This 20W amplifier was found in 283 circuits from the 90s. The MOSFET admits equivalents. The power supply must be dual, and the transistors must be mounted on good heat sinks.
This low current parallel or shunt type regulator was found in documentation from the 60's. The...
This circuit is found in a 1975s documentation for radio amateurs. It was developed to recognize a...
The displayed relay operates with an audio signal applied to the input. The transistors can be...