WMFN

WMFN (640 AM) is a radio station broadcasting a Spanish Contemporary music format. The station is known on-air as "Radio Activa." The station is owned by Birach Broadcasting. Licensed to Zeeland, Michigan, it first began broadcasting in 1990 under the WBMX call sign, and has been through a number of different formats and call signs since, including the Radio AAHS children's format, mainstream talk, sports talk and most recently (prior to the current format) Regional Mexican. During its sports talk days former NFL great Ray Bentley hosted his own afternoon program.

AM 640 was originally a MOR station in 1990 when it signed on as WBMX, using the call sign that had recently been vacated by a popular urban contemporary station in Chicago, Illinois. The following year, the owners of WROR-FM 98.5 in Boston, Massachusetts, bought the WBMX call letters from AM 640 in order to debut "Mix 98.5" there; in return, AM 640 received the WROR calls. Its format did not change. In 1993, WROR-AM was sold and converted to Radio AAHS as WISZ, freeing the WROR calls to be used again in Boston, where they were again placed beginning in 1996.