OTHER STAB USALS Arc question

iBoston

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Jul 15, 2014
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Top dead center for me is 89w.

#1. does anyone know what the limit is for a STAB USALS? I can get 30w but not 20w ? What is the degree limit?

#2. The logic in my brain says no, but ill ask just in case. Is it possible to have a USALS top of ARC (position 0) aligned to 30w and then be able to move east to get the rest East?? In another words, put the USALS at Top Position (O position) and then align the dish so it picks up 30w, and then be able to scan the arc East of that to hit the satellites down to my end of line horizon?
 

KE4EST

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  1. Somewhere between 60 and 70 degrees.
  2. Well you could if you put in the wrong Lat. and Long. for your area....but then since you are not really living there it may throw things off. I have thought about trying it before. Leave the Latitude the same but change the Longitude. It could get confusing though, since you would have to use the wrong numbers. Instead of 30 you would have to label it a satellite position near your actual Longitude.
 

iBoston

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Hopefully someone might chime in thats done this. I have a second USAL motor that im not currently using, and i thought that might be a good purpose for it. Yea, i did already think of the fact that all the numbers would be wrong. But, i would hopefully like to come up with the mathimatical formula so i would know what numbers to plug in.
 

a33

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Feb 4, 2015
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Well, why don't you use normal GotoNn diseqc commands instead of USALS GotoX commands, while you are at the extremes of the arc?

Or, if you can give raw diseqc commands, you can give GotoX commands that go further than usual USALS-bouderies, AFAIK. As I understood it, the USALS algorithm refuses to calculate GotoX commands further than about 60 degrees from zero, but that doesn't mean that the motor wouldn't understand GotoX commands for more than 60 degrees, I would think. But I never tested it.

Setting the zero-alignment of your setup other than at actual zero, would cause arc-following problems, that cannot be counteracted by maths. So it would be a very sub-optimal solution, arc-wise.

One extra remark: you could also mount a byrider-LNB, to look further than the USALS-bounderies! :)

greetz,
A33
 
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iBoston

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Jul 15, 2014
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You know, i had issues with saving Diseqc positions with my USALS in the past, but i must admit that was about 5 years ago. I would like to get down to 15w. That should be about my horizon limit. Would i be able to get that much further down with Diseqc goto commands?
 

a33

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Feb 4, 2015
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netherlands europe
That would depend on the limit switches, maybe?
I once made a spreadsheet making Hour angle and USALS calculations, and in the diseqc protocol there is room enough to rotate 180 degrees, IIRC.
So I personally wouldn't think the angles would cause a problem (other than that the motor might have a problem to return the dish to zero from so far an angle).

greetz,
A33
 

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