The station had humble beginnings, starting in a back bedroom of the Harold Way home of Fred Christian, who was a former ship-to-shore wireless operator. He eventually started working at a radio supply store, the Electric Lighting Supply Company, one of only two radio stores in Los Angeles at the time.
While working at the store, Christian started selling parts to amateur radio operators and on September 10, 1920, he set up a ham radio station, with the call letters 6ADZ .
He played phonograph records to give his customers a sense of how radio sounded and something to listen to. There was only one other person broadcasting music at that time in Southern California. Because ham radio operators had only one frequency at the time, he had to take turns getting on and off the air.
At the time, Christian was still using the station to sell radio parts, but there was no advertising at the time, which meant Christian was limited in how he could finance the station. So in October of 1924, he sold KNX to Guy Earle, who was publisher of the Los Angeles Evening Express newspaper. Earle had the finances to turn KNX into a first-class station, and also had a vision in mind to make it a bigger part of the Hollywood scene.
Along with the regular KNX programming, Guy Earle always wanted to make the station bigger. In 1925, there was breaking news in Santa Barbara County when an earthquake hit and the station's first owner, Fred Christian set up an emergency ham radio system and using Morse code, was able to relay news back to the station. KNX aired the news bulletin and that was thought to be the first accurate news on the quake.
KNX broadcast the Rose Bowl game in 1928 through a telephone connection, even though the phone company had already sold the broadcasting rights to another station. And in 1931, Earle tried to have KNX broadcast a "sensational" murder trial in Los Angeles, despite objections from the judge in the case and local newspapers. Earle would eventually do re-creations using the transcripts with radio actors.
KNX would continue to branch out in Hollywood, as Earle signed a five-year contract with Paramount Pictures in 1929. The KNX studios moved to the Paramount movie lot and taking advantage of its connections, it became the first station to broadcast the Academy Awards in 1930. Movie stars continued to make appearances on KNX, promoting their latest movies and further legitimizing the station as "The Voice of Hollywood."
KNX and Earle became a test case, as the FCC set up a license renewal hearing over its advertisement of Marmola, a purported fat-reducing product that the Federal Trade Commission called "ineffective and dangerous." The hearing did not go well and under pressure, 1n 1936, Earle sold KNX to the Columbia Broadcasting System for $1.25 million, which at that time was the highest price ever paid for a single radio station.
KNX would become the key station for CBS on the West Coast and with plans to bring in the biggest stars, the network built out the Columbia Square studio complex on Sunset Boulevard in the heart of Hollywood. It opened in 1938, and the station had a daylong special including "A Salute to Columbia Square," which featured music, drama, comedy, and an address from the head of CBS, William S. Paley, who said the new studios would provide everyone an opportunity to create programs that "entertain, inform and make people think," which he called the three pillars to allow broadcasting to fulfill its rightful role in American life.
With much of network radio in the 1950s switching to a disc jockey format, KNX followed suit. Steve Allen would host a late-night show where he was originally scheduled to play music, but he turned it into more of a talk show before leaving for television. Perhaps the most well-known DJ during that time on KNX was Bob Crane, who hosted a morning show from 1956 to 1965. His irreverent style (skits and gimmicks) caught on with listeners, along with his very popular celebrity interviews. He would eventually move on to television, starring in "Hogan's Heroes."
1968 would prove to be one of the most consequential in KNX's history. Massive protests were held across the country, including in Southern California, against the Vietnam War, the draft, and the Tet Offensive. The civil rights movement was holding strong but on April 4, 1968, Martin Luther King Jr. was assassinated on his hotel room balcony in Memphis, Tennessee. A little more than a week later, KNX adopted an all-news format.
One of the first major stories the station covered would garner national attention as Democratic presidential candidate Robert F. Kennedy was shot and killed at the Ambassador Hotel in Los Angeles, shortly after winning the California primary. KNX broke into its primary coverage with live reporting from the Ambassador, the headquarters of fellow Democratic candidate Eugene McCarthy, and Central Receiving Hospital, where Kennedy was taken for emergency surgery. He would be pronounced dead the following morning.
KNX would continue to cover news, both locally and nationally, everything from earthquakes, fires, and storms, to shootings and politics. After 67 years at Columbia Square, KNX would broadcast its final show there on August 12, 2005.
KNX would move into new studios in the Miracle Mile neighborhood, where it would continue its all-news format. And in 2017, Entercom Communications acquired KNX when it merged with CBS Radio.
The station continues to follow the top local stories across Southern California, along with the news making headlines across the rest of the world.