105.7 Reactor (CDMX)

Reactor 105.7 (XHOF-FM) is a Mexico City station broadcasting on 105.7 MHz, playing alternative rock and hip hop, mainly in English and Spanish. Its transmitter is located in Ajusco, south of the city. It used to broadcast in HD, but the digital signal went silent in early 2020 due to operating costs.

The station's origins go back to 1967, when the Department of the Federal District (DDF) applied for a radio permit. The process was troubled: a month after the permit was issued, the government was still evaluating technical parameters, and in April 1968 the original XEDO-FM callsign had to be changed after it was discovered a Michoacán station had used it since 1961. In March 1969, the SCT informed the DDF it still had not met construction requirements, but Radio Departamento launched on May 1, 1969, from the top floor of the DDF building.

In 1983, the Instituto Mexicano de la Radio (IMER) was created, incorporating all stations run by the federal executive branch, including XHOF; however, the SCT did not transfer the permit until 2005, on IMER's fourth request. From 1992 to 1994, the station was operated under contract by Radio S.A. (RASA). Over the years it went through several names and formats: Radio Cosmos, Estéreo Joven, Láser FM, Conexión Acústica and Órbita 105.7. In 2005, the Legislative Assembly of the Federal District asked then-mayor Andrés Manuel López Obrador to recover control of the station from IMER, but no action was taken.

The current Reactor format was formed after the closures of Radioactivo 98.5 and the old Órbita 105.7, and some of the most popular hosts from those stations joined Reactor. Because of the station's official nature, it strongly promotes Spanish-speaking or Mexican bands, making it a unique outlet for Mexico's independent alternative music market. In 2019, XHSPRM-FM 103.5 in Mazatlán switched from simulcasting Radio México Internacional to simulcasting Reactor.