Suggested by a 90s Popular Electronics this circuit is intended to receive volleys or whistles from thunderstorms in the wave range below 20 kHz. The coil consists of 300 turns of wire 26 in a ferrite rod.
This circuit was obtained from an old documentation, but as it uses still current components it can be...
This audio circuit has an output power of 1 W. We found it in the Radio Electronics magazine of...
This circuit that uses only discrete components (transistors) mimics the sound of an American...