This is a diagram of a 1970s reel or tape recorder. It is an Italian Geloso recorder, quite popular at the time. The circuit is a reference for equipment recovery.
This circuit makes use of a PLL 567 and the components must be calculated according to the desired...
The transmitter can be that of CB9574E. This receiver uses a PLL to directly trigger a sensitive relay....
This circuit is from a 1967 US publication. The configuration can serve as a basis for designs...