CHUM is a Canadian radio station in Toronto, Ontario, broadcasting on 1050 kHz. The station is owned and operated by Bell Media. CHUM's studios are co-located with TSN at 9 Channel Nine Court in the Agincourt neighbourhood of Scarborough (with auxiliary studios located at 250 Richmond Street West in the Entertainment District of downtown Toronto), with its transmitter array located in the Clarkson neighbourhood of Mississauga (near CFRB's own transmitter array). TSN 1050 is simulcast on Bell Satellite TV channel 989, and on Shaw Direct channel 867. The station is also carried on the 3rd HD digital subchannel of CKFM-FM. Station history CHUM AM has been broadcasting continuously since 1945, through a variety of format changes. The station's history can be broken into eight distinct eras, as follows: The "full service" era: 1945-1957 CHUM was founded by four Toronto businessmen, including Al Leary, a former sportscaster, who had been the station manager at CKCL for 14 years. CHUM received its licence in late November 1944 to operate a station with 1,000 watts. CHUM launched as a dawn-to-dusk radio station on October 28, 1945, with John H.Q. "Jack" Part, an entrepreneur in the business of patent medicines, as its president. The station, operating from 1947 in studios at 225 Mutual St., broadcast a format typical of the late 1940s, with a combination of information, music, and sports. When CHUM was about to debut, Leary told the press that the new station would be known for community service and in-depth news, in addition to live talent and the most popular phonograph records. CHUM was taken over in December 1954 by Allan Waters, a salesman from Part's patent medicine business. Waters' first major move was to secure a licence for 24-hour-a-day broadcasting for CHUM, along with a power increase to 5,000 watts. The Top 40 era: 1957-1986 Less than three years after Waters acquired the station, and soon after bringing the new full-time transmitter online, a major programming change was made. On May 27, 1957, at 6 AM, Waters switched the station to a "Top 50" format that had proven itself popular in some U.S. cities; Elvis Presley's "All Shook Up" was the first song played. 1050 CHUM pioneered rock and roll radio in Toronto, and was noteworthy for hosting many noteworthy rock concerts including, among others, visits to Maple Leaf Gardens by Elvis Presley (1957) and the Beatles (1964, 1965, and 1966).