In the 1970s and 1980s, CHNO was Northern Ontario's most listened-to and most influential radio station, broadcasting a Top 40 format branded as 55 CHNO, Rock Radio CHNO 55, "Sudbury's Best Rock", and "Sudbury's Hit Music Leader", NO55.
1980–1982[]
1982–1985[]
1985–1990[]
1990–1992[]
1992–1994, 1997–1999[]
1994–1995[]
1995–1996[]
1996–1997[]
LOGO MISSING
1999–2006[]
SVG NEEDED
In November 1999, CHNO dropped its oldies format and adopted its new CHR/Top 40 format under the Z103 branding.
2006–2010[]
At 12:00 AM on January 1, 2006, with little or no warning, the station flipped to a variety hits format branded as Big Daddy 103.9 with slogan "Playing Anything".
2010–2021[]
SVG NEEDED
On May 21, 2010, the station dropped adult hits and switched to its current classic hits format as Rewind 103.9, playing 1960s, 1970s, 1980s and 1990s music with the slogan "Sudbury's Greatest Hits".
