This circuit is used in transceivers, enabling input selection by diode switching through polarity reversal. The circuit is from an old American documentation on telecommunications.
This circuit is from Radio Electronics from February 1987. The frequency is given by the crystal that...
In this circuit, a light-sensitive SCR or Light Activated SCR determines the operation of an...
This 3-transistor circuit was found in a Mullard manual from 1960. The transistors are germanium of the...