The station began broadcasting in 1993, holding the call sign WJDK and airing an adult contemporary format.[1][5] In 1997, the station was sold to Big City Radio.[6]
WYXX
In February 1998, the station's call sign was changed to WYXX and it adopted a rhythmic oldies format branded "Chicago's Heart and Soul", simulcasting 103.1 WXXY in Highland Park, Illinois, with the station's call sign and adult contemporary format moving to 95.7.[2][6][7] In August 1999, WYXX and WXXY adopted a 1980s hits format as "The Eighties Channel," with the station patterned on high-energy CHR stations of the 1980s.[8][9][10] The station featured longtime Chicago area radio personalities including Robert Murphy, Fred Winston, and Mark Zander.[8][10]
In 2001, WYXX and WXXY adopted a Spanish hits format, branded "Viva 103.1".[11][12][13] By January 2003, the station had ended its simulcast with WXXY, and adopted a dance hits format as "Party 103.1".[14]
WCSJ-FM
In late 2003, the station was sold to Larry Nelson for $426,000.[15][16] In January 2004, the station's call sign was changed to WCSJ-FM, and it adopted a mix of soft oldies and adult standards as an affiliate of ABC Radio's "Timeless" network.[17][18]
After the shutdown of Timeless in February 2010, WCSJ-FM adopted a classic hits format.[19] It combines hits of the 1970s, 1980s and 1990s with local news and high school sports.