You can look at LyngSat - Lyngemark Satellite for what they think is on what satellite. Basically 99(a) and 103(a) are only local into local channels while 103(b) is where all the new MPEG4 HD national channels are coming from, along with some local into local channels.
Are you looking at the 103 (a) or (b) ?
(b) should have signals on it, the (a) may or may not depending on where your at and if your locals are there or not.