Schematics Depot >> Transmitters >> Miniature FM Transmitter

miniature fm transmitter:
Miniature FM Transmitter
click here to enlarge schematic

Transmitter Parts:
R1, R4, R610K resistor
R21Meg resistor
R3100K resistor
R5100 ohm resistor
R71K resistor
C1, C20.1uf capacitor
C30.01uf capacitor
C44-40pf variable capacitor
C54.7pf capacitor
Q1, Q22N3904 transistor
L18-10 turns of 22gauge wire around non-conductive 1/4" diameter form
Elec MikeElectret Mic
This miniature transmitter is easy to construct and it's transmissions can be picked up on any standard FM receiver. It has a range of up to 1/4 of a mile or more. It is great for room monitoring, baby listening, nature research, etc. L1 is 8 to 10 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.
Return to: Schematics Depot, or Transmitter Circuits

Site by Andrew Wilson. Copyright 1997-2006 All Rights Reserved unless otherwise noted.
Schematics in Schematics Depot were found on the internet and assumed to be in public domain. Contact webmaster if the copyright holder wants them pulled for any reason.