[Closed] TV Ariel experts help please.

Ive got an issue with my tv reception. Basically its dreadful. The ariel is a year old and all looks ok. It was fine but just before christmas but it deteriorated to the point where its unwatchable. we have a BT vision box which also uses the ariel but that is absolutely fine. Any ideas? Tried retuning it and all that did was lose a load of channels. The ones that remained are still really bad. The bt vision box drives me nuts though because the user interface is crap. And before you say it, i don't want sky/virgin. Couldn't afford it even if i did want it but its about 500 channels of rubbish.