KSOS was a radio station broadcasting on 800 kHz from Brigham City, Utah.
On March 17, 1997 the Federal Communications Commission (FCC) announced that eighty-eight stations had been given permission to move to newly available "Expanded Band" transmitting frequencies, ranging from 1610 to 1700 kHz, with KSOS authorized to move from 800 to 1660 kHz.
[6] A Construction Permit for the expanded band station was assigned the call letters KBDF on March 23, 1998.
[7] KSOS was famous for its weekly Hispanic-oriented "El Ranch Rio Grande show" hosted by a local and veteran broadcaster George Gonzales.
An FCC policy allowed both original stations and their expanded band counterparts to operate simultaneously for up to five years, after which owners would have to turn in one of the two licenses, depending on whether they preferred the new assignment or elected to remain on the original frequency.