quality cable / location problem

[altadata]

Hi...
I have finally found the IA5 ( 97W ) at the current location of the dish and I'm getting 62 tv channels.
Many channels are missing though and many are very weak ( they come and go ).

I definetelly have a location problem ( my dish for IA5 is pointing at my neighbor's house which is 50 feet away and the dish is near the ground - the elevation is 32 degrees and it seems it is not large enough to point above his house ).

My other concern is the coaxial cable.
I bought from a satellite store a cable ( made in China ) with a very good price ( cheap compare to HomeDepot ):

QSat Coaxial cable for Satellte TV, MATV and CATV
Professional Grade
18 AWG Copper Clad Steel
60% Aluminium Braid Shield
100% Aluminium Foil Shield
Swept Tested to 2250MHz

Given my location problem, how important is the quality of the cable? Should I try to buy a more quality cable or is it not going to improve things, given the location problem?

Thanks.

 

[mrweather]

Unfortunately, coax will do nothing for you if you already have a location problem.

What good-quality cable will do is take out a variable from the equation of "things that can go wrong".

Glad to hear you found IA5!

 

[Anole]

There are calculators that will let you find out if you can see over your neighbors house.
(given how high it is, how far away you are, etc )
Actually, there are optical devices you could use, though they cost a lot.
Ya might get out there with an angle finder, an empty paper-towel roll, and do a creative look-test with basic rocks 'n sticks.
(or a camera, tripod, telephoto lens, and that angle finder)

If there is a problem, maybe raising your dish a few feet, or moving it away from the neighbor, could be all it takes to get that bird.

 

[Zero]

If you are getting 62 channels, line of sight seems to be OK for me. If the house is 50' away and your inclination is 32deg, the house has to be 63.9' tall to block your LOS. You may have to check skew or fine tune the LNB. Fine tuning the dish will get you better quality.

 

[Anole]

Zero has a good p;oint.
So, how big is your dish, and what sort of LNB do you have?
Maybe upgrading those would be the answer (after you tweak what you have, of course).

 

[altadata]

Zero has a good p;oint.
So, how big is your dish, and what sort of LNB do you have?
Maybe upgrading those would be the answer (after you tweak what you have, of course).

I have a standard LNBF
I have a Fortec Star 36 inch dish which I understand is more than enough for my location ( Ottawa Canada ).

The elevation angle should be 32 degree, but in fact on my antenna I read around 25 degree. Anything higher is getting me 0, anything lower is getting 0 quality.
I'm not sure if the reading of the elevation on the dish is broken or what, but by looking at the antenna, it seem more like 25 deg, not 33 deg. In theory it should be 33.8 deg according to http://emantechnology.com/lookangle.asp
And also by looking at the antenna in the way it is right now, it clearly points to my neighbor's house, not above it.
Any idea why this elevation aberation?

Thanks.

 

[Wescopc]

According to Fortec - your dish has an offset of 24.62 Degrees. This means that it is looking 24 degrees higher than it appears when looking at the dish. Because the LNBF is offset (toward the ground) the radio waves that are refected need to arrive at the dish with an equal offset in the opposite direction. Hope this helps explain why you are getting signal from a dish that appears to be aimed at a house.

BTW It is not unusual to see the elevation scale off 8 degrees.
Bob

 

[altadata]

According to Fortec - your dish has an offset of 24.62 Degrees. This means that it is looking 24 degrees higher than it appears when looking at the dish. Because the LNBF is offset (toward the ground) the radio waves that are refected need to arrive at the dish with an equal offset in the opposite direction. Hope this helps explain why you are getting signal from a dish that appears to be aimed at a house.
Bob

So if my location requires 33.8 elevation, I should set it so that the indicator on the back of the dish reads 33.8-24=9.8 ?

Thanks.

 

[Wescopc]

No the elevation scale is calibrated with the offset figured in. The factories sometimes don't get the elevation scale stamped into the metal accurately.

You have the dish aimed at the Satellite - you may be able to tweak it 1 to 1.5 degrees - left/right or up/down and get better signal but no more then that.
Bob

 

[mrweather]

My Fortec 90cm was about 6 degrees off from what the scale said. It seems the figures you get from sat finder calculators are more guidelines than absolutes.

Set the dish to whatever it says but tweak for best signal and quality, which means you might be off -- sometimes substantially.

 

[Anole]

I have the same Fortec antenna.
That long arm holding the LNB need be tweaked only a little bit to throw off your elevation.
That's not necessarily manufacturing tolerance - it could just be slightly tweaked from handling or shipping.
Some even worry about a too-heavy LNB.

 

[altadata]

I have the same Fortec antenna.
That long arm holding the LNB need be tweaked only a little bit to throw off your elevation.
That's not necessarily manufacturing tolerance - it could just be slightly tweaked from handling or shipping.
Some even worry about a too-heavy LNB.

That might be what happened. But how can I get it back to the original shape ( angle ) ? What is the original arm's angle supposed to be?

Thanks.

 

[altadata]

I still thing that is a location problem.
I read somewhere that you don't need only a clear line of sight ( line one single line ), you need some angle above and under that line ( starting from your dish going up to the satellite ).

I was looking today and it points in the direction corresponding to the highest point of his roof.
If the distance is 50 feet away, and the elevation should be 33 deg, a height of 32 feet would block my line. A 2 story house can reach I think 32 feet when you add the top of the roof.

Otherwise I have no explanation why I'm getting so weak signal on some transponders of IA5 ( 0 to 10 % ). There are a lot of transponders that I'm not getting anything from.

 

[Tron]

If his house is blocking the signal, you won't get anything. It would be different if there were trees with leaves that move in the wind, allowing some signal to get through. Think of the satellite as a star in the sky (a pinpoint of light). If you can see it at all above his house, you can see all of it.

I'm betting the dish just needs to be tweaked a bit. Have you tried fine-tuning the LNBF skew, or pushing/pulling the LNBF closer and farther away from the dish until you get optimal signal?

 

[Zero]

I still thing that is a location problem.
If the distance is 50 feet away, and the elevation should be 33 deg, a height of 32 feet would block my line. A 2 story house can reach I think 32 feet when you add the top of the roof.
.

Add 24 deg (which is the offset agle for the dish reflector) to 32 deg=56 deg. That's how I calculated 63' as the obstruction height (Infact, I had added 20+32=52deg) for calculation. So 2 stiry house cannot block your LoS.

Your dish elevation could be off due to
1. error in manufacturing
2. Your pole may not be plumb.

Check if your dish is deformed. If looks OK, hold on the edges and try pushing it or pulling it to see if there is any change is SQ.

Move the LNB in and out and check if there is any improvement.

Some LNBFs are off by 90deg (I do not remember which one). Try changing the skew of LNB..

Always patience pays. You have to be really sloooooow and wait for few seconds before moving again. SQ stabilization takes some seconds 1 to 3 seconds.

Good Luck

 

[altadata]

Add 24 deg (which is the offset agle for the dish reflector) to 32 deg=56 deg. That's how I calculated 63' as the obstruction height (Infact, I had added 20+32=52deg) for calculation. So 2 stiry house cannot block your LoS.

Your dish elevation could be off due to
1. error in manufacturing
2. Your pole may not be plumb.

Check if your dish is deformed. If looks OK, hold on the edges and try pushing it or pulling it to see if there is any change is SQ.

Move the LNB in and out and check if there is any improvement.

Some LNBFs are off by 90deg (I do not remember which one). Try changing the skew of LNB..

Always patience pays. You have to be really sloooooow and wait for few seconds before moving again. SQ stabilization takes some seconds 1 to 3 seconds.

Good Luck

Why do you add 24 deg to the elevation of 32 deg for a total of 56 deg ?

The line of sight has nothing to do with the offset that my dish could have.
The los is established when you survey the location. From the possible location that I want to choose if I point 32 deg in the sky, that line must intersect nothing. A house of 30 feet may obscruct that line.
So it's 32 deg not 56 deg.

I found a webpage but I don't remember the url. It explains that the satellite is actually a big object and you don't need only a line of sight. You need something like a cone starting from your dish to the satellite. I'll try to find that page again.

If that cone intersects with the top of the neighbor's roof, I might get some transponders that are not obstructed, and I may miss on ones that are obstructed. There are some transponders that shows nothing.

How do you explain that a transponder has 63% Q, while others have 0% Q ?

 

[Wescopc]

altadata
The satellite is 23,000 miles away so it is but a dot for the dish to see. The "cone" would be more like a cylinder the diameter of your dish here on the good ol' terra firma.
Your line of sight would be the elevation given for the Satellite at your location - 32 degrees in your case. You are correct in not worrying about the offset.
Bob Westcott

 

[altadata]

altadata
The satellite is 23,000 miles away so it is but a dot for the dish to see. The "cone" would be more like a cylinder the diameter of your dish here on the good ol' terra firma.
Your line of sight would be the elevation given for the Satellite at your location - 32 degrees in your case. You are correct in not worrying about the offset.
Bob Westcott

There are 3 things that I'll check next:
1) I'll take the antenna apart and I'll check that the lnb arm is the same shape as the one at sadoun. I printed a copy of the arm's picture from the website and I'll measure the angle of the arm and compare with the angle in the picture.

2) I'll turn the dish upside down and make sure the edges touch a planar surface.

3) I'll increase the current elevation that gives me IA5 signal right now by my dish offset ( increase by 24 deg ). In this new position the dish will be looking straight to the IA5. I'll draw an imaginary line perpendicular from the dish to the sky and see how far away is from the roof and other obstacles.

And maybe check again for plumb.