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AM Broadcasters, Hams Have Common Interest in Cleaning Up Noise Sources

04/28/2014

Radio amateurs and AM broadcasters have some common ground in wanting to clean up “a worsening RF noise environment in the AM broadcast band,” according to recent comments filed with the FCC by the Society of Broadcast Engineers (SBE) on the issue of revitalizing AM broadcasting. ARRL General Counsel Chris Imlay, W3KD, who is also general counsel for the SBE, drafted the remarks.

 

“There are numerous complaints from Amateur Radio operators of severe interference from power line noise annually,” said the SBE comments, filed earlier this year. “Power line radiation in the HF and MF Amateur allocations will in most cases directly translate to preclusive noise in the AM broadcast band. The Commission has relied completely on the good faith efforts of electric utilities to resolve these.”

While that approach has succeeded in “some cases,” Imlay wrote, “more often, utilities do not have available to them — and are not willing to retain — persons skilled in RF interference resolution, and the cases at FCC are allowed to languish unresolved for years…without any enforcement action at all.” The SBE noted that AM listeners often are in vehicles adjacent to power lines that “frequently radiate RF noise” at levels to make AM reception difficult or impossible.

The SBE comments also pointed to “substantial numbers of complaints of harmful interference to Amateur Radio stations” from LED lighting systems, noting that many RF light bulbs could be within range of a typical AM broadcast receiver in the typical residential neighborhood. Imlay used recent ARRL Laboratory RF lighting test results as one example to illustrate the problem.

The SBE comments cited an RF lighting ballast used for indoor gardening that generated excessive conducted emissions that could “preclude AM broadcast reception over entire residential subdivisions.” The ARRL formally complained about the device to the FCC last month. The SBE also pointed the finger at radiation from unintentional emitters, such as plasma TV sets, and conducted emissions from devices such as pulse-width motor controllers.

“The Commission does not now have, and in fact has never had, a complete understanding of ambient RF noise levels and trends thereof over time,” the SBE said. “Furthermore, the Commission has uneven regulations and policies governing noise-generating intentional, incidental, and unintentional radiators; and its enforcement efforts in this context have been and are both impractical and insufficient.”

“[T]he goal of AM revitalization will never be realized in the medium and long term in the face of the headwind of a worsening RF noise environment in the AM broadcast band,” the SBE said, noting that the same concerns apply to all bands between 9 kHz and 30 MHz. “Some regulatory relief is absolutely necessary,” the SBE concluded.

The SBE pointed out that consumers suffering from noise issues on AM radio broadcasts have “other media options” available that RF noise “will make them exercise.” The same argument does not necessarily apply to Amateur Radio operators, however. AM radio listeners “are not like some other interference victims, such as licensees in certain services,” the SBE said.

The situation may already be improving. This month the FCC cited a Washington resident for operating an “incidental radiator” — apparently some sort of lighting device — that has been causing harmful interference on Amateur Radio frequencies. The Commission has ordered the individual to stop using the device.

 

 



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