KZAC

KZAC
Currently silent
Broadcast areaSan Francisco Bay Area
Frequency560 kHz
Ownership
Owner
KNBR, KNBR-FM, KSAN, KSFO, KTCT
History
First air date
August 1, 1925 (1925-08-01)
Former call signs
  • KTAB (1925–1935)
  • KSFO (1935–2024)
Former frequencies
  • 1390 kHz (1925)
  • 1250 kHz (1925–1926)
  • 990 kHz (1926–1927)
  • 1070 kHz (1927–1928)
  • 1280 kHz (1928)
  • 550 kHz (1928–1929)
Technical information
Licensing authority
FCC
Facility ID34472
ClassB
Power5,000 watts
Transmitter coordinates
37°44′43.7″N 122°22′43.9″W / 37.745472°N 122.378861°W / 37.745472; -122.378861
Links
Public license information

KZAC (560 AM) is a commercial radio station in San Francisco, California, that used the call sign KSFO from 1935 to 2024, and is currently silent. Owned by Cumulus Media, KZAC's transmitter is located near the Islais Creek Channel.

KZAC began broadcasting in 1925 as a station licensed to Oakland with the call sign KTAB, on a frequency of 1390 kHz. Owned by a Baptist church in Oakland, KTAB had a religious-focused format in its first year before changing to a commercial, non-religious format. After several frequency changes, the station moved to its current 560 kHz frequency in 1929 and became KSFO in 1935, re-licensed to San Francisco. KSFO joined the CBS Radio Network in 1937.

In 1956, KSFO was purchased by Golden West Broadcasters, a company co-owned by Gene Autry and Bob Reynolds. Golden West programmed a full service format for KSFO featuring popular music, news, and sports, with a popular jingle "The Sound of the City". Golden West sold KSFO to King Broadcasting Company in 1983, after which KSFO became a pop standards station. Then in 1986, KSFO shifted its music format to reflect 1950s to 1970s oldies, before becoming a simulcast of KYA-FM in 1987. Sold again to First Broadcasting Company in 1992, KSFO had a combined oldies and sports talk format before changing to a full-time talk radio format in 1993.

Capital Cities/ABC Inc. bought KSFO in 1995 and shifted its programming to emphasize conservative talk, and was one of the most popular stations in San Francisco through the late 1990s. Michael Savage and his show The Savage Nation, which was later nationally syndicated, originated from KSFO through the majority of its run. Other local hosts included Geoff Metcalf, Melanie Morgan and Brian Sussman. Through its history, KSFO has also broadcast local sports teams, including Stanford Cardinal football, San Francisco 49ers, San Francisco Giants, Oakland Athletics, Oakland Raiders, and California Golden Bears men's basketball. A 2024 programming realignment by current owner Cumulus Media saw KSFO's format and branding moved to 810 AM and this facility renamed as KZAC; in 2025, the station went silent.