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.
This adding amplifier with the operational LM324 is from the SGS integrated circuits manual of...
This sophisticated circuit with a low, medium, and high treble filter is from 1990 documentation. The...
The author of this project found in a 1980 documentation gives the radio in two versions: the...