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What frequency range? Additionally I assume you want to connect the audio out (maybe line audio) from the TV and listen to it on what? Phone to me implies telephone? Maybe you mean an FM receiver with headphones?
The guy here in the forums who is good with things like this is AudioGuru who could likely suggest a good circuit. The problem with most circuits like this is parts placement and environment. The majority of these little transmitters drift frequency with temperature, humidity and other variables.
Ron
Simple FM transmitters work very poorly:
1) Their radio frequency changes when something moves toward or away from the antenna.
2) Their radio frequency changes when the supply voltage changes so a voltage regulator is needed.
3) Their radio frequency changes when the temperature changes.
4) They do not have pre-emphasis (treble boost) like all FM radio stations so the de-emphasis (treble and hiss cut) in all FM radios reduces high frequencies and makes muffled sound.
Silicon Chip magazine in Australia had an FM stereo transmitter project (The Micromitter) about 7 years ago that uses a modern Rohm IC with a crystal controlled frequency synthesizer with phase-locked-loop. The same line of ICs is used in MP3 to car radio FM transmitter products available.
But it is a very poor design. One of the worst I have seen.
Where is the circuit???