i just got mine 8500 x50 yesterday, it is a 2 and a half years unit. I just tried it this morning, 2 different cops are in front of me but my RD still did not pick up any signal. What is the problem with that? I did not even pick up a lot of X or K or KA band, only like in a weak signal. What should i do? another question is how do i set up to expert mode? and should i use C or H instead of A? i am using Auto all the time right now. My friend told me is not working because the cops did not turn on the radar. But can anyone else help me? sorry for being a newbie but i did tried to search but seems cannot find an answer for me. thanks for helping.