W8EH observes: Part of the trouble that I observed with AO-51 is some stronger stations (without PL) or illegal cordless phones, are blanking out the uplink. I had trouble after the switch to V/U. I usually run 2 watts to a CP KLM beam. Even with the rig boosted up to 45 watts, I couldn't overcome whatever/whoever was blanking out the sat most of the time. Out of two passes this morning, I made only one contact. Lots of stations on, but only the strongest seemed to make it over whatever was blocking us. Strange that I didn't have that trouble at all when it was in V/S mode earlier.
=========================================================== I noticed the same thing - it was like AO51 had the squelch set too high. I would hear stations call me and when I keyed the mic to answer I couldn't hear myself in the downlink. It seems to happen more when AO51 is at a high elevation, maybe because the offending non-pl tone station is in my part of the country or maybe it is just that my transmit antenna (KB6KQ loop) works best at lower angles. Don't notice it on SO50.
-- Dave W8IJ