I don't know ,if it makes a difference to get such an awsome quality on
IA5 if you live down south. One of the tps that has a good quality is 11749 (91&up). I also found out that adjusting the height of the dish can improve quality. At first , I thought by setting my dish too high ,I would get the best quality. But , it was the opposite,and I actually lost picture on some tps by raising my dish a little higher. I don't know if you need to adjust elv of dish whenever you change its height ,or maybe if you lower the dish you can get a better quality, of course as long as you have no obstructions.