Superman, SuperDJ

In May of 1939, National Allied Publications printed Action Comics #12. It is the sole instance of Superman appearing at a radio station.  In it, the classic comic book character  Superman commandeers the radio station WVUX. It is a fictional radio station.  I first became aware of this appearance because of a reference in the book Media Representations of September 11  by Steven M. Chermak, Frankie Y. Bailey, Michelle Brown.

The story is somewhat nonsensical in contrast to the modern character. In the story, Superman, as Clark Kent discovers that a man he knows died in a car accident. He changes into Superman, breaks into a radio station threatens the engineer, and declares war on reckless drivers. He then proceeds to terrorize bad drivers and destroy a number of automobiles. More here.

There of course is no WVUX presently licensed in the radio bands. There was an LPTV station WVUX-LP licensed in Clarksburg, WV in 2011. There are also a few instances where the call letters of Xavier Universitie's WVXU and Villanova's WXVU are typoed as WVUX.To date it has never stood alone on the AM or FM band.