This circuit was found in a 1967 US documentation. It shows how to build a gain control by digital signals. The circuit can be used as a shield. FET can be a modern equivalent.
Amphenol Sine eco | mate ™ connectors can be purchased from Mouser Electronics for a variety of...
For those who have multimeters that do not test transistors, in the figure we have a circuit that...
This sensitive receiver with earphone was found in an English documentation from 1963. The...