This telegraph monitor was found in an American documentation for radio amateurs from the 1970s. The indicator is a common 1 mA full-scale milliammeter.
We found this configuration in documentation from the 1980s. It applies to almost any operational...
This circuit was found in a 1966 publication using a microwave transistor of the time. The circuit...
In the figure we have the way to use the transistors of an old-paired pair as a trigger circuit. The...