This circuit uses a diode as a radiation sensor. The operational ones are old because the publication is from the 80's, but modern low voltage equivalents can be tested.
This circuit is from a Radio Electronics from August 1992. The transistor used allows the control of...
This circuit can be used with 3 receivers and is intended for low frequencies (medium wave range). We...
This useful benchtop power supply uses a single LM350 integrated circuit as a regulator. The...