This circuit was obtained from an Electronics Design of 1964. The circuit makes use of tunnel diodes that are uncommon today. The circuit works with very weak signals.
Using the name of varactor this circuit was found in the Radio Electronics magazine of July 1982....
We found this circuit in a 1960 Radioarama magazine. The instrument tests common general-purpose transistors...
This circuit uses an RCA module from the time. The circuit is from a Radio Electronics magazine from...