I have had the same experience as Perry with AO-73 with regards to signal problems. I have an IC-910 transceiver and a M2 2mcp14 (2 meters) and M2 436CP30 antenna with a Yaesu G-5500. I have the IC-910 set to about 25 watts on UHF. I have made one contact on AO-73. It has taken me forever to get the doppler correct as I usually cannot hear my signal. Last night my returning signal was extremely strong for about 1 minute. In comparison, the received signal from FO-29 is extremely strong so I am assuming that my UHF antenna is working fine. Like Perry, I have never experienced this before. At times AO-73 takes some very deep fades (telemetry). With such a small little cube, I would not think the satellite is blocking the antenna (although 4 inches is starting to get close to 435 wavelength. The frequency offset confused me at first. I just kept cranking up the frequency and there I was but very, very weak. I'm not gripping as I am having a blast. Those of you with experience are probably getting a laugh at what I report. I am a newbie to this satellite stuff and learning as I go and extremely excited to make even one contact. Maybe the geese overhead are causing me some problems. :-)
73, -james W5AOO ...a ham for 50+ years and enjoying every minute of it!