The first thought that comes to mind, is the pole 100% plumb? With a 12' dish, heavy wind and rain, perhaps the dish settled in the ground slightly.
Secondly, is there any lost motion in the dish moving hardware? Any free play in the mechanism will cause the pulse count to change. Binding can cause similar problems.
Thanks for the comments, Corrado, Lak7, Sergi, and Gabshere. Corrado the pulse count changed only after the severe windstorm, which unbelievably also knocked out the Declination from 6.6 up to 7.2 degrees, but I got the reception quality back on 97.0W after resetting Declination again back to 6.6 degrees yesterday, ...hope I don't have to do that again since it lasted 3 months previously. Also nothing is evident re loose hardware I'll check again. Corrado the Dish is on a Tripod and I can adjust it - it reads 99.8 on the Digital Level on the
Pole and 99.9 in 4 directions on the
Pole Cap of the Dish, and I can easily adjust it up to 99.0. But with only 1 welded Nut & bolt, and 1 screw without a welded Nut on the other side (instead of the required 2 Screws on each side on the Pole Cap) I wonder if this could this cause a Clark Belt tracking problem?
Gabshere, I have tried that procedure of Raising and Lowering the dish at various points, which worked well on my 1 meter Dish, - but it just doesn't seem to do anything on the 12 Footer, maybe the Dish is just too big?? Sergei, I definately agree that small adjustments are the way to go, but I'm just not sure what to try next!!