I have a PSR 300. I would like to be able to scan the Marine Band if I "To start a Marine(SR0), CB(SR1), or FRS(SR2) search, press search until SR0 (for Marine) or SR1 (for CB) or SR2 (for FRS) appears in the top left of the display. Press FUNC then SRCH to start searching. The channel numbers and search band name will appear in the display. Pressing FUNC and SRCH again will stop the search." al I get is a beep and it will not scan (maybe it is but nothing on the display changes) If I follow the same steps for Railroad it works. What i'm I doing wrong.