 With the enactment of the North American Regional Broadcasting Agreement (NARBA), KYUM moved to 1240 AM on March 29, 1941.In 1948, the Yuma Broadcasting Company received approval from the Federal Communications Commission to move KYUM to 560 AM with 1,000 watts full-time; the move became effective on April 1, 1951.In 1961, KTAR bought out the remaining shareholders in Yuma Broadcasting Company, owning KYUM outright.