|Broadcast area||Chicago, Illinois|
|Slogan||Chicago's #1 for throwbacks|
|Frequency||104.3 MHz (also on HD Radio)|
|First air date||1961 (frequency first used March 12, 1949 by WCFL-FM)|
HD2: Sports (WSCR simulcast)
|HAAT||480 meters (1,570 ft)|
|Callsign meaning||We are the Black Music EXperience (trading off former call letters of WVAZ)|
(CBS Radio of Illinois, LLC)
|Sister stations||WBBM (AM), WBBM-FM, WCFS-FM, WSCR, WUSN, WXRT-FM|
The call letters WBMX were originally assigned in the Chicago area to 102.7 on the FM dial in Oak Park, Illinois from 1974 to 1988. (That station frequency is now home to R&B station WVAZ.) The call letters were then assigned to 640 AM in Zeeland, Michigan until 1991, when they were transferred to 98.5 FM in Boston to reflect the station's "Mix" branding. On December 4, 2017, the call letters were transferred from Boston (where they had moved to 104.1 FM in 2009) to 104.3 FM in Chicago.
The 104.3 allocation in Chicago was originally licensed in 1948 to the Chicago Federation of Labor, and went on the air as WCFL-FM on March 12, 1949. Though licensed for 22,000 watts, it only broadcast from 3--9p.m., as a 400-watt simulcast of WCFL (AM) from an antenna on top of the studio. In early October 1949, the Federation shut down WCFL-FM and announced that they would surrender their FM license because they saw no possibility to make money with it.
The station signed on, with the current license, in 1961 as WJJD-FM, co-owned with 1160 WJJD (now WYLL) by Plough Broadcasting. Originally the FM station simulcast the AM station's signal during their operating hours, but changes in FCC rules eventually led to a separate format for the FM. By 1977, the station was known as WJEZ and had a "beautiful country" format, playing instrumental background music with country overtones. This was not a ratings success, and by 1980, WJEZ had a more conventional country music format. In the early 1980s, the station gained competition as WUSN (99.5 FM) also adopted a similar format. At that point, WJJD 1160 adopted a pop standards format and became known as "Music Of Your Life". In 1983, Infinity Broadcasting acquired both WJJD and WJEZ.
On August 4, 1984, WJEZ dropped country and flipped to an oldies format as "Magic 104" with the call letters WJMK. Initially, it was similar to what RKO's 103.5 WFYR was playing, except that WJMK played more 1950s and early 1960s music. WJMK initially also played 1970s and 1980s music, along with a new song every hour. By early 1985, all songs released after 1972 were dropped.
The station focused primarily on songs released between 1964-1969, with a good amount of 1950s and 'early 1960s music as well. In 1991, the station's moniker was changed from "Magic 104" to "Oldies 104.3". During the 1990s, they only played a 1970s song every 90 minutes, and it was an early 1970s song with a couple exceptions. In 1992, another acquisition by Infinity made WUSN sister stations with WJMK. In 1996, Infinity was sold to CBS, adding classic rock station WCKG (105.9 FM), 1970s-based oldies station WYSY (107.9 FM), rhythmic/CHR WBBM-FM (96.3 FM), and AAA WXRT (93.1 FM). To stay within the station ownership limits for the Chicago radio market, Infinity/CBS sold WYSY to the Spanish Broadcasting System. That move left CBS/Infinity with its limit of 8 stations; 5 FM and 3 AM stations, in addition to WBBM-TV.
In 1998, they began to add more 1970s music to the format, cutting off at about 1975, and playing 2-3 1970s oldies per hour while still playing 1-3 1950s songs an hour, as well as a total of 3-4 pre-1964 oldies an hour. In 1999, with new competition from the new Jammin' Oldies format of WUBT, WJMK added a few disco songs and played 3 or 4 1970s songs per hour and playing songs throughout the decade from 1970 to 1979 in the mix. They also added several dozen early 80's songs playing about one every 2 hours. They cut the pre-1964 songs to about 3 an hour with one to two 1950s songs per hour still being played. They also began a 1970s and early 1980s rock show on Saturday evenings, replacing a more traditional 1950s, 1960s and early 1970s oldies show.
WJMK dropped the moniker "Oldies 104.3" and returned to their former moniker "Magic 104.3" on February 8, 2002. WJMK continued with their oldies format, though they modified the playlist over the years, by cutting back on the pre-1964 oldies playing down to one to two per hour. By 2003, the pre-1964 oldies were just about eliminated and WJMK now focused on 1964 to 1979 oldies, playing just under 50% 1960s and just under 50% 1970s oldies with 2 or 3% of the music pre-1964 or post-1979. In July 2003, the station once again changed monikers, going back to "Oldies 104.3" and added some 50's and early 60's oldies back to the playlist, mixing in with the 1964-1979 hits. WJMK also began airing Dick Bartley's syndicated "Rock and Roll's Greatest Hits" on Saturday nights (which they dropped at the beginning of June 2004 to return the "Saturday Night 70s" show). By the winter of 2004-2005, all except about a dozen pre-64 oldies and about 25 songs from the 1980s were gone. At this point, WJMK played almost entirely songs from 1964 to 1979, and the station dropped the "Oldies" moniker and became known as just "104.3 WJMK".
In the spring of 2005, Infinity (the radio division of CBS) had contracted with SparkNet Communications, which owned the U.S. trademarks of an adult hits format known as "Jack FM", which had seen success on a few Canadian stations, to put a variety hits format on stations in some of their markets. That April, they flipped KCBS-FM in Los Angeles and WQSR in Baltimore, Maryland to the new format. On June 3, 2005, at 4 p.m., at the same time long-time oldies station WCBS-FM in New York was flipping to the format, WJMK became "Jack FM" as well.
Jack FM was a format featuring mostly rock and pop songs that appeal to adults. The roughly 2,000 song playlist consisted mostly of music from the 1970s, 1980s, 1990s, and the 2000s, in addition to a few current tracks. Though WJMK's previous oldies format continued to be streamed online and on their HD Radio subchannel, complaints about the change were prevalent, but not nearly to the extent of those in New York City with WCBS-FM.
The former WJMK airstaff returned to the air on WJMK-HD2 in October 2005. Also, that Fall, WZZN (now WLS-FM), seeing a format void and after many years of struggling with different formats, switched to ABC's "True Oldies Channel", a satellite-delivered oldies format. On July 13, 2006, in a cost-cutting move by CBS Radio, the entire airstaff of WJMK-HD2 was laid off, though the oldies format continued to stream online without air talent. Since then, WLS-FM had added a lot of WJMK's former airstaff.
With a format change on WCKG from talk to adult contemporary, Steve Dahl and Buzz Kilman moved from there to WJMK to host mornings. They started on November 5, 2007, as the only live personalities on Jack FM. Dahl continued there until December 5, 2008. At that time, Jack FM reverted to having no live personalities. The station's ratings continued to struggle more when Bonneville International debuted "Rewind 100.3" (a mostly 1980s-based format) on rival WILV in June 2010.
On March 9, 2011, CBS announced that on March 14, beginning at 1:04 p.m., WJMK would switch to a classic hits format known as "K-Hits", dropping the Jack FM format and brand. The change marked the station's return to an updated version of the oldies format it dropped in 2005. Station management described the format as "high energy, music intensive and locally driven".
The final song on "Jack FM" was "Goodbye to You" by Scandal, after which one last liner featuring Homer Simpson was played advertising "a new radio station coming to Chicago that just so happens to be on this frequency," before a montage of songs between 1966 and 1989 was played (similar to what WCBS-FM did in 2007 when it relaunched its classic hits format, and using the almost exact same montage that launched the oldies format of WOCL-FM/Orlando in 2008). "K-Hits" then launched with "Beginnings" by Chicago.
Chicago radio personalities Ed Volkman and Joe "Bohannon" Colborn (Eddie and JoBo) would anchor the station's morning show, along with Gary Spears hosting middays, Bo Reynolds in afternoon drive, and George McFly for evenings.
Volkman and Colborn would remain the morning hosts until December 6, 2012, when they were released, with the station citing low ratings as the main factor. Mornings were thereafter hosted by Dave Fogel, formerly of WLS-FM. The rest of the station's final airstaff included Brian Peck in middays and Jeffrey T. Mason in afternoon drive. Weekend airstaff included Ken Cocker, John Calhoun, and Dona Mullen.
In its last year, the station played less music from the 1960s (save for major artists such as The Beatles, The Rolling Stones, and Creedence Clearwater Revival) and focused mainly on songs from the 1980s, with a moderate amount of 1970s music, and a small amount of 1990s music.
Jingles were done by Reelworld Productions in Seattle as of 2017. JAM Creative Productions in Dallas, Texas previously did all station jingles.
On February 2, 2017, CBS Radio announced it would merge with Entercom. The merger was approved on November 9, 2017, and was consummated on the 17th. On that day, at 10 a.m., after playing "The Long and Winding Road" by The Beatles and "Changes" by David Bowie, WJMK began stunting with a heartbeat and other sound effects, and sound clips of a man giving occasional comments to the like of "What's going on here?" and "It's almost time to start". One hour later, WJMK flipped to classic hip hop as "104.3 Jams", with an introduction by rapper and station voiceover MC Lyte. The first song on "Jams" was "Hypnotize" by The Notorious B.I.G.. Entercom applied to move the WBMX callsign to 104.3 from their sister-owned station in Boston to match the new format; the calls had previously been used by new rival WVAZ from 1974 to 1988. The change took effect on December 4, 2017. In addition to WVAZ, WBMX also competes with WPWX and WGCI in the urban market. WBMX is the second station in Chicago to use the "Jams" moniker; it was originally used in the mid-1990's on WEJM (now WSRB).