The REC listings for HD reflect which stations have given the FCC notification that they were using HD. Since there's no process for notifying the FCC that a station has stopped using HD, they're not going to reflect the reality that very few AM stations that once used HD are still using it now.None of the AM stations in Milwaukee run HD. I recall WTMJ dumping it years ago because the delay messed with sports broadcasts. That, and they're on 94.5 HD2 and the 103.3 translator, making it even more irrelevant. WISN doesn't run HD either, but is on an HD subchannel on FM.
Audacy dumped HD on WSCR and WBBM as well.
The REC listings are pretty incorrect on the HD notations in general. For example, in Milwaukee, they show 98.3 and 106.9 in HD, but neither uses it.
Actually, there is a process - file another Digital Notification and select the type of notification as Reversion from Hybrid to Analog. That's what Wisconsin Public Radio did last year. It's not common for stations to do this though - Digital Notifications are more commonly filed for stations that have begun broadcasting in HD, or are about to begin.The REC listings for HD reflect which stations have given the FCC notification that they were using HD. Since there's no process for notifying the FCC that a station has stopped using HD, they're not going to reflect the reality that very few AM stations that once used HD are still using it now.

Another station that is also in AM Stereo is WHIT (AM 1550) and another one that I've seen WNCW (AM 1190) - I have noticed WNCW only carries AM Stereo randomly, not 24/7. I have witnessed both WLMV and WHIT packing AM stereo without fail and it appears to be 24/7. There appears to be a noise that sounds like farting or slow motion burping on AM 1550 - my guess is that's AM Stereo not locking in but WLMV does not have this bizarre farting or slow motion burping sound.Absolutely no idea if they're still using the equipment, but 1480 in the mid-80s when it was still WISM was "Solid Gold Stereo".
Good Question I wondered that too - I wish I had the answer on that particular licensing question.Is (was) AM HD part of the deal when manufacturers paid for HD "licenses" for their FM receivers too? Or was (is) it extra?
DXing is of less than zero interest by stations. The largest AM DX club in America has less than 1000 members.One possibly nice side effect of the turning off of HD on AM signals is that it might assist those DX-ing on frequencies adjacent to the frequencies that had the HD signal.
Back when HD was introduced, in a presentation to HBC, Bob Strubel of iBiquty said that licensing was a single price and single chip for radio manufacturers.Is (was) AM HD part of the deal when manufacturers paid for HD "licenses" for their FM receivers too? Or was (is) it extra?
The station license charge was significantly reduced in the early years of HD and is not a significant cost. It's based in part on the station facility and its market size as well.If you are a radio station licensee - HD Radio can get expensive very quickly - and not every radio supports HD Radio.
Yeah it was very cheap when it first came out - things have changed since 2008. It's not too expensive but Very few brand new stations launch as HD Radio stations. The last NCE window in 2023 shows no signs of new stations launching with HD RadioThe station license charge was significantly reduced in the early years of HD and is not a significant cost. It's based in part on the station facility and its market size as well.
At no point was it "very expensive".