KHJ went on the air at 720 kHz on April 13, 1922. The station switched frequencies several times in the late 1920s in response to increased interference on the AM band. The Federal Radio Commission (FRC) regulated the band in 1927–28 and reassigned KHJ to the regional-service frequency of 900 kHz with 1,000 watts of power, where it remained until 1941. At that point, a reorganization of the AM band by the Federal Communications Commission (FCC, successor to the FRC) in conjunction with the North American Regional Broadcasting Agreement raised KHJ's power to 5,000 watts and moved to 930 kHz, where it continues to operate.