60's crystal radio (CB22171E)

Found in an English publication from the 1960s, this circuit uses period components, including the commercial grade coil.

Decade Counter with Nixie Tube (CB20141E)
This is an old test circuit for integrated TTL counters, feeding a Nixie tube, common at the time....
Two-Transistor Oscillator (CB1387E )
This old oscillator using germanium transistors has a high impedance headphone as inductor to...
Tone Control Preamplifier (CB18561E)
This preamp with several inputs using germanium transistors from the time was found in Japanese...