On Mon, 01 May 2006 12:23:17 GMT, David wrote:

''...a draft Report and Order to allow all U.S. AM
stations to use HD Radio at night is reportedly sitting on the
FCC Chairman's desk. Insiders say the document will allow all
stations (with equipment in place) to light up simultaneously.
Hopefully an interference resolution mechanism is included in the
paperwork. Broadcast engineers surveyed on the floor of the NAB
were not optimistic about the long-term prospects of AM HD at
night, but iBiquity investors will undoubtedly make a concerted
effort to make it work.''

This is as it should be. AM stations will never discover or correct
nighttime IBUZ interference until they can hear it. Daytime only use
of IBUZ won't work. The quality difference between AM analog and
digital is more dramatic than FM, especially when loudness wars are
likely to continue and the alleged quality improvement will get lost
in the dust. The real advantage of the FM system isn't improved
quality, it's secondary channels that will compete with their main
channels for ad dollars.

In 3006 when there are enough receivers to make a difference,
listeners won't tolerate the dramatic drop in audio quality. That
would, effectively, make all AMs using the system daytimers as
listeners tune away when muddy analog comes back at 6pm..

Now is the time for stations to do whatever rebuilds they need rather
than waiting until everyone has to do it at the same time. I've
proposed that the first stations to make the required transmitter
plant improvements be granted priority over others that might
interfere with them. No station should have to modify its plant
multiple times as adjacents light up.

Rich