In your first post you say you have an 18" Dish with a DPP Quad LNBF. The 18" Dish was only made for single Sat reception, so if it is indeed an 18" Dish, you will struggle to get good signals. The correct Dish for 2 Sat reception is the 20" (51cm) one, which is the same as the Dish 500.
Try covering the 82 side of the LNBF with Tin Foil. Then peak the signals using 91. If the skew is correct and the mast is vertical, you should have 82 when you remove the foil and run a Check Switch.