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SSB Transceiver Era Begins in 1957

ssb transceiver era

For me, the Hallicrafters SR-150 truly started the SSB transceiver era because it included Receiver Incremental Tuning or RIT. 

Before single sideband went mainstream in the 1960’s, hams used AM and CW. Hams used “separates” – separate transmitters and receivers. In part, because many hams bought a receiver and built a transmitter. In part, because that was the way radios had been designed. Especially so for the tons of cheap surplus radios that arrived after World War II.

Around the time SSB started to be noticed by hams, Collins Radio made the first SSB/CW transceiver in 1957. The KWM-1 was revolutionary – both a transmitter and receiver in one box! Now, before we get carried away, remember that the KWM-1 still needed two separate power supplies (AC and DC) that weighed 25 and 15 pounds respectively.

But transceivers were cost effective. They shared the most expensive mechanical parts and electronic circuits for frequency control. Crystal filters, also expensive, could do double duty on receiving and transmitting SSB signals. You could get more for your money.

Most of the famous names in the SSB transceiver era arrived in the 1960’s – Drake, Galaxy, Swan, Hallicrafters and others. Japanese transceivers – ICOM, Kenwood and Yaesu -arrived in the 1970’s. Today, it is almost impossible to buy a separate transmitter. And many radio listeners just use their ham transceivers for listening. Even with the arrival of software defined radio, radio signals are easily created using digital to analog conversion (DAC) and bandpass filters serve duty both ways. You still need a separate circuit to amplify output, however.

SSB Transceiver Era Clarification

Single sideband signals are hard to tune – you need to get the frequency just right. This was never a problem with separates, as you tuned your receiver independently. But the early SSB transceivers provided no way to tune the receiver without changing transmitter. So, as hams made slight adjustments to better clarify the audio, they would also move the transmitter frequency. This caused silly situations where folks in a conversation would keep chasing each other across the band.

The 1963 Hallicrafters SR-150 radio, shown above, was the first SSB transceiver to include receiver incremental tuning RIT, also called a Clarifier. RIT just made small adjustments to received frequency, usually ± 2 kHz. That was all you needed to fine-tune SSB audio.

Most other manufacturers resisted RIT for years. For some, it was hard to do given the way they had designed their radios. But I think many just wanted to sell you a second outboard VFO. Amateur radio magazines were full of “how to” articles as hams modified their gear to get RIT, which was equally useful on CW.

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