I think you guys are correct. I am in Granby, which is about 55 miles or so from Garfield, where POSY is located. But I can still hear the traffic at work in Carthage, which is roughly 75 miles away from POSY. I'm surprised I can still receive the signal that far away, but like you say, it all depends on the antenna. My only other repeater experience is with the Joplin, MO repeater, and I can only receive and transmit on that repeater within a few miles of it; the Joplin repeater is on a 30' pole in the middle of town, though.