In the 1950s and 1960s, WIP-FM carried a full service format of middle of the road (MOR) music, news, sports and talk. The station's license was voluntarily reassigned by the FCC to WIP Broadcasting, Inc. on September 17, 1958, followed by another voluntary reassignment to Metropolitan Broadcasting Corporation on December 29, 1959. The FCC granted a licensee name change from Metropolitan Broadcasting Corporation to Metromedia, Inc. on May 11, 1961. On August 6, 1962, Metromedia applied for a construction permit to relocate the station's transmitter and antenna from 35 South 9th Street, Philadelphia to 12 South 12th Street, Philadelphia (the address of the PSFS Building). This resulted in raising the station's height above average terrain (HAAT) from 430 feet to 668 feet, while decreasing the station's effective radiated power (ERP) from 20,000 watts to 7,500 watts. The FCC granted Metromedia a new license for the station with the new facilities on September 30, 1963.