[mythtv-users] Comcast just made things worse
beww at beww.org
Sat May 8 20:45:54 UTC 2010
On Saturday 08 May 2010 12:53:45 pm Douglas Peale wrote:
> VHF Low (2-6) is uncommon. The FCC is discoraging its use for major
The OP mentioned the situation with channel 6 in Philadelphia, a bad situation
that I am unsure about how it came to pass.
Philly has always had an unusual broadcast situation. One of the only 2
stations east of the Mississippi with a "K" call sign (the other is KDKA in
Pittsburg), and the musical chairs network affiliations a few years ago (similar
to what happened in Denver, and for similar reasons (ownership changes and
> VHF High (7-13) is still being used (though I wish it weren't).
I agree. There were certainly enough UHF assignments available to eliminate
any need for VHF, not sure why it happened. Perhaps broadcasters lobbied for
VHF assignments due to lower power costs and/or legacy thinking that VHF is
Power cost for a UHF station is much higher than for a VHF. Not a big factor
for the major broadcasters, but significant to some of the smaller market
operators, who sometimes asked for and received authority to run at reduced
power due to "economic hardship" (This happened in Kingston NY for example).
Reduced power was mandated or allowed for other reasons, for example channel
31 in NYC, to prevent the radiation levels on the public observation platform
at the WTC from exceeding allowable limits (not a factor now).
> VHF High + UHF antennas are about half the size of full range antennas,
> but UHF only antennas could be much smaller.
I hadn't seen any of these, good to hear that they are available, since as you
say they can be made much smaller than full-band VHF antennas.
> In my area, channels 7, 8, and 12 are in use.
Unusual to have adjacent channels in use in the same market. This was never
done with analog assignments. Perhaps you are picking up stations from 2
(Cable TV systems can get away with using adjacent channels by reducing the
power of the aural carrier to 15-17 db. below the visual, as opposed to 10 db.
down used by OTA analog stations).
The FCC also mandated +/- 10 Khz. frequency offsets to prevent inter-market
interference with adjacent channels 2 or more markets away, and sometimes
approved reduced aural carrier power for similar reasons.
Note that 4 and 5 are not adjacent, nor are 6 and 7, due to the frequency
allocations., so you would sometimes see those combinations approved.
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