If you need a simple FM transmitter for a project, the miniFM Transmitter from The Streaming Suitcase might do the trick. The instructions are VERY detailed.

“We will build a FM transmitter. This will allow you transmit audio from any electronic sound device (such as a minidisc, cd player, computer) to FM radio receivers.

To make the transmitter you don’t need any previous experience. We will use a circuit designed by Tetsuo Kogawa which requires minimal parts, and which only requires some basic soldering. ”

Via: Make