We found this circuit in an American 1980s documentation. The circuit uses a piezoelectric transducer unusual in our day. The transistor is general purpose type.
We found this transistorized AM receiver of the regenerative type of excellent quality in a...
This circuit, which appears at other times on this site has this version obtained in a Hands On of...
The circuit shown can be connected in parallel with the speaker of a sound system. Its purpose is to...