Signal Tracer and Capacitor Tester (T1241E)

This mains powered two-in-one instrument was found in a Radio Craft from March 1948. The headphone must be high impedance.

Two-Transistor Darlington Amplifier (MSB035)
This two-transistor amplifier can be used as power stage for intercom, experimental receivers,...
Electroscope (CB22132E)
This sensitive circuit was found in old English documentation. Transistors may be modern...
Logarithmic Converter (CB19486E)
This configuration, already presented in other points of this section and website, is of a...