- My Satellite Setup
- Thomson HD
- My Location
It is indeed a PF dish ... strings...tight beam torch
It looks like you may have a prime focus dish. This is the case where all three arms are the same length and spaced equally and the lnb is held dead in line with the centre of the dish - also the dish will be totally circular rather than a slightly elongated shape. If this is so can you also confirm it is a one piece dish - i.e. it is made of a single piece of metal rather than made up of 6 segments or petals - some poorer PF dishes are contracted like that and present a whole new problem. If indeed a PF dish then checking for warp is much easier - just fasten a piece of fine string right across the dish going from the edge and across the centre and to the far edge - then fasten a similar string at 90 deg from the first again going across the centre. If the dish is OK the strings will meet at the exactly the same point without any difference in height from the dish centre. You can add further strings at say 30 deg and 60 deg to check the entire dish is OK - if nice and tight all strings must meet in the centre at the same height. If they don't you dish is warped. Now assuming the dish is not warped the next thing to check is if the lnb is actually pointing at the centre of the dish - sometimes the arms or even the bracket can get distorted and this results in the lnb pointing a bit off centre - a simple way is to replace the lnb with a tight beam torch and check that it illuminates the dish evenly and is not pointing off centre - but for this to work you need a torch wichi is round and fits snugly into the lnb holder and these are not always easy to find. Also the torch beam may not be true so try turning it around to check the illuminated part of the dish stays the same - if the beam wobbles then its not going to work.