This is the power supply circuit for the amplifier in the previous circuit. The source is adjustable and uses power transistors of the time. The AC transistor must be mounted on a heat sink.
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...