the end of October the FCC released the eagerly awaited NPRM for AM
improvement, previewed at the fall Radio Show in Orlando. The
commission mostly grabbed the low-hanging fruit, proposing to get rid
of a number of old counter-productive and restrictive rules that have
often frustrated real AM improvement. A proposal to open an FM
translator window for AMs-only was the big prize.
Ajit Pai certainly needs to be credited as the main force pushing
through the new FCC proposals in this NPRM. Like a good politician,
Pai has been campaigning actively for AM, visiting and engaging
numerous AM stations to feel their pain and discuss how to best fix
AM’s thorny problems.
Translator Gold Rush
an FM translator filing window for existing AM licensees presents an
overdue opportunity for stations to extend or perhaps move their AM
programming to an FM channel. Daytimers and stations with poor
nighttime coverage have been lobbying for this for decades.
Unfortunately, pending translator grants and new LPFM applicants are
poised to grab many of the available channels still left due to
already scheduled windows. Practically all AM stations in market
sizes larger than 150 will be shut out of even applying for a FM
translator. Only smaller-market AM stations will likely benefit
directly from this proposal.
of the details on how such an AM-only translator window would work
have not been decided, especially for markets where the demand will
exceed the available supply of channels. There’s an opportunity
here for the commission to enact bold new initiatives. How about
letting stations applying for an FM translator obtain preference if
they opt to relinquish their AM channel as a new mechanism for AM
a new translator covers most of the target audience, AM owners will
likely prefer to give up their AM allocation in exchange for a
permanent FM license rather than a vulnerable translator. A new Class
A1 category could be created to serve this need, and the old AM
allocation would then be permanently retired and closed to any new
that can buy an existing FM translator and then retire their AM
should be afforded the same opportunity to convert to a permanent
license. Such a rule would instantly restore significant new value to
AMs everywhere, something AM owners have lost over many years of
negative unintended consequences.
nothing in the FCC AM NPRM addresses combating or reducing noise
interference, the most destructive universal agent spoiling AM
reception. As I pointed out in my previous column (“Last Stand for
the AM Band,” RWEE June 12), enforcing existing rules or enacting
new laws that could mitigate AM noise generation would appear to be a
challenge simply out of reach for an understaffed and underfunded
and the other commissioners have publicly said little about the
benefits of all-digital AM HD as perhaps our long-term solution to
the AM problem. They mostly encourage those stations interested in
adding the AM HD hybrid mode to do so. Nor have they addressed the
possibility of a future analog sunset date for AM.
all-digital testing is needed and that initiative has been quietly
proceeding. Limited data from two more tests in North Carolina were
recently announced, following last year’s WBCN impressive daytime
tests in Charlotte unveiled at April’s NAB Show.
Media’s WBT, Charlotte and Beasley’s WNCT, Greenville have tested
all-digital in recent months, both reportedly producing similar
results as WBCN for robustness and dramatically improved quality.
Greater Media Vice President of Radio Engineering Milford “Smitty”
Smith says WBT’s all-digital AM-HD signal was “remarkably robust”
in the Charlotte metro: “For the most part it just hung in there
and didn’t fail.” Regarding nighttime performance, Smitty says,
“The WBT digital skywave propagation was at least on par with
analog propagation and was far superior in terms of quality.”
instincts tell me all-digital will continue to do quite well in
future testing and will also yield room for further improvements as
more is learned and the coding is tweaked. You can be sure that
effort is moving forward.
a few of my engineering brethren who’ve had a longstanding love
affair with AM radio have been hyper-critical of AM HD. They say it
can never work and it’s especially harmful to existing adjacent
channel neighbors. I would have to agree with those who say the
hybrid mode has been a failure. Even the iBiquity inventors
undoubtedly realized at the beginning it was going to be tough to
make this version of their technology succeed.
AM band was already clogged with too many allocations without
adjacent channel guard bands. Interference levels were already too
high to hang digital sidebands that spill into their neighbors to
expect good results.
you remember how HD Radio was born, the NAB and major groups all
insisted that upgrading and migrating the radio services to digital
had to include AM as well as FM stations. The hybrid mode of HD Radio
would simply be transitional.
AM, that meant lots of new interference and somewhat marginal
performance and coverage because of the low injection levels required
to protect the analog host. We’ve already increased FM digital
power limits to give FM HD hybrid performance significant
improvement. Such is not possible for AM. So AM HD in the hybrid mode
really never had a chance to succeed.
HD naysayers rarely acknowledge that the AM band is in fact in very
deep trouble, even without hybrid HD. There simply aren’t enough AM
HD stations still operating to cause that much interference. It’s
all the manmade noise and existing analog stations interfering with
each other that are the obvious culprits.
every passing year, fewer and fewer folks are using AM, now only 17
percent of all radio listeners, according to one number I’ve seen.
For the under-30 demo, the share is about 4 percent, according to
Edison Research. Extrapolate the curve out another five and then
another 10 years and it’s clear AM radio in its present form needs
a major makeover to give it a chance to survive and compete in the
all-digital electronic world.
lot of AM analog fans still maintain it’s all about content and
that the medium doesn’t matter. If only station owners would put
their best content back on AM, all would be well with the senior band
actually been tried in a few markets with dismal results.
those folks missed the great migration of successful music stations
from AM to FM in the ’70s and ’80s. When decent FM receivers
became mainstream, everybody discovered that music sounded much
better on FM. And in recent years, we’re all painfully aware that
even AM talk sounds bad riding on a sea of noise and interference.
Way to Look?
difference between the old-school view of what’s good for the AM
band and my view is all about which direction you are looking. Those
who look backwards dwell on the digital hybrid mode being a disaster.
A few even suggest analog DSB would be a better way to extend AM’s
analog longevity. If only the FCC would just force all receiver
manufacturers to build AM sections with synchronous detectors.
prefer to look forward and place my bet on a digital future. But like
it or not, there’s only one de facto digital standard with
significant and growing receiver penetration we have to work with.
Digital Radio Mondiale has a fan base of engineers, but it simply
hasn’t gained traction anywhere with receiver manufacturers or
consumers. Even Canada is reportedly bypassing DRM in favor of all
digital AM HD.
is the last major electronic medium not to have fully converted to
the advantages of digital delivery. FM is making reasonable and
steady progress with its digital conversion. Does the anti-HD crowd
really think the AM band has a future staying all-analog? As the
wireless Internet takes over increasing chunks of dashboard real
estate, do they really think car radios will include the AM band
car companies might be saying they have no plans to ditch AM for now,
but how low will AM’s share of audience need to drop before they
change their minds? 10 percent? 5 percent? If the industry doesn’t
make significant moves soon to stem that waning tide, it’s not
going to be very long before we see AM analog receivers begin to
disappear from the car.
AM band has been steadily losing stations in recent years. Increasing
numbers of owners, even large corporations are selling the real
estate and either turning in their licenses or giving them away for
tax deductions. As more AMs migrate to FM channels and give up their
AM allocations, the overdue AM over-population cleansing will
HD detractors say digital skywave reception will never work. I don’t
think iBiquity has begun to fully evaluate the potential improvements
that fine-tuning the AM HD coding scheme might deliver in the real
world at night when all-digital is implemented. With all-digital
modulation that incorporates forward error correction and buffering
with time and diversity delay, much of the lost reception due to
ionospheric fading should be able to be recovered.
mandated sunset of Ancient Modulation forces all existing AM owners
to decide which path to take. Do they want to keep their AM stations
and be part of an all-digital future? Do they prefer to tough it out
with analog-only and hope until the inevitable end? Or would they
choose to give up or sell their interests to others who see the value
of all-digital AM and want to make it work?
those who are willing to pursue the opportunity of improving a
station that achieves wide-area coverage, high-fidelity audio and new
display features with the potential of dramatically reduced
interference, the choice of all-digital should be compelling.
those who’ve been losing money keeping marginal AMs alive with few
listeners and are unwilling to take more risks, the decision
shouldn’t be that hard. Get a replacement FM translator or sell out
to somebody else who is committed to AM long-term. AMs that want to
expand coverage and add all-digital HD should consider buying and
retiring stations that limit their existing coverage.
years should be more than enough time for stations to make these
decisions. By then, a very large majority of vehicles on the road
will be equipped with HD Radios that can hear AM all-digital HD. As
HD becomes the mainstream radio preference, we’ll see more AM and
FM HD-equipped tabletop and portable sets available in the
fewer AM stations populate the dial, it makes perfect sense for the
FCC to redefine channel allocations and protections so that most of
the adjacent channel interference issues can be eliminated. If 10
years is not quite enough, the sunset deadline for analog can be
extended as it was for HDTV.
clock is ticking and the race to save the AM band is finally getting
started. It’s shaping up to be quite the horse race. Like it or
not, Ancient Modulation is fading into the noise. I’m betting on
the all-digital mount who is ready to run faster and farther. We can
only hope there will be a finish line and a pay off.
Wire is the pseudonym of a veteran broadcast engineer. Read his
archive under the Columns tab at radioworld.com.
on this or any story. Write to firstname.lastname@example.org.