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Single Transistor SOTA?


A recent transceiver by Roger G3XBM has got quite a few people interested. His design is for an HF transceiver using just a single transistor (14 components in total). Of course there are certain compromises to the design (like 15mW output) and a slightly insensitive receiver but the design does work. G3XIZ built one for 80m and has had quite a number of contacts with it. To date he has had 16 contacts and 51 reports from across Europe. It might be fun to try one for SOTA so I may build something similar myself. Anyone else fancy trying?

The design is online at:


Maybe there should be a Single Transistor on the Air award?




In reply to G3CWI:

Interesting. Before I became a radio amateur, I was building these one diode or one transistor receivers from a classic Finnish radio hobby book. For “DX” I would move the frequency to 30 or 20 m band, since antennas with better efficiency are more easy to realize on these shorter waves. The regenerative RX is not adviced in general due to possible QRM as it may start to oscillate. Fortunately the price of one transistor is quite low in our days.

73, Jaakko OH7BF/F5VGL