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.

Monostable 4528 (CB11321E)
A positive transition at the input of this circuit changes the outputs state for a time given by...
Telephone interface (CB8663E)
Following the American FCC rules, this 90s Radio Electronics circuit shows how to use a...
10 W Transistor Amplifier (CB997E)
This is a traditional complementary configuration that provides good audio power with excellent...