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                   THE CGC COMMUNICATOR
                         CGC #853
                Friday,  September 5, 2008
                          ________
             Robert F. Gonsett, W6VR, Editor
             <cgc (at) cgc333.connectnet.com>
  Copyright 2008, Communications General® Corporation (CGC)
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  SPECIAL FEATURE:
  A POTENTIAL ONSLAUGHT OF WIRELESS MICROPHONES IN THE
  944-952 MHZ AURAL STL BAND
  Recently, Richard Rudman, chairman of the Southern
California Frequency Coordinating Committee, Inc. ("SCFCC"),
received a sales brochure from Location Sound Corporation.
Location Sound sells radio equipment to television and motion
picture production companies, and one of Location's front page
articles touted the virtues of using 944-952 MHz for wireless
microphone applications.  Richard spread the word.
  That article set off alarm bells with a number of engineers
in Los Angeles -- and will undoubtedly soon concern radio
broadcast stations across the United States as churches and
others seek new spectrum outside of the 700 MHz band.  As most
of you know, 944-952 MHz is the licensed studio-to-transmitter
("STL") band relied upon by many radio broadcasters and the
band is extremely sensitive to interference hits.
  Because of the immediate need to protect the 944-952 MHz
spectrum and because Location Sound had not amended their
advertising article after being contacted, a formal complaint
was filed with the FCC.  The complaint contains the thoughts
and suggestions of a number of southern California broadcast
engineers and is reproduced in its entirety below (less the
attached pdf data file).
  Undoubtedly SBE, NAB, NPR and others will take a very close
look at the issues involved, and hopefully some accommodation
will ultimately be reached.  Watch the trade press as this
story develops.
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  LOCATION SOUND NEWSLETTER ARCHIVED
  If the Location Sound newsletter mentioned below
disappears from the Web, use this address for an archived copy:
  http://earthsignals.com/add_CGC/Location_Sound.pdf
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  TEXT OF THE WIRELESS MICROPHONE COMPLAINT
  Filed with the Los Angeles FCC office September 3, 2008:
  This formal complaint concerns the marketing practices of
Location Sound Corp. (LSC) of North Hollywood, CA.  Particular
reference is made to their recent newsletter posted at
<http://www.locationsound.com/pdf/Newsletter.pdf>.  On page 1
in the right hand column of that newsletter, there is a story
entitled, "Important RF Spectrum News" that encourages non-
broadcasters to use the 944-952 MHz spectrum for wireless
microphone applications.  The first paragraph claims in part
that, "This little known area of UHF spectrum is, for the most
part, wide-open and available for production use."  In fact, it
is neither wide-open nor available to non-broadcasters such as
TV and film producers and operators of theme park shows.
  944-952 MHz is intensively used for licensed aural Studio-
to-Transmitter (STL) broadcast links across the United States.
With current wireless microphone users moving out of the 700 MHz
band, 944-952 MHz may appear to be virgin territory for frequency
relocations, but this is not the case.  Operations in the 944-
952 MHz band must be licensed under Part 74 and the only parties
eligible to use this spectrum are broadcasters.  See FCC Rule
74.832(d).
  The Commission is urged to:
  (a) promptly contact LSC to request, at a minimum, that LSC
retract or suitably amend its "Important RF Spectrum News" story
so as to emphasize that all 944-952 MHz users must be licensed
and that only broadcasters are eligible to use this spectrum,
  (b) request that LSC notify all parties who purchased 944-
952 MHz transmitters from LSC of the true and correct licensing
and eligibility requirements for using this spectrum,
  (c) investigate the marketing practices of others, such as
Shure and Sennheiser mentioned in the LSC newsletter, to determine
if they, too, are failing to properly alert prospective equipment
purchasers of the strict limitations involved in using the 944-
952 MHz band,
  (d) issue a Public Notice reminding manufacturers, distributors
and users of wireless products that low power auxiliary operations
by cable television companies and motion picture and television
program producers are authorized only in the bands allocated for
TV broadcasting as spelled out in Rule 74.832(d) -- and not in
the 944-952 MHz band, and
  (e) determine what authorization, if any, Location Sound relied
upon when "LSC recently installed 944 band (equipment) at the
"Blues Brothers Review Show" at Universal Studio Tour" (Location
Sound newsletter, page 1, paragraph 4) since this show was stated
to be "right in the middle" of a theme park and was, therefore,
apparently ineligible to use the 944-952 MHz spectrum.
  Prompt FCC intervention is respectfully requested to prevent
debilitating interference from wireless microphones (or IFB or
other transmitters) to existing aural STL systems.  Thank you for
considering the issues presented in this complaint.
  Postscript: One Los Angeles consulting radio engineer has
written as follows. "Right now I have two clients that are being
hit with random signals that drop out their on-air digital STLs
- both of them are on Mt. Wilson.  The problem may not show up for
a week or so then it's an all day or all evening problem.  I've
discovered it doesn't take much to cause major bit error faults to
very robust signals.  At a minimum, Location Sound Corp. needs to
print the fact that this is a very busy band and a service monitor
or the best spectrum analyzer and antenna on the ground is not
going to discover many of the channels that are in use and being
received at highly elevated sites.
  "Knowing the production world the way I do, it wouldn't be too
long before IFB transmitters appear on the band, some using
MiniCircuits power amplifiers.  This is a common practice in other
bands.  I suspect that even with being warned about the STL
useage, many operators, with confidence, will use wireless mic
systems that have the supposed capability to search for "open"
frequencies and light up on them.  The best thing would be for
the various manufacturers to not make wireless equipment that
will operate in this band."
  The pdf file attached hereto was provided by a Los Angeles
broadcaster and contains 40 pages of data showing the intense use
of the 944-952 MHz band by existing, licensed, aural STL systems
within a 100-mile radius of Mt. Wilson.
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