WARFA: Radio On The Left Coast

There was a time when radios had just a few knobs and a dial. This is the Heathkit HW12, one of 3 monoband transceivers that Heath marketed beginning sometime around 1970 for 80, 40, and 20 meters. The sideband selection switch was an innovation that appeared in later versions of the HW12. The original series of transceivers were stuck on the default sideband for the band each was designed for. Did you know that we amateurs are the only radio people who routinely use lower sideband?

The little radios made around 100 watts PEP output.

The S meter could double as a plate current meter when that slide switch was in the "bias set" position. When transmitting, it gave one a relative indication of ALC voltage.

The inside of an HW12. Notice the sweep tubes instead of Heathkit's usual 6146s for finals and the very nearly unified construction with practically the whole of the radio on a single PC board. This was a fairly easy kit to build, a far less daunting task than putting together one of Heath's 5 band rigs.

There was no loading capacitor, just the plate tuning capacitor which was simply adjusted for maximum indication on the S meter with the radio in tune mode.

Many of the other 12 tubes on that PC board were dual triodes or triode/pentode combinations. If you could find them anywhere, new finals for this rig could get rather pricey, since TV sweep tubes were designed to do one and only one thing well, painting the picture on the face of a TV picture tube. Demand for sweep tubes dropped dramatically in the late seventies. It was a sort of nice engineering accident that they turned out to be highly suitible for power amplifier service in SSB transmitters.

Bart, WA6HZN, the WARFA web rat: webrat@warfa.org (BTW, I know so much about these radios becasue I owned one when I was a kid.)