Fm Radio Transmitter Circuit
Posted on Jul 9, 2012 5820
An FM radio generates an interference signal that can be picked up on another FM radio tuned 10.7 MHz above the first one. The 50-k0 potentiometer adjusts the modulation level to maximum without distortion. The RC network improves the fidelity of the transmitted signal and provides dc isolation. The component values shown are provided as a starting point. They can vary somewhat for different radios. Note that if you can`t get the signal at 10.7 MHz above the frequency setting of the first radio, try tuning at 10.7 MHz below.
Also, note that both tuned frequencies must be unused. Otherwise, you will hear your audio on top of the audio that is already there. You might have to play with both frequencies until you find two blank spots that are 10.7 MHz apart.