BTW, based on a suggestion someone posted to another newbie like me in another thread:
Using Google Earth I drew a line from approximately where I'd place an antenna, out from there at 42-43 degrees and it "appears" to not be obstructed by any trees. I'm not sure exactly how accurate this is (the Google image is 6 months old and even my half dead tree might have grown) but at worst case there MIGHT be a few leaves in the LOS. Also, I'm not opposed to taking a chainsaw to my tree (or a neighbors tree if there's plausible deniablity!)
