I think that the most likely thing now, as aerial is out is the actual radio itself.
They can be repaired however, I know someone who does these as well as pretty much any make, he's the main uk repair centre for Kenwood as well as a few others, also sells B graded stuff with new gaurantee.
I bought a as new b graded warranty return CD multi changer, with 12 months warranty, as it had 1 tray missing from the boxed changer, he gave me a spare tray which simply pushes in, was well under half the price of everyone else.
tabetha