An FM transmitter is a portable device that plugs into the headphone jack or proprietary output port of a portable audio or video device, such as a portable media player, CD player, or satellite radio system. The sound is then broadcast through the transmitter, and plays through an FM broadcast band frequency. Purposes for an FM transmitter include playing music from a device through a car stereo, or any radio.
FM is also used at intermediate frequencies by most analog VCR systems, including VHS, to record the luminance (black and white) portion of the video signal. FM is the only feasible method of recording to and retrieving from magnetic tape without extreme distortion a signal with a very large range of frequency components -- a video signal has components from a few hertz to several megahertz.
A radio transmitter design is a complex topic which can be broken down into a series of smaller topics. A radio communication system requires two tuned circuits each at the transmitter and receiver, all four tuned to the same frequency. The transmitter is an electronic device which, usually with the aid of an antenna, propagates an electromagnetic signal such as radio, television, or other telecommunications.
FM transmitters are usually battery driven, but some use the cigarette lighter socket in cars, or draw their power from the device itself. They are typically used with portable audio devices such as CD or MP3 players, but are also used to broadcast other outputs (such as that from a computer sound card) throughout a home or other building.
This product allows for very clear music, with good sound quality through your radio. Also, it scans and sets your presets automatically for the radio stations that will work best according to where you are at (you can choose to turn this option off if you'd like). I have nothing negative really to say about it, other than I had to read the instructions to understand how all of the little options worked.