LED Flasher Unijunction (CB22144E)

The frequency of this circuit depends on the capacitor. The unijunction transistor can be the 2N2646.

Delayed light (CB10091E)
This circuit for incandescent lamps was found in a 70s documentation. The circuit uses an SCR...
Ultra-simple FM or shortwave radio (CB23973E)
This circuit is from an Elementary Electronics from 1977. It can be assembled with relative ease...
Transmitter Detector (CB26100E)
This circuit detects the presence of strong signals from spy transmitters, enabling their...