The station began as WRHM (for "Rosedale Hospital" at 4429 Nicollet Avenue, Minneapolis) on August 10, 1925. In 1927, it shared time for a few months with WDGY at both 1140 AM and 1150 AM; also that year, the transmitter was moved from the hospital to Fridley and in 1929 WRHM became an affiliate of the CBS network. It switched to NBC's Blue Network on January 1, 1937. The Rosedale Hospital Company sold the station to the Minnesota Broadcasting Company in 1930 and the studio relocated from the hospital to the new Wesley Temple Building at 115 East Grant Street in Minneapolis. By this time it had operated on at least three frequencies, 1140 AM, 1150 AM and 1250 AM, which it stayed on until 1941. WRHM was purchased in September 1934 by Twin Cities Newspapers, a partnership between the St. Paul Pioneer Press and the Minneapolis Tribune, and the call letters were changed to WTCN at that time. The station remained an NBC Blue station through the network's selloff, becoming an ABC affiliate in 1945 when NBC Blue formally became ABC. The station kept the ABC affiliation until December 31, 1962. WTCN began broadcasting from a new transmitter and tower in Roseville at the intersection of North Snelling Avenue and Minnesota Highway 36 during 1935, a site that was used until 1962 when the station's transmission facilities were moved to the other side of the expanding Twin Cities metro in St. Louis Park, at a point south of what is now Interstate 394 and west of Minnesota Highway 100, using four towers. This site is the station's current transmitter site. WTCN moved from 1250 AM to 1280 AM in March 1941 as required by the North American Regional Broadcasting Agreement (NARBA) under which most American, Canadian and Mexican AM radio stations changed frequencies.