It's that time of year again - check your dish position

Latest News and Discussion about the use of the DATV transponder on Es'hail-2
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g8gtz
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Joined: Wed Apr 07, 2010 6:26 pm

It's that time of year again - check your dish position

Post by g8gtz » Sat Feb 27, 2021 10:30 am

Near every equinox the sun passes through the same position in the sky as a given satellite.

Using this website https://www.satellite-calculations.com/ ... erence.php you can calculate when the sun will be behind Eshail 2 at your QTH – and it's happening right now.

This happens for a few days every October and February/March for the UK and as long as it is sunny, you will be able to see where to place your dish by seeing where there is direct sunlight and you can check that the neighbour's pesky trees have not grown up and blocked your path!

You will also find the signals on the satellite will drop significantly for a few minutes whilst your LNB is blinded by sun noise.

73

Noel - G8GTZ

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PA3CRX
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Joined: Fri May 24, 2013 8:38 am

Re: It's that time of year again - check your dish position

Post by PA3CRX » Mon Jul 26, 2021 12:55 pm

And also be aware in case the sun shines and you have a (plastic) LNB!
I did the experiment with a small reflecting dish (my portable 6 cm station), watch the result in the video: https://www.youtube.com/watch?v=y7OEYgJ5DH8

Experience with large white dishes?

Chris PA3CRX

G4WIM
Posts: 347
Joined: Thu Jan 29, 2015 8:36 pm

Re: It's that time of year again - check your dish position

Post by G4WIM » Wed Oct 06, 2021 2:20 pm

Interestingly I've just had to relocated my CM 1.2 M dish to the other side of the garden, xyl wanted a garden room and my dish would have been directly in front of it !
So I planted the dish such that it had a clear view of the satellite - or so I thought, but the beacon signal was only 6dB MER not 9.5dB as before.

This was despite there being a clear view of the satellite albeit between two trees with a gap of about 20 feet between the foliage so providing line of sight.

No matter what I did I couldn't find the missing 3.5dB until I trimmed the branches back by about another 3 feet then bingo - all is good again.

So the moral is even if you can see the satellite, trees etc close to the bore sight could be a problem.

Regards Tim

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