This circuit that has a response from 10 Hz to 700 kHz was found in Philips documentation from 1968. Dual transistors can be replaced by matched pairs.
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...