This good power amplifier, a few tens of watts, is part of an article in the December 1972 Radio Electronics magazine. The power supply must be symmetrical with at least 3 A.
This interference rejection circuit for telegraphy was found in a 1980s documentation for radio...
We found this circuit in recent English documentation. The frequency is adjusted by the core of...
With this circuit it is possible to control the intensity of a signal digitally. The circuit is...