9AAU 1923 St. Louis, MO

Carl W. Klenk, W0ZK, ex-W9ZK, 9AAU, 9ZK and 9DS, was a radio engineer for an aircraft manufacturing company in St. Louis, Missouri in 1930 and 1940.
A 1924 issue of Radio Age magazine had an article about his station: "9AAU was well known for his consistent DX work in both receiving and transmitting and he was heard in every district in the United States."
Carl was born November 26, 1907 in St. Louis, Missouri and became a Silent Key in May 1966.

QSL, Photo NL7XM Collection
Info courtesy of W5KNE