The calls, KNUS FM 99, in Dallas first appeared in the summer 0f 1966, as a Progressive Rock station. It was part of the legendary McLendon group of station. Gordon McLendon is widely credited for perfecting the commercially successful Top 40 radio format, during the 1950s and 1960s. By 1971, the station had morphed into a rock-based Top 40 station. KNUS eventually transitioned into a more mainstream Top 40, and it actually passed KLIF in the ratings by fall 1975, becoming one of the first FM Top 40 stations to defeat its AM competitor. By the end of the 1970s, however, KNUS had fallen out of the top ten. Gordon McLendon sold KNUS to the San Juan Racing Corporation in May 1979. San Juan Racing also owned WKTU New York, WYSP in Philly, and other stations in Washington, Cleveland, & Houston. This aircheck is from the Top 40 era of the late 1970s, with Dave Collins on air.