The Department of the Federal District solicited a permit for a radio station in 1967. However, the station seemed cursed from the beginning. The Department had a hard time procuring the permit; one month after it was issued, the government was still evaluating the technical parameters. Additionally, the original callsign of XEDO-FM had to be changed when it was discovered that a Michoacán radio station had been using those calls since 1961. In March 1969, the SCT informed the DDF that the latter still had not complied with the requirements for the construction of the station. "Radio Departamento", however, soon got on track to launch May 1, 1969, from the top floor of the Departamento del Distrito Federal building, with of floor space to work with.
To IMER
In 1983, the Instituto Mexicano de la Radio was created. IMER included all of the stations operated by the executive branch of the federal government, XHOF included. However, it took the SCT until 2005 to transfer the permit of XHOF to IMER, on the fourth request by the latter. From 1992 to 1994, XHOF was operated by Radio S.A. under contract. Meanwhile, the station went through various 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 take action to "recover" control of the station from IMER, but López Obrador, like his predecessors, did not take any action. The current Reactor format was formed after the closure of Radioactivo 98.5 and the old Órbita 105.7 format. Some of the most popular and relevant radio hosts of the former stations are now working for Reactor. Because of the official nature of the radio station there is a strong tendency to promote Spanish-speaking or Mexican bands, a situation that has defined the personality of the project as the only opportunity for the independent market of alternative or out-of-the-mainstream bands in Mexico. In 2019, the SPR's XHSPRM-FM 103.5 in Mazatlán flipped from simulcasting Radio México Internacional to simulcasting Reactor.
Rock music
One half of the radio station is a rock format, and Reactor helps many Mexico City local bands to become famous by giving them airplay. Sangriento is a Hard rockradio show that airs artists like Rammstein, Korn, Limp Bizkit, and many local artists.
Hip-hop music
Reactor 105 helps many local rappers to become famous by giving them airplay time. Vendetta is a hip hop radio show that airs many American rappers like The Game, Snoop Dogg, Jim Jones, T.I., and many local artists. Reactor is famous by being the only radio station in Mexico City to give a tribute show to dead rappers like 2pac, Biggie Smalls, Eazy-E and some Mexican rappers.
