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NAB Weighs in on `Franken FMs', Channel 6 Spectrum

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(Image credit: FCC)

WASHINGTON D.C.—The NAB has filed comments with the FCC rejecting a proposal by NPR to repurpose some unused channel 6 spectrum for use as FM radio stations because that spectrum is playing an important role in the rollout of NextGen TV/ATSC 3.0 services. 

The comments were made in response to an FCC notice of proposed rulemaking relating to FM6, a.k.a. Franken FMs and on a proposal from National Public Radio that urged the FCC to repurpose channel 6 spectrum not being used by TV stations for FM radio.

The FM6 issue has reemerged as part of the transition to NextGen TV services and has been extensively covered by a TV Tech series of articles (opens in new tab) on the subject by James O’Neal. FM6 stations operate on 87.75 MHz. 

The FCC's notice of proposed rulemaking (opens in new tab) on the subject is asking for comments on whether it should allow future FM6 operations and on a wider issue of whether it should license radio stations on the 82–88 MHz spectrum in areas where Channel 6 LPTV and full-power stations are not operating. 

This would open up opportunities for new educational FM stations in underserved rural areas., NPR had argued in comments to the FCC. 

In its comments the NAB noted that “Channel 6 television stations provide critical service and…television service must have unconstrained primacy in that spectrum. NAB further submits that the existing 13 FM6 stations in that spectrum have developed a listener base, with no reports of interference, and therefore should be allowed to continue operation as presently authorized.”

In its arguments against repurposing the spectrum, the NAB reported that currently there are “presently 98 television stations authorized to operate on channel 6 in the United States. While some of these stations serve large, sparsely populated areas where the relatively low power consumption of channel 6 transmitters makes the provision of television service economical to rural Americans, others serve densely populated urban areas where no alternative channels exist in more desirable spectrum (i.e., VHF-High Band and UHF TV channels). A number of channel 6 stations also serve as `lighthouse' stations for NextGen TV, providing a critical transition path for television broadcasters as they migrate to ATSC 3.0.”

“Authorization of new FM stations in an FM expanded band created from television spectrum could also preclude new television stations,” the NAB said. “[T]here are already some channel 6 television stations serving as ATSC 3.0 lighthouse facilities, and additional such facilities may be needed as the rollout of NextGen TV progresses. The opposite need may exist near the end of the ATSC 3.0 transition. That is, DTV `nightlight' facilities on channel 6 may be needed to help ensure that legacy viewers still receive a signal. As television broadcasters voluntarily transition to ATSC 3.0 with no additional spectrum allocated by the Commission, it is important that existing television spectrum be preserved to help make this difficult transition as efficient as possible. Further, as the Commission has observed, consumer FM receivers cannot tune below 87.7 or 87.9 MHz and cannot be upgraded to do so, creating a massive legacy receiver base that cannot tune to most expanded FM band channels and discouraging FM broadcasters to propose operation in an expanded FM band. The expansion of the AM band 25 years ago may serve as a cautionary tale, with many of the expanded band channels originally allocated still fallow. NAB thus urges the Commission to reject NPR’s proposal to repurpose television channel 6 spectrum for FM services.”

While the NAB argued that the 13 existing FM6 stations be allowed to continue to operate as presently authorized as ancillary or supplemental services, it also said they should not be allowed to arbitrarily modify their operations. 

“It seems certain, however, that those 13 FM6 stations might impact FM stations operating in the reserved band (88--92 MHz), other channel 6 television stations, or their own TV6 video services, if they are allowed to arbitrarily modify their operations, for example, by increasing power, relocating, or adding Subsidiary Communications Services or In-Band On-Channel digital audio broadcasting services to their signals,” the NAB added. “There are presently no regulatory requirements that directly address FM6-to-reserved band FM (or other) interference and NAB submits it is critical to avoid increasing the risk of interference without a technical record to justify expanded uses. NAB therefore urges the Commission to restrict FM6 operations to the 13 FM6" stations currently operating. 

However, the NAB also stressed that FM6 stations must not degrade the ATSC 3.0 service and must comply with EAS requirements.

“NAB supports the proposed requirements that the channel 6 television (TV6) operation transmit rule-compliant ATSC-3 video and associated audio at all times the associated FM6 is in operation and that that the FM6 coverage area and populations may not exceed that of the TV6 operation,” the NAB said.

To avoid interference, NAB believes that “the requirement to transmit FM6 at 87.75 MHz is unnecessary and is linked to the now-obsolete NTSC television transmission system. Instead, NAB proposes requiring the 13 FM6 stations to operate on 87.7 MHz in order to give licensees the opportunity to improve analog FM6 reception while maintaining ATSC-3.0 compatibility. This small 50 kHz shift in frequency away from the FM band would presumably reduce the potential for interference to FM stations operating in the reserved band while improving compatibility and fidelity for FM receivers that can tune only in 200 kHz steps. Indeed, NAB notes that many or most FM6 operations apparently operate at 87.7 MHz and that the technical analysis done in support of FM6 operation in conjunction with ATSC 3.0 involved testing at 87.7 MHz.”

The NAB also argued that no change in the distance separation rules were justified at this time.

George Winslow is the senior content producer for TV Tech. He has written about the television, media and technology industries for nearly 30 years for such publications as Broadcasting & Cable, Multichannel News and TV Tech. Over the years, he has edited a number of magazines, including Multichannel News International and World Screen, and moderated panels at such major industry events as NAB and MIP TV. He has published two books and dozens of encyclopedia articles on such subjects as the media, New York City history and economics.