It totally depends on the diameter of the polar mount. My 10' Unimesh with a 24" would just barely do 37.5 - 139W with a couple of clicks left over on each side. I tried to do the same thing you are wanting to do, first I got a 36" Thomson-Saginaw.These suck, as they are really large so it wouldn't shorten up as much, giving me even less range to the East, plus they don't have limit switches, so it is easy to bend things. Finally I got a 36" Venture, and this does what I need it to do, it will go over past 148 and I think down to about 30 although I can't seem to get anything E of 37.5, possibly due to trees, or maybe I need to align the dish a bit better. I'm probably using around 30" of the travel, so I've had thoughts about extending the attachment point to the dish outward a bit to slow it down and gain counts.