Why do radio stations begin with “K” or “W”?

Radio may not be quite the media force it once was, but there are still thousands of stations around the country, and the letters of appeal for almost every one begin with “K “Or” W “.

Why? Because the government said so.

During the telegraph era, operators began to use short letter sequences as identifiers, calling them letters of call or call signs. The early radio operators continued the practice, but without a central authority assigning call letters, radio operators often chose letters already in use, which is confusing.

To alleviate the problem, the Bureau of Navigation (part of the Department of Commerce) began assigning three-letter call signs to US ships in the early 1910s. Ships in the Atlantic and Gulf of Mexico have a K prefix; in the Pacific and the Great Lakes, a W. The precise reasons for choosing these two letters, if any, are unknown (the bureaucracy operates in a mysterious way). At the 1912 London International Radiotelegraph Convention, letter ranges were allocated to each of the participating countries and the United States was urged to continue using the W and most of the K range (military stations used NOT.)

When the federal government began licensing commercial radio stations soon after, it planned to issue letters of appeal to land stations in the same manner. Somehow things turned upside down during implementation, however, and stations in the east got W call signs and those in the west got K. Where exactly does the Bureau of Navigation draw the line between East and West? For a time it ran north along state lines from the Texas-New Mexico border, but moved in 1923 to follow the Mississippi River.

Some areas, however, may have both a K station and a W station in the same neighborhood. Why? When the dividing line swung, some stations were forced to change their call signs, while others were not. For about a year in the 1920s, the Bureau of Navigation decided that all new stations were going to have a K call sign, no matter where they were. Still other exceptions have been made by special requests, relocations of stations, changes of ownership and even human error.

As for the rest of the call sign: This sometimes includes the station (ABC, NBC), but can also be an acronym. WGN stands for “the largest newspaper in the world” (because it was considered the Chicago Tribune‘s radio station) while the Chicago WTTW is “Window to the World”. But nothing beats the sports resort of Saint-Louis KRAP, which given label itself very self-aware in 2014. “Our signal is KRAP,” one read on their website. “Our studios are KRAP. Even our staff is KRAP.

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