You picture quality is going to be effected by the kind of tv you have, the connection method you use to connect it (DVI, HDMI,DVI, A/V) , and if using an Off-Air ANT for HD locals , your distance and signal strength from the tower.
The signal meter strength will not give you a better/worse picture. Like "Tate" says its either there or not, specially with HD.
But if you still want to know what transponders are going to which channels, when you are watching a channel if you go to your signal meter test on the menues whichever channel you are on should have the transponders that corrispond accordingly automatically on the menue.