WNIJ in DeKalb primarily airs news and talk programming from NPR, with World Cafe, Echoes and locally produced blues music programming at night and Saturday afternoons. BBC World Service airs overnight. The station's programming is also simulcast on repeaters WNIE in Freeport, WNIQ in Sterling and WNIW in La Salle. WNIU in Rockford airs classical music24 hours a day using the syndicated classical music service Classical 24, and operates a low-powered translator at 105.7 in Rockford to improve its coverage in the northern part of the city.
Northern Public Radio began in 1954, when WNIU signed on as a 10-watt station on 89.5 FM that barely covered the immediate area around the campus of what was then Northern IllinoisState College. It aired classical music along with lectures and announcements of campus events. In 1964, it expanded its transmitter power to 2,500 watts, boosting its coverage area to all of DeKalb County. At the same time, it began emphasizing news programming. WNIU was a charter member of National Public Radio in 1971, and was one of the 90 stations that carried the initial broadcast of All Things Considered. In 1979, WNIU got permission to boost its power to 50,000 watts. This more than doubled the coverage area of the station, and brought its signal to Rockford for the first time, albeit with only grade B coverage. In 1988, WNIU moved its transmitter from De Kalb to Lindenwood, which gave it a city-grade signal to Rockford. Previously, Rockford had been the only major city in Illinois without city-grade coverage from an NPR station; the only sources of NPR programming in the area were grade B signals from WNIU and Wisconsin Public Radio's Madison outlets. NIU had wanted a second frequency for some time, and finally got it when WNIJ signed on at 90.5 FM in Rockford. WNIU became a full-time classical music station, while WNIJ was a more traditional full-service NPR station. In 1998, the two stations swapped frequencies, with WNIJ moving to the stronger 89.5 frequency while WNIU moved to 90.5. This move was made so more people could hear WNIJ's news and talk programming. 90.5 must conform its signal to protect the low-powered translator of Madison's WHA at 90.9, resulting in a weaker signal in the northern part of Rockford itself and some of the city's northern suburbs. WNIJ also scaled back its jazz programming to nights only. That same year, WNIW and WNIQ signed on. WNIE followed in 1999. Listeners in the latter three stations' coverage areas had only gotten spotty coverage from WNIU or WNIJ, depending on the location. Originally, the three repeaters simulcast WNIJ during the day and WNIU at night, but problems with switching equipment forced them to simulcast WNIJ 24 hoursa day.