Geiger counter with high voltage source (CB22333E)

This circuit includes a high voltage inverter to power a Geiger tube. We found it in an American documentation from the 60s.

50 mW Amplifier (CB24449E)
This low-power transistorized amplifier was found in documentation from the 90s. The circuit uses...
Metal Detector (CB12077E)
This circuit is from Popular Electronics from March 1991. It can still be assembled with the...
Symmetric Power Supply (CB15712E)
The voltage of this symmetrical power supply depends on the regulating integrated circuits, which...