This sonic key or vox was found in old English documentation. The operational admits equivalent as well as the transistors. The microphone is crystal.
Found in a 1966’s General Electric documentation, this circuit uses a triple diode from the time....
This circuit is from 70's documentation. The output transistors can be BC548 and BC549. The driver...
February 25, 2015 - Mouser Electronics, Inc., the global authorized distributor with the newest...