Wikipedia
WDAO
WDAO "The Real Rhythm Of The City" is a daytime-only commercial AM radio station in Dayton, Ohio operating on the frequency of 1210 kHz with a power of 1,000 watts. Its studios are currently located on West Third Street with transmitter located in South Dayton.
The WDAO calls came as a result of all stations East of the Mississippi which begins with "W", the "DA" is for Dayton and the "O" is for Ohio.