KSCO (1080 AM) is a commercial radio station broadcasting a talk radio format. The station is owned by Zwerling Broadcasting System, Ltd and is licensed to Santa Cruz, California. The radio studios and offices are on Portola Drive in Santa Cruz. The station can be heard over much of Central California during the day.

By day, KSCO broadcasts at 10,000 watts. Because 1080 AM is a clear channel frequency reserved for KRLD Dallas and WTIC Hartford, at sunset, to avoid interference, KSCO reduces power to 28 watts. It uses a non-directional antenna at all times^[2] KSCO also has three translator stations to broadcast its programming on the FM dial.

KSCO signed on the air on September 21, 1947.^[3] It originally was powered at 1,000 watts by day and was housed in a distinctive art deco building, which was constructed for the station, and still broadcasts there today. The founder was Charles Vernon Berlin, who also served as general manager and chief engineer. In 1962, he added 99.1 KSCO-FM (now KSQL).

In 1986, Berlin sold KSCO-AM-FM to Fuller-Jeffrey Broadcasting which owned numerous stations around the country. The AM station went to an automated format of adult standards. On March 10, 1987, KSCO-FM changed its call letters to KLRS (Colors) and its format to a new-age music format, the first station in North America to do so, with Mark Hammond as program director and Jay Peterson music director.

Since 1991, KSCO has been owned by the Zwerling family and has a talk radio format. The Zwerlings later acquired another local AM station, 1340 KOMY. Both Michael and his mother Kay Zwerling took an active role in the station with the former regularly hosting the call-in show Saturday Special and the latter writing and voicing politically conservative commentaries on a variety of topics, especially politics and current events. On January 3, 2017 Kay Zwerling died at 95 years old.^[4]

On September 25, 2006, the offices of KSCO and KOMY received an envelope containing white powder. The envelope, which had no return address and contained no letter, was addressed to "AUNTIE KSCO" in handwriting described by Program Director Rosemary Chalmers as "chicken-scratch." Emergency response teams arrived on scene, and all KSCO personnel in the building were evacuated by a HazMat crew. By the evening of Tuesday, September 26, an FBI lab had determined that the powder was inert, and KSCO/KOMY's broadcast studios were deemed safe. Regular broadcasting resumed at 8 p.m. None of the four people who came in contact with the envelope experienced symptoms of any illness.

On October 24, 2022, the FCC proposed a $20,000 fine for Zwerling Broadcasting System, because KSCO had been operating outside of its licensed nighttime parameters since late 1996.^[5][6] On December 15, 2022, the FCC denied Zwerling Broadcasting's appeal, and affirmed the $20,000 fine for KSCO.^[7][8]

Apparently as a consequence of the cited long-term unauthorized nighttime operations, KSCO was directed to apply for a daytime-only (Class D) license, with nighttime power sufficiently reduced to fully protect KRLD (AM). The application was submitted, and authorization was granted. The application requested 0.028 kW (twenty-eight watts) nights, non-directionally. Daytime power remains 10 kW, also non-directionally.

The new license for 28 watts at night was granted on April 18, 2024.

The station programming is a mix of local, syndicated and brokered programming (meaning a person can purchase an available hour of time and produce their own show). A host can either pay for the hour out of his or her own pocket or find local businesses to sponsor the show in exchange for advertising.

The programming is a mix of local and national shows. The morning hours feature a syndicated news and commentary show called Armstrong & Getty, followed by NewsMax host Rob Carson, financial advisor Dave Ramsey, and various local shows covering money management, real estate law, and everything about cars. Afternoon drive time comedy and local interest is hosted by Dave Michaels. Evening and nighttime offerings include Dr. Joel Wallach, Wayne Allen Root, and Coast to Coast AM with George Noory.

KSCO does not subscribe to rating services, so listenership is unreported.

Past KSCO local programs were hosted by Rosemary Chalmers, Michael Olson, Vernon Bohr, Ethan Bearman, Daryl Alan Gault, Rob Roberts, Brian Maloney, and more. Current local hosts include Pamela Fugitt-Hetrick, Duncan McCollum, and Dean Sutton.

On August 3, 2015, KSCO launched an FM simulcast on 104.1 MHz with translator K281CA from the Mt. Madonna Tower. It uses a directional antenna with most of the signal directed at Santa Cruz.

On May 11, 2017 KSCO was granted a license for translator K300DD on 107.9 MHz from the Mt. Madonna Tower. It uses a directional antenna with most of the signal directed at Morgan Hill.

On June 8, 2017 KSCO was granted a license for translator K239CN on 95.7 MHz from the Mt. Madonna tower. It uses a directional antenna with most of the signal directed at Gilroy.

• FCC History Cards for KSCO
• KSCO 1080 AM Website
• Facility details for Facility ID 41594 (KSCO) in the FCC Licensing and Management System
• KSCO in Nielsen Audio's AM station database
• Facility details for Facility ID 153874 (K281CA) in the FCC Licensing and Management System
• K281CA at FCCdata.org
• Facility details for Facility ID 88248 (K300DD) in the FCC Licensing and Management System
• K300DD at FCCdata.org
• Facility details for Facility ID 142038 (K239CN) in the FCC Licensing and Management System
• K239CN at FCCdata.org