How about Pirate Radio, The Boat That Rocked, drama about British off shore radio.
Play Misty For Me, about night time FM personality radio and a potential murder.
FM, about a local FM station that's going to be taken over by corporate radio, and the staff wants to keep it for ' the people'.
Pump Up The Volume, Christian Slater's movie on his basement pirate radio station, unbeknownst to his parents and school.
There are various movies from the 1930s-40s era featuring radio in the plot, part of a romance, helping to solve a crime, Carl Blare used to talk about watching them on Y'utube.
There are many movies with radio out there, including CB radio movies, and shortwave espionage stations and such.