Motor Reset?

[sonnetpete]

Recently I decided to re align my set up as although my position is 0.5°W, I could only get a good arc with the longtitude coordinates set on the receiver of 3°W. I put this down to weather conditions blowing the set up around the pole slightly. However, having realigned the whole thing, it isn't as good as before (yes I know, should have left it alone!).

I've noticed a couple of things, my latitude on the motor is out by about a degree too high and when pointing at my due south sat, Thor at 0.8°W, the scale above the motor stub shows about 5°W. Would it help if I did a motor reset? Do I do this with receiver on standby or powered up? There is very slight play in the motor but not to the extent of 5°.

 

[satelliteman]

Doesn't sound set up correctly. Calibrate the motor, enter coordinates and drive to reference satellite; align there.

Double check motor inclination / latitude markings and level mast.

 

[sonnetpete]

Phew, panic over!! Thanks Satman. did as you suggested, with much better results. Even pulling in Nilesat verticals! Have a little elevation adjustment to do and will probably drop the latitude down a degree on the motor and re adjust. Nice to have a relatively instant answer!

Incidentally, from Google Earth my longtitude is 0.9°W, checking with my satnav, standing under the dish, it's 0.5°W. I've used the satnav coordinates to set up. Thanks again.

 

[satelliteman]

Result

Dishpointer quotes -0.5157° and powered by google I believe.

 

[sonnetpete]

Result

Dishpointer quotes -0.5157° and powered by google I believe.

Strange, as I just checked both Google Earth and Dishpointer, which both returned Lat : 48.4993 Long : -0.8912 for my location. Obviously I have the advantage of knowing where I live!! I can zoom in as far as recognizing my car (red Nissan) and in Dishpointer can drop the 'green lollipop' right on where the dish is sighted. But I think that the Satnav might be a tad more accurate (though I wonder how many metres difference 0.4 of a degree equates to)

 

[Lazarus]

Obviously I have the advantage of knowing where I live!!

Hmm. Long may that continue.

 

[hexah]

It may be worth checking that the pole is truly vertical by using a plumb line. That can give an accuracy of around 0.1 degree, much better than a spirit level. And much cheaper than a digital inclinometer. This will help at the sides of the arc and give more rain fade margin on the weakest satellites like Nilesat.

 

[satelliteman]

Satnav might be a tad more accurate

Yes I've used this on site before now for accuracy.

 

[sonnetpete]

It may be worth checking that the pole is truly vertical by using a plumb line. That can give an accuracy of around 0.1 degree, much better than a spirit level. And much cheaper than a digital inclinometer. This will help at the sides of the arc and give more rain fade margin on the weakest satellites like Nilesat.

Yep, checked that yesterday with a digital inclinometer (purchased for £26 online). Was actually 0.1° out laterally, cured with Bob the Builders largeish hammer!!

 

[sonnetpete]

Hmm. Long may that continue.

Always ensure that I have a map with me and my address about my person when I go out. Short term memory loss is a terrible affliction!!

 

[sonnetpete]

Just to tie this thread up, I dropped the latitude on the motor to what it should be and peaked the dish elevation up on my due south sat. It's a little off on the extreme ends of the arc, which I can tinker with next week. I have Nilesat verticals and a couple of the stronger horizontals, so I'm pleased with my days work.....oh and thanks for your collective assistance too!

 

[satelliteman]

A small amount of inaccuracy, say 2° on the motor scale shouldn't cause too many problems with a DiSEqC motor on a 1Mtr. Might also be worth checking the dish is mounted centre of motor shaft Pete.

 

[sonnetpete]

A small amount of inaccuracy, say 2° on the motor scale shouldn't cause too many problems with a DiSEqC motor on a 1Mtr. Might also be worth checking the dish is mounted centre of motor shaft Pete.

I have checked as best I can for the dish/shaft centre but it's not easy to do without taking the dish face off. I was fairly sure it was centered when I installed it. I might try to check next week as it's just about the only variable left to verify. As you can tell I'm trying to screw every last ounce of performance out of the set up!!

 

[Lazarus]

The other thing that can happen is that it cants a bit when tightening the clamps holding the dish bracket to the stub - particularly if the clamps have got square notched "claws" ........... but I don't think that is your problem as the arc tracking would be assymetrical whereas it's just your ends that are an issue. So to speak.

 

[hexah]

Yep, checked that yesterday with a digital inclinometer (purchased for £26 online). Was actually 0.1° out laterally, cured with Bob the Builders largeish hammer!!

Not a bad price.

I have made a search online as they seem to have fallen in price recently.

It seems they are being called "angle finder", "digital angle finder", "digital spirit level", "digital protractor" because 'inclinometer' is too big a word. That explains why I had few rather expensive results looking for a "digital inclinometer".

The cheap ones are decent though, being accurate to 0.1°. They cost at least twice as much a few years ago.

As you can tell I'm trying to screw every last ounce of performance out of the set up!!

It is certainly working!

 

[sonnetpete]

The other thing that can happen is that it cants a bit when tightening the clamps holding the dish bracket to the stub - particularly if the clamps have got square notched "claws" ........... but I don't think that is your problem as the arc tracking would be assymetrical whereas it's just your ends that are an issue. So to speak.

Yes, they have got square notched claws and I must check this if the weather remains fine next week......my 'ends' are an issue it's true, I put it down to my age.

 

[sonnetpete]

Not a bad price.

I have made a search online as they seem to have fallen in price recently.

It seems they are being called "angle finder", "digital angle finder", "digital spirit level", "digital protractor" because 'inclinometer' is too big a word. That explains why I had few rather expensive results looking for a "digital inclinometer"

Got mine from that online store named after a fabled female warrior race. There are some items (mainly electronics) that they won't ship to France, though I usually look at the French store before the UK one as shipping costs are generally lower.

 

[Huevos]

I wonder how many metres difference 0.4 of a degree equates to

1 degree going in a north/south direction equates to 60 nautical miles (111.12km). 1 degree east/west at the equator is the same but at your latitude would be about 39.9 nautical miles or 73.9km. So 0.4º would be around 29.5km

 

[sonnetpete]

1 degree going in a north/south direction equates to 60 nautical miles (111.12km). 1 degree east/west at the equator is the same but at your latitude would be about 39.9 nautical miles or 73.9km. So 0.4º would be around 29.5km

Yes, I went on Google Earth and found the spot which related to the satnav position but using their map coordinates. It's a place called Lassay Les Chateaux, about an hours drive East of here.

It has crossed my mind that if someone got your lat and long from Google Earth and then entered them in their satnav as a destination, would they end up in the wrong place? Or is there something wrong with my Garmin? LOL

 

[Huevos]

if someone got your lat and long from Google Earth and then entered them in their satnav as a destination, would they end up in the wrong place? Or is there something wrong with my Garmin? LOL

Google Earth has a resolution of 4 decimal places (0.0001º) which equates to 11.112 metres (measured north/south along the local meridian). My GPS receiver reads down to 6 decimal places and always shows the exact same first 4 decimal places as Google Earth.