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.
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 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.
more than 24 years later, and radio is still as archaic as it was
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.
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.
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.
receivers were difficult to find, with manufacturers afraid to invest
in a technology that might not become a standard. Sound familiar?
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.
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.
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.
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.
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.
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.)
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.
while AM HD Radio has languished, HDTV has become a de facto
household standard, in the same or less time. Why?
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
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.
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?
time radio gets an opportunity to be fixed! No more “AM or FM.”
the new HDTV repack coming, the FCC needs to take the old TV Channels
5 and 6 and expand the radio broadcast band.
placing digital-only carriers in the low end of the spectrum and work
their way toward the existing FM band, using digital-only separation
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.
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
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.
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
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.
time AM owners are put on a level playing field, not only with FM
competitors but with the growing sources of mobile and home
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?
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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