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. On July 1, 1966, the station's call sign was changed to WMMR. The call sign reflected the name of the station's owner, "Metromedia" (and "Radio"). (From 1948 to 1993, WMMR was used unofficially as a slogan by a local student-run carrier current radio station at the University of Minnesota.) The MOR format was still being used, but with different programming from the AM side, although the AM disc jockeys' announcements were used for both stations. Studios of WIP and WMMR were on 19th Street near Rittenhouse Square. Beginning in 1968, WMMR began adopting a progressive rock format, similar to that of several Metromedia-owned stations including WNEW-FM in New York City. WNEW-FM and WMMR had a close relationship, ran similar promotions, and sometimes featured each other's disc jockeys on the air. WMMS in Cleveland, KMET in Los Angeles and KSAN in San Francisco were also part of the Metromedia chain and also helped pioneer the progressive rock format in the 1960s. Dave Herman was WMMR's first rock DJ. His show, dubbed The Marconi Experiment, debuted on April 29, 1968. Before Herman's arrival, WMMR ran an "MOR" format featuring programs such as "Sinatra and Company." The Marconi Experiment was very much an experiment for the station, with progressive rock still new to the FM band. The first song played on the show was "Flying" by The Beatles. Over the instrumental song, Herman recited these words: "Arise my heart, and fill your voice with music. For he who shares not dawn with his song, is one of the sons of ever darkness." This was known as "The Incantation" and continued as the regular show opening. Several Philadelphia FM stations tried to compete with WMMR in the late 1960s, including WIFI and WDAS-FM. Neither station stayed with the rock format for long. In 1970, WIFI switched to a Top 40 format, while WDAS-FM changed format around 1971 to reflect its AM counterpart