LM3900 Amplifier (CB25165E)

This circuit with Norton operation is from an article in Radio Electronics magazine. The gain is given by the resistors.

Tuned audio oscillator (CB22254E)
This circuit is from a publication from the 50's. Inductive components are critical, and...
Stereo Pre Amplifier (CB18559E)
This simple two-transistor circuit used transistors from the 60s, having been found in a...
Capacítancemeter (CB3878E)
This circuit uses an oscillator that generates a signal of approximately 1450 kHz to test...