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.

Series and parallel alarm (CB26225E)
This alarm with sensors in series and parallel was found in the 1995 Encyclopedia of Electronic...
Amplifier MFC9010 (CB20027E)
This integrated amplifier was used in televisions from the 70s, with good sensitivity...
15 V x 300 mA power supply (CB19404E)
This source, found in a publication from the 1980s, uses an integrated circuit that is uncommon today....