Improve the receivers, not the transmitters
Regarding IBOC-AM [from the thoughts presented by John Batison in
the May issue], I think that stereo analog AM to 15kHz with DSP would
be the easiest, fastest and best way to go. I am opposed to the use of
the Ibiquity IBOC-AM systemfor the following reasons:
• IBOC-AM is incompatible with the FCC’s approved
Motorola C-Quam AM stereo broadcasting system in use at over 300
stations in the United States. (Reference FCC ET Docket 92-298 / FCC
93-485 / 8 FCC Rcd 8216).
• IBOC-AM is not totally backwards compatible with all
existing high-quality AM radio receivers with a bandwidth exceeding
5kHz (such as GM Delco UX-1 car radios). Ibiquity IBOC will occupy more
bandwidth (15kHz) than the current NRSC 10.2kHz limit, causing
• The Ibiquity IBOC-AM system will be unusable during
nighttime AM broadcasting as skywave reception will render their
digital signal useless in many areas.
• The Ibiquity IBOC-AM system would substantially lower the
quality of existing analog AM broadcasters, who currently can broadcast
their audio with a +/-3dB frequency response out to 10.2kHz and would
require them to degrade their audio to a poor telephone-like 5kHz
frequency response. This is totally unacceptable to degrade the analog
audio to make the digital sound better.
• Other types of digital enhancements can be added to all new
analog AM receivers, which would incorporate Digital Signal (DSP)
processing, noise blanking in both the I.F. and audio stages, and DSP
reception of analog C-Quam AM stereo transmissions.
• I have used a Sony AM stereo home receiver, a Delco
automobile radio, and a Chrysler automobile stereo unit, all of which
feature analog AM stereo. These high-quality receivers can each receive
radio station WJR-Detroit (760kHz) with “FM-like” stereo
quality - in fact, sometimes reception is better than many of the local
FM stations in terms of audio quality and stereo separation. With the
digital enhancements listed in item #5, particularly noise blanking,
the reception of analog AM stereo stations would sound even better.
• The AM broadcast band should remain analog indefinitely as a
legacy or heritage radio service for the American public. Not only are
there hundreds of millions of AM receivers in use, but more
importantly, in times of crisis or emergency, an analog AM receiver
(crystal radio) can be constructed from just four common electronic
items (ferrite antenna, diode, tuning capacitor, earphone) providing
• The FCC should mandate that all new technology to be 100
percent backwards compatible so as not to obsolete receivers. The FCC
was very insightful and responsible to make NTSC color TV compatible
with black and white televisions; FM stereo is compatible with mono FM
radios; C-Quam AM stereo is compatible with mono AM tuners; NTSC TV
stereo and SAP is compatible with mono TV receivers. The proposed
IBOC-AM would cause digital noise in the better quality AM tuners, and
is therefore not 100percent compatible with existing receivers. The FCC
must continue to mandate all technical standards for broadcasting in
the US, as that is its major role to the American public.
Here are my suggestions for immediately improving the technical
quality of AM radio here in the United States without an expensive
transition to the proposed IBOC-AM system:
1. Encourage receiver manufacturers to incorporate AMAX receiver
standards in all future AM radio receivers (wider bandwidth, noise
blanking), and to clearly label these new receivers with AMAX or
AMAX-Stereo if so equipped. In fact, manufacturers could identify the
band switch not as AM (or FM), but as AMAX (and FM).
2. Encourage receiver manufacturers to utilize digital enhancements
all new AM receivers, such as Digital Signal (DSP) processing, noise
blanking in both the I.F. and audio stages, and DSP reception of analog
C-Quam AM stereo transmissions.
3. Encourage all AM stations to install, or turn-back on, C-Quam AM
stereo equipment, particularly those with a music format such as WSM,
4. Have the FCC enforce all Stereo AM broadcasting for all Expanded
Band stations (1610 to 1700kHz) that indicated a “stereo
preference” for their station, to commence stereo AM broadcasts
within one year.
5. Have the FCC request, or require, all AM Class-A clear channel
stations to commence or restart C-Quam stereo AM broadcasts within one
year. Note: many of these Class A Clear Channel stations already have
the stereo equipment in operation (such as WGN, WJR, WLS, WBAP, WPHT),
or stereo equipment is installed, but currently turned-off at the
present time (at stations such as WFAN, WCCO, WHAS, WBZ, KMOX).
6. I suggest that the FCC should require digitally-tuned FM stereo
receivers to also include AM stereo meeting AMAX standards. This would
not apply to analog tuned, or FM mono radios. Please reference an FCC
petition document awaiting a docket number, entitled Petition for
Mandatory AM Receiver Standards submitted by Scott Todd.
I suggest that the FCC enforce, or encourage, enhanced analog AM
radio transmitter and digital signal processing receiver improvements
as listed above, that will be 100 percent compatible with all existing
nnovative Controls Corporation
Mr. Pavlicka also provided a website listing of most of the AM
stereo stations in North America:
Always more online
I just wanted to thank you for making back issues, and for that
matter, current issues available online. It’s a great service
that allows me to make printer-friendly copies for the files.
Fort Worth, TX
I just read your [Viewpoint in the May issue]. It is interesting
that every time someone reports that a trade show (in any market niche)
had low attendance, the next statement is inevitably, “...but the
people that were there were all quality leads.” Personally, I
think accurate attendance statistics are the only meaningful measure of
the success of a trade show. The theory that those who did not attend
are “just tire kickers,” is not credible. If this were
true, corporate spending would remain constant. Clearly, this has not
been the case throughout the U.S. economy.
Your point on the inflationary counting method is well made, but
certainly not exclusively practiced by the NAB. I hope that trade
associations, like public corporations, will take part in the trend of
more accurate disclosure. This would solidify their credibility and
director of marketing
Old Lyme, CT
Stellar STL report
I just read your article on STLs [May 2002]. I’d like to thank
you for a balanced and informative article. You’re
right—STLs aren’t glamorous, but their 24/7 operation is
critical to any broadcast facility.
There are two items I thought worth mentioning. In your discussion
of T1 and E1 multiplexers, you said, “Most manufacturers offer
various encoding cards in addition to those for linear encoding.”
Please note that the encoder and decoder cards supplied with Musicam
USA TEAM systems support all algorithms, since the DSP code is stored
in the TEAM’s Control Processor Module and is downloaded to the
appropriate module on demand. This makes it possible swap algorithms as
necessary, even as part of a broadcast day.
The second item relates to the issue of backup. Our TEAM system
supports automatic backup via ISDN. With one or more ISDN Modules
installed, a TEAM can automatically reconfigure its mapping, dial an
ISDN number and retrieve audio via ISDN when the T1 or E1 line fails.
Then, when the wideband line is restored, the TEAM politely hangs up
and reverts to normal operation.
VP, Business Development
Corporate Computer Systems, Inc., d/b/a Musicam USA