Varactor diodes are our varicaps of today. This circuit for switching signals in an RF circuit was found in a Radio Electronics magazine from July 1982.
This circuit with low impedance output and 900k input impedance was found in the October 1993...
The figure shows the basic circuit of a relaxation oscillator with operational amplifier. The...
This circuit consists of a low-pass filter for the frequency of 440 Hz. The filter therefore...