KKSF

KKSF (910 kHz) is a commercial AM radio station licensed to Oakland, California and serving the San Francisco Bay Area. The station is owned by iHeartMedia and has an all-news radio format, with programming from the co-owned Black Information Network (BIN). The studios are located on Townsend Street in San Francisco's SoMa district.

The station's transmitter and two-tower array are located on Point Isabel in Richmond, on the San Francisco Bay. KDIA utilizes one of KKSF's two towers during the day. KKSF transmits with 20,000 watts during the day and 5,000 watts at night, using a directional antenna at all times. Because radio waves travel farther at night, KKSF must reduce its power after sunset to protect other stations on AM 910 from interference.

KKSF was founded by the Oakland Tribune newspaper. Starting in early 1922, the Tribune supplied content for Preston D. Allen's station, KZM, located on top of the Oakland Hotel. Following a suggestion by Allen, the newspaper decided to establish its own broadcasting station, and on May 3, 1922, it was issued a license for a new station with the randomly assigned call letters KLX. This authorization specified operation on the standard "entertainment" wavelength of 360 meters (833 kilocycles). KLX's first sign-on occurred at 7:30 p.m. on July 25, 1922.

For the first year and a half, KLX shared the studios and transmitter at the Oakland Hotel with KZM. Engineer Roswell Smith remembered that "they used to shut down the transmitter as KZM, and take to the air a half hour later as KLX". As part of the cooperative effort, the Herald arranged to upgrade the KLX's 5-watt transmitter by installing two more powerful transmitters, which were named for characters in the Toonerville Folks comic strip: 50-watt "Little Jimmie", and 250-watt "Powerful Katrinka."

Initially, the 360-meter wavelength was the only "entertainment" frequency available, so stations within various regions had to develop time sharing agreements providing for each station to broadcast for a few hours each week. By November 1, 1922, there were twelve "San Francisco Bay District" stations sharing time on 360 meters, and, after KZM ceded its original hours, KLX was assigned 7:00–7:30 p.m. daily except Sunday, plus 10:00–11:00 a.m. Sunday and 8:00–9:00 p.m. Tuesday.

In the fall of 1923, KLX moved to its own studio on the 20th floor of the recently completed Tribune Tower at Thirteenth and Franklin, where it would stay there for thirty years. An antenna was strung between the tops of the Tribune and Oakland Bank buildings, and the transmitter was upgraded to 500 watts.

The station later moved to 590 kHz. The transmitter power was increased to 1,000 watts by the 1930s, with the station moving to 880 kHz. With the implementation of the North American Regional Broadcasting Agreement (NARBA) in 1941, KLX moved to its current frequency of 910 kHz. In 1952, the transmitter was moved to the San Francisco Bay shoreline and increased to 5,000 watts. In late 1956, KLX moved to the Bermuda Building on Franklin Street.

KLX was owned for three decades by Joseph R. Knowland, owner and publisher of The Oakland Tribune newspaper. To pay off campaign debts related to U.S. Senator William Knowland's unsuccessful 1958 campaign for Governor of California, the Knowland family sold the station to the former publisher of Collier's magazine (which had ceased publication in December 1956).