DTV adjacent channel interference issues
 

In this decision by the FCC:

http://hraunfoss.fcc.gov/edocs_publi...CC-08-72A1.pdf

WTOV's petition to reconsider a power/antenna upgrade was denied. The
reason give it that an interference level of 2.6 would exist with WWCP
in Johnstown PA. The post trasition channels will be WTOV on 9 and
WWCP on 8.

Something about this seems wrong to me.

First of all, there are many cases (listed below) of 2 or more stations in
the same market that are on adjacent channels. So at least approximately
equal power levels do not pose an interference issue. This may require the
antennas be on the same tower or within a mile or so to be acceptable.

So it must be a case that interference can happen when one station is much
stronger than the other. In the case of WTOV vs. WWCP, they are 2 market
boundaries apart. Is the FCC trying to protect people in one of these
markets to be able to watch TV in the other (which is an entire hop over
the Pittsburgh market).

WHERE would that 2.6% interference be happening? In one or the other of
the makets these 2 stations are in? In some other market like Pittsburgh
where someone might be trying to receive out of market from one and be
interfered with by the other on the backside?

It would seem to me that if WTOV would be causing any adjacent channel
interference, it might be with WJW channel 8 in Cleveland or WOIO channel
10 near Cleveland.

TV tuners these days clearly have no trouble with a lot of adjacent
channels, at least when they are about the same strength, given that this
is happening on virtually all cable TV systems, analog and digital.

And it looks like the FCC is packing some digital stations closer than
the analog ones, on the same channel. But I do believe it would be easy
enough to even get both with a reasonably directional antenna when located
at the midway point (with a switch or separate tuners).

I used to live at about the midway point between WCMH and WOAY. I could
get both channel 4's with good clarity by just turning the antenna.

I do receive WTOV's analog signal on channel 9 snowy, and digital signal
on channel 57 transitional fairly solid (some spots moving around can break
it up) where both signals are going through or over the hill that rises 60
feet above me in my backyard. And this is with a rabbit ear antenna that
also has a UHF loop, inside the house, near the northern middle part of
Ohio County WV, near Wheeling. I'm building a portable base system to
support an antenna that I can move around, and will be putting a CM-4228
in it. It will go on the porch to begin with to see what I can get.

Maybe I can get WWCP if WTOV doesn't interfere too much :-)

Here is the list of cities with adjacent channel allocations (from the
table of allocation ... I did not check the list of actual stations).
Several of these are VHF, so it isn't a VHF/UHF thing that I could see.

Los Angeles CA 41 42 43
Monterey CA 31 32
San Diego CA 18 19
San Fransciso CA 38 39
San Jose CA 49 50
Stockton CA 25 26
Denver CO 18 19 and 34 35
Hartford CT 45 46
Fort Walton Beach FL 49 50
Miami FL 18 19 and 22 23
Orlando FL 22 23 and 26 27
Tampa FL 12 13
Atlanta GA 20 21
Hilo HI 22 23
Honolulu HI 8 9 10 11
Indianaplis IN 44 45
Topeka KS 11 12 13
Lexington KY 39 40
Portland ME 43 44
Baltimore MD 40 41
Boston MA 19 20 and 30 31 32
Detroit MI 43 44 45
Jackson MS 20 21
Billings MT 10 11
Butte MT 5 6
Great Falls MT 7 8
Reno NV 7 8
Santa Fe NM 9 10
Buffalo NY 32 33 34 and 38 39
Utica NY 29 30
Charlotte NC 22 23
Raleigh NC 48 49
Wilmington NC 29 30
Winston-Salem NC 31 32
Cincinnati OH 33 34 35
Dayton OH 50 51
Oklahoma City OK 50 51
Roseburg OR 18 19
Philadelphia PA 34 35
Pittsburgh PA 42 43
Columbia SC 47 48
Chattanooga TN 12 13
Memphis TN 28 29
Dallas TX 35 36
Lubbock TX 39 40
San Antonio TX 38 39
Richmod VA 25 26
Roanoke VA 17 18
Seattle WA 38 39
Spokane WA 7 8
Green Bay WI 41 42
Milwaukee WI 33 34 35
Lander WY 7 8
Mayaguez PR 22 23
San Juan PR 27 28 and 31 32
Charlotte Amalie VI 43 44

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DTV adjacent channel interference issues
 

In article , wrote:

....
Here is the list of cities with adjacent channel allocations (from the
table of allocation ... I did not check the list of actual stations).
Several of these are VHF, so it isn't a VHF/UHF thing that I could see.
....
Seattle WA 38 39

It could be that it's OK if they're located at the same spot.
These are KOMO-DT and KIRO-DT which are on the same hill, but
not the same tower.

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)

DTV adjacent channel interference issues
 

On Apr 12, 6:32*am, wrote:
First of all, there are many cases (listed below) of 2 or more stations in
the same market that are on adjacent channels. *So at least approximately
equal power levels do not pose an interference issue. *This may require the
antennas be on the same tower or within a mile or so to be acceptable.

Detroit MI * * * * * 43 44 45

43 and 44 share the same antenna. 45 is located a couple miles away,
and yeah, I'm having a bit more trouble picking it up, but the whole
Detroit antenna farm, except for 39, is located around there.

DTV adjacent channel interference issues
 

If the stations are at the same antenna farm it's not an issue otherwise
it can easily be an issue

check out http://dtvallocations.com for some maps and you can see in
several cases like Chicago and Peoria you will see there will be
problems.

The fcc is assuming a lot for directional antennas. Remember that if a
station chooses to stay on it's current DTV allocations the FCC gives it
protections, if a station returns to it's analog or can't stay on its
DTV allocation cause it's higher than ch 51, that station must accept
interference.

DTV adjacent channel interference issues
 

On Sun, 13 Apr 2008 03:29:48 -0500 wrote:
| If the stations are at the same antenna farm it's not an issue otherwise
| it can easily be an issue
|
| check out http://dtvallocations.com for some maps and you can see in
| several cases like Chicago and Peoria you will see there will be
| problems.
|
| The fcc is assuming a lot for directional antennas. Remember that if a
| station chooses to stay on it's current DTV allocations the FCC gives it
| protections, if a station returns to it's analog or can't stay on its
| DTV allocation cause it's higher than ch 51, that station must accept
| interference.

That seems quite unfair to me. If its digital, or its analog, was above 51,
then that station either has to be on the other (single choice) or opt for
another assignment. One big problem is the FCC handed out transition channels
above 51. Of course that was done before the decision to reduce the channel
space. But it certainly seems unfair to the stations that got those channels.
What should have been done was let those stations have the analog back under
special circumstances, like interference protection from stations that are
NOT operating on their transitional or original channel. IMHO, this is a
failure of FCC policy. It remains to be seen if the coverage of WTOV will
actually be as good digitally on channel 9 as it is on either analog on 9 or
digital on 57. If it is NOT as good on 9 digitally as it was on 57, then I
will be complaining to Congress that the FCC failed and needs to take action
to correct it. Again, it remains to be seen.

But my challege is the belief that this 2.6% interference would affect those
outside of the market for either WWCP or WTOV, and that waivers for such
interference cases should be normally granted. Presumably WTOV would not
worry about the interference to their signal for receivers near WWCP two
market areas over, since they proposed the technical changes. But what of
WWCP? The FCC didn't mention that WWCP protested the change, but rather,
that the Longley-Rice model indicated 2.6% interference. IMHO, that should
not be the exclusive model; consideration should also be made about markets.
While I _personally_ have an interest in TVDX, the model the FCC should be
dealing with is making sure people can receive their in-market stations as
well as their near-market stations when such are needed to complete network
coverage (for example the Wheeling-Steubenville market has no ABC or CW
station on the air, so we have to get them from Pittsburgh).

I'll also try to receive WWCP when it comes on channel 8. If I cannot, then
I will complain to the FCC that they are trying to protect that which cannot
be worthwhile to protect, and challenge their use of the singular model. FYI,
I have a better-than-average shot at getting WWCP for this distance, since
I'm on the hillside that faces towards WWCP (and away from WTOV). I would
not expect to get a station so far away. OTOH, a test done near here in
St. Clairsville, OH, brought in 3 stations from Cleveland (and only two from
Pittsburgh ... go figure).

Or, maybe WTOV can come up with a different antenna pattern and re-propose.

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