For the Pros(many here) this is the dumb question of the week. . . . . (1 Viewer)

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RT-Cat

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May 30, 2011
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After searching and reading at least 8 stories about setting the correct elevation for your offset style dish, I still do not have the answer. They all stated the offset must be part of the calculation and also stated that not all small dishes have the same offset, but NONE of these articles showed you how to figure what the offset IS for the dish you are working with. So, how???:confused:

RT.
 

Magic Static

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If you don't get the offset spec from the manufacturer than you can only guess. Typically about 25° offset. Then put it on a motor with a bent shaft of unkown value of about 30°~40° and you can get real confused.
 

greg harris

SatelliteGuys Pro
Oct 18, 2007
208
1
The degrees of offset may be found in the spec sheet of the dish.

You can calculate the degrees of offset if you carefully measure the dish. The Satellite Antenna Alignment tool (2.87.0.0) works very good for offset calculations. This tool may be found by doing a Google search. GregH
 

RT-Cat

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If you don't get the offset spec from the manufacturer than you can only guess. Typically about 25° offset. Then put it on a motor with a bent shaft of unkown value of about 30°~40° and you can get real confused.
No specs available.

The degrees of offset may be found in the spec sheet of the dish.

You can calculate the degrees of offset if you carefully measure the dish. The Satellite Antenna Alignment tool (2.87.0.0) works very good for offset calculations. This tool may be found by doing a Google search. GregH

Found the alignment tool. Looks interesting. May work.
Thanks guys.

RT.
 

Anole

SatelliteGuys Master
Sep 22, 2005
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Does the mount have elevation marked on it?
Are you even using the original mount?
You didn't -say- you were using the dish on a motor, so...?
If you have the LNBF properly located (because you have all the parts to the dish), then the actual offset isn't particularly critical.
... even if you -are- putting it on a motor. ;)

Too little info in the thread to offer useful advice.
 

RT-Cat

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Does the mount have elevation marked on it?
Are you even using the original mount?
You didn't -say- you were using the dish on a motor, so...?
If you have the LNBF properly located (because you have all the parts to the dish), then the actual offset isn't particularly critical.
... even if you -are- putting it on a motor. ;)

Too little info in the thread to offer useful advice.
Elevation marks - Yes.
Original mount - Yes.
Motor - No.
LNBF in center of a three hole mount.
From your first question, I take it the elevation marks on it are what can be used.

RT.
 

FaT Air

HOA Free Zone
Feb 27, 2010
6,668
913
97W 48N
Should be able to use the elevation scale on the mount (original dish and mount) Should be, at least, close. BTW: Satellite Antenna Alignment tool (2.87.0.0) will not work for elliptical dishes using the height and width of the dish. BUT, I think you can lay it flat, face up, fill with water from top lip to bottom at the center of dish. Then measure the width of the water in the face of the dish, for the width measurement.
 

greg harris

SatelliteGuys Pro
Oct 18, 2007
208
1
I have had good results using the Satellite Antenna Alignment tool to calculate the amount of offset a dish has but I do not measure the lip. This would be about the same thing if the dish was filled with water. GregH
 

Anole

SatelliteGuys Master
Sep 22, 2005
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L.A., Calif.
Elevation marks - Yes.
Original mount - Yes.
Motor - No.
From your first question, I take it the elevation marks on it are what can be used.
Yes, I'd say you're done.
The dish offset is accounted for in the elevation marks on the mount.
It may not be 100% on the money, but it should get you to within a few degrees, so long as your pole is plumb.

LNBF in center of a three hole mount.
Not sure what this means.
Show us a picture of the dish/mount/LNBF/etc.
But regardless, I think you are on the right track.

So long as you are using a large enough dish, and an LNBF with feedhorn that properly illuminates the dish, and you account for skew (either by twisting the lnbf/feed, or the dish, as appropriate).


edit: oh, and nothing at all dumb about the question.
Just took a little longer to answer due to need for full info.
Folks here are happy to help generously, when they understand the problem. - :up
 

RT-Cat

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Should be able to use the elevation scale on the mount (original dish and mount) Should be, at least, close. BTW: Satellite Antenna Alignment tool (2.87.0.0) will not work for elliptical dishes using the height and width of the dish. BUT, I think you can lay it flat, face up, fill with water from top lip to bottom at the center of dish. Then measure the width of the water in the face of the dish, for the width measurement.
Interesting about the tool. Neat way of measuring. I have a bird bath, don't need another one.:D:)

RT.
 

RT-Cat

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Yes, I'd say you're done.
The dish offset is accounted for in the elevation marks on the mount.
It may not be 100% on the money, but it should get you to within a few degrees, so long as your pole is plumb.

Not sure what this means.
Show us a picture of the dish/mount/LNBF/etc.
But regardless, I think you are on the right track.

So long as you are using a large enough dish, and an LNBF with feedhorn that properly illuminates the dish, and you account for skew (either by twisting the lnbf/feed, or the dish, as appropriate).

Took the stuff outside today. Set it up with all the info needed. Got nothing. Loosened the bolts and did some dish wiggling. Nothing. Then, WOW PBS-East on AMC 21. More adjustments and sig - 82, Qual - 79. Interesting that skew did not make much difference. Tight bolts now.
This is what I mean by in the center hole of a three hole mount.
Thanks for all the info. (hope these pics work. Not sure about just how to do it.)

RT.
ROC Dish 001.jpg ROC Dish 003.jpg ROC Dish 002.jpg
 

FaT Air

HOA Free Zone
Feb 27, 2010
6,668
913
97W 48N
But it worked for determining the offset of my 84E PrimeStar. was very close. But I can't remember what numbers I got. Made using a home made mount possible. But later- Didn't really matter, I found the original mount for it. I'll echo Anole:"Pictures" especially that "three hole mount". Guess I'm not sure what that may be, unless it's for 3 side by side LNBF's (Multi sat set up?) Ok= got it (I'm a slow typer so this got posted after your post)
EDIT- don't know how you'd skew the feed by itself - is there a way of skewing the whole dish?
 

RT-Cat

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But it worked for determining the offset of my 84E PrimeStar. was very close. But I can't remember what numbers I got.
EDIT- don't know how you'd skew the feed by itself - is there a way of skewing the whole dish?

Hope you did not think I was being :rolleyes: about the water. I REALLY think that was a good idea.
Three bolts on the back and you can rotate it a large amount.
The dish was used by a bootlegger and when Nag 3 took over, he had no use for it. So I got it cheap.:)

RT.
 

Anole

SatelliteGuys Master
Sep 22, 2005
11,819
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L.A., Calif.
Oh, a pirate dish! I see now. :up
You could have gotten all sorts of confusing advice if you hadn't posted that picture. ;)

I wouldn't worry about using anything but a stock round-feed LNBF on it, it's not really an elliptical dish, for the purpose of discussion.
(and more conveniently, the less-common rectangular-base type, as you currently have)
As long as it's big enough to discriminate against the adjacent satellites at Ku, you're good to go.
Curious what the height and width are, though.

And if you should get froggy and want to use other of the more common design LNBFs, we can point you to LNB brackets that you can bolt on to hold one.
Likewise, I won't jump up and down to encourage you to bolt on extra LNBFs beside the center one.
Might have useful spacing, might not. Most likely it'll be 9°, if you want to think about it.
For now, if you have the desired bird, no reason to complicate the discussion.

Congratulations on getting your signal.
 

RT-Cat

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Oh, a pirate dish! I see now. :up
You could have gotten all sorts of confusing advice if you hadn't posted that picture. ;). . .
. . Curious what the height and width are, though. . . Might have useful spacing, might not. Most likely it'll be 9°, if you want to think about it.
For now, if you have the desired bird, no reason to complicate the discussion.
Congratulations on getting your signal.

Thanks.
It is 29" H by 32" W. It came with a spacer bar that held the other two LNBF's outside the other two holes so he could get (think) 110, 118, 129.:eek:

RT.
 

guacharaca

SatelliteGuys Pro
Jun 5, 2010
270
1
Vernon, BC
If you rotate that dish clockwise as seen from the rear, it should improve the "quality" of your signal from 125W (PBS). Check dishpointer.com for the exact number of degrees to rotate your dish for each satellite.
 

RT-Cat

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May 30, 2011
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If you rotate that dish clockwise as seen from the rear, it should improve the "quality" of your signal from 125W (PBS). Check dishpointer.com for the exact number of degrees to rotate your dish for each satellite.

Did so. It actually is skewed. I turned the camera in the pictures and that makes it look like it is at 0 skew. In fact, I rotated that dish a VERY large amount and held signal until it got way out of wack and signal was lost. It is set at the best sig & qual I can get it at.

RT.
 

Anole

SatelliteGuys Master
Sep 22, 2005
11,819
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L.A., Calif.
The dish size and geometry are fine for receiving high-powered circular satellites such as DishNetwork.
It's on the small size for real FTA work.
Use it on higher powered transponders.
But, if you want another dish, go for something larger.
 

RT-Cat

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"My person-well trained"
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May 30, 2011
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Cold, Cold,Michigan USA
The dish size and geometry are fine for receiving high-powered circular satellites such as DishNetwork.
It's on the small size for real FTA work.
Use it on higher powered transponders.
But, if you want another dish, go for something larger.

I was really "playing" with this dish just to see if it would work for anything. For my FTA viewing I use the BUD in the picture. It is a 10 footer, C & Ku. Oh, my, it is getting so old it is growing some mold on it. Guess I will go out and clean that up. . . . . .

RT.

BIG Dish.jpg
 
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