The station was in operation from 1971 to 2002 as a private affiliate of CBC Television, and then continued until 2012 as a network-owned rebroadcaster of CBLT in Toronto.
On the same day, the existing television station in North Bay, CKNY, switched affiliation to CTV.
Until 1980, CHNB and CKNY aggressively competed with each other for advertising revenues, leaving both in a precarious financial position due to the North Bay market's relatively small size.
On April 13, 1978, the CBC was given approval to add a television transmitter at Témiscaming, Quebec, on channel 21 with an ERP of 75 watts to rebroadcast the programs of CHNB-TV.
[2] All four ceased to exist as separate stations on October 27, 2002, becoming rebroadcasters of Toronto's CBLT, with CHNB's call sign changing to CBLT-4.