The 940 frequency in Tucson first went on the air on August 10, 1963 as KHOS. From its sign on until the late 1970s, it was a country music station. From 1978 to 1981, it was soft rock KMGX "Magic 94." But with music listening moving to FM radio, the station's owner, Grabet Radio Enterprises, wanted to make a change. In July 1981, AM 940 switched to a news/talk format, taking the KNST call letters. A few years later, 940 AM was sold to Nationwide Communications, a subsidiary of Nationwide Insurance. KNST carried talk shows from the ABC Talk Radio Network, broadcasting on 940 AM until it was moved to 790 AM on April 4, 1993. The 790 frequency has more power and a larger coverage area. Today, 940 AM is the home of KGMS, a Christian radio station.