Found in an Electronics World of 1966, this circuit makes use of FETs of the time. Modern equivalents can be used. The high voltage supply suggests its use with tube amplifiers.
This static switch circuit or solid-state contactor was found in a Motorola documentation from...
of the National Semiconductor of 1994. The same technique can be used with other operators and the...
Have you not yet memorized the color code used to identify resistors and capacitors? Do you have...