ARRL, the national association representing amateur-radio licensees, tomorrow is expected to ratify a court appeal of the FCC’s latest order regarding permissible emissions levels from broadband-over-power line (BPL) providers.

ARRL’s executive committee will make the decision tomorrow to file in the U.S. Court of Appeals for the District of Columbia Circuit, CEO David Sumner said in an interview with MRT. While ARRL filed petitions for reconsideration to the FCC’s October 2004 order regarding BPL, the August 2006 order “made matters worse,” Sumner said.

One new rule contained in the order “basically gives BPL systems a free pass” to interfere with mobile amateur-radio stations, Sumner said. Under the rule, BPL operators are required only to reduce emission levels to 20 dB below the maximum allowable limit below 30 MHz—or 10 dB below the maximum limit above 30 MHz—even though the resulting environment typically still is about 25 dB above the median noise level without the BPL emissions.

“If there’s still harmful interference to mobile stations, that’s just too bad,” Sumner said. “We think that’s simply intolerable. The commission can’t define away its obligation to protect licensed services from harmful interference.

“The commission is basically saying, ‘You can degrade HF mobile communication by 25 dB, and we’re not going to bother you.’ We’re not going to stand for that, and we’re going to the court of appeals.”

Another aspect of the FCC order that ARRL expects to appeal is a “40 dB per decade” assumption used to calculate field strength emitted from BPL lines. While the extrapolation factor might be accurate for a point-source radiator, it is not accurate when the emissions come from a power line—an explanation detailed in filings by ARRL and others, Sumner said.

“There’s no perfect way to predict what the decay rate will be from the line, but it’s definitely not 40 dB per decade,” he said. “It’s significantly less than that. ... The right number is a whole lot closer to 20 [dB] than to 40 [dB]. It’s clearly not 40 [dB]—you can demonstrate geometrically that it’s not 40.”

Although ARRL asked the FCC to change several items in its BPL ruling, it likely will not ask the court to revisit each of these, Sumner said, as such an appeal would be “fruitless” in aspects where the FCC order cites a reasoned explanation for its finding. But that was not the case with the FCC seemingly ignoring multiple filings favoring ARRL’s position on the “40 dB per decade” assumption, he said.

“The commission dealt with all of those showings with the flat statement, ‘We’re not persuaded that there is any basis for changing our original decision,’” Sumner said. “That was it—that was the sum total of their argument. That’s just crying out for the court to tell them to go back and do it right.”

ARRL does not take such court action lightly, as Sumner noted that the suit would be the first filed against the FCC by the organization since a challenge of the commission’s 220 MHz reallocation in 1990.

“It’s not something we do every day,” he said. “We wouldn’t do it if we didn’t feel that the consequences of leaving the rules as they are is serious not only for amateur radio but for all licensees. And we wouldn’t do it if we didn’t think we could win.”