Engineer Says AM Interference Will Continue

This is one in a series summarizing notable comments being filed to the FCC on its AM revitalization NPRM. Read other summaries at

Nonbroadcast interference to AM radio is not going away.

That’s according to engineer Sam Brown, who believes the FCC is asking the right questions when it comes to helping those who own stations on the beleaguered AM band.

His is one of the now 200 or so filings to the FCC regarding the agency’s rulemaking on AM revitalization. Brown, a radio and telecom professional in the Washington area is also a former AM station owner. Currently, he works for NPR’s Public Radio Satellite System, however he filed his comments as an individual.

The common use of compact fluorescent lights, computers and appliances with microprocessors results in so many interference sources that it’s impossible to track them all, he tells the commission. Reduced audience and multiple alternatives to AM have created less public demand for noninterfering equipment, he tells the agency. “Imagine if a new light bulb had been brought to market in 1966, but it interfered heavily with AM reception. This was [a] time when listeners routinely tuned into stations that were well below 2 mv/m. If people at the far end of Long Island couldn’t get WABC, or folks on Cape Cod lost WRKO, or Washington no longer had cool top 40 from Baltimore’s WCAO, it would have been unacceptable. Most purchasers would have returned their bulbs, complaining that ‘my radios didn’t work when I used your product.’ Apartment buildings and condos would have banned them due to interference with neighbors’ reception.”

He continues: “Today, the remaining niche AM listeners know that “it works in some places and not others,” or “some noise is normal,” and most people listen to FM, MP3s or Internet radio.”

Brown supports the concept favored by many previous filers to open a special application window for those AM owners who would like to apply for an FM translator. “Many AM stations, particularly those outside of urban areas, serve several distinct communities within their coverage area. Additionally, directional stations often have two or three lobes in their patterns. There are also situations where a suitable antenna site for a translator that would best serve the station’s coverage may be unavailable, infeasible or prohibitively costly” he writes. In those cases, a single FM transmission may make that AM viable, according to the engineer.

Because some have filers have suggested to the FCC that no new AMs should be licensed, and others should stop operations, Brown suggests this argument be carried further and that those AMs “benefitting sufficiently” from an FM translator should be able to discontinue their AM operation. “There are already AM stations which mention only the FM translator frequency, and a listener would not even know they have an AM signal unless aware of the meaning of a quickly-uttered legal ID. AM power, towers, maintenance and land may be unnecessary expenses undertaken primarily to feed a 250 W FM ‘station,’ which just happens to be a translator.”

The 87.7 MHz frequency should be available for translators of AM stations in areas where no TV station transmits on Channel 6, he suggests. Regarding so-called “Franken FMs,” our words, not his, low-power TV stations on Channel 6 that transmit their analog audio on this signal have demonstrated an ability to garner “significant’ audience, he tells the commission. “Channel 200, 87.9 MHz in the reserved band is only assigned to two stations nationwide, thus leaving 87.7 MHz available in many places that would otherwise be out of frequencies,” according to Brown. He suggests a larger discussion needs to take place about expanding the FM band to accommodate AMs, but says this change could be implemented regardless of whether a larger expansion occurs or not.

Regarding HD Radio, all-digital operation should continue to be tested and encouraged if it works well, however he recommends eliminating hybrid IBOC AM altogether: “It is a ‘clear failure,’ as the coverage is very limited, the interference with adjacent and second-adjacent stations is substantial, and the switching back and forth between digital and analog audio bandwidth and fidelity makes it virtually unlistenable.” He also recommends FM stations should be encouraged to lease HD multicast channels to AM broadcasters.

The deadline to file reply comments to Docket 13-249 is today, March 20.

Watch our page for summaries of other comments to the FCC NPRM.  

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Comment List:

I am curious whether DRM will be better able to handle the interference?
By Gary on 4/17/2014
I might be late to the party here. Most of the comments here seem to be from people working in the broadcasting industry or 'old timers'. As a common man and a young listener, I don't care about AM revitalization for the simple reason that I can't even listen to AM radio. Except for 2 very strong local stations in the car, I can't listen to any AM station. There is so much interference that it is impossible to decipher what is being said. And, I do have a DSP receiver both at home and in the car which operate on digital IF and do try to clean up the signal. Still it is impossible to listen to any station other than the strongest one. I don't have much hope for AM in its present form. In 30 years, both the stations and the listeners will be dead.
By Gary on 4/17/2014
Last week, I got a call from the new RFI Guy at our local power company, telling me he was just given a Trouble Ticket for an interference problem that had my name on it. After several minutes of "head-scratching", we were able to ascertain that it was from a call I made to their hot-line last fall, when a freak snow storm made the interference on my Sunday morning commute so bad that I thought a sub-station was about to shut down. I had called and identified myself, including the fact that I have chased RFI for them in the past, and that I was concerned for their equipment and a potential holiday outage (the radio noise was deafening, and sounded like recurring flash-overs on an insulator).
By Ken W. English on 4/1/2014
"The 87.7 MHz frequency should be available for translators of AM stations in areas where no TV station transmits on Channel 6" Why not also include 87.5 MHz in the above ? A sizeable proportion of existing radios will tune to 87.5 MHz. 87.5 would not be any more of an interference risk to distant Channel 6 digital TV than is the case with 87.7, and is less risk (than 87.7) of any interference to distant low-power analog TV (which can continue until September 2015) on channel 6. 87.5 would be in addition to (not a replacement) of a station's existing AM frequency, no existing listeners would loose out.
By KPL on 3/25/2014
I'm a AM listener, mostly sports talk. This past weekend I had to replace my Dell computer monitor. When the monitor was on, I could not pick up anything above 800Khz. It was a constant hum. I ended up spending $199.00 on a new AOC monitor. I would not purchase another noise making Dell. I actually walked into Best Buy with a transistor radio and found a monitor that wasn't emitting noise on the AM band. Now, I can be on the PC and listen to the sports talk on the highend of the dial. The way I see it, I was forced to spend the 199 bucks because there seems to be no type of AM noise regulation. Someone else in my situation might not have the 199 dollars, there goes another AM listener. FCC has got to crack down with this type of interference!
By Jose Reyes on 3/24/2014
"If people at the far end of Long Island couldn’t get WABC" How can I on the east end of Long Island be able to get in crystal clear on the crappiest of radios CHML out of Southern Ontario yet I can't get in crystal clear WABC? What Canada do that America no do?
By What? on 3/22/2014
Well, I have CFL's, and a computer that's always on. I live in a city, and I occasionally listen to AM with very little noise. Seems to me, it's the type of CFL. And the type of computer. I believe that the interference problem can be solved, but it will require the FCC to get tough on external devices. And I hope they do so before a plane crashes. But that's another story.
By Duke and Banner on 3/21/2014
The best and most honest comments yet. OBVIOUSLY, non-broadcast AM interference is NOT going away, and in fact, likely will get significantly worse. The FCC attampts to police that non-broadcast interference are not only absolutely futile, but also a tremendouse waste of their limited resources.
By Chip Giannettino on 3/20/2014

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