I know the Merc II quality meter reads a little lower than other boxes. My Pansat by comparison has
University at 99
CBS at 80-83
Aghapy at 75
FSSN last night was between 70-80
This is on a 76cm winegard and a dual LNB so I wonder if maybe the LNB needs to be skewed a little more...you might want to try and lean into the dish (if accessible) and see if the numbers move. If you lean into the dish and the signal jumps up, then the dish is off by a little bit.