Realigning motorised dish

[cric2k]

Hi,

Last year I got my 85cm Penta motorised installed by a professional and at the time I was getting about 85% SNR on 28.2e, similar on 19e and about 65% on 13e.

Now after a few storms my signal levels have dropped right off to about 30% on 13e and 50% on 28 and 19.

I've got round this in the past my slightly changing longitude and latitude in the USAL settings which has brought the signal levels back up, now thought I can't seem to manage it through the positioner.

So I installed my first static dish a few weeks back and have it pointed at 28.2e fiine - I was wondering what's the best way to go about realigning the motorised - any why simply changing configuration settings in USALs isn't now helping the situation?

Cheers

 

[Lazarus]

First of all, you should only change the Longitude, not the Latitude.

Secondly, this only works for small displacements from correct physical alignment (say half a degree or so) so, if the motor has slipped around the pole by more than a small amount, the only solution to maintain correct tracking right across the arc is to shift it back to the correct alignment.

And if the dish, the mount or the entire assembly is tilting forward or back then you won't track anyway.

Therefore, send the dish to 5W, go and check your mount is still plumb, then correct the alignment by shifting the motor/dish as one around the mount and by tweaking (if necessary) the dish bracket). Hopefully it's just azimuth that is too far out.

 

[rolfw]

The dish and motor have more than likely moved around the mast. It's easy to check this, simply send the motor to a satellite, then whilst someone is watching the strength and quality measurements on the receiver, gently tip the dish to the left and right, if it improves in one or other direction, loosen the motor clamp on the mast and move it around the mast in that direction, a couple millimetres at a time.

When you have the best possible signal, tighten the clamps.

If moving side to side produces no improvement, try up and down, but it sounds to me like the whole assembly has moved, or possibly even the dish clamp on the motor stub.

 

[cric2k]

thanks I'm going to give it a go now. I've been 'Step East' and 'Step West' ever so slightly to try improve signal on the receiver but it hasn't been helping so I'm not sure moving left to the right on the physical dish should show an improvement?

 

[satelliteman]

Whilst your there, as mentioned above, check the dish hasn't moved on the stub.

 

[Robbo]

thanks I'm going to give it a go now. I've been 'Step East' and 'Step West' ever so slightly to try improve signal on the receiver but it hasn't been helping so I'm not sure moving left to the right on the physical dish should show an improvement?

It should.

When you step east or west using the motor, the elevation of the dish changes at the same time, i.e it points lower and lower as you move away from centre, following an arc. Wheras shifting the motor around the pole moves your whole arc left or right

 

[cric2k]

ok got it sorted.

Turns out the elevation of the satellite had dipped, when pushing the thing up slightly my little satellite finder went nuts and with a little bit of a twist I've now got even better signal levels than I had before. I was wondering why my motorised dish seemed to pointing in a different direction the static I fixed last month when pointing at 28.2e, turns out my static was pointing in the right direction.

Thanks for the help lads. Taking the plunge to learn how to do these things myself is already paying dividends. :-)

 

[Lazarus]

Excellent result - well done!

 

[satelliteman]

Result.

Why not mark up the brackets with a permanent marker?

 

[cric2k]

Will mark it with a permanent marker thanks, it's already apparent with the scrapes on the metal where things used to be which helped a bit when moving it back.

My USALS longitude is still quite a bit off what it officially should be (I should be like 005.900 and I've set 003.500) but I'm not going to fiddle any more while it continues to work well!