Thanks Pete for your quick response.
I have another small problem (or not that small) which I can not figure out how to solve.
My whole system (SG2100, Lifetime Ultra, Winegard 2076) works OK now. All the channels are using USALS.
Yesterday, I found one soccer channel's quality is pretty low, about 49%, as the picture moved very fast, the pictures are very bad. I switch it to use 1.2, I found out if I Nudge it just one press west (I don't know how much is "one press"), the quality will increase about 7-10%. So I tried several satellites, for some of them, the quality increased, others no change.
Appreciately my reference position is "one Nudge press" east offset. I tried to correct it, but it is not as easy as I thought. I can only set reference using USALS, but if I move from 1.2 to USALS, the USALS automaticly go to original reference and it doesn't have Nudge either.
Anyone have good ideas to do this without climbing up to my roof to set there?
Thanks.