Early in the 20th century, Radio communications was a new product and was initially used as a wireless telegraph. The messages were transmitted in Morse alphabet code. To reduce the number of dashes and dots required to recognize every party, the radio stations on both land and ship adopted the practice that was familiar in telegraphy, to commence messages with identifiers called call letters. Due to the lack of an omnipresent authority to hand over call signs, operators chose their own, and commonly chose ones already functional. Later, an international convention recognized that every operator should have a unique, 3 letters call sign. However, it was left in vague how to ensure uniqueness.
To get rid of this confusion, the United States started licensing of terrestrial radio stations in the year 1912. From the inception, it has started to assign call letters beginning with K and W prefixes. The stations in the west generally got letter K whereas stations near the east were issued letter W as the first letter of the initials. The letters assigned were the result of international agreements proposed at the International Radiotelegraphic Conferences held at London, in the year 1912. The outcome of the conference was the assignment of definite letters to certain countries, to recognize their television and Radio signals â€“ the United States of America was given letters A, K, N, and W.
W and K were specifically chosen for commercial use while N and A were chosen for American military radio stations; A to Army and Air Force, N to Navy and Coast Guard. Initially,Â Stations were permitted to choose the letters that followed the W or the letter K, and the combination was of three or four letters.
However, radio call signs are reversed out on the ocean. On the Atlantic side ship radios starts with letter K, and radios on America’s Pacific coast start with W. It’s uncertain whether this exercise, which precedes call signs for terrestrial radio, is by intention (the distinction between radio stations on land and at sea) or the outcome of miscommunication. In the beginning, the border between W land and K country had to be fixed geographically. However, that dividing line set additionally further to the west than it does now. The W/K boundary touches north from the Texas-New Mexico border, New Mexico in the west with Texas and Oklahoma in the east.
This was perhaps done to carry on the division between the land radios in Texas (which started with W when it was an ‘eastern’ radio state) and ship radios in the Gulf of Mexico (which started with K). It was in the late January 1923, when the first federal regulation of station call signs, the K/W boundary got shifted east to the existing border of the Mississippi River, turning Texas and 10 other ‘eastern’ (W) states into ‘western’ (K) ones.
In the later year more efforts were made to regularize and improve radio broadcasting. Therefore, the U.S. Congress passed theÂ Radio Act of 1927, which formed the Federal Radio CommissionÂ (FRC). Its purpose was to discipline and organize the licensing of transmitters, including assigning radio station frequencies, power limits, and call letters. FRC regulated some of the existing rules. Accordingly, new radio stations in the switchover states would be assigned a K call initial rather than a W one. However, the main clause provided that those radio stations in those states which already had a W call sign could keep it. This is the reason some of the inconsistent call signs still in exist today. There are at present 27 exceptions to the general K/W divide -18 Ws in K Land and 9 Ks in W Country.