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.
This circuit was found in a 2003 documentation. Its purpose is to check if the transmitter of an...
Found in old English documentation this circuit evaluates the power of a transmitter. The circuit has...
The circuit shown is suggested by National Semiconductor's Linear Applications Handbook. The base...