Miniature FM Transmitter

This miniature transmitter is easy to construct and it's transmissions can be picked up on any standard FM receiver . it has a range pf up to 1/4 of a mile or more . it is great for room monitoring , baby listening , nature research , etc . L1 is a 8 to turns of 22 gauge hookup wire close wound around a non-conductive 1/4 inch diameter form , such as a pencil . C4 is a small , screw-adjustable , trimmer capacitor. Set your FM receiver for a clear , blank space in the lower end of the band . then , with a non-conductive tool , adjust this capacitor for the clearest reception. A little experimenting and patience may be in order . Most of the parts values are not critical , so you can try adjusting them to see what happens.

Reference : " Cyber Circuits "

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