IME (CS24C, Krakatoa and Shockwave) that's all your going to get if it's not in their terms "line of sight" take that very literal, make certain there is not even light grass or anything obstructing your view of the call. Elevating it will help but I wouldn't ever expect much more than 50 yards or you might find yourself doing the walk of shame back out to bring the call closer. Been there done that! Good luck