WTKM (AM) began broadcasting in 1951, and also has an FM sister station at 104.9 MHz, which began broadcasting in the 1970s. Both stations ran a polka and full service format for most of their existence. Most of WTKM's programming was a simulcast with the FM, although it aired separate German Language and music programming on Sunday afternoons called "The Voice Of Germany" and "The Rosary" weekday afternoons.
On December 1, 2009, the AM station launched an oldies format, as "Cruisin' 1540", no longer simulcasting WTKM-FM's programming. Branding itself as "Good Time Rock 'N Roll" the station airs a mixture of 50s-70s oldies.