The station began broadcasting on March 9,
1959 as WDHF, owned by
Hi-Fi systems and record store owner James deHaan. Its call sign stood for deHaan Hi-Fi. Its transmitter and tower was in
Oak Lawn, at 97th and Central. Controlling interest in Federal Broadcasting was owned by comedian
Bob Newhart. In 1971, the station's transmitter was moved to the
John Hancock Center on the
Near North Side of Chicago. In 1973, the station was sold to
Metromedia for $2.75 million and it adopted an
adult contemporary format. The following year, WDHF adopted a
top 40 format. During this era, WDHF was the local broadcaster of the weekly syndicated program
American Top 40. Jim Channell, known on the air as "Captain Whammo", was a DJ on the station during its top 40 years. On December 1, 1976, the station's callsign was changed to WMET, while retaining its top 40 format. In 1979, Metromedia flipped WMET to an
AOR format. In 1982, WMET was sold to
Doubleday Broadcasting for $9.5 million. WMET called itself "Chicago's Classic Rock" in 1981. On January 11, 1985, at 3 p.m., WMET switched to an adult contemporary format. As a promotional stunt, in the days leading up to the format change the station periodically interrupted the rock programming with static and a man's voice stating "enough is enough". In May 1986, the station's call sign was changed to WRXR, and it adopted an early version of what would later become the
adult hits format (described as "Male Adult Contemporary" by station management), with a playlist featuring artists like
The Beach Boys,
The Doobie Brothers,
ZZ Top and
Sade. In 1987, WRXR was sold to Pyramid Broadcasting for $15 million.
Smooth jazz era On August 3, 1987, the station's callsign was changed to WNUA and the station adopted a format which featured
new-age music and
smooth jazz, along with music from
R&B and
rock artists that were compatible with the station's sound. WNUA's original slogan was "Music For a New Age", and New Age was the source of the station's call letters. "Smooth Rock" would later be dropped from its slogan. In 1995, the station's owner, Pyramid Communications, was acquired by Evergreen Media. In 1997, Evergreen merged with Chancellor Broadcasting. Chancellor merged with Capstar and restructured as AMFM, Inc. in 1999, and in 2000 merged with
Clear Channel Communications making WNUA a Clear Channel station. WNUA was the home of the now-defunct
Ramsey Lewis morning show, and it was also where he recorded his syndicated show,
Legends of Jazz (which showcased the music of instrumentalists
Charlie Parker,
Oscar Peterson and
Miles Davis, as well as vocalists
Louis Armstrong,
Billie Holiday and
Ella Fitzgerald) for distribution to other
smooth jazz stations across the nation. The show lived on in Chicago on
WLFM-LP during that station's run, and later on
WDCB. Other on-air staff included Karen Williams, Rick O'Dell, Danae Alexander,
Dave Koz, Bill Cochran, Scott Adams, Annie Ashe, Dona Mullen, Glenn Cosby, and Porsche Stevens. Rick O'Dell was also program director/music director. In late 2006, three
smooth jazz personalities, WNUA's
Ramsey Lewis, Annie Ashe, and
Dave Koz, were tapped by Broadcast Architecture to syndicate their respective shows on its Smooth Jazz Network. WNUA won
Radio & Records Smooth Jazz Station of the Year award eight consecutive years, from 1998 to 2005, and was the recipient of the
Marconi Award for
NAC/Jazz Station of the Year in 2004.
Spanish-language era On May 22, 2009, at 9:50 a.m., after playing
Richard Elliot's "Here And Now", WNUA stunted for 5 minutes with a ticking clock and an announcer saying "In _ minutes, 95.5 reaches its big/mega event." Along with the clock sound, they aired a recap of jingles and moments from its history as WDHF, WMET, WRXR, and WNUA. 95.5 then had a countdown from 10 to 1 switching in the middle from English to Spanish. Following lackluster ratings as
Mega 95.5, on June 19, 2012, after playing "Creo en Ti" by Mexican rock band
Reik, WNUA switched to a
Regional Mexican format known as "El Patrón 95.5" to more directly compete with
WLEY and
WOJO. However, the station's ratings failed to improve; in the December 2014 ratings report for the market, WNUA held a 1.9 share of the market.
Big 95.5 On January 5, 2015, at 12 p.m., WNUA flipped to
country as "Big 95.5", giving
WUSN its first local competitor since
WKXK in 1997. The first song on "Big" was
This Is How We Roll by
Florida Georgia Line. WEBG would serve as the Chicago affiliate of
The Bobby Bones Show, first in evenings on a delay before being moved to mornings in August 2018.
Rock 95.5 While WEBG, unlike many past competitors, was able to put up a fight against WUSN, they would still finish behind them, and typically hit a 1 or 2 share in the Nielsen ratings, putting them in the lower echelon of commercial stations in the crowded Chicago market. While the last ratings, released just two days before the format ended, saw a decent upward trend (seeing them tie the July 2020 results with a 2.1 share, up from a 1.7 in June and just .2 points behind WUSN), it was ultimately too little, too late for the "Big" format. On September 3, 2020, at 11 a.m., after playing "
Happy Trails" by
Roy Rogers, WEBG began
stunting with music from various genres (the first song being "
It's the End of the World as We Know It (And I Feel Fine)" by
R.E.M.), punctuated by liners during the top-of-the-hour
station identification stating "It's going to sound weird here. Keep listening". The country format moved to the HD2 subchannel of the station; the previous smooth jazz format on that subchannel was subsequently moved to a new HD3 subchannel. At 5 p.m. that day, after playing "
The Final Countdown" by
Europe, WEBG flipped to rock as "Rock 95.5". The first song on "Rock" was "
Enter Sandman" by
Metallica. The format, while playing similar music to what it had during the days of WDHF, WMET, and even WRXR, also features a variety of rock reaching into the 1990s and as far as the late 2000s. The flip positions WEBG between
Hubbard's
classic rock-formatted
WDRV and
Cumulus'
alternative-formatted
WKQX, and brings a harder-edged rock station back to the market for the first time since
WLUP was sold and flipped to
K-Love in 2018. Following the format change, WEBG applied to change its call sign to WCHI-FM; the change took effect on September 14, 2020. On September 14, 2020, iHeartMedia announced that Angie Taylor from sister station
WKSC-FM would host mornings on WCHI, alongside Abe Kanan. After a social media campaign for the slot, night host Maria Palmer was moved to mornings alongside Matthew (Marris) Harris and Michael Mason. They launched the "January 6th Erection" of the Morning Mosh Pit on January 6, 2025. ==HD Radio==