Polar Mount Setting Declination Angle

wium78

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1617778356664.png
How would I set the declination angle of the enclosed picture dish?
 

ozumo

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The gold-coloured bolt at the top of the mount adjusts declination.
 

Channel Hopper

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I would use a better tripod, plus some concrete blocks under it (or make a proper plinth) or it will fall over.
 

SimonE

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Hi Wium78,
I will have a go at explaining this for you.... Your dish has a polar mount intended to track distant objects at near infinity. Because the geostationary satellites are not at infinity a progressive correction is required as you track left and right. Here in the UK [52deg N] my dish requires a declination angle of 7 degrees. See attached chart to determine roughly the angle for your location and set it. Next find a satellite due North of you and optimise the dish for that satellite. If you have set the Declination Angle right the dish will track the arc perfectly. This is rarely the case and you will need fine adjustments of Azimuth and Declination Angle to achieve perfection. Lots of patience will be required!
Good Luck,
SimonE
 

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wium78

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Many thanks SimonE.Where I am in South Africa My declination to my due North satellite is 5 degrees.I agree with you lots of patience.
 

a33

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Where I am in South Africa My declination to my due North satellite is 5 degrees.

So you are at the southernmost point of south africa, Lat -35 degrees (see the chart)?

Greetz,
A33
 

jeallen01

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I would use a better tripod, plus some concrete blocks under it (or make a proper plinth) or it will fall over.
As above - as it is now, that dish will fall over in any sort of "wind" as the tripod legs are too short (and likely to bend /distort), and it will be very difficult to accurately align anyway because the whole setup will "rock" very easily as you try to do that.

Edited: picture below shows my 1.25m Gibertini at the seller's house before I bought it: the NPGM is a rectangular unit (in 3 separate sections, bolted together) and was weighed down with 4x concrete slabs.

It was also located in a very sheltered spot behind the house and between two closely adjacent fences - so not likely to get blown over.
NPGM1.PNG
PS: Pity you are not in the UK as you (or anyone else??) could have that NPGM "very cheaply" as the Gibby is now on a mast!)
 
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moonbase

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The picture from "wium 78" is the illustrative picture taken from the SSS webite, it aint an actual install.
I cant believe anyone thought that was the actual install of "wium 78".
 

Terryl

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The gold-coloured bolt at the top of the mount adjusts declination.
I think that one is for fine tuning the dish, the one I marked behind the motor is for adjusting the dishes elevation. (declination above the horizon)

1617778356664.png
 

ozumo

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I think that one is for fine tuning the dish, the one I marked behind the motor is for adjusting the dishes elevation. (declination above the horizon)

View attachment 135632
Yes this is the bolt I was referring to for declination adjustment :)
DC6EC224-280F-4E15-8DEF-B13FDDD428F1.jpeg
 

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The picture from "wium 78" is the illustrative picture taken from the SSS webite, it aint an actual install.
I cant believe anyone thought that was the actual install of "wium 78".
The question with the image was

How would I set the declination angle of the enclosed picture dish?

I'm surprised the dish is standing upright, must be some trickery going on.
 

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moonbase

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The question with the image was

How would I set the declination angle of the enclosed picture dish?

I'm surprised the dish is standing upright, must be some trickery going on.


That SSS aint a bunch of tobies, they know plenty of tricks. They might soon be selling anti gravity paint along with wad remover.
 

wium78

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With my declination being about 5 degrees is there a way I can measure it on the dish in question?
 

ozumo

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South Durham
With my declination being about 5 degrees is there a way I can measure it on the dish in question?
Declination is the angle between the axis of rotation (red line) and the dish face (blue line). Your total declination is about 5° + the offset of the dish (IIRC a Channel Master is 22.50°) so around 27.5° total.
7C8B08DB-071A-49D4-A136-5692D3BBD754.jpeg
 

wium78

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Thank you,appreciated.
 
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