Here’s some immediate reaction and followup to the announcement that the FCC will allow AM radio stations to use all-digital transmission if they wish.
THE CHAIRMAN LOVES AM
Ajit Pai hasn’t lost his lifeline affection for radio. In an official statement after the vote, Pai wrote: “Freddie Mercury memorably sang in Queen’s 1984 hit Radio Ga Ga, ‘Radio, someone still loves you.’ Thirty six years later, that remains true; I love radio, as do millions of my fellow Americans. And that love extends to the AM band.”
Pai repeated his frequent praise for stations that cover local events and sports, provide a forum for discourse, offer foreign-language programming and provide information in emergencies. He reminded us that in the AM revitalization initiative, more than 2,100 FM translators are on the air rebroadcasting AM signals, with another 700 pending. “Countless AM broadcasters have told me that their FM translators have given their stations a new lease on life.”
APai said that a transition to all-digital service “presents a singular opportunity to preserve the AM service for future listeners.” He also thanked Ben Downs of Bryan Broadcasting, the proponent of this proposal who hosted Pai at his stations in Texas years ago “and planted a bug in my ear about this idea.”
WHAT WILL BEN DOWNS DO?
Radio World reached Ben Downs this morning as the FCC was set to vote. “I’m glad we had a chance to be a part of this proceeding,” he told us. “David Layer at NAB conducted tests on the system over a period of years and Hubbard’s WWFD was the proof of concept.
“To me it just seemed we needed a slight push to take us to the next step. The FCC staff apparently agreed that this was a well-tested and proven system. Regulator changes never happen as fast as you might like, especially with the burden of Covid, but the FCC staff moved really quickly to get this to today’s vote. The fact it was unanimous shows that the work done was based in solid engineering.”
I asked Downs if he will convert his own stations. “I have two of four that makes sense to convert,” he replied. “My decision tree says that if it’s a full-time station with a backup cross-band translator, then it’s an easy decision to choose to convert. Especially if you’re playing music.
“Two of my AMs have a very good sized footprint and would benefit from being able to broadcast without that noise and narrow bandwidth that defines today’s AM radio,” he said. “And, to the best I can determine, their RF facilities will require only minor adjustments.”
Just how many others will get on board is uncertain. The FCC sounded optimistic, writing that “AM broadcasters overwhelmingly support the proposal to allow all-digital AM broadcasting, as do broadcast engineers; technology companies, and some individual listeners.”
It said that “commenters believe that all-digital operation will increase the format choices that AM broadcasters can offer to their audiences, including the option of music programming (in full stereo if using enhanced mode). Hubbard asserts that all-digital operation will also allow AM broadcasters to provide program and station information along with the main audio stream more reliably than in hybrid mode. Finally, commenters note that the all-digital mode is designed to potentially support an HD-2 second programming stream.”
But Radio World is eager to hear from stations that are planning to make this move anytime soon. Anecdotal evidence has suggested to me that there may not be many stations ready to jump. I certainly have sensed no wave of pressing interest. And comments I have received personally have been doubting or downright negative. Now that the window is actually open, advocates can put their money where their mouths have been.
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MIKE RAIDE ON THE INVESTMENT
On the topic of what adjustments stations will need to make, Radio World also checked in with Mike Raide of Xperi. We asked him: If an AM station has HD Radio equipment installed, what technical changes and further investments will they need to make now in order to go all digital?
“They will need to make sure their antenna system is capable of handling an HD signal,” Raide said. “The antenna system will need to meet the required bandwidth to properly transmit an MA3 signal. This may require some additional components to properly increase the bandwidth, and some consulting work done by some familiar with AM antenna systems.”
What about stations that do not yet have any HD Radio gear? “They will need to reach out to the equipment manufacturers for the necessary equipment,” Raide replied.
“The required equipment at least would be an exciter or exporter and a transmitter capable of transmitting an MA3 signal. An MA3 signal places greater demands on a transmitter, even more so than an MA1 hybrid signal. A station would have to reach out to an equipment manufacturer to see if their solid-state transmitter is capable. A vacuum tube transmitter is not capable of any digital signal and would have to be replaced.”
On the subject of costs, the FCC wrote this in its order: “We note that all-digital broadcasting places fewer new demands on the transmission system than hybrid operation, therefore minimizing the technical and equipment costs of conversion. Kintronics sets out in detail the system parameters that would be needed for all-digital conversion, concluding that ‘the measures required on the antenna system for many sites will be minor, and the majority of antenna systems should be capable of digital transmission.’ The cost of conversion for AM stations that are already broadcasting in hybrid mode is likely to be minimal. For facilities requiring a major overhaul to accommodate all-digital transmissions, however, the costs will be considerably more.”
The commission noted that Xperi currently offers AM stations a perpetual license to use HD Radio technology with no initial or recurring costs, as we’ve reported.
FURTHER NOTABLE DETAILS
There are extensive technical discussions in the order under headings for nominal power, digital spectrum emission limits, power measurements, use of digital subcarriers, carrier frequency tolerance standard, prohibited interference and remediation procedures, night operation, EAS and other facets.
You can read the order here.
But here are a few notable takeaways:
-All-digital operation will be allowed both day and night.
-There’s a 30-day waiting period before converting to all-digital “so that transitioning AM stations can provide adequate notice to the commission, consumers and other potentially affected stations.”
-The order requires each all-digital station to “provide at least one free over-the-air digital programming stream that is comparable to or better in audio quality than a standard analog broadcast.” Beyond that though, digital subcarriers can be used for broadcast or non-broadcast services, including song and title information.
-Stations will be able to use their additional digital bitrate capacity for broadcast or non-broadcast services, with the capacity varying depending upon the mode of operation. “WWFD initially operated in core-only (reduced bandwidth) configuration while it modified its facility to enable transmission in enhanced mode (greater bandwidth),” the FCC noted. It will permit each broadcaster to select either mode as their situation dictates. (It opted not to require that additional digital data capacity be used only to enhance audio fidelity, particularly stereo audio, as some had requested.)
-Each digital station still must participate in the national Emergency Alert System. The station must ensure that any others that monitor it can still receive and decode an all-digital EAS alert, or adjust their monitoring assignments to receive EAS alerts from another station.
-The commission declined requests to consider Digital Radio Mondiale for AM digital operation, saying there has been no fully developed proposal or testing. “We approve the HD Radio MA3 mode, but do not foreclose the future consideration of alternative transmission technologies.”
-The FCC agreed to use average power of the all-digital signal (including the unmodulated analog carrier power and all of the digital sidebands) to determine whether the station is complying with the nominal power limits set out in the rules. This was a change from its original plan. “We find that this nominal power limit is technically feasible, as demonstrated in the NAB Labs experiments and WWFD’s experimental operation.”
-About interference, it wrote: “Although testing indicates that the digital signals may cause some increased degradation to analog signals, in most cases this will be masked by the noise floor, and in any case there is no evidence that interference will occur within service areas that are currently protected under our rules.”
-The FCC did not impose stricter spectral emissions limits as had been proposed in the NPRM. It said the consensus was that existing emissions limits will adequately protect stations on adjacent channels. Also, “the record indicates that these stricter HD Radio emissions limits may not be set at technically feasible levels and may need to be revisited in light of field data from all-digital experimental operation.” The FCC said stricter limits could hamper deployment of all-digital service but said it could revisit that later.
-The FCC declined to incorporate the NRSC-5D Standard by reference into its rules, for several reasons. Among them: “If we were to consider incorporating by reference the NRSC-5-D standard in the future, we would likely aim for consistency across services, and thus would consider AM all-digital, AM hybrid, and FM hybrid technical standards at the same time.” But it emphasized that it was not trying to undermine confidence in it as a voluntary standard.
-And the FCC declined to take certain other actions that had been urged upon it, saying these were beyond the scope of the proceeding. These ideas included increased enforcement to reduce noise floor levels; the sunset of AM translators; establishing a Low Power AM service; waiving regulatory fees for all-digital AM stations; allocating television spectrum for FM replacement facilities for AM broadcast stations on a primary basis; allowing translator rebroadcasting from an all-digital AM primary station to originate programming; disallowing use of HD Radio hybrid mode; authorizing AM programming on audio-only channels in ATSC 3.0 TV broadcasts; widening the FM band; other AM revitalization-related proposals, such as eliminating third-adjacent channel protections; and receiver standards.