The engineers on the info-radio.com discussion boards are tracking the demise of HD radio on the AM band. Bob Savage reports:
UPDATE! AM-HD continues its slo-mo Croak-O-Rama. June pop-count drops a few more stations, to 248:
That’s about 50 stations off the high-water mark. Can’t we just call it a (hiss-free) day already?
Earlier, the tech discussion went something like this:
Yes, HD-AM Version 17.2 in the continuing parade of IBOC software tweaks (all presumably requiring new exciter purchases or upgrades) providing 10.2 kHz analog bandpass without IBOC noise has generated about as much consumer-listener excitement as the FM digital power increase. Which is to say: zero. How many freakin’ improvements, upgrades, and patches are the HD nuts going to trot out to try to convince people HD Radio actually works? Attention, all you HD-types who labour mightily to draw a historical parallel between FM radio’s slow adoption and HD: please point out for the class, ONE example of how the whole FM mode had to be revised to correct poor and/or unacceptable performance as experienced in the field after its deployment. Back to HD-AM. So . . . the “improved” codec provides us with bandpass . . . equivalent to non-HD stations! Wow! That’s dramatic! We’ve gone through three years of 78 rpm sound, and now . . . research, development and “improvement” have restored the 2005 status quo for analog listeners! Talk about progress . . . NOT.
Bottom line, It’s still real bad for the folks “who live next door,” in the worst possible way, with interference that would have, anytime before the ’80s, been subject to FCC actions, and if continued, that would have put the station off the air until effective repairs to the transmission facilities were effected. In the old days this was overmod splatter, usually transitory. Today it is pure 100% duty-cycle roaring on the 1st adjacent. As someone who spent 3 years in years in radio engineering school and was taught the whole time how much of our responsibility was to maintain a station’s signal and respect the spectrum of others, AND HELP other stations’ engineers do the same, I am still baffled that this mess could even happen.
One more observation: the AM band is still a mess due to IBOC hiss here in SW Michigan at night. Most of the dial is awash in noise. Less than 150 miles from Chicago, all of the major 50 kW stations are unlistenable due to IBOC hash from the adjacent channel stations out east. The NY signals on 660, 710, 770, and 880 pound in at night here, and their IBOC sidebands just kill the Chicago stations. Think you’re gonna listen to the Cubs on ‘GN? Not unless it’s a day game. The only consistently usable signals here at night are 650 and 740.
If they wanted to just go out and kill the AM band entirely, it would be hard to imagine a more effective vehicle than IBOC. Especially when you layer in the cynical legal manipulations which deprive victim stations of any effective petition for relief. The willingness of these HD-pushers to self- and mutually-annihilate is just mind-boggling. At least to those of us with operational minds.
iBiquity’s own web site pretty much answered my question: WLS is no longer on their official list of HD Radio stations. Neither is WABC. It seems like Citadel is dropping AM IBOC like a hot potato . . . or in this case, a rotten one!
If HD doesn’t completely go away, a nighttime ban would do — for now!
It would take a major upheaval for the FCC to rescind their rule allowing nighttime use of AM IBOC. They will likely just let it die out on its own. Indeed, AM stations which are abandoning IBOC are doing so full-time, not just at night. The one thing we might have a chance of seeing is an improvement in the way the FCC deals with interference complaints, because as the WYSL vs. WBZ case proves, the existing procedure is pretty much worthless. Under Kevin Martin, the FCC made up its mind that skywaves have been rendered obsolete, and therefore nighttime AM IBOC interference is not possible.
As to the tally of stations dropping HD, “JohnnyElectron” adds, “There’s a couple more off on a ‘temporary basis’ while they repair their inoperable iBiquity hardware, like WSPD.” In succession, the following posts were added:
The list still shows KCBS 740 as on with HD. I seem to recall they shut off the AM HD as their “sounds like FM” was mocked by 106.9, which is really FM quality. That being the case the count is 247 and falling.
I’d take a “Buzz Free Day” any day. Just tell me how to nuke a few dozen Plasma TV sets, a hundred or so switched-mode power supplies, and a few thousand feet of neon-installed-by-the-lowest-bidder-and-maintained-by-nobody.
Yeah, but there are a couple of other errors the other way — for example WHTK 1280 has the buzzsaw back up and running, so I would guesstimate that net-net we’re still talking 248 or so. The overall trend, though, is decidedly down. Especially when you consider that 32 of the piddling alleged 85 or so 24-7 HD-AM signals are on the 6 graveyard channels. That means that only approximately 1% of licensed AMs are operating with HD 24-7. Considering that factor, it’s amazing that the remaining 53 unlimited-hours operating HD-AMs are causing the awful adjacent-channel racket. Can you imagine the mess if HD actually saw widespread adoption in the MW band? AM radio would be totally useless. At night, in the east, between 1000 kHz and 1220 kHz and 660 kHz and 880 kHz, it already is on some nights.
At night in VA the adjacent channel racket makes those 2 portions of the AM band a mess. On the lower portion of the 1000 to 1220, it is awful with WBZ’s buzzsaw being very loud, loud enough to bury most of WHO’s and KDKA’s signals. WPHT’s IBOC is also loud.