Post by Eric Johnston on Sep 15th, 2011 at 7:28pm
Just one thought. Can your dish see low down in the sky towards the south west or is there an obstruction ?
It is likely that your dish is misaligned slightly.
This diagram shows a view of the sky, facing south. The red line and red dots represent satellites. The vertical red line is exactly due south of your longitude and this should be the directlion your dish is pointing when the motor is centralised.
The green line shows the probable path of your dish. Two things are wrong. Your centre position is slightly to the right (west), maybe 1 or 2 deg off. The overall width of your curve is also too wide, this means the polar axis is slightly wrong.
Before contemplating and making any adjustments note that setting up a polar mount is highly skilled job. You only need to make a small random change and you may find yourself spending several days getting back to the starting position, if at all. Be warned !!.
Your dish pointing angles are here: https://www.satsig.net/maps/satellite-tv-dish-pointing-uk-ireland.htm
Ideally you need to align your dish, initially using accurate scale measurements, and then by pointing to the satellite nearest to your own longitude to peak up your pointing with the motor almost centralised. Getting the whole mechanism accurately aligned to due south is difficult.
The nearest satellite you mention is Hotbird at 13 east (which is rather far away for this purpose). Line up on 13E exactly using the motor. Can you now read or measure the sideways angle movement of the motor ? It should read 14.5 deg. If it does not read 14.5 deg you need to drive the motor until it does read 14.5 deg exactly. You will no longer be pointed at Hotbird 13 east. Now loosen the mount on the pole (or otherwise rotate the pole) and turn the entire mount and antenna manually till Hotbird at 13 east is again pointed accurately. This procedure should set your antenna pointed exactly south when the motor is driven back to the central position.
The above is only one step in the alignment process. If you have any doubts about making adjustments do call a local satellite TV installer with polar mount expertise, to help you. It is remarkably easy to mess it up and never get it right.
There are two further settings, the main motor axis angle (53.6) and the small downwards tilt (-6.9) of the dish. These two angles combined make up the beam elevation angle for an imaginary satellite which due south of you.
wxw
Best regards, Eric.
It is likely that your dish is misaligned slightly.
This diagram shows a view of the sky, facing south. The red line and red dots represent satellites. The vertical red line is exactly due south of your longitude and this should be the directlion your dish is pointing when the motor is centralised.
The green line shows the probable path of your dish. Two things are wrong. Your centre position is slightly to the right (west), maybe 1 or 2 deg off. The overall width of your curve is also too wide, this means the polar axis is slightly wrong.
Before contemplating and making any adjustments note that setting up a polar mount is highly skilled job. You only need to make a small random change and you may find yourself spending several days getting back to the starting position, if at all. Be warned !!.
Your dish pointing angles are here: https://www.satsig.net/maps/satellite-tv-dish-pointing-uk-ireland.htm
Ideally you need to align your dish, initially using accurate scale measurements, and then by pointing to the satellite nearest to your own longitude to peak up your pointing with the motor almost centralised. Getting the whole mechanism accurately aligned to due south is difficult.
The nearest satellite you mention is Hotbird at 13 east (which is rather far away for this purpose). Line up on 13E exactly using the motor. Can you now read or measure the sideways angle movement of the motor ? It should read 14.5 deg. If it does not read 14.5 deg you need to drive the motor until it does read 14.5 deg exactly. You will no longer be pointed at Hotbird 13 east. Now loosen the mount on the pole (or otherwise rotate the pole) and turn the entire mount and antenna manually till Hotbird at 13 east is again pointed accurately. This procedure should set your antenna pointed exactly south when the motor is driven back to the central position.
The above is only one step in the alignment process. If you have any doubts about making adjustments do call a local satellite TV installer with polar mount expertise, to help you. It is remarkably easy to mess it up and never get it right.
There are two further settings, the main motor axis angle (53.6) and the small downwards tilt (-6.9) of the dish. These two angles combined make up the beam elevation angle for an imaginary satellite which due south of you.
wxw
Best regards, Eric.
