The author at work. “Allocation issues, especially at night, were the primary reason IBAC would not work; yet what we call IBOC is, essentially, IBAC and became the standard.” The author is chief engineer of WLS(AM), a 50 kW Class A station in Chicago, and of sister station WLS(FM). Opinions are his own and not necessarily those of his employer.
In the fall of 1989, I was the assistant chief engineer for KSD(FM) in St. Louis, then owned by Gannett Co. Inc. That year, transmission of digital signals on FM started to become a reality, and I was lucky enough to be one of the first field engineers to work on the project. Our motto was “For the broadcaster, by the broadcaster.” As months went by with some positive progress, a consortium of broadcasters joined Gannett in helping to develop the technology.
It’s more than 24 years later, and radio is still as archaic as it was then.
I am not writing to go down memory lane but to vent my frustrations as a longtime engineer who is passionate for the work and industry in which I and many others have devoted our lives.
Many will recall the debacle of the FCC choosing a standard for AM stereo; you may not be aware that the commission had the same issues with digital. So the FCC seems a good place to start this conversation and likely a good place to finish.
The fact that the commission failed to create or choose a standard has been the primary issue with regard to the advancement of radio technology. In AM stereo, receiver manufacturers weren’t interested in investing in multiple standards — though Sony did build a very nice tuner, the SRF-A100, which as far as I can recall was the only one that supported multiple systems. I still have one.
But receivers were difficult to find, with manufacturers afraid to invest in a technology that might not become a standard. Sound familiar?
Digital radio faced similar issues as those confronting AM stereo; but the technology also required broadcasters to pay a “license fee” in order to participate. This created more of a chicken-and egg effect than had been the case for AM stereo.
The burdens were piling up, but the development team was still trying to figure out how to put a wide digital carrier in a voice spectrum of narrower-than-optimum amplitude. The commission didn��t want to talk about radio needing more spectrum; so the project’s scope of work was guided by ancient rules and allocations that had not anticipated the needs of today’s technology.
For AMs, the thought of being able to transmit digitally and compete with analog FM sound quality was a shot in the arm. This was around the time AM began its big switch to talk programming. Managers felt AM could not compete with FM quality and saw higher-quality digital players hitting the market too. So AM would focus on voice, where audio quality wasn’t deemed as important.
That’s the environment in which the digital development team was working. But the AM band presents hurdles for digitally transmitting audio. There are many factors: interference, antenna/transmitter bandwidth, directional antenna complications with phasors/antennas and the like, not to mention limitations deriving from AM’s 10 kHz allocation.
I recall the AT&T/Lucent IBAC (in-band, adjacent-channel) demo in New Orleans. We on the USA Digital Radio team knew this was not a solution and subsequently hit the NAB Show floor, poo-poohing the whole idea. Uh, do you know how your AM digital transmitter works today? See Page 4 of www.nrscstandards.org/SG/NRSC-5-B/1082sE.pdf.
Allocation issues, especially at night, were the primary reason IBAC would not work; yet what we call IBOC is, essentially, IBAC and became the standard.
The FM system is basically the same in design in that the digital carriers surround the analog carrier. (A history sidebar: The first transmissions of IBOC were truly that. On WILL(FM) in Champaign/Urbana, Ill., the first transmission of four phase-adjusted FSK carriers in 1992 were superimposed on top of the FM signal, not in sidebands. It worked, though not as well as what you hear today.)
FM digital’s saving grace was that there was sufficient bandwidth for the added carriers, using the current technology, to be placed in the existing mask. Again, the FMs benefited, while AMs have yet another nail added to their coffin.
Now, while AM HD Radio has languished, HDTV has become a de facto household standard, in the same or less time. Why?
For one, you didn’t see the FCC constraining TV stations to allocation rule adherences as they did radio. Why does radio continue to be the bastard child? Why hasn’t the NAB been a better voice to the FCC for radio?
Actually, temporary relocation and expected repacking likely will make TV operations even better than before by allowing the commission to apply new allocation standards in the repacking. Digital-to-digital separations are much less tedious and critical compared to analog, especially given our current state of technological evolution.
Many articles have raised attention to “AM revitalization.” Peter Gutman and Ted Schober have written intelligently on this topic elsewhere. Clearly there will be no revitalizing of the AM band with any of these proposed ideas. Who does the commission think they are fooling? Why isn’t the NAB all over this?
It’s time radio gets an opportunity to be fixed! No more “AM or FM.”
With the new HDTV repack coming, the FCC needs to take the old TV Channels 5 and 6 and expand the radio broadcast band.
Start placing digital-only carriers in the low end of the spectrum and work their way toward the existing FM band, using digital-only separation requirements.
Move all of the AM stations into the new allocation first, then transition the existing FM analog stations to digital-only, with a plan to shut off the analog carriers.
Further, allocate the existing medium-wave “AM” band to local communities, townships and cities to program public notices and other public information on. Allocate them based on coverage needed — low frequencies for the larger cities, higher frequencies for the smaller.
LEVEL THE FIELD
No more screwing around. It doesn’t take a brain surgeon to fix this problem. The longer we wait to take the initiative to fix the problem, the more death we’ll suffer.
The days of costly high-powered AM transmitters, complicated antenna arrays, miles of copper buried in large plots of land and tons of steel to maintain need to go. There are fewer and fewer engineers who can maintain, let alone build, AM arrays; that number will continue to drop.
Broadcast owners have suffered for years due to major change freezes preventing them from improving their properties and the inability to achieve technological competitiveness. Many realized higher costs of operations for little return and, during the consolidation boom, wound up paying 20+ times cash flow and then saw business opportunities plummet with economic downturns.
It’s time AM owners are put on a level playing field, not only with FM competitors but with the growing sources of mobile and home streaming.
You know, there’s been a lot of buzz about the FM chip in cellphones. I see it as another nail in AM’s coffin. I also question whether this helps the consumer during an emergency. Frankly, few markets have news/talk FMs; and generally speaking, many FMs, in my opinion, don’t have the personnel or procedures in place to be much benefit during emergencies. I’d much rather get my information from a seasoned news host than a minimum-wage disk jockey. (I won’t even get started on EAS.) And what about HD reception in cellphones? Who’s talking about that?
If the commission would react and provide radio broadcasters expansion down to 76 MHz, we could see a great turnaround for the entire industry. Let’s stop throwing garbage at the wall to see what will stick and instead get to work on a solid solution.
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