulb was matched to the voltage that drove it Over the years advances in technology and the need to meet spe cial requirements forced develop ment of a wide variety of optically linked devices that solve tough de sign problems at very low cost and with high reliability In this article we will explore the various types of solid state optical isolators that are commonly avail able to the designer and experiment er Our basic intent here is to famil iarize you with the various devices available Plain Vanilla Devices Although the early lamp photocon ductor a photoconductor is a light sensitive resistor optical coupler is still available it has long since been Fig 1 Schematic symbols and pinouts for A general purpose transistor B Darlington transistor C bilateral FET D light activated silicon con trolled rectifier LASCR E triac F Schmitt trigger eclipsed in availability popularity and reliability by devices in which are a light emitting diode LED and a phototransistor shown in Fig 1A in the 6 pin dual inline package DIP that ty
179. r via its keyboard or on a more advanced system through a digitizing tablet These entry meth ods however are cumbersome and subject to error A far better ap proach would be to connect the ex periment or circuit directly to your computer This would provide direct data acquisition and eliminate the possibilities of errors due to manual entry of data You can build the An alog Acquisition Unit described here to give your computer this capability With the AAU interfaced with your computer you can connect up to four analog signals directly to your computer via the latter s RS 232 serial I O port The project is relatively inexpensive and easy to build simple to program and re quires no modification to your com puter system About the Circuit At the heart of the AAU is a Motoro la MC68705 microcomputer on a chip This versatile device contains all the circuitry needed to make a complete analog data acquistion sys tem As shown in Fig 1 on chip ele ments consist of an 8 bit CPU 112 bytes of RAM memory 3 8K bytes of EPROM memory a 4 channel an alog multiplexer an 8 bit A D con verter and all the support circuitry needed to form a complete micro computer A complete schematic diagram of the AAU s processing circuitry is shown in Fig 2 while Fig 3 shows the power supply circuitry for the project Microcomputer chip C2 in Fig 2 has in its EPROM a program that constantly checks for a valid se rial ASC
180. ram and sounds You should hear the sound M reach graduation No residence schooling re clearly from the amplifier s speaker quired for qualified Electronic Technicians Through this Special Program you can pull all of Adjust sound level as desired the locse ends of your electronics background If everything IS okay power down together and earn your B S E E Degree Up z grade your status and pay to the Engineering your computer and disconnect the ca Level Advance Rapidly Many finish in 12 if months or less Students and graduates in all 50 bles from bite ane Reassemble States and throughout the World Established the amplifier s enclosure and plug Over 40 Years Write for free Descriptive Lit erature COOK S INSTITUTE _ The ane Dow dei ix pur OF ELECTRONICS ENGINEERING into service Now sit back and enjoy 347 RAYMOND ROAD the sound you have been missing ME ob GN err JACKSON MISSISSIPPI 39209 the cables coming from the computer back into the appropriate jacks E SS SSS oS A a SCOPE PRICE BREAKTHROUGH Now you can own a professional quality 20MHz dual trace scope for under 450 Best of all it s a full featured instrument from B amp K PRECISION famous for quality dependable products Compare these outstanding features then compare price e Dual or single trace cperation e 2mV div sensitivity e 20MHz response at a true 3dB e AUTO NORM triggered sweep operation with AC TVH TVV and Line
181. rce S pads and connect C70 be tween ground and point B Use heat jusiciously when soldering the tran sistors and crystal to the transmitter board and the diodes LEDs transis tors and ICs on the other boards in the system to prevent heat damage to these delicate components A photo of the wired board is shown in Fig 8 Trim 4 of insulation from both ends of three 36 lengths of 22 guage stranded hookup wire Loosely twist together two of these wires and tie a knot 2 from the prepared end of the third wire Pass one end of the twisted pair through the sensor wire hole in the enclosure and connect and solder it to either the NC or NO depending on the type of sensor you re using with the specific trans mitter pads on the board Solder the 4 SS SS SS aw rpec t pro pnipm 46 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics prepared end of the single wire to the ANTENNA pad on the board Then solder the red and black wires from BI s snap connector to the B and B pads respectively Label each board asit is wired with its channel number Mount the board in the enclosure with the chan nel number of the board installed in it and the sensor type NC or NO for which the circuit is wired Pass the free end of the antenna wire through its hole and plug a 9 volt battery into the snap connector Assemble the enclosure Referring to Figs 9 and 10 wire the tra
182. rd Solder all lug pad connections Setup and Use Plug the Programmer into the User November 1986 MODERN ELECTRONICS 57 Program 1 BASIC Loader for 2764 EPROM Burner 5 REM BASIC LOADER FOR 2764 EPROM BURNER 10 FORX 49152 TO 49767 20 READ A POKE X A 30 Q Q A 40 NEXT 50 IF Q 81167 THEN PRINT ERROR IN DATA STATEMENTS END 55 SYS49152 60 END 100 DATA 76 12 192 76 8l 192 76 215 192 76 110 DATA 6 194 169 186 141 239 193 32 22 192 120 DATA 88 96 120 169 10 141 4 220 169 0 130 DATA 141 5 220 109 dl 141 14 220 173 239 140 DATA 193 141 12 220 162 50 202 208 253 173 150 DATA 221 9 4 141 O 221 173 0 221 160 DATA 41 251 141 0 221 169 104 141 4 220 390 400 410 420 430 440 450 450 470 480 490 500 519 520 530 540 550 560 570 580 590 600 610 620 630 640 659 660 670 680 650 700 710 REA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DY 169 66 141 5 220 169 17 141 14 220 05 120 169 186 141 239 193 32 29 192 169 184 141 239 193 32 22 192 169 O 133 38 169 96 133 39 169 0 141 3 22 1697 160 Vals 259 193 3
183. rent voltage monitor ing fuse protection vented steel cabinet Maximum cur rent 1 amp per channel UL listed AC 422 121 Memory Storage gt All pushbutton operation plus features that compare with meters costing much more Built in 31 position bargraph in addition to a high contrast digital LCD Full autoranging Built in transistor checker and buzzer continuity mode 211 isx 8x 43 4 With probes and High Performance manual Batteries extra 22 195 Radio Shaek A DIVISION OF TANDY CORPORATION Prices apply at participating Radio Shack stores and dealers With instructions 22 304 17 95 UL listed AC Backup battery extra 63 765 24 95 Over 1000 items in stock Binding posts Books Breadboards Buzzers Capacitors Chokes Clips Coax Connectors Fuses Hardware ICs Jacks Knobs Lamps Multitesters PC Boards Plugs Rectifiers Relays Resistors Switches Tools Transformers Transistors Wire Zeners more CIRCLE 24 ON FREE INFORMATION CARD Say You Saw It In Modern Electronics November 1986 MODERN ELECTRONICS 3 Call or Write PO Box 00017 Ceo T YL 813 936 2397 ee s Thar x Mn eec cat ano 6 5 oe TN d on wD Ta P ot e KK vei a e YU ears os Ode aue 160 e SON aes C apte Ko i De a E one nt 1a a me us en eC nO9 ges cgit o LO aie gon AT P NC 3t m Ch P SON ee got Quo 97 Tour AD A aeo go
184. ress Space to Mark Uneark magazine reviewer as stu ttrikute I Clopy IDJirectory Tree Elrase IFlind 8llobal F3 Help CLOSE CE DUE magazine Tuy wenas s p Llos Disk Mlark elNicrypt IPlrint H enamo Slort U iew Esc Exit pid Rather than asking where it can fin the DOS files whether in your root direc tory or elsewhere the installation pro gram copies your entire DOS master disk into the Le Menu subdirectory For a program that boasts that it saves disk Besides providing menus for rookies Le Menu knows its way around DOS directories ter automatically logs onto the proper subdirectory and starts the program or batch file A menu choice can call a submenu and so on going five levels deep for over 11 million theoretical choices menu entries can pause for parameter input or use de fault responses Each menu entry can have an access password with a master password required for Le Menu s other functions or exit to DOS computer us age can be tracked and printed for nosy supervisors That s nice enough but press F2 for Directory Desserts and Le Menu be comes a powerful directory manager like Bourbaki s 1Dir March 1986 p 70 Leafing through directories sorted lists or an overall tree diagram you can run programs or copy delete rename type or change attributes of files marked indi vidually or with wildcards where Le Use the free info card How do I get more data Free Product
185. rom neophytes to old hands The inside front and rear covers contain circuit symbols and the re sistor color code respectively Within the body of the book itself are almost 50 ready to wire circuits all of which have un BOOKS ill been tested by the author prior to publi cation These circuits range from flashers to light meters to light and dark activat ed relays to simple lightwave transmitters and receivers and more All are low in cost and all can be breadboarded or wired in minutes NEW LITERATURE VCR Users Guides Maxell has two new guides that can help consumers make in telligent selections of videocassettes to suit specific needs The 48 page Maxell Video Tape Handbook tells how video Cassettes capture audio video images diagrams the differences between stan dard and Hi Fi Beta and VHS systems and describes the company s line of vid eocassettes It details the qualities to look for in tapes tells what Maxell videocas sette to use for various applications and offers tips on recording TV programs ERROLD CORDLESS CABLE TV CONVERTERS Moptt DRX3 105 400 60 channels Remate channel changing e Remote ON OFF switch Rernote fine tuning JERROLD CORDLESS CABLE TV CONVERTER Model DRZ 450 JERROLD CORDLESS CABLE TV CONVERTER Model STARCOM CS V CABLE TV CONVERTER Mode 6510 79 ea Volume control e VOLUME 68 channels Mute contro Inst
186. rom the new 8 bit I O port available at pins 5 and 6 control counter 7C3 This 12 bit counter provides the lower 12 bits of the address of the EPROM being programmed The output at pin 5 of IC3 provides the reset that clears counter IC4 to all Os while the out put at pin 6 of C3 increments the count in JC4 Likewise the outputs at pins 2 9 12 and 15 of IC3 provide address 12 chip enable output en able and program signals to the EPROM plugged into zero inser tion force ZIF socket SO at pins 2 20 22 and 27 respectively Programming relay K in Fig 1 is controlled by the output at pin 7 of IC3 The last bit is unused The re maining I O pins of the C 64 s User Port are connected to Data pins C through L that are in turn con nected to pins 11 12 13 15 16 17 18 and 19 respectively of SO1 Reading and programming a 2764 EPROM with the Programmer con sists of issuing commands via the computer s serial port to the new I O port in the Programmer latching the new commands with JC3 and using the User Port I O pins to either pro vide the data to be programmed into the EPROM or read the output data from the EPROM Construction Though the 2764 EPROM Program qo P PU es EX s e 0 v j x Un U I 9 o Solder S 9 o e e p Q o mer can certainly be assembled on perforated board with the aid of suit able soldering or Wire Wrap
187. ronics action that reduces the time a sold ered joint must be heated and there fore less chance of damage to com ponents or the pc board In this article we describe two ver sions of the Super Solder Sucker The basic tool consists simply of the vacuum pump which you use with your present soldering iron or pencil The deluxe version adds a desolder ing iron that makes the Super Solder Sucker a dedicated desoldering tool that can be operated with a one hand Modifying the Pump The Basic Tool Before modifying the bicycle tire pump around which the Super Sold er Sucker is built read the Precau tionary Notes box The bicycle tire pump used for the photos through out this article is shown in Fig 1 If you can t find this particular pump any similar one can be used Start your modification by unscrewing and discarding the hose and pressure gauge from the end of the pump s cylinder Remove the nu from the end of the pushrod The cap that Precautionary Notes Whenever you do a machining opera tion it is important that you observe certain safety precautions This is par ticularly so when machining metal The description of the machin ng process outlined in this article facilitates build ing the project without requiring spe cial taps dies drill bits etc Be sure to wear suitable eye protec tion when drilling any metal parts When drilling holes larger than 1 4 al
188. rtification level exceeds that of Maxell Dennison Elephant Verbatim Wabash DataTech or Bonus which we also sell at the lowest prices in the Country They are certified error free at a whopping 759 o above industry standards with jackets 25 thicker than industry standards They come with Tyvek sleeves labels and write protect tabs Now you can buy discs far above industry standards at far below competitive prices Shipping 3 00 per hundred or part APO FPO AK HI amp PR add S6 more Visa or Mastercard orders under 50 add 2 00 Orders under 30 add 3 service charge Money orders cashiers checks and personal checks earn a 2 discount but personal checks delay shipment for up to 14 days for clearance New Jersey residents add 6 sales tax We ship COD cash or certified check only for a 3 00 charge Quantity discount on GD2 196 300 200 500 4 1 000 P O Box 249 11 Osage Road Rockaway N J 07866 50 0 Extra COMPUTER SUPPLIES 201 627 9472 800 367 2897 Deduct an extra 5 from our discount prices when you mail this coupon with your order Telephone orders refer to coupon ME 2 This coupon valid through November 15th only E amie eal CIRCLE 45 ON FREE INFORMATION CARD November 1986 MODERN ELECTRONICS 5 E MODERN ELECTRONICS NEWS i COMPUTER UPGRADES You can expect new computer models to be intro duced in quick succession by major players in the indust
189. ry IBM has already announced its upgraded PC XT with Intel s faster 286 cpu and a 20 MB hard disk drive while Compaq debuted its 286 based computer to be followed shortly by a new multiuser machine using Intel s more powerful 80386 microprocessor Another major this time a software one Lotus Development is shipping Symphony Release 1 2 an enhanced version of its original An open architecture Macintosh with IBM PC compatibility is rumored as soon to debut So is a WordStar 4 0 For both it would be long overdue Software giant Microsoft has intro duced a new version of its Windows operating environment package now Release 1 03 that has drivers for Apple Computer s Laserwriter Hewlett Packard s LaserJet Plus and more R F ANALOG ENGINEERS WANTED In a supposedly digital world it s in teresting to observe a great shortage of engineers with radio frequency analog experience There s been an increase of about 30 in demand over the last year noted Dick Govatski of Christian amp Timbers a Box borough MA and Cleveland OH based executive search company VIDEOCASSETTE HAPPENINGS VCRfacts tech service documentation for videocassette recorders has been introduced by Howard W Sams amp Company The new repair information product retails for 21 95 for each brand model with a format similar to the company s line of Photofact and Computerfact packages Sams promises to have 52 brand and model specific units by February 1987
190. s and energizes KJ whose contacts then close and deliver the 22 volts to the EPROM At all other times the pin that receives the programming voltage must be held high This con dition is satisfied by D6 which de livers 5 volts as shown As shown in Fig 2 the digital sec tion of the Programmer must supply 25 input and output lines However the C 64 s User Port has only nine pins for I O see Fig 3 and the ac companying Table The remaining I O bits are obtained with serial to parallel converter JC2 which creates a new 8 bit I O port without sacrific ing any of the I O capabilities of the existing port There are two serial ports on the C 64 s User Port for 8 bit synchro nous data By using one of these as November 1986 MODERN ELECTRONICS 55 Say You Saw It In Modern Electronics C 64 User Port Contacts Used in EPROM Programmer 1 Ground 2 5 volts 4 Serial port clock 5 Serial port data 10 9 volts ac 12 Ground A Ground C Data O D Data 1 11 9 volts ac K Data 6 L Data 7 M Latch enable N Ground E Data 2 F Data 3 H Data 4 J Data 5 Fig 3 Pinout diagram for the C 64 User Port an output and C2 as a shift register eight bits of I O are obtained The data outputs of IC2 are latched by IC3 so that the I O pins do not change as new data is sent through the shift register Latching the data with IC3 requires one bit of actual I O on the C 64 s User Port Two of the outputs f
191. s this is not an uncommon occurrence Inexpensive desoldering vacuum bulbs plungers etc are compromises that allow this type of problem to happen at one time or another The better safe way to desolder components from a pc board is with an electric vacuum type desoldering workstation Un fortunately this more sophisticated tool usually sells for 250 or more which puts it beyond the budgets of most home experimenters and many small repair facilities Enter the Super Solder Sucker a tool that sa crifices all electric vacuum action but otherwise operates like the pro fessional workstation at a cost of 20 to 25 for the basic version Building the Super Solder Sucker around an inexpensive bicycle tire foot pump gives up the convenience of electric action but at the same yr ARE Lf Z z NOR 226766 7 a is e Pa eee aan M m EAT Ta F 60 MODERN ELECTRONICS November 1986 GEA Ey time saves you 225 or more on the cost of the tool What you get how ever is super sucking action with very little pumping effort And like the professional tools the Super Solder Sucker s valve action elimi nates liquid solder blow back on the return stroke You get fast sucking Fig 1 A typical bicycle tire pump that can be used in this project This is the one illustrated in all photos in this article any similar one can be used if you can not find this one o LE aam o emet les Say You Saw It In Modern Elect
192. software includes a spreadsheet and utilities for plotting graphics patterns Optional 8K and 16K battery backed RAM cards al low the computer s user memory to be expanded to a maximum of 21K Including built in plotter printer the PC 2500 measures just 11 75 W x8 25 Dx 1 75 H and weighs only 3 Ibs with built in plotter printer 395 75 and 125 for optional 8K and 16K RAM cards CIRCLE 33 ON FREE INFORMATION CARD Say You Saw It In Modern Electronics SMD Soldering Kit Satellite TV Receiver 0 With Bells amp Whistles Built into R L Drake s microproces sor controlled Model ESR2400 satel lite TV receiver are virtually all the features one can conceive an anten na positioning system a VideoCy pher II decoder DNR audio noise re duction and an on screen display generator among others The receiv er can also be had without the decod er which can be added later The on screen display contains such infor mation as tuned channel satellite selected polarity and signal strength Among the receiver s other fea tures are priority view allows up to 19 channels to be preprogrammed in to memory for instant recall paren New from Jensen Tools Inc Phoe nix AZ is a shop field soldering kit designed specifically for work on surface mounted devices SMDs The kit includes a Soldermaster min iature soldering iron for use on high density board assemblies and a vari ety of SMD style tips for lea
193. ssword in return There s no charge If any qualified group wishes to duplicate this system in other cities the software is available for one dollar that s 51 6 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics CABLE TV LOWEST PRICES ANYWHERE BO NANZA SINGLE LEALER UNIT 1 UNIT PRICE PRICE RCA 36 CHANNEL CONVERTER CH 3 OUTPUT ONLY 2995 18 00 ea PIONEER WIRELESS CONVERTER OUR BEST BUY 8895 7200 ea LCC 58 WIRELESS CONVERTER 9295 76 00 ea JERROLD 450 WIRELESS CONVERTER CH 3 OUTPUT ONLY 105 95 9000 ea SB ADD ON UNIT 10995 5800 ea BRAND NEW UNITS FOR SCIENTIFIC ATLANTA Call for specifics MINICODE N 12 109 95 5800 ea MINICOCtE N 12 VARISYNC 11995 6200 ea MINICODE VARISYNC W AUTO ON OFF 17995 11500 ea M 35 B CH 3 OUTPUT ONLY 13995 7000 ea M 35 B W AUTO ON OFF CALL FOR AVAILABILITY 19995 112500 ea MLD 1200 3 CALL IF CH 2 OUTPUT 10995 8 00 ea INTERFERENCE FILTERS CH 3 2495 1400 ea JERROL 2 400 OR 450 REMOTE CONTROLLER 2995 18 00 ea ZENITH SSAV CABLE READY DEALER PRICE BASED ON 5 UNITS 22500 165 00 ea SPECIFY CHANNEL 2 or 3 OUTPUT Other products available Please Call Output mi Channel California Penal Code 8593 D forbids us SUBTOTAL from shipping any cable descrambling unit Shipping Add to anyone residing in the state of California 3 00 per unit D t Prices subject to change without notice P s ree PLEASE gt R
194. suggest possible solu tions for specific timer applications you might have A Bait Well Aeration Timer Though the circuit described here was de signed specifically to aerate a bait well in a fishing boat it has many other applica tions For example it can control a drip irrigation system a flashing light a mo tor and any other system or device de II ELECTRONICS Custom Timer Circuits tS TO 1S V Ri iM RZ iK e C 1 OL TO 1 000 pF COR N 4 GROUND Tog q 5 G 55 S lo 10 5 4 7 e d me 2 s4 TO 3 Su Ni 1s OUT PIN LS Fig 1 A simple programmable timer signed to automatically cycle through a programmable repetitious off on se quence As for the aeration system recall that a bait well should be aerated for a few min utes every 10 minutes or so One possible solution might be two cascaded 555 tim ers The first 555 would determine the in tervals between aeration the second would control the duration of the aera tion periods While this approach seems workable 555 timers work best at maxi mum timing intervals of several minutes A 10 or 15 minute 555 timer can be de signed by using large RC values but its operation might not be reliable Figure 1 shows a better solution Here the output of a 555 or 7555 CMOS tim er is connected to the count input of a 4017 divide by 10 counter The 4017 con tains a binary counter and a built in 1 of 10 decoder The 555 is
195. switch on a small air pump to oxygenate the water in the bait well Af ter a few rounds of this my father asked if it might be possible to design a solid state timer that would switch the pump on for a few minutes every 10 minutes or so After I offered to equip the air pump with such a system it occurred to me that there are few circuits that command as wide a range of applications as timers In developed countries virtually every home is equipped with so many electro mechanical and solid state electronic timers that we take them for granted Try to imagine appliances like washing ma chines dryers and stoves without built in timers Stand alone timers are often used to switch on lamps or radios at night es pecially when the occupants are absent Then there are clock radios alarm clocks and watches miniature countdown tim ers darkroom timers and telephone tim ers Finally personal computers can be used in a variety of timing modes Despite the wide range of commercial ly available timers there remain many applications for which a custom timer must be designed A good example is the one suggested by my father Then there are applications for which a commercial digital timer would be ideally suited if on ly the device were equipped with a suit able output port such as a relay driver P describe examples of both custom timer circuits and modified commercial digital timers here Perhaps these circuits will find use in or
196. t by setting trimmer control R7 to mid position and the slug in L7 flush with the top of the coilform Place the transmitter near the TV receiver still turned on and tuned to channel 2 Drape the transmitter s antenna wire over the TV receiver s rabbit ears antenna and turn on the trans mitter Adjust L s slug until inter ference lines appear on the TV screen and the display to pause at the cor rect location Decide on the locations in which to mount the transmitters If possible orient the antennas vertically off the floor and away from metal objects including electrical wiring Fasten the sensors so that they toggle when monitored doors and windows are opened You can locate the receiving module in any convenient location within the protected premises where there s an ac outlet into which it can be plugged Then when the system is fully installed make several test runs to ascertain that the system is work ing properly Orient the antenna vertically At this point you can elect to have your system sound a siren or loud bell activate a sump pump turn ona sprinkler system turn on flood lights etc via the relay in the receiv er Be aware however that this re lay s contacts are rated for relatively light duty loads If you wish to have it control an item that draws a lot of power such as floodlights have the internal relay control an external power relay that in turn controls the load Parting Comment
197. t range 1 pF to lt a included 2000 uF LSI circuit provides high 31 2 Digital Multimeters reliability and curability e Lower power FEATURES e DC Voltage 100 uV 1000 V AC Voltage 100 uV 750 V AC DC Current consumption Crystal time base 200 uA 10 Amps e Resistance 20 Megohms Capacitance DVM 636 638 1 pF 20 uF e Protected from charged caoacitors e Overload Protection e Auto decimal LCD readout Polarity indication e 300 hour e Frequency range 800 Hz to 8 Hz battery life with 9V transistor battery Low battery indication Service amp Shipping Charge Schedule ASK FOR FREE CATALOG Continental U S A Money orders checks accepted C O D s require 2596 deposit FOR ORDERS ADD S25 S100 S45 101 S250 6 00 Toll Free 5251 500 8 00 501 750 1050 800 645 9518 te S1 00t 1500 S16 50 1 501 2000 20 00 In NY State 800 832 1446 2 001 and Up 52500 260 Motor Parkway Hauppauge NY 11788 CIRCLE 63 ON FREE INFORMATION CARD
198. t the smaller 2 ong size that is used in soda water makers and CO powered models These are available at hobby shops and hardware stores The larger 3 4 long cylinders used in BB guns are too long There are several ways to attach the neck of the cartridge to the iron Brazing silver solder and threading will all work if you have the neces sary equipment I used a 4 28 tap and die but a small hose clamp makes a very Satisfactory connection Drill out the neck of the cartridge to the same diameter as the tube on the iron Radio Shack s is 4 With a hacksaw cut two deep slots down the neck of the cartridge Center punch the opposite end of the cylinder and using pilot bits drill a hole Thread the hole using your 4 pipe plug or 1 4 27 N P T pipe tap Remove all burrs and sharp edges from both ends of the cartridge with a file Make a filter for the hose barb by rolling a 1 x 34 piece of copper window screen into a cylinder and in sert it into the hose barb Close the end of the screen by folding it over and soldering the end Using as little solder as possible seal the seam and put a small daub of solder to hold the filter in the fitting Next remove the tip assembly from the iron by loosening the larger setscrew Cut the tube off about 3 4 from the head Clean up any burrs or sharp edges with a file Install the as sembly back in the iron The ele ments that make up the deluxe de sol
199. ter When a normally open security switch is used Q3 and R11 must be omitted allowing the external secur ity switch to turn on and off the transmitter directly The Receiver Decoder Shown in Fig 2 is the complete sche matic diagram of the receiver de coder with Q operating as a super regenerative detector It serves as RECEIVER DECODER PARTS LIST Semiconductors IC1 LM358 op amp IC2 LMS567 tone decoder IC3 CM7555 CMOS timer 1C4 74LS90 TTL counter IC5 74LS42 TTL decoder Q1 2N918 npn transistor Capacitors C1 C3 90 0033 4F ceramic disc C2 C4 24 pF high Q disc C5 10 uF 16 volt radial lead electro lytic C6 0 037 4F Mylar C7 0 1 4F Mylar C8 10 pF high Q disc C9 22 yF 16 volt axial lead electro lytic C10 C11 1 F 50 volt axial lead elec trolytic C12 0 0022 ynF Mylar C13 0 015 pF Mylar C14 0 022 uF Mylar C15 0 0027 4F Mylar C16 0 0039 pF Mylar C17 0 01 uF Mylar C18 0 012 pF Mylar C19 0 018 F Mylar C20 0 027 uF Mylar C21 90 039 4F Mylar C22 220 pF 16 volt radial lead elec trolytic C23 5 pF high Q disc C24 100 yF 6 3 volt miniature radial lead electrolytic Resistors 1 4 watt 5 tolerance R1 2 200 ohms R2 R12 10 000 ohms R3 47 ohms R4 2 000 ohms R5 R6 R13 100 000 ohms R7 470 000 ohms R8 4 700 ohms R9 6 200 ohms R11 20 000 ohms R14 56 000 ohms R10 100 000 ohms 1 tolerance Miscellaneo
200. the phone wouldn t ring while you re sleeping One solution is to add a ringer on off switch Besides the trouble of turning the switch on and off there is also the possibility of forgetting to turn it back on and missing calls better solution is described here With it the ringer automatically silences when the room lights go off and turns back on when the lights go on A photocell installed in line with the ringer circuit of an inexpensive electronic telephone does the trick To make the modification simply open the phone s case and drill a 5 hole through the top half to provide an opening for the photo cell to show through Cement the photo cell with its sensitive surface facing out ward over the hole using plastic cement or silicone adhesive Then connect and solder an 8 hookup wire to each lead 5nip one of the wires going to the ringer s piezo buzzer Trim the wires at tached to the photocell as needed and connect and solder them to the ends of the wire you just cut For best results place the phone di rectly under the source of light for ex ample a bedroom lamp When light hits the cadmium sulfide Cds photocell Radio Shack Cat Mo 276 116 or equivalent the resistance decreases and the phone rings normally In the absence of light the resistance increases to the point where the phone will not ring The calling party will get the normal signal just asif the phone was ringing and you didn t answer it You c
201. them to become desoldered Final ly be sure to observe proper polarity when you connect the timer output leads to the SCR circuit Otherwise the SCR will not trigger properly Youcanuse a digital timer modified as described here to control indoor and out door lights a darkroom enlarger vari ous appliances and radios and televi sions For best results the interface cir cuit should be installed in an appropriate enclosure equipped with an output jack or a pair of binding posts connected to the relay s terminals The timer can be at tached to the enclosure with self adhesive hook and loop fabric strips This will permit you to remove the timer to change the battery or to use it for some other application Warning You must follow safe wiring procedures if you use this or any of the other circuits described above to control devices controlled by the ac line Insulate all exposed connections Do not exceed the contact rating of the relay Of course these timer circuits should not be used in any application in which a circuit mal function or power interruption might cause injury to people or property Going Further The best known analog timer chip is the venerable 555 If you would like to find out more about this versatile chip you might wish to see Engineer s Mini Note book 555 Timer Circuits one of a series of inexpensive 99 to 1 49 books I have written for Radio Shack If digital timers appeal to you and po
202. then will output the product of that input and the digital word These are called multiply ing D A converters One important use is as digitally controlled attenuators for audio and video applications If you are allowed to input only a posi ANALOG 9 45V OUTPUT 0 2 56 V top view tive voltage to a multiplying converter you have a one quadrant circuit If you can input either positive or negative ana log values you have a two quadrant converter Finally if you can input either positive or negative analog values as well as negative or positive digital values by using a suitable code you end up with a four quadrant multiplying converter Multi quadrant converters are consid erably more expensive and complex than the one quadrant versions Pricing of D A converters starts from under a dol lar each Figure 5 shows a simple circuit of an older low cost microprocessor compati ble D A converter Important suppliers of sanely priced D A converters include Analog Devices and Texas Instruments What s new in tech lit Lots of good technical stuff has shown up in the mail lately The Tntersil Appli cation Handbook has lots of goodies on data acquisition and A D conversion in it From SGS came an L 296 switching regulator evaluation kit that s free if you send a request on letterhead The kit in D2 03 D4 D5 D6 D gt O O 000 Isb msb DATA BUS
203. to independently position the magnified sweep with reference to the unmagnified sweep Magnifica tion is selectable in 5x 10x and 50 x levels With its 500 u4V sensitivity the Model 2225 is four times more sensi tive than previous Tek Model 2200s which makes it ideally suited to ap plications involving low level signal measurements The high sensitivity vertical channels can be used in a dif ferential mode for making signal comparisons as well as in an add mode Trigger filtering allows the user to selectively filter out unwanted low or high frequency components from the trigger signal Other features in clude normal peak to peak auto single sweep and TV line and field triggering variable holdoff for trig gering on complex waveforms a beam finder for quick waveform lo cation simplified front panel layout high brightness contrast flat CRT with built in graticule and carrying handle that doubles as a tilt stand Also available is a Model P6103 10x 50 MHz passive probe with screw in replaceable probe tip 995 for Model 2225 oscilloscope less than 50 for Model P6103 probe CIRCLE 30 ON FREE INFORMATION CARD Picture Within Picture VCR RCA has announced the first video cassette recorder for the home mark et capable of providing two separate programs simultaneously on the same TV screen Its picture within picture capability lets the viewer watch a taped program and in a sep arate on screen window
204. tput from IC5A remains low 7C3 will hold the last BCD number from the receiver This means that each LED in the DISI array corresponds to a unique transmitter location After pausing for a few seconds DISI returns to scanning If a trans mitter is still active the display again pauses on the appropriate LED Construction You build the Wireless Home Secur ity System in stages starting with the transmitter s Printed circuit board wiring is recommended for all cir cuits The actual size etching and drilling guides for the transmitter receiver decoder and power sup ply display pc boards are shown in Figs 4 5 and 6 respectively You can fabricate your own pc boards us ing these guides or purchase ready to wire boards from the source given in the Note at the end of the Power Supply Display Parts List Select a plastic enclosure it can Say You Saw It In Modern Electronics C8 22 yuF 16 volt axial lead electro lytic C9 1 4F miniature radial lead electro lytic C10 0 1 n F Mylar Resistors 5 tolerance R 6 2 ohms watt R2 R3 R10 750 ohms watt R4 R6 R7 R8 R9 10 000 ohms V4 watt R5 100 000 ohms watt Miscellaneous K1 12 volt spst relay Omron No G2U 112P US PB Piezoelectric buzzer any 5 volt type RFC R f choke on No FT 23 43 toroid core see text S1 Normally open momentary action spst pushbuttor switch T1 12 volt ac wall transformer Printed circuit boar
205. ude a small pipe clamp a modified CO cylinder and a hose barb left to right above desoldering iron can be used for the Super Solder Sucker PVC tubing is available at most hardware stores It is inexpen Sive but is not heat resistant and is not as flexible as rubber It can only be used with the basic version Pref erable for this project is silicone rub ber tubing such as the kind used as fuel line on model aircraft engines I used Aerotrend extra large no inch size is given which is sold by the foot at most hobby shops It is extremely flexible and won t melt if you touch it with the hot tip of a soldering iron Radio Shack s catalog no 64 2060 desoldering iron can be easily con verted for use with the foot pump You can of course use a similar de soldering iron from another source if you wish To convert the soldering iron for desoldering purposes you must first fabricate a solder collecting chamber using a spent CO car tridge Caution Use only a CO car tridge not a butane propane or N O nitrous oxide cartridge Any other cartridge although dis charged could contain enough resi dual gas to explode during the ma chining process Also do not release the CO gas by puncturing the seal with a nail If you do the cartridge could become a dangerous missile Ask the dealer from whom you pur chase the CO cartridge to discharge it for you CO cartridges come in two sizes Ge
206. unted cas sette changer player that plays up to six tapes in any order fiber optic link that uses a single pulse coded digital light beam couples the control head unit and the player changer to greatly reduce ignition noise from entering the system The cassette changer features a tape magazine that can be individually set to the appropriate type of noise reduction dbx Dolby B or Dolby C for each tape an HLTAC tape head Alpine s GZ transport mechanism an Auto Cassette Initializer that rewinds the selected tape to its beginning and a Programmable Music Sensor that lo cates any of nine selections per tape New Radar Detector Road Alert 30 heads up a new line of radar detectors from Sparkomatic This dual conversion X K band de tector features antifalsing circuitry that identifies and eliminates inter ference signals to assure accurate ra dar detection Among its other fea tures are a LED signal strength The AM FM stereo radio unit of fers 12 FM and 6 AM presets unique Radio Monitor function al lows listening to the radio when a tapeisin fast forward or rewind The LCD time frequency display ap pears in green in the tape and red in the radio modes Specifications Tape 0 05 wrms wow and flutter 20 to 20 000 Hz 3 dB frequency response 40 dB sepa ration 86 72 64 55 dB S N with dbx Dolby C Dolby B no noise reduction Tuner 1 8 pV usable FM sensitivity 12 pV AM 2 0 dB cap ture ratio 35 dB se
207. us FB1 FB2 Vhf ferrite bead RFCI RFC2 R f choke 14 turns 28 gauge magnet wire wound on No FT 23 43 toroid core see text Tl Receiver transformer special order only see Note below Printed circuit board sockets for ICs 22 gauge stranded hookup wire 8 7 conductor ribbon cable ma chine hardware solder etc Note For components and kit availabili ty see Note at end of Power Supply Display Parts List 40 MODERN ELECTRONICS November 1986 Say You Saw It In Modern Electronics c8 1 pF C1 0 0033 pF 7 conductor ribbon cable from power supply display circuit EI R6 C6 R8 0 039 uF 4 7K NOTE IC1 LM358 O A C12 0 0022uF C13 0 015 pF IC5 74LS42 Fig 2 Schematic diagram of receiver tone decoder circuit both an r f amplifier and an AM de tector Transformer T is tuned to the 49 890 MHz carrier The incoming signal from the an tenna goes into the C4 L tank cir cuit and combines with the 49 MHz oscillator signal causing the ampli tude of the oscillations to increase If the incoming signal is amplitude modulated oscillation strength var ies in accordance with the variations in amplitude of the received signal Any audio tone that amplitude modulates the transmitter appears as amplitude variations across QI s base emitter junction Although it s tuned to oscillate at radio frequen cies QI has considerable gain at Say You
208. ushrod Drill only through the plastic Stop when the bit contacts the metal rod Now sup porting the piston in a vise without GU i m vd Fig 3 Carefully drive the pushrod down using a hammer and punch Fig 4 Center punch the pushrod be fore drilling the hole for the screw that holds the cylinder in place Say You Saw It In Modern Electronics November 1986 MODERN ELECTRONICS 61 Fig 5 Using a hammer and block of w ood ge rod until it is flush with the end of the rod gripping the pushrod carefully drive the rod down using a hammer and punch or metal rod Fig 3 It is not necessary to hammer hard the plastic will shear where the piston meets the rod Next holding the piston in the vise with the aid of rubber jaw faces or blocks of wood drill through its cen ter using a bit the same size as or pre ferably a little smaller than the pushrod You want a press fit when remounting the piston The end of the rod must be drilled for the screw that will hold the piston onit If you have a tap an 8 32 screw is the right size If not a 8 x 1 4 or sheet metal screw will work fine If you use the tap drill the hole with a 29 drill or drill The 8 sheet metal screw also takes a 94 bit and definitely center punch the rod be fore drilling Fig 4 Holding the rod vertically in the vise keep the top on axis with the piston and carefully cut the threads i
209. uyers think 495 is too steep for the adult program s features and support they can console themselves with the thought that they re paying off his house More Than a Modem Even before this summer s new Tandy models made mine an orphan I was suf fering from a common ailment among PC Gf not XT owners the five slot blues With expansion slots stuffed with my video board 384K multifunction board and disk controllers I couldn t reconcile my need for a modem with my dreams of other add ons What to do Buy Practical Peripherals Multifunction 1200 a 13 inch board that combines a memory and interface card with a 300 1200 baud modem The Practical 1200 bristles with fea tures jumpers and DIP switches ade quately explained by decent documenta tion There s a clock calendar you have to change a DIP switch after setting it a serial port switchable for communica tions or printer use and a parallel port that dangles from an auxiliary cable and helpfully changes from LPTI to LPT2 if you already have a parallel port on your video card As for the modem it s Hayes compat ible I made text and Xmodem transfers with several auto dial auto answer pro grams and bulletin boards squawks and beeps just as loudly as other internal mo dems and generally works like a charm I m pleased with Practical s five year warranty too Carrying 512K memory the board ex pands a 256K computer to 640K plus 128K for the supplied pri
210. ve to use a commercial unit Most commercial digital timers actu ate a piezoelectric buzzer at completion of their timing cycle It s possible for the timer to drive an external relay by using the buzzer signal to switch the gate of an SCR I ll explain how this is done short ly but first I want to review some specific digital timers The simplest and most common digital timer is a digital watch or clock operated in its alarm mode Since both watches and clocks can be opened it should be possible to connect an external device to the terminals of their piezoelectric buzz ers However successfully connecting leads to the tiny circuits of digital watches and some digital clocks may prove to be very difficult The best stand alone digital timers in clude a front panel keyboard for pro gramming One such unit is the West Say You Saw It In Modern Electronics bend Electronic Timer This count down timer has a liquid crystal display and sounds an alarm after a user pro grammed interval of from 1 second to 99 minutes and 99 seconds The unit is pro grammed bv keying in the desired delay and pressing a start button When the count reaches 00M 00S on the display the timer emits a series of chirps The alarm can be silenced by pressing a stop reset Key Another widely available timer is the KMC Handy Timer This unit which doubles as a digital clock has a 24 hour maximum countdown time Though the display indic
211. w monitor does full 65C816 as sembly disassembly tracing and de bugging It also includes the SANE float ing point numerics set with up to 80 bit precision A new front desk bus is supported by a second microprocessor This is sort of a party line for input mice keyboards keypads trackballs graphics tablets whatever The keyboard itself is config urable into nearly two dozen different languages and layouts including Dvor ak Internal character sets are available for most major languages everywhere in the world Things are a mite hectic around here just now but as soon as I get some real hands on time with my machine I ll give you a full report In the meantime you can use our Hardware Hacker help line as a II GS hotline I need a very cheap EPROM eraser How does 6 sound Read on EPROMS short for erasable and pro grammable read only memories are ideal hacker components in that you can re program them over and over again To 39K 1 2 watt Ae 350 volts Brel Say You Saw It In Modern Electronics 4 ANALOG OUTPUT 0 5 V Fig 3 A manual D A converter erase an EPROM you have to expose it to very strong ultraviolet light that has a very short wavelength of 2532 Ang stroms This wavelength is far shorter than most UV poster lamps rock hound lamps or germicidal types so a very special lamp is needed Up to now you had two ways to erase an EPROM
212. want to select a larger less flat one This will allow you to ar range things so that the LEDs mount on the front panel via small grom mets or panel clips and the 12 volt ac and interface cables plug into stan dard power and DB 25 connectors respectively mounted on the rear panel Locate the LEDs directly in line with their respective input jacks Make sure to use insulating tubing on the leads of the LEDs Connect the positive probe of a dc voltmeter to pin 3 or 4 of IC2 the negative probe to ground Set the meter to a 10 volt full scale range and plug in the wall transformer You should obtain a reading of ap proximately 5 volts Now connect the positive and negative probes to the and pads of C4 and note that the reading now is approximate ly 5 to 5 6 volts If everything appears to be okay unplug the trans former and install IC1 and JC2 in their respective sockets Make sure both ICs are properly indexed as shown in Fig 5 before seating them in their sockets Finish assembling the project Then use a dry transfer or other type of lettering kit to label the LEDs as shown in the lead photo Interfacing amp Calibration A 25 pin DB 25 is the most likely se rial port connector on your comput er Sincethe gender of this connector can vary from computer to comput er you must obtain the mating half to connect to the Analog Acquisition Unit If the serial port on your com puter is configured to operat
213. wer for this circuit is de livered through a 12 volt ac wall transformer via the 12 Vac input connectors An optional 12 volt backup battery can be wired across the connectors at the upper left Electrical noise is filtered out of the line by RFC1 and RFC2 radio frequency chokes and CZ through C4 and DI prevents current flow from the ac driven supply into the battery supply A 5 volt power supply is made up of RECTI ICI C5 and C6 Ex cept for K1 and the LEDs that make up the display and indicator systems ry TENELO SR a Aen MU Doce CER MN E S1 C9 R6 RESET JP 10K DI R2 1N4001 750 LEDI Q 750 ALARM which operate from the pulsating 12 volts dc available at the output from RECTI all receiver decoder driver circuits are powered by the 5 volt supply When a tramsmitter is active the logic 0 pulse generated by the tone decoder in the receiver is coupled in to the Fig 3 circuit via pin 2 of the miniconnector through C7 into timer IC4 s trigger input at pin 2 The timer lengthens this pulse to a few seconds and passes it to IC5A The low signal at pin 3 of IC5A is then used to arm piezoelectric buzzer PBI to tell you that a transmitter has been activated The low output from ICSA also sets a flip flop made up of 42 MODERN ELECTRONICS November 1986 NOTE IC5 74LS03 e x B D2 i 1N4001 K1 POWER 8 pin connector with 8 conductor ribbon cable R9 10K
214. y coded 2 of 8 output Clocked by low cost 3 58 MHz crystal not incl With data circuit examples 4276 1303 12 95 Voice Synthesizer Team SPO256 AL2 Speech Synthesizer Easy to interface with most computers With detailed data and circuit examples 28 pin DIP 2276 1784 12 95 CTS256 AL2 Text to Speech IC Translates ASCII char acters into control data for synthesizer Connects to RS 232 With data 40 pin DIP 4276 1786 16 95 go witch A Rama 16 17 19 16 Illuminated SPDT Push On Push Off 3 amps at 120 VAC Lamp requires 12 volts 4275 676 4 95 17 Round Button Version 4275 677 4 95 18 SPST Rocker Switch Rated 6 amps at 125 be Mounts in 3 4 hole 4275 690 19 DPDT Knife Switch Screwdriver terminals i projects antenna switching model trains Rated 0 5 amp at 250 VAC 275 45375 M 158 WW I e 99 Antennas Selection and Installation are v Improve Your Reception This new book is packed with information on TV FM CB Cellular phone Satellite and shortwave antennas It helps you choose the best antenna for your particular needs and provides valuable installation tips Illustrated 8562 1083 xa 3 95 Dual DC Power Supply Selectable Independent Slave Modes 59595 Quality and fealures you wouldn t expect at this low price Adjustable O to 15 volts up to 30 volts in series mode Has front panel meter for cur
215. zt Felt tip marking pen see text Teflon tip From Sold a vac No 8 x 4 sheet metal screw and flat washer Misc Teflon pipe tape or RTV sezler petroleum jelly roll or cotter pin see text flat washe 4 pipe plug copper screening rail and 4 x 4 x 4 plywood for stand Note The following items ace available from O H Electronics P C Box 564 Say You Saw It In Modern Electronics Wind or CA 95492 0564 Unmachined foct aperated tire pump far 6 50 dis caerzzd CO cartridge for 1 00 two hose barbs for 2 00 6 feet of silicone rabter tubing 6 00 or 1 3 per foot larze 10se clamp for 1 0C small hose ciam p for 75 2 copper screening for 1 25 and screw and washers for piston salit tin and Teflon tape for 1 00 com plete kit of above parts for 19 50 Also available are foot pump ki with all ma dhinizg done includes pums one hose ta b large hose clamp and xiscellaneous tardsare but no silicone tubing for 19 50 machiaed desolde mg iron kit inc ude Radio Shack des kiering iron CO za tridge hose barb and copper creer ing but no silicone radber tubing to 9 75 complete macFiaed kit with all izems to assemble Deluxe Super Solder Suc lt r including tubing fcr 32 95 Pay by check or money order A11 4 50 P amp H for each kit California residents please add ate sales tax to protect it from the hammer If you cut a slot in the cap to

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