Site survey for elevation angles

Before purchasing any equipment, I want to be certain I will be able to get to at least some satallites because I live in a village full of large trees. I have made an angle finder from a couple of paint stirring sticks and a protractor. I cannot see the horizon, but from a south facing second floor window, if I keep the lower leg of the finder level, would the angle between the legs be valid for finding a satellite?

Eg - elevation of AMC3 is 39.9d. If the line of sight angle from dish to the top of a tree equals or exceeds this angle, I should be able to receive a signal, correct?

Also, in determining the angle, how much space should be allowed over the top of an object as a margin for errror?

Thanks for any help.

[wejones]

Originally Posted by HappyJack

Before purchasing any equipment, I want to be certain I will be able to get to at least some satallites because I live in a village full of large trees. I have made an angle finder from a couple of paint stirring sticks and a protractor. I cannot see the horizon, but from a south facing second floor window, if I keep the lower leg of the finder level, would the angle between the legs be valid for finding a satellite?

Eg - elevation of AMC3 is 39.9d. If the line of sight angle from dish to the top of a tree equals or exceeds this angle, I should be able to receive a signal, correct?

Also, in determining the angle, how much space should be allowed over the top of an object as a margin for errror?

Thanks for any help.

Sounds OK. Not much margin requirred, basically the diameter of the dish, ie the bottom of the dish must see over the obstruction. But are you saying that you're going to have the dish looking through a window? Can be done, but isn't as easy as it sounds.

Originally Posted by wejones

Sounds OK. Not much margin requirred, basically the diameter of the dish, ie the bottom of the dish must see over the obstruction. But are you saying that you're going to have the dish looking through a window? Can be done, but isn't as easy as it sounds.

Sorry for not making it clear:

No, I'm not thinking of having the dish point out of the window. When the snow is finally gone here, and we get leaves on the trees, I would mount the dish on the fireplace chimney, about eight feet higher than this window's elevation. This is the most elevation I can reasonably get.

I've read that a satellite's elevation is the angle between it and the horizon from a point where the reading is taken. Since I can't see the horizon, what I'm asking is - if the lower leg of my angle finder is level (about 900 ft above sea level), can I rely on the angle between it and the upper leg in order to determine if I can see the satellite. I just don't want to spend the money and do a pile of work only to discover I can't receive anything.

[rainman]

Originally Posted by HappyJack

Sorry for not making it clear:

No, I'm not thinking of having the dish point out of the window. When the snow is finally gone here, and we get leaves on the trees, I would mount the dish on the fireplace chimney, about eight feet higher than this window's elevation. This is the most elevation I can reasonably get.

I've read that a satellite's elevation is the angle between it and the horizon from a point where the reading is taken. Since I can't see the horizon, what I'm asking is - if the lower leg of my angle finder is level (about 900 ft above sea level), can I rely on the angle between it and the upper leg in order to determine if I can see the satellite. I just don't want to spend the money and do a pile of work only to discover I can't receive anything.

What i use is a protractor, compass and a straight edge if you have a clear line of sight when sighting down the straight edge set to the sat angle you should be able to receive the sat.

[pmb1010]

do any of your neighbors have directv or dish?

That will give you approximate "look" for 110 degrees, which is about south west on a compass.

If you stand at their dish and look about where it's aimed, you can get an idea where you mount your dish - what it would need to see.

It has to be quite clear for FTA. Dish and Directv can tolerate a couple branches (sometimes) but anything in the way of FTA is trouble.

[wejones]

Originally Posted by pmb1010

do any of your neighbors have directv or dish?

That will give you approximate "look" for 110 degrees, which is about south west on a compass.

If you stand at their dish and look about where it's aimed, you can get an idea where you mount your dish - what it would need to see.

It has to be quite clear for FTA. Dish and Directv can tolerate a couple branches (sometimes) but anything in the way of FTA is trouble.

Except it's kind of hard to tell what direction one of these offset dishes is aiming. But doing what you say, you would get an idea of how high a tree you can see over.

Re Dishnet/DTV being more tolerant, I think this is not really that they can tolerate a branch or two more than an FTA dish, but instead, I think it is because those little 18" dishes only need an 18" hole between the branches, whereas a 3' dish needs a 3' hole, and a 10' dish needs a 10' hole, etc. A few branches will affect DTV or Dishnet the same as any other dish, in fact, since the DBS dishes are smaller, it seems more likely that a single branch will block a higher percentage of the signal to me. I think that there is a feeling that since DBS signals are stronger, that they will go branches better, but this isn't the case, because the dishes are smaller, and the actual signal that reaches the receiver is pretty much the same for DBS or linear FTA sats, so I really think they are equally susceptable to a percentage of the signal being blocked.

[pmb1010]

I am only going by expreience from guy a few doors down the street.
His Directv dish points thru a bunch of branches, and works.

The signal does move around on the box's signal meter when the wind blows so I know the branches are affecting the signal, but he gets enough to watch TV and he's happy with results.

G10R for me (on my main 4 foot dish) looks thru some branches. I cannot get anything. One time I did get a JCPenny tile for a one-time instructional seminar, but nothing since.
Using same dish on C band and analog receiver, I can see something is there but it's so low in the mud it's unusable.

The guy was looking for "any help". Trying to locate even where the dish is going to generally point can sometimes be a challenge.

[wejones]

Originally Posted by pmb1010

I am only going by expreience from guy a few doors down the street.
His Directv dish points thru a bunch of branches, and works.

The signal does move around on the box's signal meter when the wind blows so I know the branches are affecting the signal, but he gets enough to watch TV and he's happy with results.

G10R for me (on my main 4 foot dish) looks thru some branches. I cannot get anything. One time I did get a JCPenny tile for a one-time instructional seminar, but nothing since.
Using same dish on C band and analog receiver, I can see something is there but it's so low in the mud it's unusable.

The guy was looking for "any help". Trying to locate even where the dish is going to generally point can sometimes be a challenge.

Sorry for sort of hi-jacking the post topic, because I think I'm drifting off topic here, but what you say above kind of matches what I have seen, and is kind of interesting.

Re an 18" DTV dish, and a 3' FTA dish, I don't think there is much difference. On one side of my house, I can't see ANY satellites without looking through tree branches. When I first moved in, I was able to find a 3' hole to aim an old Primestar dish through, and found another hole between branches to aim an 18" DTV dish through. Both behaved similar to what you describe, ie whenever the wind blew, I'd tend to lose signal for a while. However what you describe with your 4' dish supports something I have suspected for quite a while, and that is, that I am convinced that these dual C/Ku feeds or LNBFs do not completely illuminate the dish on Ku.

When AMC6 first appeared at 72, I got good reception, but then last year I lost reception. At first I thought that freeze/thaw or a windstorm had knocked my dish out of alignment, but when I went out and tried to peak the sat, I found that it was already peaked as good as I could get it. Confused, I thought that perhaps my feedhorn might be not positioned properly, so I went up on my front end loader while the dish was aimed at AMC6, and moved the aim of the feedhorn a bit. To my surprise, I found that I could about double my KU signal by aiming the feedhorn at the top half of my dish, rather than at the center of the dish. I soon realized that it was because a couple pine trees had grown about 5' during the previous growing season, and had blocked the view of the bottom half of my dish (I's since cut these trees down).
But the interesting (to me) thing, is that while those C/Ku feedhorns "see" (illuminate) the whole dish on C-band (helped by positioning those scalar rings), it looks to me like on Ku, they must only see a fraction of the dish. Ie If the whole dish was illuminated, I would have still been seeing the signal from the top half of my dish when aimed at the center. The thing is though, that with a big C-band dish, you don't need the whole dish to get good reception on Ku. My guess is that a C/Ku feed is probably only looking at perhaps a 4' or 5' diameter circle when looking at a 10' dish, and when you have such a feed on a 4' dish, I'm guessing that it would be even smaller since you're closer to the dish.
I'm curious..... can you compare the signal from your 4' dish on Ku to the signal from a 3' ku only dish, which has an lnbf properly illuminating the dish? I know that the signal I get from my 10' dish is only a little bit better than what I get from my 3' dishes, even though you'd expect it to be MUCH better. Although part of the problem with my 10' dish is that it has a very low F/D ratio. I think the effects I'm talking about would be less for a high F/D dish.
Anyway, an interesting topic. Sorry for getting away from the original question.

Thanks for the replies. Dead south of me is AMC5 at 79.0w, with an elevation of 40.6degrees; no problem there. But as I scan east & west from south, I'm guessing I might get 35 degrees max. and as wejones mentioned, the trees will continue to grow. A few years ago, I had a DirectTV dish up, but it did point in between some trees. I'm guessing I'll get at least the highest elevation satellites. Thanks again.

[pmb1010]

Mine is also 79 deg.

To get around the problem you are talking about, my dish is on a pole about 15 feet off the ground, and can "see" over the major tree I have in the yard about 30 feet away.

There was a discussion about using the sun to track where the clark belt is, and you can watch the shadows of the trees to know if they block visablitiy. Not sure when that will happen again (or soon enough for your analysis) but that was interesting for me. My dish was illuminated by the sun all the way till Satmex 5, which is tree in neighbors yards that prevents me from that section of satellites.