On Aug 6, 3:46*pm, wrote:
*It’s a dramatic idea that would change infrastructure reaching back to the
*very roots of our industry. *A group made up primarily of broadcast
*consulting engineers proposes a new use for TV Channels 5 and 6 in the
*United States once their occupants migrate to digital. It recommends the
*reallocation of part of that spectrum for the use of the country’s AM
*stations. * The group, calling itself the Broadcast Maximization Committee,
*recommends the conversion and migration of all AM stations over an extended
*period of time and with digital transmissions only. * It also proposes
*relocating the LPFM service to a portion of this spectrum and expanding the
*NCE service into the adjacent portion. * The group made its proposal in a
*filing to the FCC as part of the broadcast diversity proceeding (Docket
*07-294). Comments in that proceeding were due this week. Other
*organizations also have used the proceeding to discuss how the radio
*spectrum should be structured; but these comments are likely to draw new
*attention to the plight of AM stations and possible ways to help the
*occupants of the senior band. * Engineering Consultant John Mullaney, a
*proponent of using Channels 5 and 6 for radio, is part of BMC. Noting that
*similar proposals to use that space for radio stations have been dismissed
*by the commission as premature until the DTV transmission is done, the
*group says the time is ripe for this proposal. *Although LPFMs and NCE
*stations would benefit, AMs would gain the most, the group contends. The
*proposal would move virtually all AM stations to the new band. * The
*engineers lay out a plan under which all or most of the current AM
*occupants would move and parts of the existing band would be designated for
*users like municipalities and LPAM stations. *“For clear-channel (Class A)
*AM stations we are proposing that the FCC will increase existing
*protections on the AM band and possibly re-allocate the Class As that stay
*in such a way that they will have enough protection from other AM stations
*so that they can operate HD Radio day and night without creating
*interference,” BMC member Bert Goldman told Radio World. *“This reduction
*in AM noise will allow the remaining Class A stations to increase their
*daytime and nighttime interference-free service by removing all other AM
*stations.” *Each channel is anticipated to be structured in such a way that
*the station may decide if they want greater robustness of signal (and
*greater coverage like in rural locations) or less robustness and up to four
*program channels. BMC is not proposing a digital standard at this time..
*BMC has also proposed a way to move the estimated 24 post-transition DTV
*stations out of Channels 5 and 6. *The proposal is signed by Mullaney,
*Goldman, Mark Lipp, Paul H. Reynolds, Joseph Davis, Clarence Beverage,
*Laura Mizrahi, Lee Reynolds and Alex Walsh. * *

Nuts and Bolts of BMC’s AM Migration Plan
8.01.2008
*Here are the nuts and bolts of the Broadcast Maximization Committee’s
*proposal http://www.radioworld.com/pages/s.0100/t.14794.html to use old
*TV spectrum for a migration of AM stations. *Under the BMC plan, AMs could
*transition to the Channel 5/6 spectrum (100 channels 77.0 to 86.9 MHz) and
*operate in the digital mode. In this way, AMs “can solve the current
*digital problems they are experiencing, especially at night,” the group
*states in its proposal. * BMC is proposing to: Extend the FM band to
*include frequencies 76.1 to 87.7 MHz FM Expanded Band (EXB) with a 100 kHz
*channel spacing, creating 117 new channels. The first eight channels (87.0
*to 87.7 MHz) would be reserved NCE channels since they are contiguous to
*the current NCE band. 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. One channel on 76.9 MHz would be set
*aside for NOAA DHS use nationwide. The last eight channels (76.1 to 76..8
*MHz) would be for LPFM use. The vacated AM band (540 to 1700 kHz) would
*open up for multiple uses, including improved AM broadcast service or other
*use. While the policies, standards and priorities for an AM migration would
*need to be developed, BMC has offered a technical plan to show that its
*proposal is possible and to encourage further discussions. * “Above all, AM
*stations can become competitive, financially viable and immediately have
*some hope for better days.” * * * * *

I think the problem here is AM radio, as it exists today, would make
no sense relocated to VHF.

The benefits of medium wave AM radio:
1. Daytime coverage: Ground wave propagation exists down here. A
reasonably powerful AM station can cover a much broader geographic
area during the daytime than a VHF FM station.
2. Nighttime coverage: Skywave allows relatively strong regional
coverage.
3. Cheapness. An AM radio can be very cheap.

Moving an AM station to VHF would eliminate ALL of the above
advantages. It would simultaneously address AM's worst disadvantage:
medium fidelity sound at BEST, and serious nighttime interference
making reception pointless, at worst.

But my take is, AM has already adapted into niches where high fidelity
and absolutely quiet no-interference reception is not required or
expected.

The bottom line: if AM stations would benefit from moving up to VHF,
they would have probably moved to the FM band a long time ago.
There's a reason they're on AM (niche/limited appeal programming,
mostly).

Asking people to buy yet another radio to listen to narrowcast content
will probably not fly on 76-88 Mhz unless the radios are CHEAP and the
content is FREE. Otherwise, it's just another XM/Sirius deal but
delivered terrestrial, and that would probably flop.