AM, You Want a Fix? I Got a Fix!
     

 
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.

IBAC
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.

MY IDEA
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.

Comment on this or any story. Email radioworld@nbmedia.com.


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Comment List:

I've got a fix too - no digital on AM. Revive clear channels with 500KW and nobody else on their frequencies. Change the remaining stations to 20KHz spacing so that they can broadcast full 10KHz analog audio after moving all locals to TV5 & TV6. Restore AM stereo, and mandate all FM stereo radios must include AM stereo meeting AMAX specs (just like VHF must include UHF). NAB to encourage niche music formats on AM again. Fast-track all of this within 2 years or just forget it all together. FCC to enforce Part 15 on imported junk noisemakers.
By John Pavlica on 3/5/2014
If you are going to be one of the remaining AM stations the minimum power level should be 500 kW. The noise floor has increased 20 dB in the last 15 years and you need someway to get over the top of it. Get the FCC to rein in the RFI generators (CFL and LED and switching power supplies) and handout fines to the power utilities for line noise. Ex Broadcaster
By Ex Broacaster on 2/25/2014
No. Just no. There are too many stations that can barely staff or meet their public service obligations as is. No more free FMs to license holders who didn't budget and don't have a product that sustains itself. No more handouts and welfare to radio stations that never should have been allocated in the first place, and no more crowding the bands. The translators, main studio waivers and AM on FM and HD fed translators have created madness. End it now, turn in the licenses of the AM stations that aren't profitable, and move on. It is not my fault as an FM license holder that AM owners haven't planned ahead. They had the same opportunities I did, and passed.
By Chris Stevens on 2/23/2014
You guys are getting it! This solution absolutely creates the ability for competition in the digital broadcasting arena. I don't think World DAB is a consideration, as Eureka-147 was out before we started working on HD here and the idea of a common transmitter system seems to be more a political nightmare than a community antenna. The other issue, in the eyes of the FCC, who would be responsible for the transmitter? Though there is an argument that can be made that the HD consortium has played pretty well together, I don't see the U.S. doing this. As for DRM+, yes. They're a direct competitor for Ibiquity now. Vucast is another. Derrick Kumar was very instrumental in creating a working system when with USADR and later with DRE. Now with VuCast, they too are still working in this field.
By Scott Clifton on 2/21/2014
Peter, Why invent a new system when there are already two free all digital systems used outside of North America. Australia has been full time broadcasting at high power DAB+ since 2009 to 60 % of the population. All existing broadcasts are transmitted along with numerous new broadcasts from both commercial and government broadcasters. Even community broadcasters are in the ensemble of programs. Digital Radio Mondiale, www.drm.org and DAB+ www.worlddab.org are both free, but as in all inventions you have to pay for the technology used for example the AAC V2+ compression system to Dolby. The above systems already have developed markets and radios available. This keeps the receiver price low because of high volumes of receivers. Alanh
By Alan Hughes on 2/21/2014
Agreed. Why not use the empty analog TV channels 2-6 = 54 - 72, 76 - 88 MHz giving 300 x 100 kHz DRM channels and put all broadcasters on these frequencies. This will eventually release the FM band for another 199 channels Currently there is 216 AM/FM channels. That's a level playing field. All stations can transmit HQ surround sound if they wish. Reception holes can be filled with on channel repeaters so another frequency is not needed. There is now single chip HDradio/DRM/FM/AM receivers available to manufacturers for autos, phones etc. FCC should make this type of receiver compulsory as soon as possible, and give broadcasters the above frequencies free for 6 years. All broadcasters must transmit alternative frequency table to enable auto switchover to DRM or AM/FM if required.
By Alan Hughes on 2/20/2014
After the "AM" band is cleared there should be only one station on each channel if the power is 50,000 watts or more. No more than three stations should be allowed on any channel during night-time or critical hours. Daytime only stations with less than 1,000 watts should be allowed on the band with no hope of ever having any broadcasts during critical hours or night-time hours. We should use our own system of digital broadcasts in the 76 to 88 MHz band. Our system could have the same carrier spacing as "I-D Radio" (AKA "HD Radio") but we could avoid the encryption that iBiquity Digital "I-D Radio" uses. We could use the superior Opus codec but otherwise the system would be a cross between DRM and "I-D Radio" taking what is best from each. Call the new free system DRA.
By Peter Wankerman on 2/20/2014

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