Receiving SSB on a radio without a BFO

Single sideband transmission is a way to transmit radio signals more efficiently. It’s used by amateur radio operators and commercial services. Most of the crop of moderately-priced shortwave receivers can’t receive SSB transmissions, making them sound like Donald Duck. More expensive receivers have a feature known as a beat frequency oscillator (BFO) to allow SSB to be heard normally.

All that’s needed to make it work is another carrier wave signal from another source. I happen to have an RF signal generator that I built from a kit in the 1960’s. Remarkably, it still works and all I have to do is tune next to the SSB transmission frequency I want to receive, placing the radio near the generator, and voilà, SSB reception. Tuning is rather tricky but possible. Maybe I can modify the unit to add a fine tuning control.

The generator is also useful in locating a very weak station on a radio with a rough analog tuning dial. I tune the station with a digital radio, tune the signal generator to be heard on the same frequency, and then tune the clear strong signal generator signal on the analog radio. Sometimes, it’s the only way to see if a station can be heard on one of these analog radios.

An alternative is a dedicated external BFO running near the IF frequency of the radio, 455 KHz (where I should have tuned the signal generator when I tried it). TenTec makes a kit for $11 and I have one on order. I should be able to put it in a small case and carry it around in my radio bag. I built kits when I was a teenager, even a 4-band tube type shortwave receiver (a Lafayette KT-340). This should be a piece of cake.

About Kevin

Just an old guy with opinions that I like to bounce off other people.
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