This simple metronome, from 1985 documentation uses only transistors and has two settings. For voltages above 6 V, up to 12 V, replace the BC557 with a BD136.
We found this circuit in a 1973 documentation. The null adjustment trimpot is 10k. The circuit can be...
This commercial transistor radio was manufactured in Japan in the 1960s. The circuit has only 3...
This FM transmitter was described in the Radio Electronics magazine of June 1963. It operates in...