FTA Dish vs Trees

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8valve

SatelliteGuys Family
Original poster
Oct 13, 2010
65
1
Adirondack Mts
I have just finished installing my FTA System with motor drive dish. I am very pleased with the amount of satellites I can hit due to the heavy forest around my home. Presently Galaxy 18 at 123W is as far west as I can hit. I would like to receive AMC14 at 125W. I have a signal of 60, but quality of only 5. Here's the problem. Back in 1980's in my C Band days with prime feed dishes, I would mount a spot light on the LNA nose cone, square it up and then at night swing the dish to different Sat's and find the offending trees. I dont know how to do anything like that with the OffSet feed dishes we use now. I only need a little tree pruning to get AMC 14, but have no idea what tree or trees is the offender. My question, where on a offset feed dish can I sight to determine the offending trees. I dont believe I can use the strut the LNBF is mounted on as the dish is looking higher than the strut points. Any suggestions ? Thanks 8Valve
 
one way:

There are other techniques, but . . .
Some fellows have used a laser pointer affixed to the dish.
Problem is determining how much elevation to give it to match the reception angle of the dish.
If you look up the specs to your dish, you may find that it has an offset of 24° (just example).
So, if you were to place a yard stick/board vertically across your dish, and then use a protractor to aim the laser pointer, it would need to be "up" 24° from a line perpendicular to the yardstick.

Most dishes have a vertical offset of somewhere between 22° and 26°, so make sure you look it up for your particular unit.
 
you could also use dishpointer.com and it will tell you the maximun height for an obstacle to obstruct the signal for a particular distance away from the dish. it also shows you with a green line the exact direction where the sat signal is coming from therefore you know which tree is the ofender.
 
another memory:

I think it was back when Dee Ann was poking around in her back yard, she or someone came up with this more simple idea:

Print out a simple chart of satellites, with azimuth and elevation.
Go to your yard at night, and using a hand-held laser pointer, aim it with a compass and an inclinometer.
You want it to be about the same height and location as your dish, but it doesn't need to be attached.
For instance, ya might make up something simple, using a block of wood and a camera tripod...
Wherever the dot shows up on the trees, you've got a problem.
Sometimes, relocating your dish a few feet, may let you miss a neighbors house, street sign, power pole, or other obstacle.
A green laser may show up better, however since you can get red ones at the 99¢ store for.. a buck.. start with one of those first! - :up

WARNING: most of the cheapo lasers do NOT put out a beam coaxial¹ with their housing!
edit: or... concentric
 
That would work also. I have a high power rifle laser I could take off to use. It will project 1000' . Way more than I need to find the offender. Moving the dish is not a option as its side mounted on my tower. 8Valve
 
Well if you had asked this 3 or 4 weeks ago, the best answer would have been to use the sun, at the time when AMC21 was undergoing a solar outage. Now, however, the sun will be considerably lower than where the sats are, but you can still use the sun for the azimuth, and use a digital level or inclinometer for the elevation. This is what I did a couple years ago when I was deciding upon where to put my fixed Primestar, which BTW I have aimed at AMC21. First, find Azim/Elev of AMC21 for your lat/lon, then go to the USNO site, and find out what time of day the sun has the same azimuth as the sat. Put a digital level on a tripod, and put it in front of your dish, such as: http://www.eskerridge.com/bj/Sat/Levelsetup_1385.jpg and aim it in the direction of the sun, and then raise the elevation until the angle on the level or inclinometer is the same as the sat's elevation. THEN, you can sight over the top of the level or inclinometer to see where the sat is in the sky, such as: http://www.eskerridge.com/bj/Sat/level-view_1387.jpg Worked well for me, and my Primestar has been fixed on AMC21 since. Ie done this way, you don't have to worry about the offset angles that can really be confusing, or about magnetic deviation. I have also used digital levels which have pretty strong laser pointers to locate offending trees for other purposes (clearing views of distant mountains), and that can work if the trees are close enough, but I really think using the sun is more accurate. I have spent years here cutting down a dozen or so good sized trees, and using rope saws thrown over limbs that are 60' up in trees clearing holes to get views of sats, only to find that when you remove a limb, the trees generally go into hyper-drive growing back even thicker foilage in a couple years. I finally gave up and moved my dishes to a better place.
 
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