Found in a PE Hobbyst Handbook, this circuit checks if there is voltage in a power outlet by emitting sound and lighting an LED.
This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit...
This two-transistor circuit was found in a 1969 US documentation. Modern equivalent transistors can...
This JFET amplification stage was found in the April 1993 issue of Electronics Now. The input...