Medium impedance stage (CB20563E)

We found this circuit in an English publication from 1963. The circuit uses germanium transistors of the time.

Two-Tone Decoder (CB19928E)
Using two 567 PLLs, this circuit recognizes two audio tones in sequence providing a signal for a...
Transmitter LM371 (CB19454E)
We found this transmitter in a documentation on espionage from the 90s. The circuit is...
Dual Power Supply 12 + 12 V x 1 A (CB1182E )
We find this circuit in a Radio Electronics of July 1984. It consists of the traditional version of 1 A...