This circuit is intended for use with common oscilloscopes having been found in documentation on instrumentation from the 1970s. The capacitors are of the ceramic type with low parasitic inductance.
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...