RTTY Demodulator (CB21760E)

This circuit was found in a 1977 radio amateur manual. Integrated circuits are operational amplifiers of the time.

Reinartz Oscillator (CB25318E)
The coils determine the frequency of this oscillator that we found in the January 1996 issue of...
Decade neon counter (CB6618E)
Found in a 1969 documentation, this neon lamp circuit may have the number of steps increased. The power...
Microphone Amplifier (CB12918E)
The first transformer is a driver found on transistor radios and the second a small output...