RTTY Demodulator (CB21760E)

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

Dual 18 V power supply (CB25266E)
Suggested to power the previous circuit, this power supply was found in the December 1990 issue of...
Autotransformer (CB24077E)
This is a very useful autotransformer circuit on the bench. We found it in the September 1970...
Driver Darlington (CB8957E)
This circuit was obtained in a 1960 documentation of General Electric. It is applied in the...