This silencer or squelch preamp circuit was found in a documentation for radio amateurs. It completely mutes the circuit when there is no sound picked up by the microphone.
This circuit was obtained in a 1960 transistor manual from Sylvania. The circuit uses small...
This 1980s documentation circuit uses a 741 in a different high-speed comparator configuration. The feed...
This is the typical circuit of a 60's tape recorder. The circuit uses only two transistors and has a...