UPDATE DEC.1, 2014: our demo unit of the BW Broadcast DSPXmini-FM SE audio processor arrived today. It's been installed on 88.1FM and initial tweaking is complete. The sound seems markedly improved. I'll be fiddling with it further to adjust it across different programs.
ORIGINAL ARTICLE: About a week ago, your intrepid engineer made some changes to the airchain on our 88.1FM that should've, in theory, been wholly beneficial and with no potential for downside. However, around that same time I started getting reports of an odd whistle...or just high-pitched static...that would come and go with no apparently rhyme or reason.
These reports aren't widespread, but there's been enough that I'm no longer inclined to think it's just an odd run of people happening to have poor reception. The only commonality is that it seems to occur only when reception of 88.1 isn't very good to begin with. Not necessarily "poor" reception at all, just not "super-solid".