According to the radio affiliate listings on their respective web
sites, the Rays radio network only extends as far north as Gainesville.
The Marlins radio network goes as far north as Orlando. The Braves
have radio affiliates in several north Florida cities including
Jacksonville, Panama City and Crestview. I don't know why there is no
Rays or Marlins radio coverage in the northern part of the state.
Maybe it's just long-time loyalty to the Braves. I recall listening to
Braves radio when I lived in Tallahassee, but that was long ago, before
either the Marlins or Rays existed.