Supply for photo multiplier tube (CB8123E)

Found in a magazine 73 for radio amateurs of the 90s, this circuit shows how to supply a photo multiplier tube with high voltage.

Hybrid trigger with tunnel diode (CB6817E)
This circuit was found in a 1967 General Electric documentation. The circuit generates signals...
Schmitt Trigger (CB221E)
Sine signals are converted into square signals by this simple circuit. The maximum frequency is...
Touch Switch (CB6451E)
We found this touch control on a Popular Electronics from 1970. The circuit makes use of an...