JF> To: All Date: 20 Sep 97  16:25:00 Subj: Warped?
 JF> OK, so here is the question.  When my eight foot dish was installed I
 JF> could not get a couple of the birds in clear.  The dealer told me that a
 JF> tree on my neighbor's property was in the way.
If you have any doubts about whether a tree or anything else is
obstructing some satellite, this is a good time of year to check it
because the sun is passing behind the satellites. Aim the dish
at a satellite you have a question about, and look at it during
the day at the time when the shadow of the feedhorn is directly in the
center of the dish (assuming it's sunny enough to see the shadow.)
Then look to see if there are any other shadows on the surface of the
dish. Any tree etc casting a shadow from the sun is also partially
blocking the satellite.
You can be more accurate knowing which day the sun will be directly
behind the questionable satellite (even predicting what time it will
be there) if you run a program that predicts sun outages -- eg,
SUNOUT.ZIP from ftp://ftp.planetc.com/tvlistings .  But a simple
eyeball test during the next few weeks ought to be close enough for
you to spot shadows of trees on the dish. If you find a spot that is
sunny all day long around this time of year, a dish at that spot would
see all the satellites.
 JF> (BTW my dish is sitting
 JF> in the lake which was the only shot we could get clear of trees.)
You mean you have to wade in?! How did you get a firm mounting? If
the pole has shifted, you're lucky to get any satellite.
 JF> F1
 JF> never came now that new birds have come into play, I find that I also
 JF> can not get S4 or S3 although W1 and G4 are clear on either side of S4.
Missing the ends of the arc like F1 and S3 while getting the middle
could mean you need a declination adjustment -- but that would not
account for missing S4 while getting nearby satellites like W1 (GE1)
and G4.
 JF> After much tuning I called the dealer to have them come and look.  They
 JF> say that the dish is warped because of the "pattern" of birds that are
 JF> not coming in clear.
That doesn't sound likely to me; a warped dish would be bad on all
satellites, I think, and you could see it by looking at the dish, if
you didn't have to tread water. From all points along one edge you
should be able to look straight across at the other edge and see both
edges look straight.
 JF> I guess what I am wondering is.....Was the dish warped from day one
 JF> since F1 falls into that pattern and it is only now being noticed when
 JF> programming moved around.
 JF> Any comments or ideas.  Besides....I wanna see STARS.  Grin...
I dunno. Somebody suggested a polarity problem, but that doesn't seem
likely to me either if you get both odd and even channels clearly on
ANY satellite. I still wonder about declination; aim the dish at S4
and watch the picture while somebody in a boat BEHIND the dish pushes
up or pulls down on the bottom of the dish. If the picture gets better
by changing the elevation like that, I'd bet the declination
adjustment is wrong.
... TV Agent -- customization, details, timeliness -- 130+ TVRO channels
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