radio
Networks and call letters of stations are full caps, no periods or spaces:
CBS
radio station WGMS
VOA (Voice of America)
Without call letters:
American Broadcasting Company
Public Broadcasting Service
The names of radio programs appear in italic without quotation marks:
listening to A Prairie Home Companion
Capitalize radio when part of a formal name:
Radio Free Europe/Radio Liberty
Lowercase when used descriptively after a name:
Havana radio