How much clearance is needed?

[cowboys31]

I am having trouble getting directv hooked up because of no line of site. I found a place to put the dish that would be pointed thru some trees directly at the satellie. It will be pointed thru a "cutout" between a few trees. The opening will have about a 20' diameter and I am pretty confident that i can keep the branches trimmed back so future growth will not be an issue. Does anyone know if this size opening thru the trees is large enough to get a strong enough signal? Any info would be appreciated.

 

[dewdude420]

a 20' diameter?

i'm sure that should be PLENTY. the one thing to consider is you really only need enough clearence for the signal to pass through...and the wavelength of a Ku-band signal is pretty small, 12 GHZ is somewhere around 2.5CM in length.

in theory (mind you, i've never offically taken calsses and only read some books), you just need enough for the wave to fully fit through...if your AIMING was percise, you could in theory send a signal through a 3cm hole..however, since that would require some major percision...it's not practical..however, your 20 foot hole should be more than enough, provided things don't get too crazy wind-wise and cause stuff to blow into the hole..i've got that problem with a E* sat every time the wind blows.

 

[Joe Diamond]

Everyone a clear eyed satellite guy:

You really gotta get a transit and shoot the elevation and azimuth to hit a dish location. As noted you just need a small hole if you can find the right spot for the dish.
Having explained to customers that the hole in the trees is fine but the dish must go in the center line of the street a few times...I suggest going to spots on your property where a dish is possible.......near the electric bond and not under roof overhang and not on building walls and not near doors or windows and not in the driveway..............
Most installers will pass on the questionable Line of Sight deals because if it doesn't work they will not only not be paid, they will be late for a next appointment. They will be back charged for being late if they stop to explain all this. The installation companies all used to pay $25.00 to go look and explain. Now none do.
Think about cutting trees, doing a self install or doing some careful survey work.

Joe

 

[cowboys31]

"the dish must go in the center line of the street a few times"

What does this mean?

 

[Joe Diamond]

There is a LINE of Sight that begins at the dish location and ends at the satellite, 22,000 miles out in orbit along a line at 101 degrees west longitude etc. The dish can be anywhere on that line. When trees block the line you have to move the dish and tune or point again until the signal makes it to the dish. Many dish locations that will work for signal are not acceptable for other reasons. So the centerline of the street won't work nor will the roof or hood of a parked car unless you remove the wheels.

Like that,

Joe

 

[cowboys31]

Where can I find an elevation transit?

 

[charper1]

I hope he is not talking about a transit like surveyors use? I think even a pocket travel model runs $270 + (OUCH!)

I would think a simple heading compass & and angle finder will do just fine; for less than $40;

or a combo tool/inclinometer if you want to have a fancier tool.

 

[iwc5893]

While the 101 sat carries most of D*'s programming, it may be necessary for you to have a larger window depending upon what type of dish you are installing. A 3 LNB dish requires a minimum of a 18 degree arc (from the 101 to the 119) and really should have a 30 degree arc to account for surprises.

In addition, you really need a 10 degree vertical arc to ensure that you are pulling in all of the sats.

20' may be enough, depending upon how close to the dish the window is. If it's more than a few feet away, you may have problems.

 

[charper1]

While the 101 sat carries most of D*'s programming, it may be necessary for you to have a larger window depending upon what type of dish you are installing. A 3 LNB dish requires a minimum of a 18 degree arc (from the 101 to the 119) and really should have a 30 degree arc to account for surprises.

In addition, you really need a 10 degree vertical arc to ensure that you are pulling in all of the sats.

20' may be enough, depending upon how close to the dish the window is. If it's more than a few feet away, you may have problems.

How true!

Cowboy: you aren't still thinking about mounting on the tree itself are you?

 

[cowboys31]

First off i want to thank everybody on this website for all your help. I cannot live without NFL Sunday Ticket and will not stop until I get it. I am looking at mounting the dish approx. 40' from the hole that I am talking about because this will put the dish right on the edge of the woods in my yard. I was planning on mounting the dish on a SCH40 ploe that someone recommended. I can move the dish closer but then it will be located in the woods and not sure if that effects anything? The only thing that i care about is the football package so I don't know anything about multiple satellites. I was told by Directv that my dish needs to be pointed at 37.3 degrees and I have no idea what dish I actually need?

 

[cowboys31]

after more research and talking with a directv rep again i found out that i need a 101 satellite. Rep was somewhat confident that the opening in the trees would be large enough. Thanks for all your help!

 

[Mike500]

I hope he is not talking about a transit like surveyors use? I think even a pocket travel model runs $270 + (OUCH!)

I would think a simple heading compass & and angle finder will do just fine; for less than $40;

or a combo tool/inclinometer if you want to have a fancier tool.

A surveyor's transit is exactly what he is talking about.

To get a good sighting, a hand held tool just won't do.

Here is the one that I have and use for critical line of sight obstruction issues;

http://www.dewalt.com/us/products/tool_detail.asp?productID=8182

 

[vurbano]

why not just cut the 20' hole and try it.

 

[Jimbo]

A surveyor's transit is exactly what he is talking about.

To get a good sighting, a hand held tool just won't do.

Here is the one that I have and use for critical line of sight obstruction issues;

http://www.dewalt.com/us/products/tool_detail.asp?productID=8182

I would NEVER spend $280-350 to determine IF I could do something.
Perticularly if your not doing this type of work for a living.
I suggets he goes out and trys it, I think he will have no problem with it and he can save his $300.
With that money he saved he can pay for a receiver or programming

Jimbo

 

[Jimbo]

why not just cut the 20' hole and try it.

He said the hole is already there, but he will have to keep it cleared when needed.

Jimbo

 

[iwc5893]

If all you need is the 101 sat for all of your programming, then go for it. 20' should be plenty big enough for a single sat.

 

[Joe Diamond]

Well maybe not a transit for every job,

I use a compass and a plastic angle finder. I also do not attempt to hit the center of a small hole in trees.. A transit with a laser pointer will get you there but you are so close to the trees I just pass on the job. You will end up with a temp mast mount, a dish and a signal meter in any case.

The satellite will not move. Your hole in the trees will not move. So, you have to put the dish in the same line of sight that goes through the hole where ever that is...no choice.


Good luck,
Joe