KCBX (90.1 FM) is a

non-commercial A non-commercial (also spelled noncommercial) activity is an activity that is not carried out in the interest of Profit (economics), profit. The opposite is Commerce, commercial, something that primarily serves profit interests and is focused on bu ...

radio station Radio broadcasting is the broadcasting of audio (sound), sometimes with related metadata, by radio waves to radio receivers belonging to a public audience. In terrestrial radio broadcasting the radio waves are broadcast by a land-based rad ...

that is licensed to

San Luis Obispo, California ; ; ; Chumashan languages, Chumash: ''tiłhini'') is a city and county seat of San Luis Obispo County, California, United States. Located on the Central Coast (California), Central Coast of California, San Luis Obispo is roughly halfway betwee ...

. The

public radio Public broadcasting (or public service broadcasting) is radio, television, and other electronic media outlets whose primary mission is public service with a commitment to avoiding political and commercial influence. Public broadcasters receive ...

station is a member station of

NPR National Public Radio (NPR) is an American public broadcasting organization headquartered in Washington, D.C., with its NPR West headquarters in Culver City, California. It serves as a national Radio syndication, syndicator to a network of more ...

and airs a wide variety of programming, including ''

All Things Considered ''All Things Considered'' (''ATC'') is the flagship news program on the American network National Public Radio (NPR). It was the first news program on NPR, premiering on May 3, 1971. It is broadcast live on NPR affiliated stations in the United ...

'', ''

Democracy Now! ''Democracy Now!'' is an hour-long TV, radio, and Internet news program based in Manhattan and hosted by journalists Amy Goodman (who also acts as the show's executive producer), Juan González, and Nermeen Shaikh. The show, which airs live ...

'', and

jazz Jazz is a music genre that originated in the African-American communities of New Orleans, Louisiana, in the late 19th and early 20th centuries. Its roots are in blues, ragtime, European harmony, African rhythmic rituals, spirituals, h ...

and

classical music Classical music generally refers to the art music of the Western world, considered to be #Relationship to other music traditions, distinct from Western folk music or popular music traditions. It is sometimes distinguished as Western classical mu ...

. KCBX has a network of

repeater In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction. Some ...

s and

translators Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. The English language draws a terminological distinction (which does not exist in every language) between ''transl ...

that enable the station to be heard throughout the

Central Coast of California The Central Coast is an area of California, roughly spanning the coastal region between Point Mugu and Monterey Bay. It lies northwest of Los Angeles and south of the San Francisco Bay Area, and includes the rugged, rural, and sparsely populat ...

. Full-power repeater is KNBX (91.7 FM), licensed to

San Ardo, California San Ardo, formerly known as San Bernardo (Spanish language, Spanish for "St. Bernard"), is an Unincorporated area#United States, unincorporated community and census-designated place (CDP) in Monterey County, California, Monterey County, Californ ...

. KCBX itself broadcasts in

HD Radio HD Radio (HDR) is a trademark for in-band on-channel (IBOC) digital radio broadcast technology. HD radio generally simulcast, simulcasts an existing analog radio station in digital format with less noise and with additional text information. HD R ...

History

KCBX first signed on July 27, 1975 and began airing a variety of

programming, plus

, and foreign-language shows. KSBX, a full-power repeater of KCBX in Santa Barbara, began broadcasting April 1, 2003. From the 1970s through the end of 2012, KCBX broadcast live meetings of the

San Luis Obispo County San Luis Obispo County (), officially the County of San Luis Obispo, is a county on the Central Coast of California. As of the 2020 United States census, the population was 282,424. The county seat is San Luis Obispo. Junípero Serra fou ...

Board of Supervisors. In its decision to drop coverage of meetings, the station cited a lack of interest in the radio broadcast as county residents can stream meetings online.

Repeaters

KCBX operates two full-power

stations: KSBX on 89.5 MHz in

Santa Barbara, California Santa Barbara (, meaning ) is a coastal city in Santa Barbara County, California, of which it is also the county seat. Situated on a south-facing section of coastline, the longest such section on the West Coast of the United States excepting A ...

and KNBX on 91.7 MHz in

Monterey County Monterey County ( ), officially the County of Monterey, is a county located on the Pacific coast in the U.S. state of California. As of the 2020 United States census, its population was 439,035. The county's largest city and county seat is ...

. The station also operates several low-power FM

scattered throughout the Central Coast. KSBX was shut down on December 31, 2022, with KCBX citing that

tropospheric ducting Tropospheric propagation describes electromagnetic propagation in relation to the troposphere. The service area from a VHF or UHF radio transmitter extends to just beyond the optical horizon, at which point signals start to rapidly reduce in st ...

had brought in unacceptable interference from

KPBS-FM KPBS-FM (89.5 MHz) is a non-commercial educational station, non-commercial, listener-supported, public radio station in San Diego, California. It is owned by San Diego State University (SDSU) as part of KPBS Public Media, and is a sister statio ...

San Diego San Diego ( , ) is a city on the Pacific coast of Southern California, adjacent to the Mexico–United States border. With a population of over 1.4 million, it is the List of United States cities by population, eighth-most populous city in t ...

, an issue it had tried and failed to address through a failed relocation to 89.9 FM. The KSBX license was surrendered and cancelled on February 13, 2023.

Translators

KPBS-FM interference problem in Santa Barbara

In parts of the Santa Barbara area, sometimes during atmospheric ducting, co-channel

can override or interfere with the KSBX signal. At one time, KSBX was a 9-

watt The watt (symbol: W) is the unit of Power (physics), power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantification (science), quantify the rate of Work ...

translator on 89.9 MHz; later, another station began using that translator. Eventually a deal was reached that would vacate that frequency. In 2006, KCBX applied for a

Federal Communications Commission The Federal Communications Commission (FCC) is an independent agency of the United States government that regulates communications by radio, television, wire, internet, wi-fi, satellite, and cable across the United States. The FCC maintains j ...

(FCC)

construction permit Planning permission or building permit refers to the approval needed for construction or expansion (including significant renovation), and sometimes for demolition, in some jurisdictions. House building permits, for example, are subject to bu ...

to move back to 89.9 MHz and increase the

effective radiated power Effective radiated power (ERP), synonymous with equivalent radiated power, is an IEEE standardized definition of directional radio frequency (RF) power, such as that emitted by a radio transmitter. It is the total power in watts that would ha ...

from 50 watts to 350 watts. As part of the application, the station enclosed copies of numerous letters and emails from listeners complaining about the signal override or interference from KPBS. In support of the frequency change, a consulting broadcast engineer was hired to analyze the situation, make signal strength measurements during ducting, and fully explain the technical causes of the problem to the FCC. Making the interference problem worse is the fact that the KPBS signal travels completely over water. In 2010, KPBS-FM was granted a construction permit to increase its

from 2,700 watts to 26,000 watts. The consulting engineer explained to the FCC that if KSBX's frequency change was not granted, this would worsen the interference problem. In February 2012, the FCC dismissed the construction permit application from KCBX. KPBS started broadcasting with the new 26,000 watt signal on October 1, 2012. KCBX announced on December 20, 2022, that it would close down KSBX by the end of the year, stating that

climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

had increased the ducting and its related interference.

References

External links

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FCC History Cards for KCBX
{{NPR California CBX NPR member stations 1975 establishments in California Radio stations established in 1975