How badly do trees interfere?

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madpoet

Too Much Hi Def!
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Mar 3, 2004
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Vernon, CT
Ok... was all excited to get the DirecTivo HD unit, until I talked with a local installer who told me the orientation and elevation of the D* birds. I think I'm screwed :(. I've got a hill with trees starting about 50 feet away in the direction I need to shoot, and at a 23degree elevation I don't think there's any possible way of a clear shot at the bird. Am I dead meat?

Thanks,
MP
 
You should take a protractor with a straw and sight through athe 23 degree elevation to make sure. Due to the way the dish bounces the signal onto the LNB, you can't go simply on how you see some dish antennas pointed.

For example, I've seen antennas in town house developments that look like they are pointed directly at the back of the unit behind them. Yet they pickup the bird just over the ridge of the roof.

But yes, if you have to look directly through trees, it's going to be a real problem. The moisture in the leaves attenuate the signal from the satellite, effectively blocking it from passing through at a sufficient strength. It's such an issue with DBS dishes because of the shorter wavelength of the signal used. C-band dishes are not impacted as significantly.
 
The Dishes used for DBS are offset fed dishes so if you look straight out from where the dish seems to point you are not looking where the signal actually comes from, there is about a 22 degree offset above the dish. In worst case scenarios you can use more than 1 dish to look at the three satellites Directv uses, you may not be able to see all three locations with one dish. Talk to a local dealer he will be most familiar with your location and will want you as a customer so he should work to get you a signal.
 
If these are decidous trees you may get it set up just fine now and then lose sevferal points of signal when the trees are full
 
I was told that for the bird my locals are on, it's 23. The trees are a mixture of pine and maple. I used a ruler and protractor from the roof. I clear the hill, but don't come close to clearing the trees. It would take a LOOONG pole to clear them.

Using that little freeware program that tells you coords I got:
110 bird is a 243/29 shot
119 is a 251/23

No idea what the 101 bird is.

And in looking at the DirecTV site, here's the info it gave me:

Azimuth 233.9
Elevation 33.8

I had an installer tell me however that the 119 bird was definately at 23. Soo... *shrug* I think I'm going to just force them to come out and try.

-MP
 
A professional installer will have a very accurate compass/inclimeter and will be able to perform a site survey which will accurately tell you if you are able to receive a signal or not. Tall trees on a tall hillside which is close to the house is without a doubt the worst case scenerio.
 
A hill 50 feet off the back of the house is pretty close..how big is the hill and how tall are the trees?Do you have a two story house?could you put the dish on a pole behind the house?
 
The yard slopes away behind the house, making it even more impossible there I think. Hill is due west, house faces the hill, yard slopes off even further to the east.
 
A Suunto Tandem Inclinometer can tell you (check ebay, expensive though). It has two sites you look through, one for AZ and one for Elevation. It is a great tool.

The azimuth and elevation you got from DirecTV is for the 101 satellite (the main satellite). The installer telling you 119 is at 23 is correct, it's azimuth is also at about 252 depending where you are. (It appears you are in the northeast).

Basically you need from 230 to 255 Azimuth clear at 20-35 Elevation.
 
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