I think the biggest problem for listeners in the distant/troublesome areas of WKSU's signal is that they're using a cheap radio, even if they have the antenna fully extended and have oriented it or moved the radio to a different location. Radios that have the frequencies on the dial tightly spaced apart are essentially useless, as stronger adjacent stations will bleed over or auto-tune away from the desired weaker station. Using or finding an older radio where the frequencies are spaced farther apart on the dial should yield in better reception. A shelf/stackable or tabletop radio/amplifier from the '70s or even the '80s that has a tuning indicator across the entire front of it would be the best choice, as they are pretty good at receiving weaker stations and rejecting interference from adjacent stations due to their generous frequency spacing. Such units usually have the ability to add an external antenna, which can also help improve reception. A simple, fully extended wire for an external antenna usually does well in most cases, but it should be about 4.5 feet (half-wave) in length for the entire FM band, or 5.4 feet (half wave) to be tuned to WKSU's frequency of 89.7.
For the most part, radios with digital tuning (LCD indicator display) should work fairly well, though that may not always be the case as they don't always pull in weaker stations well, at all, or reject interference from adjacent stations. They should at least center in on the frequency to provide the best possible reception.