This circuit was found in a 1964 documentation. It shows how to achieve automatic gain control for an oscillator. The transistors are of the time and the circuit controls signals from 2.6 to 3.1 kHz.
This simple circuit to monitor the frequency of the power grid uses an analog indicator. The...
) This variable frequency oscillator was found in an old American documentation. Transistors allow more...
We found this universal preamplifier circuit in a March 1994 Electronics Now. It has several types...