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Kenwood TH-D72A Dual Band Handheld Transceiver

1. D72A transmitted a position beacon The communication is bi directional as received positions appeared on the G5 screen and accumulated in its APRS Contacts list This interface can also be used with Davis and Peet Brothers weather stations via menu selection A wiring diagram is provided in the documentation to support these connections GPS Receiver System I am an avid power walker and wear a Garmin GPS watch to capture my treks and record my stats for later review I am able to export a file that can be imported into Google Earth Once I have done that I can share my treks with my friends So one of the first things I wanted to learn was if I could use the TH D72A s internal GPS receiver in similar fashion The answer is yes In ad dition to providing position information to the internal APRS there is full flexibility as to what you can do with the GPS receiver data Before I left for my walk I went into the Figure 1 The jog control at the upper left of the keypad is used to navigate through the menus Figure 2 Station list with QSY frequency information see text received at another D72A or D710A it is indicated on the Station List Figure 2 On the TH D72A while viewing the Station List pressing MENU and selecting TUNE will tune the non data band to the QSY frequency tone and shift if provided of the selected sta tion I tested to see what the D710A would do with the additio
2. max 440 MHz 0 13 1 4 V max Audio output 0 3 W 0 44 W at 10 THD into 8 external speaker THD at 1 V RMS 1 9 Transmitter Transmitter Dynamic Testing Power output VHF 5 W high 0 5 W low 146 MHz 5 3 W high 0 6 W low 0 05 W economy low 0 1 W eco low 440 MHz 5 3 W high 0 5 W low 0 1 W eco low at 8 4 V dc full charge Spurious signal and harmonic suppression 146 MHz gt 70 dB 440 MHz gt 70 dB gt 60 dB highest transmit power meets FCC requirements Transmit receive turnaround time PTT release Squelch on S9 signal 136 ms to 50 of full audio output Not speci ed Receive transmit turnaround time tx delay 70 ms Not speci ed Size height width depth 5 5 2 3 1 6 inches including projections Weight 13 1 ounces Price 500 PB 45L 7 4 V 1800 mAh Li ion battery supplied Replacement battery 90 PG 3J cigarette lighter adapter 40 PG 2W dc power cable 20 KSC 32 rapid charger 65 BT 15 battery case 6 AAA cells 35 Measurement was noise limited at the value indicated the LIST key displays the last five received stations call sign SSID time heard and QSY frequency indicator eg W1HSR 6 16 04F the F indicates that there is a QSY frequency in the Status text field more on this later You can use the jog control to navigate the station list There are nine pages of informa tion for each station tha
3. ed Intermodulation distortion IMD Not speci ed 3rd 5th 7th 9th order 23 43 54 62 dB below PEP Size HWD 4 2 6 9 11 inches including protrusions weight 4 6 lb Price 479 These are new measurements described on the QST in Depth website at www arrl org qst in depth July 2011 51 Bottom Line Tennadyne T 28 VHF UHF Log Periodic Antenna The Tennadyne T 28 log periodic is ruggedly built and will get you on six amateur bands with some gain and a single feed line 25 W output for an IF drive level of 10 mW gain is adjustable internally or an external low power HF transceiver can also be used On receive better than 1 0 dB noise figure and 17 dB of conversion gain help you hear weak signals without the need for a preamp The unit operates from 12 V dc and draws 6 A maximum The transverter s enclosure is topped with an oversized heat sink and cooling fan see Figure 4 you can run this unit hard at full power and it should be able to dissipate the heat easily The transverter seemed to be rugged enough for rover use The transverter is available as a kit as well as fully assembled the model tested ARRL Lab measurements can be found in Table 2 Interfacing and Using the L222 28 The L222 28 can be configured to split the receive and transmit inputs and outputs or combine them into a common signal path standard Keying requires the usual switch to ground PTT signal positiv
4. getting the Nylok nut started on the screw Both 3 8 and 5 16 inch nutdrivers are required for this operation and a punch awl is handy for lining up element holes inside the boom A portable workbench with a vise to hold the boom while you work makes things easy Once each individual boom is assembled double check that you have the right element in the right place before final assembly and attachment of the feed line Figure 7 shows the partially completed antenna Mounting the antenna on the mast is straightforward and can be done by one per son The antenna weighs less than 20 pounds but it is unwieldy and with so many elements you have to hold it above your head while attaching the boom to mast hardware The mounting point is not at the balance point there is more weight towards the front of the antenna so if that is important perhaps Figure 6 The parts and pieces received from Tennadyne Assemble the antenna over a smooth surface to prevent losing any dropped pieces Figure 7 Be sure to alternate the elements as described in the manual Figure 8 The T 28 at about 35 feet looks a lot like a TV antenna while doing an effective job on six amateur bands you have a lightweight mast you ll want to add some weight in the hollow booms at the rear Metal rod or bar works well and can be secured with a screw through the boom T 28 Performance Up in the air with plenty of time before the VHF Sweep
5. Once a station is heard the volume can be increased When you re listening to CW or SSB signals you ll want to turn the REGEN control until the circuit begins oscillating Educational and Fun Please remember while this is a Ten Tec it s not a Ten Tec Eagle transceiver The 1054 is a simple regen receiver which means it is sensitive but not selective Even so I suspect even a veteran ham will get a fair amount of enjoyment from this kit With a 30 foot piece of wire I listened to many amateur and short wave stations In fact I was pleased enough to purchase the optional solid wood case with speaker The Ten Tec 1054 is a perfect first kit for a beginner or a clever entertaining diversion for the experienced amateur Manufacturer Ten Tec 1185 Dolly Parton Parkway Sevierville TN 37862 www tentec com tel 800 833 7373 39 Oak accessory cabinet 39 Bob Allison WB1GCM ARRL Test Engineer wb1gcm arrl org What s a low cost electronic kit that can be built in a couple of hours by a novice builder That s the question I pondered while planning this year s kit building exhibition at the ARRL Expo at the Dayton Hamvention Novice builders of all ages have sat in our Expo work area to build small but useful Amateur Radio related kits for the past two years enjoying the ex perience of following instructions soldering and using hand tools while being mentored along the way To accompa
6. not to overdrive the transverter and it pretty much does the rest The trans verter s model number 222 28 describes the frequency conversion process to operate on the 222 1 MHz calling frequency required that I set the radio to 28 1 MHz The unit can withstand high SWR although probably not indefinitely at full power input also per sonally verified SSB and CW reports were good both strength and quality I had an odd monitor feedback problem at first but that turned out to be a radio configuration error Manual and Examples The manual for the transverter is okay it has have enough information to get you from the cardboard box to putting out a signal but in a dense format that assumes a lot of the new user or builder Equipment such as a transverter that is used in association with other gear can be very hard to install cor rectly sometimes luckily not in my case leading to accidental damage I realize that the manual cannot contain an example of every possible radio interface but manufacturers should encourage their users to post descrip tions of their successful configurations on the company website or in a free Yahoo or Google group By definition transverter customers need this information make it easy for them to find it without having to spend time searching the Internet Summary If you are considering adding 222 MHz to your rover or base station the L222 28 is a solid package ruggedl
7. used in some displays is easily readable Included in the box are the antenna wall charger USB interface cable A Mini B type PB 45L 1800 mAh Li ion battery belt hook instruction manual and a CD with detailed information on all the features and options MCP 4A Desktop Software MCP 4A desktop software USB drivers and firmware updates are available for free download from the Kenwood website The software interfaces with the D72A via its USB port Such software is almost a neces Kenwood s TH D72A seam lessly folds APRS operation and a packet TNC into a full featured easy to use dual band handheld Reviewed by Howard Robins W1HSR ARRL Contributing Editor w1hsr arrl net My adult working life began in 1969 in a digital integrated circuit develop ment lab at Bell Telephone Laboratories in Allentown Pennsylvania So I have more than a casual interest in how the technology has evolved I suppose I should not be so impressed with this handheld when I think about all the things my smart phone can do I am impressed though Kenwood has es sentially put TM D710A mobile radio functionality plus a GPS receiver sys tem into a rugged weather resistant package that runs for a long time on a rechargeable Li ion battery fits in your hand and can be worn on your belt 1 It s a big step forward from the older TH D7A that I used previously 2 In addition to being a great sounding true dual band rad
8. 46 July 2011 1H Robins W1HSR Kenwood TM D710A Dual Band Mobile Trans ceiver Product Review QST Feb 2008 pp 45 48 Past QST reviews are available to ARRL members at www arrl org product review 2H Robins W1HSR Kenwood TH D7A G Dual Band Handheld Transceiver Product Review QST Apr 2008 pp 45 47 and S Horzepa WA1LOU The Kenwood TH D7A Dual band H T QST Aug 1999 pp 58 62 3APRS is a software program and registered trademark of Bob Bruninga WB4APR interference and audio distortion caused by intermodulation from nearby signals The TH D72A has all the features normally found in a modern dual band handheld and they work well and are easy to use Most hams will buy this radio for the unique APRS and packet features and I ll concentrate on those areas in this review Description The TH D72A top panel has a male SMA ANTENNA connector GPS receiver antenna concentric twist controls for VOL UME and for channel frequency option control On the left side are buttons for PTT LAMP and MONITOR SQUELCH The right side has the following ports that are covered with rubber flaps ear phone 2 5 mm microphone 3 5 mm mini USB APRS COM 2 5 mm and 13 8 V dc input On the face are a POWER switch and an 18 button keypad The four posi tion jog control is used to index through and select menu options Figure 1 The high resolution LCD is quite good Even the smaller font
9. ansmit 2 0 A 30 mA power save 133 mA TNC on high 0 8 A low 0 5 A eco low at 7 4 V dc no signal transmit 2 0 A high 0 7 nominal voltage with external 13 8 V dc A low 0 4 A eco low at 8 4 V dc full 1 6 A transmit high power charge 1 4 A high power at 13 8 V dc Receiver Receiver Dynamic Testing FM sensitivity 12 dB SINAD lt 0 18 V For 12 dB SINAD Band A 146 MHz Band A lt 0 22 V Band B 0 14 V 440 MHz 0 16 V Band B 146 MHz 0 15 V 440 MHz 0 15 V FM two tone third order IMD dynamic range 20 kHz offset Band A 146 MHz 74 dB Not speci ed 440 MHz 69 dB 10 MHz offset 146 MHz 81 dB 440 MHz 70 dB Band B 146 MHz 73 dB 440 MHz 69 dB 10 MHz offset 146 MHz 79 dB 440 MHz 70 dB FM two tone second order IMD dynamic range Band A 146 MHz 89 dB 440 MHz Not speci ed 99 dB Band B 146 MHz 89 dB 440 MHz 98 dB Adjacent channel rejection Not speci ed 20 kHz offset Band A 146 MHz 77 dB 440 MHz 69 dB Band B 146 MHz 73 dB 440 MHz 68 dB Spurious response Not speci ed IF rejection Band A 146 MHz 122 dB 440 MHz gt 133 dB Band B 146 and 440 MHz 121 dB Image rejection Band A 146 MHz gt 134 dB 440 MHz gt 133 dB Band B gt 133 dB Squelch sensitivity lt 0 13 V At threshold Band A 146 MHz 0 14 1 4 V max 440 MHz 0 15 1 6 V max Band B 146 MHz 0 13 1 4 V
10. ate You can manually enter or save marked waypoints as target points Up to five such points can be saved and used as a navigation tool By this I mean that the radio with the GPS locked on your position can tell you distance and direction to the target The TH D72A s real time clock is set by the GPS and there is a menu item to set your local time zone Packet TNC I put the TH D72A into PACKET12 mode by pressing the TNC 2 button on the keypad PC access to the internal TNC is via the USB port so I used HyperTerminal on my PC run ning Windows XP Home Edition The Packet PDF file that comes as part of the instruction manual CD does not tell you how to physically connect to the TNC via USB or serial port Also that PDF docu ment includes a list of the commands that the TNC is supposed to respond to I tried to set up the internal mailbox but none of the mailbox commands worked I sent e mails to Kenwood Support concerning these issues and received responses from them within a few hours Unfortunately they told me that the command list was copied from the TM D710A user manual and that the TH D72A does not have a packet mailbox I was able to connect to the internal TNC and found a fairly robust AX 25 command set I tested the switch from 1200 to 9600 baud and observed that the icon on the LCD did change from PACKET12 to PACKET96 with the parameter change I had no way to actually test 9600 baud packet with a
11. ble packet station and it worked flawlessly at both ends I sent a message to the D72A and it sent back the automatic reply message that I had set up Then I replied to the message using preset phrases and they were received I also created a new message using the keypad and the twist control on top That was pretty easy to do Using the twist control as you move one character position to the next the last character used is in the buffer so you are not always starting at the beginning of the character set I find this efficient Message and Bulletin Group filtering is supported so you can set it up so only group members can exchange messages APRS Serial Port Interface I tested the TH D72A with my AvMap G5 GPS receiver using the APRS serial port and an interface cable that I use with my TM D710A There are port settings that can be made using the keypad in menu mode or via the MCP 4A software and the USB port and cable I set the baud rate to 9600 input to GPS and output to waypoint Waypoint can be set to NMEA Magellan or Kenwood I used Kenwood and nine character length Once all these settings were loaded simply pushing F function and MARK GPS 1 toggled between the internal and external GPS In external GPS mode the icon on the LCD changes from iGPS to GPS After satellites were located and my position was known the GPS icon changed from static to flashing the G5 and D72A were talking to each other and the
12. contester with one of the now ubiquitous HF VHF UHF transceiv ers an IC 7000 that covers all amateur bands from 160 meters through 70 cm Except that is for the 11 4 meter band of 222 225 MHz ARRL VHF contests have a four band Lim ited Rover category www arrl org general rules for arrl contests above 50 mhz that dangles the tantalizing 11 4 meter carrot before the noses of Missouri mules like me who have the easy three 6 2 and 70 cm but haven t made the leap to a fourth band So when the ARRL asked if I d like to give the 25 W version of the Down East Microwave DEM L222 28 transverter a try it was an easy yes Not one to leave any cookies in the jar I suggested adding a four band antenna to the review the Tennadyne T 28 described in the accompanying review Done with the January ARRL VHF Sweepstakes contest coming up it was game on L222 28 Transverter Overview The L222 28 s standard version has a Down East Microwave L222 28 11 4 Meter Transverter Bottom Line The Down East Microwave L222 28 transverter is a fine solution for ama teurs looking to expand station cover age to the 11 4 meter band It can be adapted to interface with a variety of radios and receives and transmits well Figure 4 The L222 28 transverter features a simple front panel and an oversized heat sink The power meter is an LED bar graph style Figure 5 The rear panel of the L222 28 f
13. e keying is also supported and four step sequencing is also provided An option for RF sensing is provided and a negative voltage ALC output is available on the rear panel AUX connector to control transceiver output power Figure 5 shows the connections available DEM in cludes a useful selection of connectors and adapters for both control and RF connections I appreciate that gesture As a rookie transverter user I made pretty much every configuration mistake you could make I could sense the L222 28 patiently waiting for me to get the interface configura tion right sighing deeply and drumming its fingers on the shelf Involving both radio and transverter this process was not trivial and while a setup process is given in the manual it s not all that easy to figure out DEM offers a helpful page on transverter interfacing on their website See the section Manual and Examples The user s manual is essentially drawing free block diagrams needed and the technically dense text assumes a familiar ity with VHF UHF operation that I don t yet have Nevertheless I persevered and then I got it the combination of rig settings and IF connections got er done and at the next tap of the key paddle the L222 28 s power meter LEDs blinked red and my wattmeter needle jumped up scale I was on 11 4 meters CW and SSB Once you get the transverter and radio hooked up correctly operation is automatic You take care
14. e used as a TV antenna if you used an appropriate diplexer or antenna switch It might require a bit more rotator than the standard TV antenna I m using a Ham IV but a sturdy installation is in everyone s interest if you get my drift I m sure the armchair lawyers are already wondering about antenna restrictions and TV reception and that sort of thing This is not a high gain antenna the specifications claim 6 3 dBd and that s about right from what I observed on the air The front to back ratio was observed to be anywhere from 3 to 5 S units 18 to 30 dB at 6 dB per S unit during the contest Tip do not try to do a product review and make a decent contest score at the same time All in all it was a lot better than a dipole or whip and not as good as long boom Yagis on taller towers Assembling and Installing the T 28 Figure 6 shows the parts that you get when you open the box and sort them out there are lots of pieces including small ones The smaller tubes are not bagged count them before beginning and be sure you have retrieved all 56 element halves from the packing Read through the instructions com pletely before beginning and practice with the elements clamps and inserts to be sure of correct assembly Make sure you understand 52 July 2011 a Bird wattmeter to measure the SWR on 6 2 11 4 meters and 70 cm with the following results averaged across each band through 50 feet of RG 213 c
15. eatures an AUX connector with all control signals so that no additional connectors are required if the con guration is changed Table 2 Down East Microwave L222 28 11 4 Meter Transverter serial number 1015 Manufacturer s Speci cations Measured in the ARRL Lab Frequency coverage Receive and transmit As speci ed 222 223 7 MHz Power requirements Transmit 6 A maximum Transmit 3 85 A at 25 W output 13 8 V dc Receive not speci ed receive 520 mA at 13 8 V Modes of operation CW SSB AM FM PSK As speci ed Receiver Receiver Testing Conversion gain 17 dB minimum 28 MHz 18 6 dB 29 7 MHz 17 3 dB Noise gure lt 1 0 dB 0 8 dB Image rejection Not speci ed 103 dB Third Order Output Intercept Not speci ed 9 dBm Transmitter Transmitter Testing Frequency accuracy Not speci ed 28 000 MHz in 222 000004 MHz out 0 018 ppm error Frequency drift not speci ed After one hour in standby ve cycles of 30 s key down 30 s key up 0 04 ppm or 9 Hz After 10 minutes key down 0 09 ppm or 20 Hz Transmit RF input 10 mW maximum Adjustable see text Transmit RF output 25 W As speci ed Power output drift not speci ed After one hour in standby ve cycles of 30 s key down 30 s key up 0 4 or 100 mW After 10 minutes key down 1 2 or 300 mW Spurious and harmonic suppression 73 dB meets FCC requirements Not speci
16. h APRS12 PACKET12 and NO TNC With APRS12 the internal GPS locked on position and BCON displayed BEACON button pressed to turn on beaconing the radio transmits that position Station ID icons are supported for 57 stations versus about 30 on the D710A others have been added in subsequent firmware updates Station List There is capacity to store information for 100 received stations New data replaces old for the same stations on the Station List and the 101st station will replace the oldest on the list Repeatedly pressing the LIST key cycles through different display options The first press displays the last three stations received call sign and secondary station identifier SSID The next press displays the last five received stations SSIDs and their equipment for example W1HSR 6 TH D72 using a reduced font size The third press of Table 1 Kenwood TH D72A serial number B0B00353 Manufacturer s Speci cations Measured in ARRL Lab Frequency coverage Receive Band A As speci ed 136 174 MHz 410 470 MHz Band B 118 174 and 320 524 MHz transmit 144 148 MHz 430 450 MHz Modes FM Data FM FM narrow data Power requirements With PB 45L battery pack Receive battery power 325 mA max receive with no signal 100 mA single band volume no signal lights on dual band 150 mA dual band 135 mA TNC on no 150 mA standby lights on dual band signal 30 mA battery saver on tr
17. io can operate on two bands at a time with wideband receive capability the TH D72A includes an internal GPS receiver Automated Packet Reporting System APRS and a fully functional 1200 and 9600 baud packet radio terminal node controller TNC 3 Digipeater EchoLink Sky Command II and weather alert are also included capabilities The D72A includes a feature called Advanced Intercept Point AIP which helps eliminate PRODUCT REVIEW Mark J Wilson K1RO Product Review Editor k1ro arrl org Bottom Line Key Measurements Summary 2 M 70 cm Off Scale Key Values shown are for band A receiver PR061 250 50 T R 136 Tx Rx Turnaround Time ms 136 100 800 Snd 440 Audio Output mW 60 110 Img Image Rejection dB 134 133 60 110 IF 133 IF Rejection dB 122 ChRej 50 90 69 Adjacent Channel Rejection dB 77 40 70 I3 Rx 69 20 kHz Receiver 3rd Order Dynamic Range dB 74 20 kHz I3 Rx 70 10 MHz 90 60 Receiver 3rd Order Dynamic Range dB 81 10 MHz 0 25 0 1 SINAD 0 16 Receiver Sensitivity 12dB SINAD V 0 14 Kenwood TH D72A Dual Band Handheld Transceiver July 2011 47 sity to manage any radio with 1000 memory channel capacity and so many features and options It is good to be able to back up all settings and channel information MCP 4A will import repeater list files from ARRL Travel Plus for Repeaters I tested th
18. is with an older version and it worked flawlessly MCP 4A software also communi cates with the GPS via the USB port There will be more about GPS later If you perform a firmware update do not forget to back up all of your settings before you start The last step in the update process is to do a total system reset Menu System Very much like the TM D710A the TH D72A has a tiered menu system to adjust settings All user settings can be entered or modified by MCP 4A software via the USB port or by keying in on the transceiver itself There are four major areas available for programming 1XX Radio 2XX GPS 3XX APRS and 5XX Sky Command Note that there is no 4XX range addressed in the user documentation Pressing the MENU key on the radio brings up the main menu display with these four selection items You can scroll through these with the jog control or one of the twist knobs Pressing the jog control down or up indexes through the op tions pressing to the right selects the options The menu items options are not necessarily in alphanumeric order but rather in some logical order for their use This tiered system along with the jog control makes managing so many settings on a handheld very easy APRS Much of the functionality in the TH D72A is the same as the TM D710A so I will focus here on what is different and particular to the handheld Pressing the TNC 2 button on the keypad toggles throug
19. ist A text paragraph with several steps may contain the necessary information but a check list augments the graphics by 10 dB Putting supplementary information online would cost nothing and avoids adding paper pages Summary The T 28 log periodic is a good single antenna compromise to getting on the VHF and UHF bands without breaking the budget It s not a high performance tight pattern band burner but it gets you on six amateur bands with some gain and a single feed line Giving the evaluation unit a permanent home on my roof was an easy decision Manufacturer Tennadyne PO Box 352 Alto MI 49302 616 622 4968 www tennadyne com the process of alternating elements between booms See the comments below on Manuals and Examples I recommend that you assemble the antenna either indoors measure the exterior door first do not ask me how I know to do this or in the garage or somewhere over a smooth surface on which a 6 32 nut can be seen after you drop it Tennadyne kindly supplied some extra hardware for the inevitable Oops Because there are so many elements of not so different lengths I also recommend that you pair them up and sort by length so that you minimize the chances of installing them out of order Don t ask me how I know to do this either Start with the small elements to learn the right technique of inserting the element through the boom then the screw through the element and
20. le to 1 2 4 or 8 minutes or Auto When set to Auto the GPS off time starts at 1 minute for the first time then progresses to 2 4 and 8 minutes each additional time The GPS off time remains at 8 minutes there after After having determined your position for the duration however if the GPS cannot pinpoint your location the GPS off time will restart at 1 minute APRS beacon rates whether controlled by an algorithm or SmartBeaconing will affect the life of a battery charge I set the D72A to beacon a position every five minutes at high power and with the internal GPS receiver on all the time I started with a fully charged battery and let it run until it shut itself off It ran like that for 17 hours It took six hours to fully recharge the battery with the supplied wall transformer Thanks to AC4XQ and K4ABB for digipeating and igating my beacons for all that time Bottom Line The TH D72A is an impressive work of art It might seem pricey but when you consider all that you are getting true dual band radio GPS receiver system 1200 and 9600 baud TNC computer interface cable and great software there s really nothing else to buy It is an amazing package Manufacturer Kenwood USA Corp 3970 Johns Creek Ct Suite 100 Suwanee GA 30024 tel 310 639 4200 fax 310 761 8290 www kenwoodusa com 50 July 2011 Reviewed by H Ward Silver N AX ARRL Contributing Editor n0ax arrl org I m a budding VHF
21. nal information received from the D72A My D710A did in fact tune to the received QSY frequency and the associated tone and shift set automatically Beaconing Method Options Manual PTT TX Interval Time Decay Algorithm Proportional Pathing and Smart Beaconing are supported 4 SmartBeaconing causes positions to be beaconed based upon speed of movement and turn angle You can set the low and high speed thresholds and beacon rates for each For example you can set beaconing to occur every 30 minutes for speeds below 5 MPH and in a nonlinear fashion increase beacon rate to every 60 seconds for speeds between 5 and 60 MPH and above In addition you can set position beaconing to occur when a combination of settable turn angles and speeds are measured on the GPS receiver There is a page dedicated to Smart Beaconing in the APRS menu of the MCP 4A software that graphically displays the effects of your settings When SmartBeaconing is turned on the TX Interval Time Decay Algorithm and Proportional Pathing features will not operate Quick Beacon is another option When METHOD is set to any value other than Manual you can manually transmit a beacon by pressing F BCON 6 Message Handling The TH D72A has eight user program mable preset phrases versus four on the D710A In addition you can set up an au 4Beaconing options are described very well with tables in Kenwood TH D72_10_ APRS_E pdf which is part
22. nother node I was unable to find an actively working packet node of any type where I was doing this review but I was able to connect to my portable packet station automatically go into CONVERSE mode and send and receive text on both packet terminals This worked well I was also able to connect to the PBBS in the KPC 3 TNC and leave a test message I have a bit of experience with interfacing radios and TNCs with computers This was by far the easiest to make work There are no mic and speaker connections or audio levels to adjust no special interface cables just a standard USB interface cable and readily available PC terminal software Battery Power Conservation There are several strategies available to extend the life of a charge Radio options include automatic power off timer and bat tery saver mode which will turn the receiver circuit off for a settable period from 0 03 to 5 seconds if squelch is closed and no key is pressed for more than 10 seconds RF power output can be set to Economy Low 0 05 W Low 0 5 W and High 5 0 W GPS options include GPS off GPS only mode and GPS battery saver mode Battery saver turns the GPS off if position data is not determined during the maximum catching time approximately 5 minutes Also when there are many satellites in range and the GPS is stabilized and position data can be determined the GPS power source repeat edly turns on and off Off time is user set tab
23. ny our new code practice oscillator kit I needed another practi cal project I was pleasantly surprised to learn that Ten Tec offers receiver kits for sale I picked the model 1054 a regenera tive four band receiver covering 5 9 6 4 6 9 7 4 8 5 10 2 and 11 5 16 5 MHz The 1054 manual is geared to the beginner it explains what shortwave radio is what can be heard on each of the four bands logging page included what regeneration is and how the circuitry works The back cover of the manual has several useful charts a resistor color code chart inductor and capacitor chart for the parts used Ohms Law and even a chart with the formula for a quarter wave antenna Build It and Listen The completed kit is powered by two 9 V batteries one for the receiver circuit the other for the LM386 audio amplifier circuit All controls are on the front panel At left there are three push buttons one for power on off and the other two for selecting the frequency range Three controls dominate the rest of the panel varactor tuning regenera tion and volume The 1054 kit has been around for a while and understandably some parts are different from the initial design so Ten Tec includes an addendum sheet of part corrections and manual instructions The instructions are Steve Ford WB8IMY QST Editor sford arrl org Ten Tec 1054 Shortwave Receiver Kit SHORT TAKES The Ten Tec 1054 receiver in its optional oak accessor
24. oaxial cable Frequency Average SWR 50 54 MHz 1 4 1 144 148 MHz 1 8 1 222 225 MHz 1 7 1 430 450 MHz 1 9 1 I do not have equipment for 902 and 1296 MHz at the moment The specification is for a peak SWR of 1 75 1 and these figures are within the range of measurement error of meeting that spec Once the antenna was installed sufficiently above the roof and with additional clearance from the wire doublet it played well and contin ues to play well Figure 8 shows the antenna against a high January sky I received good signal reports and could work any station I heard Swinging the beam back and forth confirmed the expected directivity We ve had several episodes of high wind or storms and I ve noticed nothing amiss with the antenna I recently noticed an unexpected feature while working in the backyard garden What was that faint calliope music and where was it coming from As it turns out the open ended elements were resonating in the breeze with different notes sounding as the wind speed and direction varied You get free wind chimes with the antenna if that might be a problem a piece of sponge or foam inserted into the end of each element will eliminate it Manual and Examples As with the L222 28 transverter the manual is okay but assumes a lot of the builder In particular for this complex an tenna with many opportunities to get things wrong why not supply a step by step check l
25. of the Owner s Manual on CD and available for free down load from www kenwoodusa com Support Amateur_Radio SmartBeaconing is from HamHUD Nichetronix www hamhud net July 2011 49 Figure 3 The TH D72A recorded my walk for display on Google Earth GPS menu and set LOG SETUP to use time as the RECORD METHOD and INTERVAL to ev ery 10 seconds You can use DISTANCE with intervals from 0 01 to 9 99 miles You can alternatively use BEACON as your log record method a waypoint would be recorded each time an APRS beacon is transmitted A little quirk mentioned in the documentation is that the GPS logger cannot be turned on while the APRS COM port input is ON This became an issue as I tested the D72A with the AvMap G5 before I tested logging I had to turn OFF the APRS COM port input Simply pressing F 2 starts and stops the log The iLOG icon appears in the GPS position on the LCD when the log is on Up to 5000 track points can be recorded The MCP 4A desktop software uses the USB port to read GPS logger data from the D72A Once the data is read it can be stored in various standard formats that can be imported In my case I saved the data as a gpx file that instantly imported into Google Earth I was able to share this file with friends so they could also view my trek on Google Earth Clicking on that file brings up my trek on Google Earth Figure 3 You have the option of clearing the track log or letting it accumul
26. stakes I was able to give the antenna a spin Initially the SWR seemed a little high particularly on 6 meters when the antenna was aligned with the rearward elements parallel to a nearby wire doublet hardly a surprise In the final installation I found it necessary to have the antenna at least 3 feet above the composition roof and clear of the doublet before SWR stabilized on the 2 meter through 70 cm bands I used July 2011 57 construction time took me about two hours which included many What are you doing Bob con versations in the ARRL Lab The Purpose of the Ten Tec 1054 kit is for the beginner to experience the joy of kit building With that in mind Ten Tec has left the purchase of knobs a case and antenna connections to the builder I found inexpensive knobs online at Jameco www jameco com A clip lead cut in half served as antenna and ground tie points Before operating I strongly suggest trying out the receiver for the first time with headphones off until you get to know how the regeneration control works Loud squeals can be generated while adjustments are be ing made Once you learn the ropes you ll become comfortable with how to tune the radio Learning the quirks of the REGEN con trol is key To listen to an AM station such as a shortwave broadcaster all you need to do is carefully tweak the REGEN knob until you find the point just before regeneration breaks into oscillation
27. t can be viewed with the push of the jog to the right You can back up by pushing the jog to the left Pushing the 48 July 2011 jog up or down will display the same page for stations above and below on the list respectively The list is easily and quickly sorted by call sign date time or distance Filtering by station type weather mobile digipeater and so on is also a quick menu selection Voice Alert Common practice among many APRS users is to set up their radios to send a 100 Hz tone with beacons and set CTCSS to the same tone This squelches the receiver normally and only opens it to allow packet clatter to be heard when stations are within simplex range of one another This is a settable menu option called Voice Alert on the D72A The idea is if you are close enough for the tone to open squelch you are close enough for simplex voice communication This could be used in conjunction with the QSY function described next QSY Function The TH D72A has an implementation of Automatic Frequency Reporting System AFRS that embeds your non data band frequency and other parameters tone fre quency shift and more into a Status Text see www aprs org freq AFRSspec txt When this QSY frequency information is tomatic reply message These phrases and messages can be created using the MCP 4A software or on the handheld itself via the keypad and menus I tested sending and receiving messages with my porta
28. y built that works well with modern HF transceivers It has enough interface options to adapt to a variety of radios and is robust enough to deal with life in the ham shack If I decide to get seri ous about VHF contesting I ll seriously consider buying one for 222 MHz Manufacturer Down East Micro wave 19519 78th Terrace Live Oak FL 32060 tel 386 364 5529 www downeast microwave com Table 3 Tennadyne T 28 Speci cations Frequency coverage 50 1300 MHz Boom length 12 feet Half power beamwidth 50 degrees Front to back ratio up to 45 dB Weight 17 pounds Wind load 3 square feet Turning radius 7 5 feet Typical max SWR 1 75 1 Feed point impedance 50 Price 415 Reviewed by H Ward Silver N AX ARRL Contributing Editor n0ax arrl org The T 28 delivers useful performance over four and a half octaves of frequency from 50 MHz to 1300 MHz on a single structure See Table 3 for specifications The log periodic s usual crisscross transmis sion line that drives the array of 28 elements is integrated into the supporting double boom a pair of square tubes to which the elements are mounted In fact with its 12 foot boom and turning radius of 7 5 feet the T 28 looks just like a super sized version of a standard TV antenna and that s what the neighbors will think it is when you put it up Whether you enlighten them is up to you of course In fact the T 28 can b
29. y cabinet An inside look at the Ten Tec 1054 clear starting with taking inventory of all parts and hardware I always lay out parts neatly on an uncluttered work area If you ve never soldered before have someone show you or check out some of the how to sol der videos on line don t forget your safety goggles About one third of the way into construc tion the audio amplifier circuit is completed and a simple test for audio hiss is performed For listening an inexpensive set of stereo headphones work best though there are la beled points on the circuit board for a speaker I noticed the 1 8 inch headphone jack is wired for a stereo plug A mono two conductor plug could damage the audio circuit Overall

Kenwood TH-D72A Dual Band Handheld Transceiver

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