This circuit was found in a 1970 IEEE publication. The circuit functions as a voltage controlled variable resistor and can be used with audio signals. Transistors admit current equivalents.
In the figure we have the way to use the transistors of an old-paired pair as a trigger circuit. The...
We found this synchrodyne receiver for the medium or short-wave band in the Radio Electronics...
This old circuit, from a 1992 documentation, was used with tape recorders acting as playback. The...