DXRK

RK era: 1979–2002

DXRK was launched on December 26, 1979 by then Mayor Pedro "Oloy" N. Roa, through his company P.N. Roa Broadcasting System. The station was then called 99.9 RK, bearing the slogan "The Rhythm of the City" (inherited from 99.5 RT Manila (now 99.5 Play FM)). Its format was more of contemporary hit radio (CHR). On December 27, 1979, 99.9 RK it had its first broadcast and it operates 24 hours a day, 7 days a week. On February 3, 1997, 99.9 RK limited its broadcast from 8:00 AM to 12:00 MN.

99.9 RK ceased broadcasting on December 31, 2002 after 23 years of broadcasting.

Bay Radio era: 2003–2010

Acquired back then by Baycomms Broadcasting Corporation, DXRK changed its callsign to DXBD and began its test broadcast on January 27, 2003. On February 24, 2003, it was relaunched as 99.9 Bay Radio Cagayan de Oro. The station signed on at 5:00 AM. The format of the station is Hot AC music. It initially operates from 5:00 AM to 12:00 MN. At that time, its studios and transmitter were located at J.R. Borja St. In 2008, its callsign was reverted to its original callsign, DXRK. From March 2, 2009 to March 28, 2010, Bay Radio began broadcasting 24 hours a day except on Mondays where it signs off at 12:00 MN to 5:00 AM. From April 5 to December 18, 2010, Bay Radio began broadcasting 24 hours a day, 7 days a week.

After 7 years of broadcasting, 99.9 Bay Radio signed off for the last time on December 25, 2010 in Christmas Day with the last program of Foreign Saturday Nights and the last song "Already Gone" by Kelly Clarkson. Since the next day, 99.9 FM was left dormant. During that time, the station was sold to Magnum Broadcasting Inc., and its studios moved to its present location at 2nd floor, SBS Building, C.M. Recto Ave. and transmitter moved to its present location at Osmena St.

On January 1, 2011, in New Year's Day, 99.9 FM installed the new management of Magnum Broadcasting, Inc.

Magnum Radio era: 2011–present

On February 1, 2011, after a month hiatus. 99.9 FM returned on air as a test broadcast. On February 28, 2011, 99.9 FM was relaunched as Magnum Radio at 4:00 AM. It initially operates daily from 4:00 AM to 12:00 MN.^[1] Under the new management of Magnum Broadcasting Inc., the main format of the station is news/talk and music, similar to 89.5 Brigada News FM General Santos.

On October 1, 2012, Magnum Radio began broadcasting 24 hours a day, except on Mondays where it signs off at 12:00 MN to 4:00 AM.

Magnum Radio has ranked #1 in Cagayan de Oro, based on the recent Kantar Media Radio Research Council Survey. It got 3.775% of audience share.