Advice Needed Tweaking longitude settings - common practice?

dankargo

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Hi all,

I've been posting recently how my signal levels have somewhat dropped slightly in the past few months, which has led me having to manually edit the satellite positions to get them at their peak. (0.8w > 1.2w, 16.0e > 15.6e).

I was given some advice to try tweaking my longitude settings using the same 0.4 offset as I had to the satellite positions. So I went from 0.017 E in longitude to 0.057 and quite surprisingly, doing this and putting the satellite positions back to their original positions has sorted everything out.

The dish is located near to the chimney which is pretty difficult to get to so I am massively grateful to the user that suggested this. Is it common practice to need to tweak longitude every few years or whenever there is a noticeable difference in signal levels, is it something you guys have done before with your motorised setup?

I am a little concerned though that the dish has most likely gone out by 0.4 degrees (especially with the strong winds season approaching!)
 

Lazarus

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Much else.
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The adjustment you've made is pretty much par for the course. Depending upon how exposed the dish is and what direction the wind comes from, adjustments for weaker Satellites can be necessary on a relatively frequent basis, especially with bigger dishes (eg 1.1m as opposed to, say, 80cm) where alignment is more crucial. Matters far less for strong birds.

I don't tend to worry until the error creeps towards a degree or more, then I might go out and tweak the dish and tighten a few clamps etc.

Quite frankly, there is likely to be backlash in the H-H Motor as well, so setting Longitude in USALS to precision of two or three decimal places is a waste of time as it'll hardly ever be accurate.
 

hvdh

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I make longitude tweakings on a regular basis, with my SG-2100A using USALS.
I think because my dish only is moving in the Eastern half, this "runaway" is worse for me than for others, that move the motor to the Western half as well.
The more often the motor has moved, the more correction is needed. There are no loose bolts involved!
After some months entering a longitude several degrees more East than the actual 5.5°E longitude where I am.
This offset does not noticeably make the pointing to sat positions worse.
Nevertheless, I go to the dish every few months to give a reset, via the pin-hole.
 

sonnetpete

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Seperate 80 cm dish on 28E with a Humax Freesat for SWMBO.
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I often have to tweak the USALS settings to compensate for the stronger gales moving the dish and motor. I try not to do up the clamps super tight, as I'd rather the whole lot move rather than put extra strain on the motor and dish. However unlike you, I can get to the dish pretty easily. Lazarus is correct, it's best not to let the error go further than a degree which would lead to problems, especially on larger diameter dishes..
 
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