ALFA 91.3 (CDMX)

Alfa 91.3 (XHFAJ-FM, 91.3 FM) is a Mexico City station owned by Grupo Radio Centro carrying a contemporary hit radio format. It broadcasts in HD, with its transmitter located in La Mesa/Villa Alpina in Naucalpan, on the western outskirts of the city.

The station signed on in 1968 as Radio Sinfonía de México, airing classical music. In 1973 it was sold to the concessionaire of XEQK-AM and began simulcasting that station. After being sold again to Radio Programas de México, it was relaunched on September 13, 1986 with its current name, playing then-current English-language music. Alfa 91.3 was created by Clemente Serna Barrera, with forerunners including Martha Debayle, Rocío Barbabosa, Edward "Fast Eddie" Muller, Eduardo Vallarta, Claudia Arellano, and Luisa Carrandi.

In April 1990, Alfa attended the opening of the Cabo Wabo in Baja California, landing an exclusive interview with Van Halen and their new vocalist Sammy Hagar. That June, it carried the first simulcast of the Knebworth Festival in England, live for 12 continuous hours, with exclusive interviews with Paul McCartney and Eric Clapton, among others. In January 1991, it covered the Rock in Rio II Festival from Maracanã Stadium, with Guns N' Roses, George Michael, New Kids on the Block, Billy Idol, Megadeth and many more.

Alfa was the first station in Mexico City to broadcast a Top 40 format with a proven formula, credited to Bruce Miller Earle. Under the slogan "Radio Bang!" (1990-1993), it held the top Nielsen positions and was the first Mexico City station to air jingles in English. It pioneered live remote broadcasts from concerts, restaurants, shopping centers, universities and beaches across Mexico via a mobile unit, including shows at the Palacio de los Deportes with Sting, INXS, Metallica, MC Hammer and others.

In 1995, after being acquired by Grupo Radio Centro, the station switched to electronic music and eurodance, becoming Mexico City's top-rated station for several months before returning to contemporary hit radio by 1999; from 2000 to 2003 it added Spanish-language hits. Through the 2000s it kept a CHR format focused on rock, pop and hip-hop, with heavy post-grunge and emo rock from 2006 to early 2009. In 2009, after losing audience to rivals like XHDFM-FM, XHSON-FM and XHPOP-FM, it shifted to 1990s music. On January 13, 2010, host Toño Esquinca joined with his show La Muchedumbre (6 am to 1 pm daily), which also aired on KXOS from November 2012 to January 2014. Latin urban music joined the programming for a time but was removed by the end of 2020.

Monterrey's XHMF-FM adopted the Alfa format in 2014, followed by Guadalajara's XHKB-FM in 2019 (replaced a year later by Planeta); XHMF dropped the simulcast on May 18, 2025. The station was also previously relayed in Ciudad Juárez over XHEPR-FM and in Cancún over XHPBCQ-FM.