This circuit employs an old germanium transistor. The circuit is from a 1950s publication and uses RC coupling.
This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit...
This circuit generates signals from 0.01 Hz to 10 kHz, but uses unusual components today. The...
This dimmer or light control for incandescent light bulbs or even small heaters, is one of many...