This circuit, bridge type, was found in American documentation from the 60's. The transistor is germanium of the time.
This is an amplifier with one of the first integrated circuits available, the CA3020 which was...
This circuit was obtained in a 1964 Electronic Design. The transistors are from the era and the...
This low power circuit for the FM band was found in a spy book from the 90s. The tunnel diode is...