This circuit is intended to recover a very weak signal at a receiver, for example, a CW signal or a tone signal. The circuit is from a Popular Electronics from the 90s.
Found in a European magazine from the 1980s, this circuit can amplify signals from 10 kHz up to...
The circuit in the figure uses the four current amplifiers of the LM3900 to generate a sawtooth signal...
This circuit is from a Radio Electronics magazine from August 1960. It is a commercial circuit for marine...