This protective circuit for power lines was found in a Radio Electronics from November 1957. The transistor used can be any general-purpose transistor such as the CK722.
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...