KVOZ signed on the air on April 15, 1952; 72 years ago (1952-04-15).[3] It originally broadcast on 1490 kilocycles and its city of license was Laredo. The daytime power was 1,000 watts and at night it reduced power to 250 watts, a fraction of its current output. It added an FM station at 94.9 MHz in 1972.
By the 1980s, the Federal Communications Commission relaxed the rules against assigning stations to clear channel frequencies. With Laredo nearly 1,200 miles (2,245 kilometers) from Chicago, the FCC granted it permission to move to 890 kHz while protecting WLS with reduced power and a directional antenna at night. It made the move to 890 kHz in 1988.