WBMJ is located in the Capital city of San Juan, Puerto Rico and has a power output of 10,000 directional watts. This station covers the San Juan Metroplex, adjacent major cities, the Central and North-Eastern portions of the main island of Puerto Rico. WBMJ's coverage area population is 2,047,093 (1999-2000 Census). It was known as 'Radio Rock' when it went on the air in 1960. CEM purchased WBMJ and changed its format to Christian programming September 29, 1986.