WDIY (88.1 FM) is a community-run public radio station licensed to Allentown, Pennsylvania with studios in Bethlehem and a transmitter atop South Mountain.

WHYY-FM in Philadelphia provides grade B coverage to most of the Lehigh Valley, while WVIA-FM in Scranton has long operated low-powered translators serving parts of the region.

Although WDIY's transmitter power was very low for a full NPR member, its antenna on top of South Mountain enabled the station to reach most of the immediate Lehigh Valley region.

Even though its South Mountain transmitter was at 843 feet above average terrain, the station had a relatively limited reach, confined for the most part to Lehigh and Northampton counties.

With its power increase to 300 watts in 2015, WDIY covers not only the Valley but now can be heard in the surrounding regions of eastern Pennsylvania as well as additional parts of western New Jersey.