Do you possibly have your longitude and latitude entries reversed in the USALS setup? Something physically stopping the dish from moving? Your longitude? If USALS is driving to 15 you must be on the east coast. I am in Indiana and can get down to 30 but no more. Will it go down past 15? From 15 to 97 is 82 degrees movement.
Sadoun says roughly 50 each way from center which if you can go farther east you most likely have full travel. I am getting 63 degrees travel each way.
You have decent movement.