Push pull amplifier (CB21941E)

Using a pair of CK722s, this booster step of a few milliwatts of power was obtained in a 1960 Gernsback publication.

Volume Expander (CB22155E)
This circuit was found in an English publication from 1989. The integrated circuits are of the...
Transistor Radio TR3B (CB18388E)
This commercial radio with 3 earphone listening transistors was manufactured in Japan in the...
RF Meter (CB20739E)
This circuit for RF measurements at 200 MHz was found in no documentation two years 80. At a...