KMA 960 AM is one of Iowa’s oldest radio stations. Its call letters, chosen specifically by the May Seed & Nursery Co., mean “Keep Millions Advised.” The May family owned the station from its beginning in 1925 until 2019. Here is a book from 1985 (large PDF) chronicling the station’s first 60 years.
KMA is one of the few three-letter K stations remaining east of the Rockies. The codes had been “assigned to the Merchant Fleet of War Vessels during the late World War,” said the April 30, 1925, Clarinda Herald. Two in Pennsylvania have weird histories and one of those may have been an accident.
KMA’s letters came after the K/W line was moved to the Mississippi River, but before 1930 while stations were still able to apply for both three-letter and personalized call letters.
(The K/W switch in early 1923 grandfathered in such well-known Iowa stations as WOI and WOC. WMT came in slightly later as a change from WJAM, which started in 1922. However, from what I can gather, the only way WHO could have gotten those letters on April 15, 1924, is by request, contradictory to its Wikipedia page. The only other three-letter W that month went to Sears Roebuck — the World’s Largest Store.)
The Early Radio History website, nearly 25 years old, is a treasure trove of information about early radio. Its creator painstakingly has dug up a lot of history.
There was another three-letter K station owned by a seed company a few miles down the road from KMA. That’ll be covered in a future post.