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iPod and iTunes Hacks by Hadley Stern

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Broadcast Your iPod to FM Radio

Share your iPod’s tunes over the airwaves with a variety of FM transmitters.

If you’ve got an iPod and you’ve got a car, then you’ve got a problem. Sooner or later, you’re going to want to drive while listening to your masterfully mixed playlists. Though there is no physical or technical barrier to jamming the cool white earphones into your auditory canals while your right foot works the accelerator, such behavior is not the best idea and is, in fact, illegal in some jurisdictions. So are you forever stuck with the commercial-addled commute? The answer is no; by adding the right equipment to your iPod, you can stream your music straight to the FM dial of your car stereo.

The equipment you’ll need is known generically as an FM transmitter. These devices will broadcast anything streaming out of your iPod to an FM radio, allowing your car, or any other nearby FM radio, to play the sweet sounds emanating from your iPod.

This hack shows how, with minimal effort, to stream your tunes onto the FM dial. All you’ll need is an iPod, an FM transmitter, and a willingness to stick an aftermarket item into various iPod ports. For an example of a specific implementation (using Griffin Technology’s iTrip transmitter), be sure to check out “Turn Your iPod Mini into a Radio Station” [Hack #13] .

Choosing the FM Transmitter

The technology used in FM transmitters is fairly rudimentary, so don’t look for a product description that’s riddled with technobabble; they’re all going to work on the same principle, and they are all going to be limited by the same FCC regulations. This isn’t to say that all iPod-compatible FM transmitters are interchangeable; in fact, there are a wide variety of form factors, features, and electronic refinements to consider.

One of the first things you’ll want to consider is where you’re likely to use your FM transmitter. If you’re going to use the transmitter exclusively in your car, you’ll probably want a different model than if you desire the ability to stream your tunes to any nearby FM radio.

Some popular models include:

DLO Transpod by Digital Lifestyle Outfitters (http://www.netalog.com; $69.99-$99.99)

  • Compatible with iPods featuring 30-pin connectors (generations 3 and 4)

  • Models available for older iPods at lower cost

  • Powered by automobile cigarette lighter

  • Full FM spectrum available

  • Recharges iPod when in use

  • Attaches directly to the iPod

FM_Transmitter by Pacific Rim (http://www.pacrimtechnologies.com; $29.99)

  • Compatible with generation 3 and 4 iPods and the iPod mini

  • Powered by automobile cigarette lighter

  • Attaches via cable to stereo mini-jack

  • Full FM spectrum available

iTrip by Griffin Technology (http://www.griffintechnology.com/products/itrip/; $35.00)

  • Compatible with all iPods and the iPod mini

  • Powered by the iPod (Griffin Technology claims no significant loss of battery life)

  • Allows selection from more than 100 FM frequencies

  • Attaches directly to the iPod

TuneCast II Mobile FM Transmitter bby Belkin (http://www.belkin.com; $49.99)

  • Compatible with any device that has the appropriate headphone jack(3.5 mm, also known as stereo mini-jack)

  • Uses two AAA batteries

  • Allows selection from four frequencies

  • Attaches via cable

  • See Figure 1-5

The Belkin TuneCast II Mobile FM Transmitter

Figure 1-5. The Belkin TuneCast II Mobile FM Transmitter

Podfreq by Sonnet(http://www.podfreq.com; $99.95)

  • Compatible with all iPods

  • Powered by the iPod

  • Features FireWire and mini USB 2.0 ports

  • Allows selection from full FM spectrum

  • Attaches directly to the iPod

  • Provides full dock functionality

irock! 400FM Beamit (http://www.myirock.com; $29.99)

  • Compatible with all iPods

  • Attaches via cable to mini-jack

  • Uses two AAA batteries or included cigarette lighter adapter

  • Allows selection from four frequencies

Nearly any FM transmitter will work, as long as it accepts input from a stereo mini-jack. The features and prices of generic FM transmitters will vary.

More Shopping Decisions

This is the most difficult part of the entire process. With the myriad of options available, which one should you choose?

Many of the devices are specifically designed to go with the iPod and try to stay faithful to the iPod’s styling. If aesthetics are important to you, take a careful look at the products by Griffin, Digital Lifestyle Outfitters, and Sonnet. These feature tight integration with the iPod and try to match its smooth look. The tight integration and good looks come at a price, though, because these products are exclusively iPod-compatible. Hence, if you find streaming to an FM receiver useful, note that the aforementioned products aren’t going to work with anything but an iPod.

While the technology might be fairly standard, all FM broadcasters are not created equal. If possible, test the transmitter you’re thinking of buying before you buy it; just remember to bring along your iPod, an FM radio, and a couple AAA batteries when you’re shopping.

Some Caveats

Audiophiles will tell you that FM radio is not the ideal mediumfor audio transmission. The careful ear can detect a substantial difference between CD-quality sound and FM broadcasts. That said, under perfect circumstances, the music being broadcast from your iPod will sound as good as any FM station. If you’re satisfied with the sound quality of the FM dial, you’ll be as satisfied with the tunes streamed from your iPod.

The power of these devices is limited by federal law, so don’t expect your transmitter to work three blocks away. The general obstruction-free range is 10 to 30 feet, and anything that is between the iPod and the FM receiver (particularly if it’s metal) is going to degrade the signal quality.

The range restriction might not sound like a big deal if you’re going to be using the FM transmitter in your car; after all, your iPod is going to be next to the radio, right? Unfortunately, the situation isn’t quite that simple. Certain cars feature a metallic film in their windshields, effectively shielding the outside antenna from the signal emanating inside your car. If your automobile has this feature, chuck the FM transmitter idea and look for an AUX input.

Getting the Best Results

If your FM transmitter supports the entire FM spectrum, and if the middle of the dial isn’t populated by flamethrower stations, set your transmitter as close to dead center (100.5 MHz) of the spectrum as possible. This will maximize sound quality by giving the largest range of stereo separation (though the improvement was imperceptible to my ears).

Choose a frequency that is unused by any nearby radio station. If you try to compete with your local 100,000-watt station, you’ll undoubtedly suffer from a condition called bleed-through. Bleed-through might sound like an extremely unpleasant medical condition, but you won’t be physically harmed; you’ll merely hear your iPod’s broadcast and the broadcast of the local station at the same time. A simple way to pick a station is to leave the FM broadcaster on while tuning the receiver. When all you hear is static—no faint music or obnoxious used-car ads—you’ve found a clear section of the FM spectrum. Tune your FM transmitter to this formerly empty frequency and enjoy.

Chris Seibold

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