CBAT originally broadcast from a transmitter located on Mount Champlain near Saint John, its city of licence until 2011,[1] and operated a network of rebroadcasters throughout the province.

The station first went on the air on March 22, 1954, as CHSJ-TV, owned by the Irving family's New Brunswick Broadcasting Company along with CHSJ radio (AM 1150, now at 94.1 FM) and located in Saint John.

Originally, CHSJ was the CBC affiliate for southern New Brunswick while CKCW-TV in Moncton served the northern and eastern portion.

Over the years, CHSJ had a tendency to preempt large blocks of network programming, forcing an entire province to miss several of the CBC's most well-known shows.

After numerous complaints, in 1988 the Canadian Radio-television and Telecommunications Commission (CRTC) ordered CHSJ to clear the base 35-hour block of CBC programming when MITV came along that year with stations in Halifax and Saint John.

In 2003, CBAT made a controversial programming decision to preempt the CBC's broadcast of Game 7 of the Stanley Cup Finals in order to carry live returns from the provincial election.

On March 23, 2011, the CRTC denied an application by the CBC to install a digital transmitter that provided coverage to Fredericton, but not Saint John.