WRFF (104.5 FM, "Radio 104.5") is an American broadcast radio station located in and licensed to serve Philadelphia, Pennsylvania. The station is owned by iHeartMedia, broadcasts a modern rock music format, and is known on-air as "Radio 104.5." A transmitter tower for the station is located in the Roxborough section of Philadelphia, and its studios are located in Bala Cynwyd.
104.5 FM first signed on in February 1965 as WRCP-FM simulcasting WRCP/1540. Both stations offered MOR formats. The stations were owned by Associated Communications, a subsidiary of Rust Craft Greeting Cards. In 1967, the stations switched to country music formats. Tightened Federal Communications Commission (FCC) restrictions on AM-FM simulcasting led to a new format for the FM in 1977.
104.5 FM broke away from WRCP in 1977 and became WSNI. WSNI initially had a soft country/easy listening hybrid format before evolving to instrumental-based easy listening.
On January 1, 1980, WSNI became known as "Sunny 104" at first, then later "Sunny 104 1/2," and eventually "Sunny 104.5," a name which was reused later on in the station's history. "Sunny" dumped easy listening in favor of an Adult Contemporary format playing the Top 40 hits of the 1960s, Top 40/Adult contemporary crossovers of the 1970s, and the Adult Contemporary hits of the 1980s up to and including then-current product.