HOW FM WORKS?

The purpose for an FM transmitter is to allow you to listen to any external audio source played through a car stereo, or any radio with an FM band. An FM (Frequency Modulated)

transmitter, which is also called an RF (Radio Frequency) modulator or FM modulator, is an after market device that you connect the audio from the earphone jack of a portable audio device, such as an iPod, a Zune, an MP3 enhanced cell phone, an MP3 player, a CD player or satellite radio system, into the FM transmitter. The sound from the portable audio device is then broadcast through the FM transmitter as an FM radio station, and is picked up on your car radio as an FM station and played through the FM band out through the speakers.
Looking at how the FM transmitter works in a stage-by-stage description, the first stage is the converter that takes in the audio output from the external audio source and converts it into analog audio within the FM transmitter. In the second stage, the now convertered analog audio signal is converted again into an FM signal by modulating the audio using FM modulation. This FM modulated signal is then laid onto an RF transmitter signal from the FM transmitter on a specific frequency as an FM radio station signal in the final stage. You can then tune your car抯 radio to the specific FM station frequency that the FM transmitter is set to transmit on and listen to the audio in your car on the FM band as an FM station.

It doesn't matter if the FM transmitter is advertised as "new and Improved" or "brand new technology" or whatever. If it takes in external audio and you have to tune your car's FM radio to an FM radio station in order to listen to it, then its an FM transmitter and the operational description in the above paragraph is how it works.