Bad radio reception Clarion 2010 Tahoe

[JOAMON]

I bought my Tahoe in Jacksonville Fl which has radio stations. Even while test driving I noticed the local stations fading in and out. I didn't think much about it at the time, I just thought it might be on the local selection instead of DX. When I got home 30 miles away from Jax it would only pick up one station even on DX. My 2001 tahoe I traded in got excellent reception. I'm not familiar with this radio, but while messing with it I ran across a screen saying locked and asking for a PIN to unlock to change settings. I'm thinking that even though I'm putting it on DX that it"s not changing to it because it's locked. Can anybody tell me away to unlock it. Or tell me what check to get better reception. I did the auto search and like I said earlier it only picks up one local station here and it's elevator music.