We found this circuit in a Japanese publication in 1967. The circuit consists of a 15 W audio amplifier with germanium transistors including a voltage indicator power supply.
We found this transistorized circuit in a 1985 documentation. The circuit can operate with...
We found this small audio amplifier in the November 1999 issue of Electronics Now magazine. The...
This low power circuit for the FM band was found in a spy book from the 90s. The tunnel diode is...