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.

SCR contactor (CB9262E)
This circuit for controlling high power in the AC network was found in a Motorola documentation from 1968....
1 to 5 W amplifier TDA1011 (CB15975E)
This amplifier is specifically designed for portable radio and recorders with a 4 ohms load....
Light-Sound Converter (CB10686E)
This circuit was found in a 1973 Radio Elettronica magazine. The Italian magazine no longer...