One possible explanation for Jonny 290's high-elevation reception difficulty might be the polarization of the eggbeater antenna. The eggbeater is linear polarization near the horizon, and right hand circular polarization at high elevation. It could be that SO-50's signal is more left hand circular polarization.

Unfortunately this theory doesn't correlate with my own experience receiving SO-50 with a RHCP yagi (and a mast-mounted preamp!). I get very strong signals at high elevation, but I also get "random" deep fades that can last several seconds at any elevation. The "random" deep fades can be caused by polarization mismatch, or by the body of the spinning satellite temporarily obstructing a portion of the antenna.

Wayne Estes W9AE Oakland, Oregon, USA