CCrane Company makes a fully built-up Stereo FM transmitter, digitally synthesized, and has a read-out. http://www.ccrane.com/fm-transmitter.aspx
It has a built-in whip antenna, but there is an internal power adjustment that can be turned up. $69.95. Here's the blurb: FM Transmitter Send streaming audio from your computer to your home stereo Broadcast a wireless signal from your XM radio to any FM receiver in your home Transfer a wireless signal from an MP3 player to your car stereo or portable radio The FM Transmitter is a way to listen to streaming or MP3 audio. Just plug it into the headphone jack of your computer's speakers or sound card and listen on any FM radio anywhere in the house. It does this by taking the audio and turning it into an FM radio broadcast. Use it to send a satellite radio signal, MP3 audio, and more, to nearby radios around your home or workplace, even in your car. FM Transmitter features: Full stereo on any FM frequency of your choice. Exceptionally clean and stable digital tuning for drift-free accurate transfer. Selectable Power-Off Timer. Approximate line-of-sight range of 70 ft. Walls and metal objects will reduce this range. Runs on included AC Adapter or (2) optional "AA" batteries. Portable, fits in the palm of your hand. Weighs just 5.8 ozs. Size: 3.1" W x 3.5" H x 1.1"
