Why do radio stations always start their initials with K or W? Because it's the law! An agency called the Federal Communications Commission (FCC) sets rules for radio stations. The FCC assigns each station to its place on the radio dial, the power it can use to broadcast and its initials. These initials are the station's call sign. East of the Mississippi River, most call signs start with W. In the western United States, they usually start with K, says 3-2-1 Contact magazine.
Radio stations started broadcasting back in the 1920s. They had only three letters in their call signs. Call signs grew to be four letters long as more stations started broadcasting. But some stations still use their old three-letter names.A radio broadcaster can ask the FCC for a certain set of call letters. You might ask to name your cool staion K-HOT or WWOW. Who wants to get stuck with a name like KLUK?