What eventually became KFMB FM began testing in 1950 from the North Park Theater on Adams Avenue. It finally signed on for commercial operation on 100.7 MHz in 1959 airing a Beautiful Music format called "Music Only For a Woman" during the late 1960s. Station Manager Ed Peters bought the rights to syndicate the format. Soon after, Peters left and started his own company known as "Peters Productions" which syndicated the format on reel-to-reel tape to over 100 stations during the 1960s - 1970s, changing the name of the format to "Music Just For The Two Of Us."
San Diego in the early 1970s had three music stations and was about to gain a fourth, so KFMB AM program director Bobby Rich and station manager Paul Palmer concocted a super high energy Top 40 format to challenge market leader KCBQ. Rich wanted to change the call letters to something with "Q" in them to become "the FM Q" but the owners refused to break up the KFMB AM/FM/TV matched set of calls. Although 100.7 is closer to 101 than 100, KGB FM had already established itself as 101KGB, so KFMB FM became "B-100" in March 1975 with the slogan "Better Boogie", eventually knocking off longtime AM powerhouse KCBQ in fall 1977, the latter being the big top 40 radio station in San Diego. B-100 was the first major market FM rocker to achieve overall #1 Arbitron ratings for all listeners over the age of 11. The station's staff during its first two years included Phil Flowers, Rich Brother Robbin, Shotgun Tom Kelly, Gene Knight, Danny Wilde, Gary Kelley, Billy Pearl, Beaver Cleaver (aka Ken Levine), Jimmy Rogers, Chris Lance and Dr. Boogie (aka Bobby Rich).
B-100 had major success in the 1980s, reinventing itself as one of the nation's first "hot" adult contemporary stations, melding top 40 hits with an adult delivery by its high-profile airstaff, including "The B-Morning Zoo with The Rich Brothers" featuring Bobby Rich (mornings at Mix 96, Tucson), Gary Kelley (a weatherman with KGTV, San Diego), Gene Knight, Danny Romero (a weatherman with ABC7, Los Angeles), Ellen Thomas (now Ellen K) and John Fox (general manager of the first tribally-owned radio station in Southern California, KOPA).
Jeff and Jer became the morning show at B-100 in the late 1980s. On May 16, 1994, B-100 ended their longtime format, and after a few weeks of stunting, the station flipped to Hot AC and adopted the moniker "Star 100.7" in June. Star 100.7 aired the Bob and Sheri syndicated morning drive show in the early morning hours. "Star 100.7" continued until April 6, 2005, at 9:55 AM, when the station began stunting with a 5-minute ticking clock and a mysterious voice saying "closer...closer", which ended with an alarm going off and a female announcer saying "Bye Star". Jack FM was then introduced with R.E.M.'s "It's The End of the World As We Know It (And I Feel Fine)." Local hosts Jeff and Jer left KFMB-FM in August 2005 and moved across town to 94.1 FM, now known as "Star 94.1". KFMB-FM is now home to the former long-time KGB-FM morning show, "Dave, Shelley and Chainsaw".