BREAKING NEWS! THE REAL REASON WHY WGN HAS DROPPED HD-AM

[Savage]

An extremely reliable source "directly involved" with Tribune's WGN tells us, on strict condition of anonymity (typical of the intrigue surrounding HD Radio):

HD-AM has been dropped because it's interfering with Arbitron PPM technology!

IOW: the self-interference inherent in HD is preventing the PPM devices from reading WGN listening in the field.  IOW:  HD Radio is directly blocking reportage of AM listening to Arbitron!   

This confirms the suspicions of most posters here about James Carollo's "explanation" that "processing changes being evaluated" being a plausible reason for shutting the HD exciter down.  Perhaps Mr. Carollo would care to chime in and confirm or deny this report.....?

Put yourself in the position of a big cash-cow major market AM General Manager.  What's gonna win?  Hiss-O-Matic Interference Generator, producing a questionable product consumed by an infintesimal segment of your audience, or...Arbitron, which directly influences revenues for your station?  (Please keep your eyes on your own paper.)

HD Radio.  Truly, this Christmas season, the gift that keeps on giving.   

[JohnnyElectron]

Hmmmmm, WJR went from 1st place with diaries to 6th place with PPM - and they've now turned-off HD. 
Hmmm, maybe we're on to something here! (not only PPM, but the analog sounds 10x better now too!)

Maybe PPM doesn't work on the 3-letter stations! (WJR, WGN, WOR, WLS, WGY, KYW) - I'd be curious to see if these stations are showing a huge drop in audience share using PPM because of HD interference with PPM??

[rbrucecarter5]

There is a real unforeseen nasty with HD-AM!  iBiquity better develop a fix for that one iQuickly, or it may be all over for HD-AM.  I have noticed that WGN seems to be BACK - for a long time their signal in Dallas was just so-so, even with some WOR hiss underneath.  Now they are peeling paint with their signal here.  Not that I listen that much, but there is something about legacy Chicago 50 kW stations that keeps me scanning for them on a regular basis.  It would be really interesting to see if WLS drops their HD - will they be "back", too?!

[Carmine5]

Well, at least Crawford won't have to worry about this little problem.  Hardly anyone listens to their AM stations anyway.  They can broadcast IBOC in full confidence.

C5

[DavidEduardo]

Hmmmmm, WJR went from 1st place with diaries to 6th place with PPM - and they've now turned-off HD. 
Hmmm, maybe we're on to something here! (not only PPM, but the analog sounds 10x better now too!)

AM in general is off in PPM, even more than it was declining in the diary based survey.

Maybe PPM doesn't work on the 3-letter stations! (WJR, WGN, WOR, WLS, WGY, KYW) - I'd be curious to see if these stations are showing a huge drop in audience share using PPM because of HD interference with PPM??

The PPM encoding is pure audio, and it does not matter if there is an HD component to the signal.

On the other hand, KFI is significantly up in the PPM as is KGO, WABC, KYW, WLS. It's the stodgy, over 65 geezer stations that are off.

[landtuna]

It's the stodgy, over 65 geezer stations that are off.

THAT'S IT!   I'VE had ENOUGH!!!!   As soon as I can find my <_{dammit, what was I looking for?}> I'm coming over there and <_{huh? ....maybe I'll remember tomorrow}>.

[DavidEduardo]

An extremely reliable source "directly involved" with Tribune's WGN tells us, on strict condition of anonymity (typical of the intrigue surrounding HD Radio):

HD-AM has been dropped because it's interfering with Arbitron PPM technology!

IOW: the self-interference inherent in HD is preventing the PPM devices from reading WGN listening in the field.  IOW:  HD Radio is directly blocking reportage of AM listening to Arbitron!   

That's bull. WGN, with HD and under PPM, had a 7.3 share in August, towards the end of the Baseball season. The season ended, and in November, they had a 4.4. Do you really think this is an HD issue or a programming one?

In August of last year, pre-PPM, they had a 6.0. And last year November had a 5.6 and December a 4.2. Maybe the rest of the station is not as good as the baseball broadcasts.... and WGN is just suffering the same fate as nearly all AM stations.

[KB1OKL]

I have noticed that AM stations that turn on the iBlock get weaker although most people don't believe me. WBZ used to be much stronger in my area. So did the Kidney channel on 1560 WQEQ. That used to barrel in here and the second they turned on the jammer their signal got much weaker. It's not only jamming PPM it's jamming it's own signals!

[syvjeff]

There's another card that hasn't been discussed on this board regarding WGN dropping HD, Randy Michaels. I've enjoyed my time of working with Randy so this is not a jab at him but a noticed pattern. Remember he is so into making sure AM gets the most miles out of itself, he would make sure that AM Stereo would be turned off at Jacor. Maybe this is part of the same philosophy of the sound of HD and how it really cuts coverage area.

I don't have an HD AM station, but have experimented with narrowing down the bandwidth of my stations and really going full NRSC and feeding your transmitter the cleanest audio is the way to go.

[Savage]

"That's bull!"  Ahhh, yes.  The musical sweet sounds of civil discourse once again grace this board.

So, if as you lecture us, "PPM encoding is pure audio" why would it "not matter whether there is an HD component?"  Anyone who has studied HD-AM for thirty seconds knows that IBOC has a profound effect on audio performance.  It has been noted not only in this thread but about 200 times before in 200 previous threads.  The too-many-to-enumerate deleterious effects of "HD encoding" include enormously narrowed analog bandwidth, contamination of the main channel with COFDM sideband data and increased susceptibility to QRM and QRN.

The fact of the matter is, it would be more surprising if "PPM encoding" which is "audio derived" were NOT affected by HD-AM.

Taking this development and reading it with James Carollo's cryptic declaration that WGN has turned off IBOC to evaluate "processing changes" - as in, "let's see if the absence of IBOC has any effect on trends" - it would seem logical that the station's research is seeing some adverse impact and perhaps they want to rule out HD as a contributor.

Of course Mr. Carollo may take me up on my invitation to clarify the station's actions and confirm or refute this report.