How easy can a transceiver be?
We’ve talked about amateur radio a lot on these pages, both in terms of the breadth of the hobby and the surprisingly low barrier to entry. It’s certainly the case that amateur radio doesn’t have to mean endlessly calling CQ on SSB with a mind-boggling expensive rig, and [Bill Meara N2CQR] there is a description of a transceiver that is so simple that only one transistor is used.
It is a 40 meter QRP or low power transceiver (7 MHz) where the transmitter has a simple crystal oscillator and the receiver has an equally simple regenerative design. What makes it so easy is the addition of a three-way switch to transfer the single transistor – a J310 FET – between the two halves of the circuit. It is not a problem with QRP radios working as they have picked up contacts from the real world.
This circuit shows us how a little can go a long way in the world of amateur radio, and we can’t help but like it for it. It is worth noting, however, that this is not without its flaws, as a key click filter and different transistor would provide a much higher quality transmitted signal. But then it wouldn’t be a single transistor rig and it would miss the point, right?