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Amateur Radio history: 1st Transceiver made

Discussion in 'Ham Radio Discussions' started by W5INC, Nov 18, 2011.

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  1. W5INC

    W5INC Ham Member QRZ Page

    Somehow I got the idea that the 1st transceiver manufactured was by Collins for the U2 program in the 50s. Looking around that big auction site, I ran across this radio here. Nice looking unit and made before the U2 program existed I'm thinking. So which company was innovative enough to produce the first transceiver made? Some QRZ members who are older then myself, that have backs that go out on them more then they do, that when you were a child rainbows only came in B & W and you can still remember that the candles on your Birthday cake, cost more then the cake itself, should be able to throw some light on this subject. :)
  2. K9STH

    K9STH Ham Member QRZ Page

    The first relatively widely distributed SSB transceiver was the Collins KWM-1, a few of which were installed in U-2 aircraft. However, the KWM-1 was NOT designed for the U-2. They were "kludged" in behind the pilot and were not used that much. The KWM-1 was the only commercially available relatively small sized SSB transceiver available when the U-2 was built and it was decided to install 1 in the aircraft for use if, and when, communications on HF SSB were desired. The actual use of the KWM-1 was rare.

    There were true transceivers (transmitter and receiver frequency controlled by a single control) for AM use back as far as the early 1930s. Many of the designs used on frequencies above 50 MHz utilized "free running" oscillators for the transmitter and the same circuitry was used for a regenerative receiver.

    Glen, K9STH
  3. W5INC

    W5INC Ham Member QRZ Page

    TNX for the information there Mr. Glen. I really had no interest in the very early radios until I started looking at the Old radio guy in QST every month. The 75 Years ago and that section is interesting to me also, giving a clue to what was the new idea was at that time.

    To me it was like driving a Model A Ford, not my cup of tea. It is truely amazing what these folks did and accomplished "pioneering" the electronic revolution very early on in it's infancy. Reading stories of stringing wire for blocks at a time in Brooklyn and having numerous stations on it @ the time, try that today. Looking at the generations of rigs, each 1 building on the guy before it shows there were soming truely brillant folks capable over overcoming the obstacles placed in front of them.

    I know this still happens today, but maybe not to the same degree. One thing about the boys/girls back in those days, they didn't need to be warned about saftey issues in their radios, as it was always present around them when they were operating them. Nothing like lighting your cig off the HV caps of a tube, just to keep you on your toes.
  4. AF9J

    AF9J Ham Member QRZ Page

    I'm not so sure the KWM-1 was the first Ham radio transceiver. The Cosmophone 35 might hold that distinction, since pre-production examples were made in 1957, and the regular units were sold in 1958. Admittedly, it was closer to a trans-receiver, than what is regarded as a transceiver design-wise nowadays, but it wasn't a true trans-receiver either.

    Here's one that's been used on occasion, to check into a vintage sideband net, in my neck of the woods:

  5. W5WPL

    W5WPL Ham Member QRZ Page

    I wonder if Pat has one?
  6. WD4CHP

    WD4CHP Ham Member QRZ Page

    During WWII the walkietalkie used then might be considered the first transceivers.
  7. AF9J

    AF9J Ham Member QRZ Page

    VERY true! I forgot about that one!
  8. VK6ZGO

    VK6ZGO Ham Member QRZ Page

    The military in every country used transceivers throughout WW2 & before.

    In the late 1920s, & into the 1930s the Flying Doctor Service in Australia used Rx/Tx units where the transmitter section was CW only.
    In normal service,they were used to receive AM & answer in Morse--They used common parts for both Rx & Tx,so you could probably class them as transceivers.
    Later into the 1930s they were replaced by AM transceivers.

    In Australia,during WW2,a lot of military transceivers were made,& many of these were bought surplus by Hams in the 1950s.
    Transceivers made especially for Amateur use would probably be mainly from the US companies mentioned by other posters,though I think the Brits may have made some in the early 1950s ,too.

  9. K9STH

    K9STH Ham Member QRZ Page


    The KWM-1 predates the Cosmophone 35 by over a year! Also, the KWM-1 is a true transceiver in that the frequency determining circuitry is common to both the transmitter and receiver. It was designed in the last quarter of 1956 and was available for sale in early 1957.

    The "walkie talkies" and "horsey talkies" of World War II were FM units. Some of the units used separate crystals to control the transmitter and receiver whereas some units had some really "neat" circuits using AFC to lock the transmit frequency to the receive frequency. The BC-1000 / SCR-300-A uses a single crystal and a "free running" variable oscillator and a mixer which uses AFC to keep the variable oscillator to keep the transmitter "locked" on the receive frequency. The BC-1000 operates in the 40.0 MHz to 48.0 MHz range and runs all of 1/2 watt output! The unit had to be carried on the back of the operator.

    I looked at the schematic of the BC-1000 (in the Surplus Schematics Handbook published by Cowan Publishing - basically CQ Magazine) and it is pretty complicated! Also, each and every BC-1000 had to be hand calibrated at the factory!

    Glen, K9STH
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