Test circuit with bridge (CB22530E)

This bridge-biased transistor test circuit measures gain in the range 0 to 300. Circuit is from Radio Electronics June 1952.

Modulated Oscillator 4093 (CB17577E)
Photometer (CB7360E)
This 1964 Electronic Design circuit uses a photo-FET as a sensor. The component is rare today. |...
Limit Detector (CB5163E)
This two-input limit detector was found in an American 1980s documentation. The circuit can be...