KFRC (610 AM), often hailed as “The Big 610,” was one of the most iconic Top 40 radio stations in American broadcasting history. Broadcasting from San Francisco, it dominated the Bay Area airwaves for two decades as a high-energy hit machine, blending rock ‘n’ roll, pop, and cutting-edge production techniques that influenced stations nationwide. Its golden era in the 1960s and 1970s turned it into a cultural force, rivaling legends like Los Angeles’ KHJ “Boss Radio.” Though the AM signal has long since evolved into other formats, KFRC’s legacy endures through airchecks, documentaries, and fond memories shared by listeners and broadcasters alike.
KFRC signed on the air on September 24, 1924, from studios in San Francisco’s Hotel Whitcomb at 1231 Market Street. Initially a low-power station (50 watts on the 270-meter wavelength, around 1110 kHz), it was owned by pioneer Don Lee and focused on general entertainment, including live music, drama, and news. By the 1940s, it had moved to 610 AM and hosted big names like a young Merv Griffin in the pre-TV era.
In the 1950s and early 1960s, KFRC experimented with middle-of-the-road (MOR) music and talk formats but struggled against dominant stations like KSFO (560 AM), which ruled San Francisco radio. Personalities like Dan Sorkin added flair with humorous bits, earning mentions in Herb Caen’s columns, but ratings lagged. The station briefly branded itself “Frisco Radio” during a low point, signaling a need for reinvention.
Everything changed in spring 1966, when KFRC flipped to Top 40 under the guidance of programmer Bill Drake, who had just revolutionized Los Angeles’ KHJ with his tight, clock-driven “Boss Radio” format. Drake imported elements like short jingles, rapid-fire playlists (fewer than 40 songs, hence “Top 40”), and high-energy DJs—no long-winded talk, just hits and hype. The rebrand as “The Big 610” (emphasizing its powerful 5,000-watt clear-channel signal reaching Northern California and beyond) was an instant hit.
KFRC quickly overtook rivals like KYA (1260 AM) and the fading KEWB (910 AM), becoming the Bay Area’s #1 station for much of the next 20 years.
March 21, 1970 – Dave Diamond (43:28)
By the late 1960s, it was a ratings juggernaut, often beating TV for young listeners. In the 1970s, under PDs like Sebastian Stone and later Gerry Cagle, it shifted toward dance/R&B crossovers as disco rose, staying ahead of national trends.
Its production was polished yet fun, with sound effects and corny one-liners that made it feel like a party. KFRC sponsored the 1967 Human Be-In in Golden Gate Park, a precursor to Woodstock regarded as America’s first rock festival. It also aired extended local newscasts under news director Bob Safford until budget cuts in the 1980s shifted focus to music.
The “Big 610 Men”KFRC’s DJs were its heartbeat—charismatic, witty, and larger-than-life. The “Class of 1966” included legends like Howard Clark, Bobby Dale, and Steve O’Shea, who set the tone with rapid patter and hit intros.
Dr. Don Rose (mornings, 1970s–1980s): The “King of Corny,” famous for vaudeville-style bits like “Little Bo Peep lost her sheep… and couldn’t keep her calves together either.” He ruled mornings with a wholesome, non-edgy vibe that resonated in the counterculture era, dying in 2005 at 70.
November 1970 – Mike Phillips (12:23)
Robin Mitchell (The Robin): Nighttime staple with unscoped airchecks still circulating among fans.
Dave “Duke” Sholin: Music director who earned KFRC seven consecutive Billboard Top 40 Station of the Year awards; later interviewed John Lennon hours before his death.
Others: Chuck Geiger, Renel Brooks-Moon (future Giants announcer), and Jack Silver (last Top 40 voice in 1986).
By 1986, FM competition (e.g., KMEL’s rise) and format fragmentation eroded AM Top 40. KFRC’s “Game Zone” contest-heavy daytime format flopped, leading to a brief return to CHR before flipping to “Magic 61” in October 1986.
With ratings in the dumpster, programming was flipped at 6 AM on August 11, 1986, to an adult standards format – Jack Silver leads up to it with calls from listeners. Dr. Don Rose introduces the new format after 6a.m. (4:36:38)
CBS Radio (later Audacy) owned it until selling the AM signal in 2005 for $35 million to Family Radio, which turned it religious (simulcast of KEAR-FM).
The callsign lived on:
KFRC-FM (106.1/99.7/106.9): Became classic hits in 2007, then MOViN’ (adult hits), and briefly simulcasted CBS News in 2008 before going all-news as part of the Black Information Network (BIN) launch in 2020. 610 is currently broadcasting a religious format.
In 2009, KFRC calls moved to 1550 AM for Scott Shannon’s “True Oldies Channel,” playing ’60s–’70s hits—ironically on a frequency once home to early Top 40 rival KOBY.