This audio oscillator is from a 1957 Raytheon publication. The tone generated depends on C2 and C2 and the handset must be high-impedance magnetic. Equivalent transistors can be tested.
Touching the sensor with your fingers, this circuit produces a machine gun sound. The circuit must...
This circuit appears elsewhere on this site. This is from an American 80's circuit manual....
This circuit was found in Maxim documentation from the 1990s. The RC circuit determines the...