|City||San Francisco, California|
|Broadcast area||San Francisco Bay Area|
|Branding||1550 The Game|
|Slogan||The Bay Area's Sports Station|
|First air date||1947 (as KSMO)|
|Format||Sports (KGMZ-FM simulcast)|
|Callsign meaning||The GaMeZ|
(CBS Radio East, LLC)
|Sister stations||KCBS, KFRC-FM, KGMZ-FM, KITS, KLLC, KRBQ|
When the station was sold in 1956, following a brief period of being off the air, it flipped to Top 40 as KOBY. The station quickly went to the top of the local ratings. They also simulcast with their new FM station at 95.7. Soon, other stations in the Bay Area switched to Top 40, and with much deeper financial resources, and the owners of KOBY decided to sell. In order to inflate station revenues, they began programming heavy amounts of commercials. This move backfired, and potential buyers were scared away from the rapidly failing stations.
In 1960, KOBY and KOBY-FM switched to beautiful music under a new owner, with new call letters KQBY. Ratings were still poor, and the owner ran out of money. The stations went dark once again until a new buyer was found.
The new owner adopted a middle of the road (MOR) format for the two stations, with the call letters KKHI, as well as personality-oriented disc jockeys. The next year, KKHI-FM, due to new Federal Communications Commission (FCC) regulations concerning FM simulcasting, switched to an automated beautiful music format. Soon after, the owner ran out of money, and with a severe cutback of station staffers (including the expensive disc jockeys), flipped to classical music once again. Eventually, they simulcast once again with their FM signal. The classical format was somewhat successful, but the owner could not dig himself out of his massive debts and sold the stations in 1965. The new owners, Buckley Broadcasting were satisfied with the revenue generated by KKHI, so the format was kept. Buckley continued to own the station and program classical music until 1994.
Group W, the owners of KPIX-TV, purchased the two stations in May 1994 and switched to all-news with the KPIX call letters on May 30 of that year. The stations did not do well in the ratings due to heavy competition with the long-established KCBS and KGO. However, KPIX was notable for its continuous coverage of the O.J. Simpson murder case. When the trial ended in the Fall of 1995, the two stations would split from the simulcast, as the AM resumed its all-news format, while the FM shifted to talk. However, ratings for both stations were still falling despite the changes.
CBS and Westinghouse merged operations in late 1995, and to comply with FCC ownership regulations, KPIX-FM was later sold to Bonneville, while the AM would be retained by CBS. On May 30, 1997, after KPIX-FM was sold to Bonneville (and flipped to Top 40/CHR), KPIX-AM dropped the news programming and began simulcasting new sister station KYCY and its then-country music format, as well as adopting the KYCY-AM call letters.
The two stations simulcasted until September 13, 1999, when the AM station switched to a talk format as "Yada Yada Radio 1550", consisting of syndicated shows from hosts Don Imus, G. Gordon Liddy, Tom Leykis, Jim Bohannon, Opie & Anthony, Larry King, Bruce Williams, and "America in the Morning". The talk format performed poorly, and rarely appeared in the Arbitron ratings books. On May 16, 2005, KYCY adopted a unique format that had never been tried on terrestrial radio before: an all-podcast format, branded as "KYou Radio".
KYOURadio was the first radio station to have output that is 100% based on podcasts, or user-generated content. Announcing the change of format, CBS Radio chief executive Joel Hollander described the new format as something of an experiment. The first program was from podcast veteran Dave Winer.
All content was submitted by listeners, and in the two weeks before launch, the station attracted over 400 submissions, and a month after launch it was broadcasting around 1,200 podcasts a week. All material was screened to ensure it conformed with US federal guidelines on decency. The station manager, Stephen Page, claimed that after six months he had over 2,000 people offering to create content for the station. These contributors were unpaid.
Around 20% of the content was speech-based, with the rest based on music.
On May 17, 2007, CBS flipped sister station KIFR from the "Free FM" hot talk format to oldies with call sign KFRC-FM. They also announced the move of some of their programs to 1550. One month later, three of KIFR's former programs debuted on KYCY, with the all-podcast format continuing outside of those shows.
It was announced on December 22, 2008 that starting on New Year's Day 2009, this station would be switching formats again, this time to an Oldies format courtesy of Scott Shannon's "The True Oldies Channel" (programmed by ABC Radio). Also, a callsign change was filed to adopt the KFRC call letters, which resided previously on the AM band at AM 610 (now KEAR).
This was not CBS' first association with the KFRC call letters; the original KFRC was an affiliate of the CBS Radio Network from 1929 through 1936, and CBS acquired that station, along with its FM simulcast, as part of its 1997 acquisition of Infinity Broadcasting Corporation.
KFRC's oldies format ended on September 1, 2011, when the station was taken over by Cinemaya Media under a time-brokerage agreement and adopted a South Asian radio format, with concentration in Bollywood and Indian American affairs, branded as "Radio Zindagi". The station featured Indian-targeted talk and Bollywood music. The founders of Radio Zindagi are Praveen Suggala, Neeraj Dhar, Ajay Bhutoria and Rohit Saini. The format later spread to the New York City and Washington, D.C. areas, and is also a syndicated format.
On February 2, 2017, CBS Radio announced it would merge with Entercom. The merger was approved on November 9, 2017, and was consummated on the 17th. Despite the merger, Cinemaya continued to operate the station via its time brokerage agreement.
On May 1, 2018, KZDG dropped Radio Zindagi (which moved to KLOK in San Jose, and is simulcast on KITS-HD3) and returned to a simulcast of 95.7 FM, which had become sports radio station KGMZ-FM, under new KGMZ calls. The station serves as an overflow outlet for KGMZ-FM, and began to air Oakland Athletics games that conflict with Golden State Warriors broadcasts on the FM signal.
The AM 1550 kHz transmitter site is in the Belmont Wetlands area adjacent to US Highway 101, and is licensed to CBS Radio East, Inc. The power level is 10 kW, and the antenna system is a 3 tower directional array with a tower height of 46.9 meters located at coordinates . The antenna system uses an open-wire 5-wire coaxial feedline system, one of the last stations in the US to use such an arrangement.  The three red tower lights were a common nighttime landmark since 1947 along highway 101, but the tower lights are no longer illuminated due to an FCC construction permit granted in 2014 in which the station filed a minor coordinate correction of the tower system, which allowed the station to avoid regulatory lighting requirements otherwise required due to the nearby San Carlos Airport. The transmitter site is surrounded by O'Neill Slough, which is part of the San Francisco Bay tidal estuary in a spartina cordgrass area and clapper rail habitat. The site has a history of flooding during storms, and in recent years it is annually flooded during extreme high tide known as king tide, whenever the level of the San Francisco bay reaches approximately +9 feet above MLLW mean lower low water datum at the Redwood City tide station.