XETRA-FM

XETRA-FM (91.1 MHz), branded as 91X, and sometimes identified as XTRA-FM, is an English-language radio station licensed to Tijuana, Baja California, Mexico. It airs an alternative rock radio format. The studios and offices are on Cornerstone Court in San Diego's Sorrento Valley neighborhood. The station is one of three Mexican outlets programmed by Local Media San Diego LLC, along with XHITZ-FM and XHRM-FM, in which an affiliated company owns a 49 percent non-voting stake. It is Mexico's first alternative radio station, and has influenced other radio stations (including XHMORE-FM) to create the Spanish-language rock radio format in 1994 .

As a Mexican station, XETRA-FM must carry mandated public service announcements, most of which are translated into English by 91X, electoral advertising, the Mexican National Anthem at midnight and 5 a.m. daily, and La Hora Nacional on Sunday nights. The station transmits with an effective radiated power of 100,000 watts. It is considered a border blaster, covering the majority of San Diego County, as well as southwestern Riverside County, from its tower located atop Mount San Antonio in Tijuana.