an FM station 7 assigned to both an AM and a TV station 8 assigned to an AM, FM, and TV station Assignments Listed below are all the assignments : AM radio (54 stations) FM radio (29 stations) In cases where an AM station exists with the same "base" call letters as an FM station, the FM station is required to include an "-FM" suffix as part of its call sign. If no AM station is currently using the same base call sign, then the "-FM" suffix is optional. Television (21 stations) As with FM stations, if an AM station currently exists with the same "base" call, a TV station must include a suffix to differentiate itself, but this suffix is optional if no AM station currently exists. TV stations may select either "-TV" or "-DT" as their suffix. Other stations of note WWV - Fort Collins, Colorado — shortwave time signal data radio clock service operated by the National Institute of Standards and Technology KPH - Bolinas, California — shortwave morse code data service operated by radiomarine.org under the auspices of the National Park Service References External links Media Bureau Call Sign Actions (Monthly U.S. Federal Communications Commission Public Notices) Call Sign Search (FCC Licensing and Management System) See also List of local television stations in North and Central America Lists of radio stations in North and Central America Call signs American television-related lists Lists of mass media in the United States