Mixed signals

Startled fans of National Public Radio stations and Christian broadcasts at the low end of the FM dial are complaining that satellite shock-jock Howard Stern has burst in on their morning drive-time listening.

"Usually they're upset, because they don't know what's going on. This isn't what they tuned in to [hear]," said Charles W. Loughery, president of the Word FM Radio Network, a group of "contemporary Christian" stations in eastern Pennsylvania.


Normal car radios can't pick up signals from satellite-based subscription services such as Sirius, which carries Howard Stern's show. Instead, engineers blame badly installed, intentionally altered or defective equipment that transmits signals from Sirius receivers into their owners' car radios on FM frequencies.

Under the wrong circumstances, these gizmos can turn cars driven by Sirius subscribers into rolling FM broadcast stations.


As they move through traffic, their satellite radio programming is relayed, however briefly, to any radio that's tuned to the same frequency. Often, that's 88.1 MHz, or nearby frequencies reserved for noncommercial, religious or educational stations.

The interference might last only a second or two - but it can go on much longer if the sending and receiving vehicles are close enough and moving at the same speed.

Four of Loughery's six small radio stations have reported broadcast interference from Sirius Satellite Radio, with Stern and his potty-mouth the most oft-mentioned offender. Public radio stations across the country are getting the same complaints.

Anthony Brandon, president and general manager at 88.1 WYPR, a National Public Radio (NPR) affiliate in Baltimore, said he's shipped 60 complaint letters from listeners to the Federal Communications Commission.

"When Howard Stern went off terrestrial radio and onto satellite radio [on Jan. 9], it seems that is when we had the most complaints, due to the shocking material, in contrast to normal NPR programming," he said.

The FCC says it is investigating the problem.

In the meantime, it is causing some listeners considerable consternation, according to Neil Hever, program director for 88.1 WDIY, an NPR affiliate in Bethlehem, Penna.

"Back in December, a gentleman called from Warren County, N.J.," Hever recalled. "He said, 'I'm not going to turn you in, but I take offense to the rap music you're playing.' We said, "We don't program gangsta rap.'"


Hever said he's forwarded 38 listener complaints to the FCC, along with one of his own. "We're upset because we know it's aggravating our listeners, and we know it [interference with a licensed broadcaster] is against the law."

FCC violation

He also worries about his own liability.

Unlike satellite radio, Hever said, "We are subject to FCC rules relating to content and language." He fears the station will be named in a complaint to the FCC because of obscene content that listeners hear over his stations' assigned frequencies. "The toughest thing about that is we're guilty until we can prove ourselves innocent to the FCC."

Sirius Satellite Radio did not respond to repeated requests from The Sun for comment. But radio experts say it may be getting the most attention because Stern has so many listeners and his voice and schtick are so recognizable - even in short bursts. But it is not the only source of the interference.

Mike Starling, chief technology officer at NPR, said Sirius' chief competitor - XM Satellite Radio - can also be an offender. He said NPR has been speaking to Sirius and XM about the issue, and "they've offered their full support to look into the problem."


But the problem may extend beyond satellite radio. Starling said interference at the bottom of the FM dial can also come from MP3 music players - or any portable audio device - if it's using a built-in or aftermarket "FM modulator" that enables it to play through a car's FM radio.

The modulator's job is to take the original signal - either from a satellite or from the player - convert it to an FM frequency, and move it into the car stereo. Many are wireless, transmitting the last few feet to the car's antenna via the FM radio band.

Newer models enable owners to choose any FM frequency, from 87.9 MHz to 107.9 MHz - but they come with an admonition to pick one that's not being used by a local broadcaster.

Older models typically have a switch that can select from a handful of often-vacant frequencies below 89 MHz. Some come from the factory tuned to 88.1 by default. Unfortunately, Starling says, that frequency is used by about 80 public radio stations or their repeater towers - and just as many religious broadcasters.

It shouldn't be a problem. On paper, the FCC's "Part 15" rules strictly limit the broadcast power and range of these unlicensed transmitters.

"We think if they were compliant with the commission's power levels, we should not be seeing these reports and problems," Starling said. But "apparently, some devices are running illegally higher power levels and transmitting a quarter- to a half-mile up and down the highway."


Boosting the signal

Some of the problem may be faulty manufacturing. But there may also be a darker explanation.

Starling says he has found numerous Web sites where hackers can learn to "juice" their modulators by turning up the power to improve signal strength and sound quality in the car and at home. Hackers may also boost signal strength by tampering with a modulator's internal antenna.

Other problems may produce even more interference, engineers say.

Higher-quality satellite radios and other audio devices connect to car stereos directly. Some plug into the car's cassette player, if there is one.

Others use wires that plug into the radio's tuner, said Cristopher A. Baker, a senior technical training coordinator for Crutchfield Corp., a Virginia-based consumer electronics retailer.


That should prevent any interference. But a faulty installation can do just the opposite - turning the car's antenna into a rolling FM broadcast tower for Sirius radio. It can drown out a legitimate station, particularly in fringe areas where the station's signal is weakest.

Legally, it turns the offending car into a "pirate" radio station. Broadcasting an unlicensed transmission strong enough to interfere with a licensed station is a violation of federal law.

It shouldn't happen, Baker said. Better FM modulators include a disconnect relay that automatically turns off the car's radio antenna when the portable device and its FM modulator are turned on.

That isolates the portable in two ways. It keeps strong FM broadcasts from stepping on the portable's signal. And it prevents the car from broadcasting the portable's signal to nearby radios.

Cheap FM modulators may not have a disconnect relay. Although many installers will provide one for a price, others - including do-it-yourselfers - are just as likely to skip it, experts say.

Without a disconnect relay, how far can a pirate signal go?


"My estimate, from my experience with products I've handled and stories related to me, would be not more than 50 to 100 feet" under ideal conditions, Baker said.

He's on the conservative end. Other estimates run to 1,000 yards or more. Either way, it's more than enough to break into scheduled programming on a crowded highway.

More trouble ahead?

Interference problems will only get worse as wireless FM devices proliferate, Starling said. His "big fix," he said, would move them all to 87.9 MHz, a rarely-used frequency at the very bottom of the FM dial. When used at all, it's generally by short-range broadcasters, such as campus radio stations.

"Most broadcasters would say that's a great place to put modulators," Starling said. That's one of four proposed standards the North American Broadcasters Association has drafted for consideration by the International Telecommunications Union. The ITU regulates radio frequencies worldwide, and has a major influence on manufacturers seeking global markets.

Broadcasters also want ITU rules to restrict power output on FM modulators and make them tamper-proof. It also wants to ensure that users can tune them to any FM frequency (to avoid conflicts with licensed stations) and mandate hacker-proof antennas.


"Then you've got as close as you can get to a de facto world standard," Starling said. NABA has won support from the Consumer Electronics Association, which has pledged to address faulty installation issues through its certification of commercial installers.

"We want to make sure all the products they're installing come with 'sexed' connectors, male and female, so they can only be connected in the proper way," Starling said.

Until then, fans of NPR and Christian rock stations may have to brace for more snippets of Stern's thoughts on sexed connectors.