Howard Armstrong. When Armstrong put his experimental FM station, W2XMN, on the air, he arranged to rebroadcast some of WQXR's programming. This ended in 1939, when Hogan and Sanger put their own experimental FM station on the air, W2XQR, just down the dial from Armstrong at 42.3 MHz. In 1941, the station began transmitting from the top of the Chanin Building, where it remained until 1965 when it moved to the top of the Empire State Building. Remnants of the original tower remain on the Chanin Building. The Federal Communications Commission (FCC) began licensing commercial FM stations in 1941, and W2XQR moved to 45.9 MHz, becoming W59NY. Effective November 1, 1943, the FCC modified its policy for FM call letters, and the station became WQXQ. "The radio station of the New York Times" (1944–2009) In 1944, Hogan and Sanger sold their holding company, Interstate Broadcasting Company, to the New York Times Company. When the FM broadcast band was moved from 42–50 MHz to its present frequency range of 88–108 MHz in 1945, WQXQ moved to 97.7 MHz. In early 1948 the call letters were changed to WQXR-FM, and its frequency, home of WQXR-FM for the next 64 years, to 96.3 MHz. WQXR was the first AM station in New York to experiment with broadcasting in stereo, beginning in 1952. During some of its live concerts, it used two microphones positioned six feet apart. The microphone on the right led to its AM feed, and the one on the left to its FM feed, so a listener could position two radios six feet apart, one tuned to 1560 and the other to 96.3, and listen in stereo. During the 1950s, WQXR-FM's programming was also heard on the Rural Radio Network on several stations in Upstate New York, including ones targeting Buffalo, Rochester, Syracuse and Albany. This ended when the RRN stations were sold to Pat Robertson's Christian Broadcasting Network. Both the AM and FM sides continued to simulcast each other until 1965, when the FCC began requiring commonly owned AM and FM stations in large markets to broadcast separate programming for at least part of the day. WQXR-FM concentrated on longer classical works, while WQXR (AM) aired lighter classical music and talk programs produced in conjunction with The New York Times. While this plan gave classical music fans two options, it also increased expenses for the stations. In 1962, the QXR