WCNI was originally an on-campus AM radio station broadcast to Connecticut College students and staff via low-power carrier current transmitters placed in college dormitories and facilities. Although the presence of the station encouraged engagement in media arts the quality of its signal was typically poor and its interference with the broadcast signal of New York City's WNBC-AM led to students sometimes turning off the transmitters in their dormitories - most notably during broadcasts of New York Rangers hockey games. This led to an application being filed with the Federal Communications Commission (FCC) in 1972 to allow WCNI to broadcast on FM frequencies. The application was filed by the Connecticut College Broadcast Association, Inc., a non-profit corporation established to limit the college's liabilities from the station's broadcasts to the general public.

In 1974 WCNI-FM made its debut on the 91.5 MHz FM broadcast frequency with ten watts of transmission power, on of a wave of college radio stations introduced in that era using low-power FM transmission facilities. Early station promotional spots created by student and staff member Ken Abel hailed it as having "less power than a common light bulb." Subsequent increases in transmission power led to a reassignment of its frequency to 91.1 FM and eventually to its current 90.9 FM frequency assignment. The original antenna tower for FM transmissions was erected atop Bill Hall on the Connecticut College campus using as its base a World War II air raid siren tower modified by Connecticut College maintenance staff to hold a steel pipe that acted as an antenna mast. The antenna was subsequently relocated to a professionally installed tower next to the Crozier-Williams student center on the Connecticut College campus, for many years the site of the station's studios and recording archives.

Early broadcasts of the FM radio station were wide-ranging, including a wide variety of music genres, old radio serial dramas, local history and live performances. To raise funds for government-mandated emergency broadcast equipment the station held its first on-air fund raising marathon in the spring of 1975. Although the early FM broadcast signal of WCNI was not strong the station had a notable body of off-campus listeners in the New London, CT area and its on-air staff included non-student members from that greater community. The eclectic nature of WCNI's broadcasts, its community involvement and the freedom of its staff to select interesting and wide-ranging music was well established from its early broadcasts and continues to this day.