At the turn of the twenty-first century, proponents of HD Radio sold the technology to the FCC by claiming that it used “no new spectrum.” Advocates of low-power FM (LPFM) radio made a spirited but ultimately unsuccessful challenge to this claim. They worried that the digital sidebands of FM-HD signals would interfere with the new wave of community stations the FCC was preparing to unleash. HD supporters dismissed these concerns.

Ten years after both HD and LPFM took to the air, the conflict between the two services is crystal clear.

Brad Johnson is a lot like me: a former participant in the corporate media who made the decision to step away from it following the passage of the Telecommunications Act of 1996. One of the careers decimated by post-Telecom radio consolidation was broadcast engineering – Brad was the chief engineer at several Citadel and Clear Channel-owned stations in central California until he was let go in the repeated rounds of downsizing the companies conducted during their station-buying frenzy.

It’s no stretch to say that the experience radicalized Brad: we both participated protests of the National Association of Broadcasters in 2000 and 2002, and Brad’s been a serious watchdog of corporate media malfeasance and facilitator of independent media more generally since then.

Following the passage of LPFM, Brad decided that his hometown of Salida (population 14,000) could use a local voice on the airwaves. There was no better candidate. He helped a local community group apply for an LPFM license, and KQRP-LP went on the air in 2003. The station broadcast at 106.1 FM from a ~65-foot tower at Johnson’s home. The “QRP” in KQRP is ham radio-speak for a low-power station.

The station specializes in alternative (progressive) news and providing an outlet for the local music scene. For example, KQRP works closely with Modesto Sound, a non-profit teen recording studio where many local bands record. KQRP not only plays the bands’ demos, EPs and albums, but the studio also produces special shows that air exclusively on KQRP. The station’s also done several simulcasts from live shows in the community. This is exactly the sort of localism to which the LPFM service aspires.

Unfortunately, 106.1 was far from an optimal frequency for an LPFM station. Two fullpower stations on the same channel bracket Salida, and given the topography and dynamic atmospheric propagation characteristics of the area, KQRP was often hammered by co-channel interference. “We got stomped,” says Brad. “We couldn’t even cover our whole town,” which is only two and a half miles wide.

But things began to look up a couple of years ago, when another full-power station in the area moved its transmission facilities and created a small opening for an LPFM signal in the area on 104.9 FM. It seemed almost too good to be true – the frequency is effectively clear of other stations in the vicinity. With the help of the Prometheus Radio Project and other kindred broadcast-engineering/FCC-spelunking spirits, KQRP filed the necessary paperwork to move to 104.9.

In order to take advantage of this opportunity, KQRP had to be moved a whopping half-mile. Fortunately, a local cheesemaster generously offered the use of his farm to site the transmission facilities, rent-free. At the moment, the station’s transmitter is in the barn and a 40-foot mast hoists the antenna. The farm’s landlord is cool with the station installing a larger mast, and there’s also a possible option to site the antenna on a nearby 400-foot (!) tower originally built for wireless cable TV service.

KQRP began test broadcasting on 104.9 in the spring of 2012. Shortly afterward, Brad secured permission to change the station’s call letters to KGIG-LP. Interestingly, KGIG had never before been used as a broadcast call sign, having originally been awarded to a Coast Guard airplane.

Since KGIG’s transmitting facilities are now technically located, according to Brad, “across the street in Modesto,” the station also received FCC permission to change the station’s community of license. KGIG’s studio is still in the front room of Brad’s house, and the signal from there is beamed wirelessly to the transmitter at the farm.

Next door on the dial to KGIG, at 105.1, is KNCI, a 50,000-watt modern country station owned by CBS Radio, broadcasting from 65 miles away in Sacramento. KNCI also runs an FM-HD signal with two subchannels: one is a simulcast of KHTK “The Fan,” a 50,000-watt AM sports-talk station, and the other a “traditional country” digital-only format stream.

KNCI was running an FM-HD signal long before KGIG-LP moved to 104.9. Brad acknowledges that while assessing the new channel he could faintly hear the noise created by KNCI’s FM-HD sidebands, which reside on the first-adjacent channels to the station’s main analog signal – in this case, 104.9 and 105.3 FM.

Even with the presence of this interference, Brad says making the move from 106.1 to 104.9 was a no-brainer. The presence of a digital FM-HD sideband was practically nothing compared to getting “stomped” by two analog stations effectively sharing KGIG’s LPFM frequency.

Brad estimates that moving KGIG from 106.1 to 104.9 improved the station’s coverage area and signal robustness by at least 50%, allowing it to cover not only Salida, but the neighboring communities of Ripon and northwest Modesto, as well as much more of the surrounding rural farm land.

KGIG lived this charmed life for a few short months…until this summer when KNCI did something to its FM-HD signal. Brad immediately noticed that the buzz-sounding interference from the FM-HD sideband on 104.9 had increased in volume – so much so that it effectively smothered much of KGIG’s coverage area. Brad says KGIG’s reach is now not much different from KQRP’s.

But this time, the interfering signal is digital, which is much more insidious. Not all radio receivers are created equal, and some are more sensitive than others to the presence of FM-HD sidebands. Generally speaking, the cheaper the radio, the worse the problem. If the receiver perceives the HD “buzz” to be stronger than the actual radio station that belongs on the channel, the listener will hear the digital drone. For example, as a car radio receiver moves down the road, KGIG’s sound will be distorted by KNCI’s digital pulses.

KGIG’s first move was to inquire with the FCC. “Basically, they said, ‘There’s nothing you can do about it, you’re an LPFM.’ It’s like being some kind of lesser person without any rights,” Brad explains. LPFM stations have secondary status on the airwaves, and must accept interference from full-power stations. In KGIG’s case, though the interference is not from the analog station, but the extra digital signal its neighbor is throwing onto Brad’s channel, the FCC’s perspective is fatalistic.

KGIG then reached out to KNCI. Brad spoke with two engineers there who confirmed that the station was running FM-HD sidebands at elevated power (in KNCI’s case, 2,000 watts), but had no real suggestions on how to confront KGIG’s particular problem.

In July, KNCI’s HD signal was off the air for six weeks, and KGIG experienced the best coverage of its nine-year life. “Without the HD jamming signal KGIG could be heard in two more towns up and down the freeway,” Brad notes. “We thought our station was just fading out before, but what was really happening was the HD signal quickly covered up our station long before it could fade out in a natural way.”

This month, KNCI resumed hybrid analog/digital broadcasting, and the dilemma for KGIG immediately returned. “It’s like our community radio station is being jammed by corporate broadcasters out of spite,” laments Johnson.

KGIG’s next move is to acquire a spectrum analyzer to do a proper analysis of KNCI’s HD signal. Has the CBS station been experimenting with asymmetric sideband operation, broadcasting a 5,000-watt digital signal (the maximum power allowable) on 104.9? It would make sense for KNCI to explore this configuration. The FM dial in the area is packed, and placing all of a station’s digital power onto the sideband that lies on a nearly-empty channel maximizes the HD signal’s coverage and robustness.

That KGIG-LP actually broadcasts on 104.9 (and at just 5% of KNCI’s current FM-HD power output) is simply collateral damage in the eyes of CBS and the FCC, both of whom still cling to the canard that HD Radio uses “no new spectrum.”

Brad Johnson is not losing hope…at least not yet. He and KGIG plan to navigate the FCC’s tortuous procedures for filing an HD interference complaint, and Brad wants to contact other stations adjacent to KNCI (on 104.9 and 105.3) to alert them and/or compare notes on any HD interference they may also be suffering. Perhaps a coalition of victim-stations might catch the FCC’s attention more strongly than if KGIG goes it alone.

Either way, this LPFM station’s on-air voice has been marginalized and will continue to be so if larger broadcasters can’t abide by the simple premise of being good spectrum-neighbors. This is the second CBS-owned station in California to be the subject of an FM-HD interference concern.

“I hope some day soon a corporate bean counter at CBS will ask why the company is wasting money broadcasting this signal that only 1% of radios can receive while costing thousands of dollars to maintain,” says Brad. “If HD Radio is ever shut off, KGIG will be able to serve most of the county.”

In the meantime, KGIG will devote more time and energy into developing its streaming platforms because, for a station focused on youth radio, that’s where the kids actually are. “They don’t listen to radio,” Brad observes. “I heard one of them say, ‘When you’re in range of [KGIG], you’re on nowhere.’ That really hurt.”