How did you connect it right now? FTA on my TV, each channel has varying quality. Maybe you could also tell us what channels you are watching to see if other members can tell you what they see.
BTW, I connect my FTA though the component jacks and the AC-3 audio. Most channels look great. Many of the international channels are not as good for me, but I don't watch them as much and I don't blame their quality on the receiver.