Inside an SSB transceiver and how it works

How a filter-type HF SSB transceiver works. The PCM Hawk transceiver pictured here was built in the 1980s and has 10 fixed crystal-controlled channels between 2 and 8 MHz. I haven't measured the RF output power but my estimate is somewhere between 50 and 100 watts. The intermediate frequency is 1.650 MHz. Crystals are be 1.65 MHz above the desired transmit and receive frequency. The SSB signal generated is lower sideband, but because it is subtracted it becomes upper sideband, which is the general standard. Widely used in outback Australia (4 wheel drive, school of the air, flying doctor etc) these transceivers were simple, rugged and designed for use (and abuse) by non-radio people. Until satellite phones, radios like these were the only connection with the outside world. Though most radio amateurs prefer frequency agile equipment so they can operate across the whole band, converting a set like this is still a great project. Luckily the set fitted has channels