XESURF-AM (540 kHz) is a Mexican radio station licensed to Tijuana, Baja California, serving the San Diego–Tijuana metropolitan area. XESURF airs a Spanish-language Christian radio format. It is operated by Zion Multimedia Inc. located in Downey, California. XESURF's transmitter site is located near Mexican Federal Highway 1D in Playas de Tijuana. By day, it is powered at 25,000 watts, with its signal heard throughout much of Southern California, including the San Diego and Los Angeles metropolitan areas, as well as northern Baja California. But 540 AM is a clear channel frequency. So to avoid interference at night, XESURF must reduce power to 100 watts at sunset. History In the 1940s, 540 AM was home to KFMB San Diego. When KFMB moved up the dial to 760 kHz, the government broadcast authorities in the U.S. and Mexico reserved 540 kHz for a Mexico-based radio station. However, for a few years in the 1980s, there was a U.S.-licensed radio station at this frequency, KSHO in Hesperia, California, and later KNNZ in Costa Mesa, California. It was not until May 13, 1991 that the concession was awarded for XETIN-AM, which was originally licensed as a 5,000-watt daytimer and owned by Víctor Manuel Moreno Torres. Ultimately, a Mexican concessionaire took over operation of XETIN for Los Angeles radio station owner Saul Levine. In 1995, XETIN became an all-news station branded as "K-News", simulcast with AM 1260 KNNS (now KMZT) in Beverly Hills and AM 540 KNNZ (now 1650 KFOX) in Costa Mesa. The three stations attempted to compete with CBS Radio-owned KNX 1070 and Westinghouse Broadcasting's KFWB 980, both highly rated all-news operations. The all-news format was discontinued two years later. The station became XEBACH-AM in 1997, and aired a classical music format. The format flip was spurred by San Diego's original classical station, KFSD, moving from full-powered 94.1 FM to a lower-power suburban station, 92.1 FM in Escondido. A year later, KNNZ moved to 1650 AM, leaving XESURF as the only station in the region broadcasting on AM 540. In June 2000, XEBACH became XEJAZZ-AM with a jazz format relayed from KJAZ (1260 AM) in Los Angeles. The format did not last long, and XEJAZZ promptly became XEBACH again in May 2001. In March 2002, motivated by low ratings and the move of the San Diego Opera to KPBS-FM 89.5, Levine opted to flip formats, and the station was relaunched with an adult