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Complaints grow about micro-broadcast devices

From "Wireless devices send mixed radio signals," by Jim Puzzanghera, Los Angeles Times, 1 November:

"Todd Lockwood, a 56-year-old writer in South Burlington, [Vermont, USA], often finds an annoying hitchhiker in his Audi when he tunes in to his local National Public Radio station. The outbursts of Howard Stern's program, which airs on Sirius Satellite Radio Inc., sometimes blare from the dial and are particularly unwelcome when his three children are in the car.

" 'It will literally replace the station,' Lockwood said of the shock jock's signal. 'It's starting to feel more and more like an intrusion.'

"The invasion is caused by wireless devices that people use to listen to their portable satellite radio receiver, iPod or other MP3 player through their car radios. These devices, called modulators, are sometimes so powerful that they inadvertently send signals into nearby vehicles such as Lockwood's.

"The interference has been a major problem for NPR because many 'plug-and-play' modulators come preset to the 88.1 FM frequency, which is used by 36 NPR stations... Ken Stern, NPR's chief executive, wrote to Federal Communications Commission Chairman Kevin J. Martin on Oct. 12 to ask for a technical review of the devices and for a recall of any that transmit with too much power. His recall request echoed one last summer by the National Assn. of Broadcasters, which complained that stations elsewhere on the dial also experienced interference.

Just how widespread is the problem?

"Mike Starling, NPR's chief technology officer, estimated that 3.4 million modulators were sold in 2005. 'It looks like it's such a huge problem we want to make sure they pinpoint the most likely source... and hopefully recall the ones that are still in the marketplace,' Starling said of the FCC. The FCC is reviewing the matter, spokesman Clyde Ensslin said.

"Modulators are sold as accessories to some portable satellite radio receivers, or separately for as little as $20. They plug into a vehicle's cigarette lighter and transmit from the receiver or MP3 player to the car radio. Modulators are supposed to operate at low power so they do not cause interference. Higher-powered modulators allow for clearer transmission of a satellite program or MP3 recording within an owner's car because they are less likely to receive interference from other signals.

"Manufacturers are required to send the FCC a report showing the devices meet technical standards. The FCC does not pretest modulators, but allows manufacturers to sell devices only after the agency has approved their report. Those companies that sell overpowered devices are subject to penalties ranging from forfeiture of the devices to fines as high as $200,000...

"NPR Labs, which Starling runs, studied the interference problem this summer. It found that about one-third of modulators operating at 88.1 FM or 87.9 FM, another common preset frequency, were too powerful. He said the number of devices over the power limit made it 'not likely the result of isolated manufacturing errors,' as some manufacturers had suggested. A National Assn. of Broadcasters study in June found that 76% of the modulators tested were over the power limit...

"Starling said there was a 'huge spike' in interference complaints to NPR stations starting in January, probably because many drivers got modulators during last year's holiday season. 'Virtually all of our stations on 88.1 and some on 88.3 reported the problems,' he said..."
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More on National Public Radio's modulator research from "NPR Finds Objectionable Interference," by Leslie Stimson, Radio World Online, 1 September 2006:

"Commercial market data on FM modulators is limited, NPR found. However, it quotes the Consumer Electronics Association as saying FM modulators and FM modulator/car chargers accounted for approximately 16 percent and 7 percent, respectively, of the $750 million personal audio player accessory market, or a total of $172 million in 2005. NPR calculated that, assuming an average cost of $50 per unit, approximately 3.4 million modulators were sold in 2005, based on CEA figures. 'This does not include a significant number of modulators sold with portable satellite radios to connect to vehicle radios,' NPR wrote....

"NPR Labs measured the field strength of signals emitted from more than 28,500 vehicles. The tests were conducted on three highways in the Washington [DC] area representing varying amounts of traffic. Measurements were taken on 88.1 and 87.9 MHz, which NPR said appear to be the two most commonly supplied frequencies for personal FM modulators. The results indicate that nearly 1 percent of vehicles were operating modulators on these two channels..."
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From "Mobile FM Transmitters - A Modulator Menace, or a Mountain out of a Molehill?" by Paul Riismandel, mediageek, 21 August 2006:

"...because Part 15 limits are so low, it's hard to see these transmitters, which operate at less than 1/10 of a watt at most, can be a real threat to a local broadcast station in any significant way. I can't imagine one of these transmitters posing more problems than power lines and other sources of electrical interference... [However,] NPR's report suggests that interference to distant stations would be possible - the measured field strength of some transmitters (at 48 - 68 dBµV) matches the field strength of the outer reaches of a station's 'rural service' area (at 56 - 60 dBµV)...

"For the user of the transmitter there's a strong disincentive to using it on frequency occupied by a local station, since it will be easily overwhelmed by any full-power transmitter. At most, what we're really seeing, then, is a few fringe-area listeners being momentarily inconvenienced while trying to listen to a distant signal that isn't strong enough to overpower a tiny transmitter that might be broadcasting a little outside the limits.

"To me, the brouhaha is just another example of the broadcast industry dedicating its efforts to stomp out any possible tiny bit of competition rather than focus on providing a valuable service. NPR's a little different here, in that it really is more listener than profit focus. Nevertheless, NPR didn't shy away from joining the NAB in trying to stomp out LPFM [Low-Power FM]...

"Frankly, I like the idea of thousands of little unlicensed transmitters operating all over the nation's highways. None are strong enough to overwhelm a local station, but any one of them might just provide something more interesting than what's on the rest of the dial.

"In a way, it's akin to Tetsuo Kogawa's idea of Mini-FM radio broadcasting ultra-local radio to neighborhoods, or just a city block.

"Over the years lots of radio activists and hobbyists have talked about creating networks of small Part 15 transmitters. So maybe the 'modulator menace' is a spontaneous version of that idea, more the result of a critical mass than any sort of organized movement. Perhaps it's even a form of unintentional civil disobedience (an oxymoron, I admit), if it's true that these transmitters are operating mostly above legal limits.

"About two years ago the blogosphere was all atwitter over the discovery that one iPod transmitter accessory could be easily modified to broadcast much further. This led to all sorts of blogger fantasies of turning their iPods into mobile microbroadcast stations, even advertising their frequency on bumper stickers.

"Of course, that fad is soooo 2004, and unwanted Stern reception seems to be the big threat here. Even if thousands of people took up the call to use their little modulators to bring something a little more intentionally unique to the airwaves I can't see this as a great threat to FM broadcasters. But that won't stop the NAB from calling out the calvary.

"If they succeed in pushing the FCC into action, then you might have to buy one of these 'high power' transmitters while you still can.

[Spectrum Policy: 1 November 2006]