[opendtv] Re: FCC on revitalizing the AM band

  • From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx>
  • To: "opendtv@xxxxxxxxxxxxx" <opendtv@xxxxxxxxxxxxx>
  • Date: Mon, 26 Oct 2015 00:33:36 +0000

Cliff Benham wrote:

The addition of HD radio signals to the AM band has rendered it
practically useless. I can no longer listen to WLW, Cincinnati,
and other power house and previously CLEAR CHANNEL stations
because the HD digital noise from adjacent frequencies blankets
the clear channel frequencies.

At night? I thought use of HD Radio in the AM band was banned at night,
although maybe that decision got reversed while I wasn't looking.

Why not turn off analog AM, replace it with HD Radio in that band, and retain
all the clear channel stations with HD Radio. Then you can do your DXing in
digital, and listen without the 10 KHz squeals, the abysmal sound quality, and
all the rest. Longwire antennas would work for HD Radio too.

The FCC wants only to get rid of standard AM broadcasting so it
won't have to deal with the technicalities involved in
directional signals [because there are more lawyers at the FCC
than there are competent RF engineers] and AM broadcasters want
to make the coverage of AM stations smaller so there is no way
listeners can hear a signal outside of their local markets.

The FCC is only talking about minor tweaks, while retaining oldfashioned AM. I
would expect that AM broadcasters would want their signal to travel as far as
possible, unless, like you suggest, ratings companies and/or advertizers get on
their case. I wouldn't know.

I own several HD radios both AM and FM and although I live no
more that 20 miles from the edge of the Philadelphia market, I
cannot receive but one or two weak crappy signals, even with a
roof mounted antenna.

Well, IIRC, in the FM band, the HD Radio signal has to be 23 dB below the
analog. And in the AM band, something more preposterous, like 35 dB below the
analog. Plus, a problem with HD Radio reception from far away, during this
hybrid mode operation, is that all of the digital signal is in the guardbands.
So it could easily be interfering with some other FM or AM stations in other
nearby markets.

In the AM band, if analog AM goes off the air, the HD Radio signal would be
back down to 10 or 9 KHz channel width, so the result should be the same kind
of channel discipline as there was previously.

AM is just too primitive, Cliff. It's time to either make effective use of that
frequency band for radio, or assign it to something totally different, like
time signals. And hobbyists can always use low power HD Radio to AM converter
boxes, which would most likely appear on the market for them?

Bert



----------------------------------------------------------------------
You can UNSUBSCRIBE from the OpenDTV list in two ways:

- Using the UNSUBSCRIBE command in your user configuration settings at
FreeLists.org

- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word
unsubscribe in the subject line.

Other related posts:

  1. Home
  2. opendtv
  3. Archive
  4. 10-2015