Belkin's TuneBase FM is an FM transmitter that lets you charge, power, and listen to your iPod in the car by sending its output to your FM stereo. While it seems like every iPod accessory maker offers a product like this, TuneBase FM has a few unique features that make it one of the best (if not the best) FM transmitters we've ever tested.

But first, a confession... I hate FM transmitters. There isn't a single one that sounds good enough to my ear. Furthermore, an FM transmitter can be working pretty well one minute, and belching hissy static the next. And having to constantly diddle with the frequency it uses -- on both the device and my car radio -- to eliminate the static and hiss, drives me absolutely batty. So I had my car dealer install a 1/8-inch stereo mini-jack in my glove box and wire it up to my car stereo's AUX function. The downside is that unlike an FM transmitter it's not portable; the upside is that it sounds great all the time.

Anyway, my wife's car stereo doesn't have an AUX function, so over the years she's tested at least a dozen FM transmitters in her car and so far she likes the Belkin TuneBase FM best because of two unique features.

The first is called ClearScan. Just push the ClearScan button and it quickly examines every available FM frequency and selects the one most likely to sound good at that moment. So rather than having to use trial-and-error to find a quiet and unused FM frequency, you just push a button and then tune your radio to the station TuneBase FM chose. You can also tune to FM stations manually. Either way you can save your two favorites as presets and recall them at the press of a button.

The second feature my wife likes is the flexible steel goose-neck with integrated antenna that holds the TuneBase FM in place. Other FM transmitters use rigid connectors that tend to slip or droop, and not keep your iPod exactly where you put it. But the TuneBase FM's stiff yet flexible steel connector combined with the included cigarette lighter adapter collar provides an exceptionally stable system that keeps her iPod right where she put it.

Photo courtesy of Belkin

Finally, there's a unique feature that appeals more to me than to my wife and that's something Belkin calls Pro settings, which add dynamic compression to the iPod's output. Pro setting #1 increases the average volume a little bit; pro setting #2 increases the average volume a lot; pro setting #3 increases the average volume a little and transmits in mono, which is great for spoken word recordings. She's not going to bother with it but I'm happy to have it because most of the time pro setting #1 or #2 makes the music sound noticeably better.

TuneBase FM supports most iPod models with dock connectors including the latest models and comes with a comprehensive selection of iPod adapter sleeves and spacer pads.

The Bottom Line

ClearScan, a better connecting system, and dynamic compression combine to make the Belkin TuneBase FM one of the best FM transmitters we've ever tested.