Are you talking about 4dtv digital or DVB?
If you are talking about a 4dtv, you must get the unit authorized before digital will be active, and then any digitals on Galaxy-10 or Galaxy-12 are very strong so you can peek the quality on those with bumping and skew till its at its max, and then do it for all the other birds.
If you are talking about DVB, then you can do a scan on most any bird and should find something, and then tune the quality to the highest with bumping and skew.