BMC's AM Migration Plan (end of AM as we know it ?)
Wed Sep 24 11:46:32 EDT 2008
From: email@example.com (Robert F. Sutherland)
Date: Tue, 23 Sep 2008 01:13:29 -0400
Subject: BMC's AM Migration Plan
Anyone have insight, comment or analysis?
"The next 100 channels (77.0 to 86.9 MHz) would be used to migrate AM
stations to the proposed FM new EXB band channels, where they would
operate in digital mode."
I just learned of it in AM Stereo Forum (Email group),
but since this was published Aug 1 2008, I could be way
behind the times.
FM / VHF transmitting facilities are quite different from AM
facilities. They don't require as much land, but they do require a
tall mast to support antennas. Of course several stations can gang up
on a single tower.
I doubt that many existing AM sites could be retooled as FM sites since
they tend to be a fair distance from city-center. Better, in Boston's
case, to gang up more antennas on top of the Pru or Hancock and sell
off all the suburban AM sites. Some are in salt-marshes or sites
otherwise unusable for construction, however.
What gets to use vacated AM frequencies ? Utility stations of some
sort ? How does this mesh with neighboring countries' planned usage of
the band ? Considerable interference to/from non-US stations is a fact
of life on the band, especially along the Canadian and Mexican borders
as well as in south Florida (thanks to Cuba).
I would envision that a network of several sub-FM-band repeaters would
be required to provide comparable Boston-station coverage to existing
50 kW's like WBZ and WRKO. Many Bostonians frequently visit places
like Cape Cod, the NH/ME seacoast and lake areas, and Foxwood's in
eastern CT. They reasonably expect to be able to hear WBZ at least and
maybe WRKO and WEEI too. Even the daily rush hour to Boston has
commuters routinely coming in from places like Fitchburg MA, the
Manchester NH area, and Sandwich on the Cape.
The big Boston FM's like WBCN come close to hitting most of the
important areas though I get WRKO AM far more dependably than any
Boston FM once I go over the Sagamore Bridge.
The other aspect of all this is the millions of radios that will be
heading to recycling, or worse, the landfill. Of course in TV-land
this process is already underway.
It would be a great commercial boon to manufacturers and I guess that's
what usually wins the day in the hallowed halls of the FCC in these
Would the digital mode stations possibly have the ability to be
scrambled so that users would have to pay a fee to have the receivers
decode properly ?
Since it will take a while for radios with this new band to become
commonplace, there may have to be some kind of overlap period when AM
and new digital band stations are broadcasting the same stations'
Mark Connelly, WA1ION - Billerica, MA
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