Simple FM Radio with improved audio gain
Simple FM Radio with improved audio gain circuit
Wind 6 turns of solid wire on a pen or pencil that is just under 1/2 inch in diameter. Remove the wire from the pencil and spread the winding to make a length of 3/4 inch. Solder C2 somewhere near the middle of the coil.
8190 28 August 2007
This circuit can be used to remotely monitor a loudspeaker, alarm, or audio source for presence of an audio waveform. It can also be directly connected across loudspeaker terminals used as a peak indicator.