This circuit was found in a Radio Electronics from February 1966. With it it is possible to trace the curve of a tunnel diode visualizing it on an oscilloscope.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...