CBF went on the air on December 11, 1937, as the CBC launched its French-language network, known as Radio-Canada. CBF operated on 910 using 50,000 watts full-time with an omnidirectional antenna as a clear channelClass I-A station. The transmitter was located in Contrecoeur. The station moved to 690 on March 29, 1941, as a result of the North American Regional Broadcasting Agreement. In 1978 the CBC consolidated its two Montréal AM broadcast transmitters and the station moved to a new transmitter site shared with CBM in Brossard. CBF started to broadcast from Maison Radio-Canada in November 1971. Commercial advertising on the station was eliminated in 1974 except for Montreal Canadienshockey games. CBF applied to move to FM and was authorized to do so by the CRTC on July 4, 1997. The AM signal covered much of the western half of Quebec, and was strong enough to be heard in Ottawa and the National Capital Region, as well as parts of New York State and Vermont. Indeed, until CBOF signed on in 1964, CBF doubled as the Radio-Canada outlet for Ottawa as well. Its nighttime signal covered most of the eastern half of North America, including much of Eastern Canada. However, radio frequency interference rendered it almost unlistenable in parts of Montreal during the day, which prompted the decision to move the station to the FM dial. The FM transmitter was put on the air ahead of schedule on January 22, 1998, and initially had special programming targeting people affected by the 1998 Ice Storm. The AM signal was shut down on January 21, 1999. CBF became CBF-FM when it moved to the FM dial. The existing station with the CBF-FM callsign at 100.7 MHz was renamed CBFX-FM. The station's old home at 690 was taken over by CKVL, which moved from 850 under the new callsign CINF. That station closed down in 2010, and the frequency remained dark until 2012, when English-language sports station CKGM moved there. To improve reception, CBF was authorized to increase its power from 17,030 watts to 100,000 watts on June 2, 2000. The power increase was implemented in mid-2001. In recent years the popularity of the station has increased significantly. The station is now usually one of the top five stations in Bureau of Broadcast Measurement ratings, after decades of being an also-ran. On September 27, 2018, CBF-FM began broadcasting in HD Radio for compatible receivers, with its second digital radio subchannel offering ICI Musique Classique, a digital-only music feed.
Transmitters
On October 17, 1986 the CRTC approved the CBC's application to change CBF-3's frequency from 1400 to 650 kHz.. CBF-FM-10 in Sherbrooke and CBF-FM-8 in Trois-Rivières were once full satellites of CBF, but began airing some local programming in 1998. They have both been licensed as full-fledged stations since 2000, despite still having rebroadcaster-like call signs. Both stations have their own local programs and news bulletins; otherwise, their schedules are similar to CBF. On July 5, 2010, the CBC applied to decrease the effective radiated power of CBF-20, and also on the same date, the CBC also applied to broadcast, on the rebroadcasting transmitters CBF-16, CBF-17 and CBF-18, the programming of CBF-8 instead of the programming of CBF. All technical parameters of the rebroadcasters would remain unchanged. On July 29, 2010, the CRTC approved the application to transfer transmitters CBF-1, CBF-3 and CBF-4 from CBF to CHLM-FMRouyn-Noranda. On October 30, 2012, the CBC received approval to change the source of programming from CBF to CBFG-FMChisasibi on the following repeaters: CBFA-1 Manawan, CBFA-2 Obedjiwan, CBFW Wemindji, CBFM Mistissini, CBFA-3 Wemotaci, CBFH Waskaganish and CBFV Waswanipi.
As of 2015, the entirety of CBF's schedule is broadcast live throughout North America via Sirius XM Canada on channel 170. In effect, CBF is one of four terrestrial stations in North America to be broadcast on Sirius XM, and the only one broadcast using the same feed as the local station.
