KNBR-FM (104.5 MHz) is a commercial radio station licensed to San Francisco, California, serving the greater San Francisco Bay Area. Owned by Cumulus Media, KNBR-FM features a sports radio format in a simulcast with co-owned KNBR. Both stations are the San Francisco affiliates for CBS Sports Radio, the flagship stations for the San Francisco Giants Radio Network and co-flagship stations for the San Francisco 49ers Radio Network (along with KSAN and KGO). KNBR-AM-FM are the radio home of Greg Papa and Tom Tolbert. KNBR maintains studios on Battery Street in San Francisco, while the transmitter is located on Mount Sutro. In addition to a standard analog transmission, KNBR simulcasts over low-power analog Pleasanton booster KNBR-FM3 (104.5 FM), and is available online. History Beautiful music The station signed on the air on February 4, 1960, as KBAY-FM. It was owned by Kaiser Broadcasting, a company started by local industrialist Henry J. Kaiser. It aired a "good music" format, mostly instrumental easy listening with some middle of the road songs and soft pop vocals. In 1963, the call sign switched to KFOG in honor of the city's fog layer, and the station aired a beautiful music format, again largely instrumental music, cover versions of popular songs with some Broadway and Hollywood show tunes. Within a few years, KFOG got competition from other beautiful music stations: KABL-AM-FM (now KNEW and KISQ) and from KOIT, as well as San Jose-based KBAY (now KBRG). For the next two decades, beautiful music was popular in the Bay Area. By the early 1980s, the format was showing signs of aging. KFOG was acquired by General Electric in 1974. "Timeless Rock" On September 16, 1982, with studios still at Ghirardelli Square, KFOG dropped the easy listening format for a blend of album-oriented rock (AOR) and classic rock, which the station called "Timeless Rock." The first song on the new format was "Rock This Town" by The Stray Cats. The station featured a wide range of music, from the psychedelic sounds of the Grateful Dead and Jefferson Airplane to newer artists such as Prince, the Eurythmics, and the Thompson Twins. KFOG avoided commercial-sounding bands such as Loverboy and REO Speedwagon, which were widely played on more mass-appeal AOR stations at the time. KFOG was inspired by San Francisco's freeform rock radio heritage, dating back to KSAN, a pioneering progressive rock station (now KYLD). When KFOG changed to rock in