From Dave Hughes’ D.C. Radio and Television news web site: Mono Returns To DC’s FM Band – 1/16 – Mono is making a comeback on the DC area’s FM band. Radio engineers have long known that a mono FM signal has more range than a stereo one does. In fringe areas, a stereo signal can feature an annoying hiss. The resurrection of mono arrived several years ago, when Bonneville’s WTOP started an FM relay on Warrenton’s 94.3, which got moved to 107.7. The mono signal improved coverage into the DC metro. And since the programming was news and talk, the loss of stereo didn’t seem to matter to listeners…
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Then, Bonneville stripped stereo from its 104.1 and 103.9, two edge-of-the-metro area signals that carried “modern” music-based Z104. It improved the coverage area, but didn’t seem to do a lot for the station’s anemic ratings. Z104 was decapitated earlier this month. And, now, Bonneville is running WGMS in mono on 104.1 and 103.9. Will classical music fans appreciate Bach and Beethoven in a more “flatter” sounding mono? A quick check of the DC FM band finds several other stations broadcasting in mono, including the new WTOP news signal on 103.5, WGMS’s old home. Also in mono: CSPAN’s wonk-talk WCSP 90.1, which battles closely-spaced Culpeper’s Christian contemporary WPER 89.9 in parts of Northern Virginia, and Mega’s Spanish “classica” music rimshots of WBZS 92.7 in Prince Frederick and WBPS 94.3 in Warrenton. Still talking in stereo: NPR-based WAMU 88.5 and WETA-FM 90.9

I found this information
very interesting. My transmitter has a stereo/mono switch. I’m assuming I can switch to a mono broadcast and still be within part 15 guidelines?
Do you suppose IBOC has anything to do with that?
Just wondering… maybe they don’t care about stereo FM anymore if they’re targeting digital listeners.
WEAK-AM
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While scanning
the dial on my old Pioneer analog receiver, I noticed a local FM station that has gone news talk, is no longer broadcasting in stereo. I guess that makes sense for a talk format. Personally, I like the stereo sound for music.