The following Transceivers use BCD programming. This will permit them to be used as a frequency agile remote base utilizing the serial data stream from your controller. Simply construct an interface using shift registers such as 4094's or 74164's and a couple of gates. You can down load a sample circuit from Link Communications in PDF format at http://www.link-comm.com/faq/faq.htm
WHAT HAVE I USED? These are some of the radios I can remember modifying, using, or owning over the last 30 years or so.
I have used the ICOM IC 2, 3, & 4 hand-held transceivers. These are good only at quiet sites. The IC-22U mobile rig is a better choice if you can find one. They have a 10-watt transmitter and the receivers are reasonably selective.
I have had good luck with the TEMPO VHF-1. This is also a 10-watt unit from about 1976. They sold for $500 and I still have mine. About 1979 they came out with the VHF-1 Plus. It was basically the same unit except 25-watts. They both had real FM not phase modulation! They will both cover the complete two-meter band and the receiver is excellent. They use varactor diodes in the receiver that is tied to the VCO ref voltage so the front ends track the frequency. There was a SSB adapter for the units and it worked quite well. This was my first side band on two meters!
The KDK FM2015R will cover 144.000 to 148.995. I had a friend that owned one of these and he used it on his business frequency of 152. Something. Just add a couple of jumpers to change the divide by ratio of the 74192 and it would cover up to about 156 MHz. This unit also had real FM and will do odd offsets with a 15-watt transmitter. This unit also has varactor diodes tied to the PLL so the receiver front end tuning tracks the frequency like the TEMPO. I think this one came on the market in 1977.
Then there was the FM144 SXR that sold for the astronomical price of $500. This was in 1976 when $500 was a LOT of money! This radio even had a crystal filter and 5 watts of audio! The transmitter was true FM and the receiver also tracked the VCO. Both units were rugged and never seamed to fail. In 1977 they came out with the FM50-10SXRII for six meters. It covered 51 to 53.995 and had the same specifications as the two-meter version. The price was $389 and they reduced the two-meter version to the same price in 1977. What ever happened to KDK (KYOKUTO)? They were well known in the commercial avionics business.
YAESUhad the "SIGMASIZER 200R" for two meters that ran 10 watts and sold for about $450 in 1975. Worked well and was fairly easy to interface. Later, the FT227RA came on the market for 2 meters and the FM627RA for 50 MHz. This was about 1979 or 80 and they worked great and were fairly easy to interface through the built in accessory socket. Sold for about $400. I still have a 627 on six meters still going strong after all these years!
WILSONmade a portable unit that was BCD it sold for $400 and was called the WE-800. I never worked on one but did use a borrowed one for a week or two and it appeared to be of good quality on the receive end but as I recall the Transmit audio left a bit to be desired in the area of fidelity.
Did one KENWOOD TR-7400 - Still have not recovered from the aggravation of the interfacing. Lots of intermod also from the receiver. You probably wont find one still alive anyway. The TR-7500 was suitable also but I never worked on one of these. They used diode programming for 6 user selectable channels. In about 1979 or 80 they came out with the TR-7600 which had a better receiver and one memory channel and the Hi-power version the 7625 which was 25 watts but otherwise identical.
CLEGGmade good equipment and was much sought after by VHFers in the 60's and 70's. They made a two meter rig called an FM-28. It was BCD and covered 144 to 148MHz and with the addition of a crystal you could have any odd offset you wished. The unit ran 25 watts. I do not know why it was not called the FM-25! They never shipped a unit in a factory sealed carton because each was tested prior to shipment and the test data was sent with each individual unit! In about 1975 they came out with the FM-DX. This was 45 watts and rated for continuous duty also. The receiver had a 16 pole crystal filter and it sold for about $600. Great rig also! Wish they were still in the business. Where did they go? They were located in Lancaster Pa. The transmitter was 25 watts and the receiver was great. They sold for about $350 in the mid seventies. If you can find one reasonable, get it! They would work forever.
DRAKEmade the UV-3. This radio was ahead of its time in that it was a modular Tri-Band unit. It had 25 watts on 2 meters and 10 watts on 220 and 440. This unit was true FM and had an exceptionally clean transmitter. The receiver was about .25 uV and no intermod! I remember Ted Wands, WD8CVH had one of these and he was the envy of N.E. Ohio. Good rig, big bucks ($995 in 1979) but worth it.
HEATH- Yes Heath mad a good remote base rig and it was a kit! The HW-2036 had BCD programming, you could add a crystal for odd offsets and the transmitter was rated continuous duty into an infinite VSWR. The receiver was about .35 uV sensitivity and pretty much immune to intermod. I built one in 1977 and installed it in my 1976 Celica. It worked great for one year and then it was stolen. If you find one with my call on the back - That's it! I would love to have it back.
PACE or PATHCOMmade a suitable unit called the Communicator II that covered the 144 MHz band. I never worked on any of these but I was told that they were true FM and had decent receivers. They were on the market in the late 70's and early 80's.
MIDLANDmade one of the few choices for 220 MHz. This was the 13-513 that covered 220 to 225 MHz. In those days we still had the bottom two Megs of the band. Anyway, the rig put out 20 watts and had a great receiver. I modified one and used it on an ACC Rc-850. Great receiver with helical resonator front end and a crystal filter. Had a FET front end with less than .1 uV sensitivity. Had a built in accessory socket for easy connection to the external world. They sold from about 1976 to 1980 for about $500. The two-meter version was equally good but I never worked on one of those.
RAMSEYmakes kits for 50, 144, 220, and 440 MHz. I believe Ramsey is the only manufacturer that presently markets a BCD programmable transceiver. The units are 12 channel and use a 16-bit matrix that is BCD programmed with diodes. I have been meaning to buy a couple of these little rigs but have yet to do so. They are modifiable but I have no knowledge as to how well they work. If you have one let me know what you think of the performance. I think they are worth investigating at $150 each! Sounds hard to beat!
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Last update 12/07/98