The purpose of this circuit is to silence the hiss that exists between the stations on an FM receiver. The circuit was found in American documentation from the 1980s.
The circuit shown in the figure makes it possible to control a stepper motor via the serial port...
This acutely tuned circuit was found in American documentation from the 1960s. The transistors are germanium...
This circuit uses a 100 kHz crystal, but nearby frequencies can be obtained with appropriate...