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This article is about the AM radio station. For other uses, see KNX (disambiguation).
City Los Angeles, California
Broadcast area Greater Los Angeles
Branding KNX 1070 NEWSRADIO
Slogan "Southern California's only 24-hour news and traffic station"
"News that matters to you, depend on us."
"News without noise."
Frequency 1070 kHz
(also on HD Radio)
97.1 FM HD2 KAMP-FM (simulcast)
94.7 FM HD3 KTWV (simulcast)
First air date September 10, 1920 (as 6ADZ)
Format All News
Language(s) English
Power 50,000 watts
Class A (Clear channel)
Facility ID 9616
Transmitter coordinates 33°51′35″N 118°20′59″W / 33.85972°N 118.34972°W / 33.85972; -118.34972
(main antenna)
33°51′38″N 118°20′57″W / 33.86056°N 118.34917°W / 33.86056; -118.34917
(auxiliary antenna)
Callsign meaning Assigned sequentially on May 4, 1922; the callsign stood for the ANneX of Spring Street Arcade.[1]
Affiliations CBS Radio Network, Bloomberg Radio
Owner CBS Radio
(CBS Radio East Inc.)
Webcast Listen Live
Website KNX 1070

KNX is an AM radio station broadcasting on 1070 kHz in Los Angeles, California, United States. It airs an all-news format. The station is owned by the CBS Radio subsidiary of CBS Corporation. KNX holds a Class A license as one of the original clear-channel stations allocated under the 1928 U.S. band plan. Its non-directional 50,000 watt signal can be heard during the day around Southern California and some nights through much of the Western United States and parts of Mexico and Canada. KNX broadcasts from facilities shared with sister stations KCBS-FM, KTWV and KAMP-FM located on Los Angeles' Miracle Mile. Its transmitter and antenna array site are located at Columbia Park in Torrance (northeast of the intersection of Hawthorne Boulevard and 190th Street).

The station also broadcasts an HD Radio signal, streams online, and simulcasts on the FM band on KAMP-FM-HD2, and on KTWV-HD3.[2] KNX is one of nine All-News stations owned by CBS.


KNX began as a five-watt amateur radio station, 6ADZ, which Fred Christian put on the air on September 10, 1920, broadcasting on a wavelength of 200 meters (1500 kHz). In December 1921, the station moved to 360 meters (833 kHz) and became KGC, sharing time with other stations that broadcast on the same frequency.[3] On May 4, 1922, the station increased power to 50 watts and became KNX. Power was raised to 100 watts in 1923. A year later, Fred Christian sold KNX to Guy Earl, owner of the Los Angeles Evening Express.[4]

During the 1920s, KNX, like most stations across the country, changed frequencies several times, landing on 1050 AM as a result of the Federal Radio Commission's reconfigurations of the AM radio band in 1927 and 1928. In 1929, the station's transmitter was upgraded from 500 to 5,000 watts, and in 1932, was raised to 10,000 watts of power. During this time, the station changed owners and was then operated by the Western Broadcast Company. In 1933, the station moved its studios to another part of Hollywood, after being granted permission by the FRC on June 7, 1932, to raise its output to 25,000 watts.[5] The following year, KNX's transmitting power was raised to the nationwide maximum of 50,000 watts, which the station continues presently.[6] It changed to its current 1070 AM channel in 1941.

CBS purchased and began operating KNX as its West Coast flagship station in 1936, ending CBS's eight-year affiliation with KHJ.[7] In 1938, the CBS Columbia Square studios[8] were dedicated for KNX as well as West Coast operations for the entire CBS radio network. That October, the station carried Orson Welles' celebrated version of The War of the Worlds . Several legendary performers from the Golden Age of American network radio broadcast from there, including Jack Benny, Bing Crosby, George Burns, Edgar Bergen,[9] and TV situation comedy star Bob Crane, who was KNX's morning host between 1957 and 1965 at the same time he was appearing as a featured supporting player on the ABC television network's The Donna Reed Show.[10]

KNX was a strong competitor in the Los Angeles market while Crane was a morning personality, but began declining in popularity after he left to star in the CBS television series Hogan's Heroes. Following the example of corporate sister station WCBS in New York City, which had enjoyed renewed success with an all-news format, KNX then became an all-news station in the spring of 1968.[11] By chance, its first major breaking news coverage was a major worldwide story that happened locally: the assassination of Democratic Presidential candidate Robert F. Kennedy, in the Ambassador Hotel in Los Angeles, on June 5 of that year.[citation needed]

In August 2005, KNX moved out of Columbia Square after operating there for 67 years, and began broadcasting from new studios in the Miracle Mile district on Wilshire Boulevard.[9]

In 2009, KNX adopted the slogan "All News, All the Time." It was previously used for 40 years by KFWB, KNX's historic rival in the news radio wars before both became sister stations through the 1995 merger of Westinghouse Electric (KFWB's owner) and CBS. KFWB's format change to news-talk in September 2009 (and currently as a South Asian station) now leaves KNX the only all-news outlet in the Los Angeles area, which is now emphasized in its alternate slogan, "Southern California's only 24-hour news & traffic station".

Emergency preparedness[edit]

As KNX and competitor station KFI are primary entry points for the Southern California Emergency Alert System, they are responsible for activation of the EAS when hazardous weather alerts, disaster area declarations, and child abduction alerts are issued.[12]


The station's antenna array features a 494-foot main antenna. The original main antenna (circa 1936) was destroyed by vandals on September 14, 1965. An unused 365-foot tower was brought in from KFAC (now KWKW) and was used while the new main antenna was constructed. This antenna was formerly in what is now a residential area to the south of the main antenna.

Non-directional Class A stations are, with very few exceptions, required to have emergency antennae as these stations serve as regional EAS stations. The 365-foot tower now serves as KNX's emergency antenna. It was later relocated when much of the site was dedicated as a park in Torrance; it is now north of the main antenna, within the park.

Only one antenna is active at a time. An experiment in the late 1960s using both antennae in a directional setup during the daytime was abandoned.

Electrical properties[edit]

The 494-foot main antenna is 0.5375 of a wavelength, or 193.5 degrees out of the 360 of a full cycle at 1070 kHz.[13] It has an efficiency of 400.73 mV/m/kW at 1 km optimum.[14] This is much better than average for a Class A station's main antenna. The FCC's minimum efficiency requirement is 362.10 mV/m/kW at 1 km.)[15]

The 365-foot emergency antenna is 145.5 electrical degrees with an efficiency of about 343 mV/m/kW at 1 km.[16] This is much better than average for a Class A's emergency antenna but inadequate for the main.

Notable former on-air staff[edit]

See also[edit]


  1. ^ Call Sign Letter Meaning Archived September 27, 2007, at the Wayback Machine.
  2. ^ HD Radio Guide for Los Angeles
  3. ^
  4. ^ Article by radio historian Jim Hilliker on September 26, 2013.
  5. ^ "KNX Gets 25 Kw" (PDF). Broadcasting. June 15, 1932. Retrieved 2 October 2014. 
  6. ^ Sakrison site
  7. ^ "Biggest station deal in history effected." Broadcasting, April 1, 1936, pp. 7, 62. [1][2]
  8. ^ Today in Radio History August 12 2005
  9. ^ a b KNX History
  10. ^ who2
  11. ^ knx1070 Our Heritage Archived March 14, 2009, at the Wayback Machine.
  12. ^ FCC Local Area Plan for the Emergency Alert System (Microsoft Word Document) - Los Angeles County
  13. ^ Paul Thurst (June 30, 2010). "Converting electrical degrees to height in meters or feet". 
  14. ^ From FCC public information files.
  15. ^ From FCC rules, 47 CFR Part 73.
  16. ^ Calculated from the electrical height, using FCC formulae.
  17. ^ Cox, Jim (2007). Radio Speakers: Narrators, News Junkies, Sports Jockeys, Tattletales, Tipsters, Toastmasters and Coffee Klatch Couples Who Verbalized the Jargon of the Aural Ether from the 1920s to the 1980s--A Biographical Dictionary. McFarland & Company, Inc. ISBN 978-0-7864-6086-1. Pp. 98-99.
  18. ^ "(untitled brief)" (PDF). Broadcasting. June 1, 1935. p. 30. Retrieved 11 January 2016. 
  19. ^ Abbott, Sam (January 17, 1942). "Hollywood" (PDF). Billboard. Retrieved 4 February 2015. 
  20. ^ "Guide to the Chet Huntley Papers 1920-1977". Northwest Digital Archives. Retrieved 4 February 2015. 
  21. ^ Abbott, Sam (January 24, 1942). "Hollywood" (PDF). Billboard. Retrieved 4 February 2015. 

External links[edit]