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.
We found this circuit in a Radio Electronics from June 1967. The transistor was in general use at...
This amplifier stage without an output transformer was found in Radio Electronics magazine from...
The component used in this circuit is uncommon today, as the circuit was obtained from Motorola's Linear...