The flagship station of the NEPR News Network is WNNZ, 640 kHz AM, licensed to Westfield, Massachusetts, which was once owned by Clear Channel Communications (now iHeartMedia). WNNZ's power output is 50,000 watts in the daytime, the maximum permitted for AM stations by the Federal Communications Commission. But because 640 kHz is a clear channel frequency for CBN in St. John's, Newfoundland and Labrador, WNNZ must reduce power to 1,000 watts at night. The antenna is a three-tower array, using differing directional patterns day and night. During the day, it provides at least secondary coverage to all of western Massachusetts, as well as New York's Capital District and the Hartford area. At night, the signal is cut back to concentrate the signal northward around the Springfield and Hartford areas.