I can certainly endorse the above comment about dish size. A standard (zone 1) Sky mini-dish is about 45cm. Mine is 65cm, and even in the heaviest of rain or snow storms, signal quality and reception remain excellent.
LNBs for Sky mini-dishes have a number of different collar fittings where they attach to the arm, so check compatibility before buying a replacement. Quads available from about £10, so worth a try.
If you are going to check your dish alignment, I suggest you mark the fixings before making any adjustments, so that you have reference points to return to, using the "trial and error" technique!
Very small movement can make a big difference. Even a cheap signal meter (mine was under £10) makes this job much easier. LNB skew (rotational position in the collar) and focus (fore and aft movement) also need adjusting for best performance, and again a meter helps to get these spot on.
Last edited by spekesoftly; 28th October 2011 at 10:36.