Citadel: No HD at night

[chuckydoll]

Last week Citadel ordered all its AM stations to turn off HD at night. This includes the oldline ABC stations that Citadel acquired earlier this year.

As a result you won't have to put up with HD hash on WJR, WABC, KGO, WBAP, WLS, etc., etc. after dark.

 

[jcolletta275]

I love how the iNiquity press release stated that they're working on a solution. The only solution is to turn the piece of crap equipment off!

 

[4dude]

YES THAT IS THE ONLY SOLUTION!!!!!!!

THIS IS RUINING THE BAND!!!!!!!!!

 

[rbrucecarter5]

As a result you won't have to put up with HD hash on WJR, WABC, KGO, WBAP, WLS, etc., etc. after dark.

WBAP does not run IBOC. Thankfully - their audio sounds great!!!

 

[4dude]

Lets hope they dont cave in and me$$ up thier signal!!!!!

 

[PhilJSmith67]

As a result you won't have to put up with HD hash on WJR, WABC, KGO, WBAP, WLS, etc., etc. after dark.

WBAP does not run IBOC. Thankfully - their audio sounds great!!!

Hah! I'm sure WBAP does sound great, if only I could null out the IBOC hash from both WGY and (I think) WCCO at the same time! Unfortunately both stations are at perpendicular directions to me. I can only null out one or the other.

 

[4dude]

Send compalints to WGY my friend,it cant hurt!

[email protected]

 

[rbrucecarter5]

Hah! I'm sure WBAP does sound great, if only I could null out the IBOC hash from both WGY and (I think) WCCO at the same time! Unfortunately both stations are at perpendicular directions to me. I can only null out one or the other.

WBAP caved to corporate zombies and went IBOC. Thankfully, being Citadel, they shut the IBOCr_p off at night. But they can say goodbye to their large daytime footprint. I'll take some field strength measurements in a couple of weeks to see how badly degraded they are.

 

[BobOnTheJob]

Hah! I'm sure WBAP does sound great, if only I could null out the IBOC hash from both WGY and (I think) WCCO at the same time! Unfortunately both stations are at perpendicular directions to me. I can only null out one or the other.

WBAP caved to corporate zombies and went IBOC. Thankfully, being Citadel, they shut the IBOCr_p off at night. But they can say goodbye to their large daytime footprint. I'll take some field strength measurements in a couple of weeks to see how badly degraded they are.

IBOC doesn't reduce the field strength of the analog signal. It just adds "digital carriers" (fancy term for a buzz saw) above & below the 5khz audio. IBOC makes the analog audio sound dull and adds hiss on a quality AM radio, but I don't believe you'll detect any reduction in carrier strength.

 

[rbrucecarter5]

IBOC doesn't reduce the field strength of the analog signal. It just adds "digital carriers" (fancy term for a buzz saw) above & below the 5khz audio. IBOC makes the analog audio sound dull and adds hiss on a quality AM radio, but I don't believe you'll detect any reduction in carrier strength.

But I've already documented substantial loss of coverage on AM stations after the conversion. Yet one more nail in the coffin lid.

 

[the_widows_son]

IBOC doesn't reduce the field strength of the analog signal. It just adds "digital carriers" (fancy term for a buzz saw) above & below the 5khz audio. IBOC makes the analog audio sound dull and adds hiss on a quality AM radio, but I don't believe you'll detect any reduction in carrier strength.

But I've already documented substantial loss of coverage on AM stations after the conversion. Yet one more nail in the coffin lid.

Please show this doumentation and the methodology used to make this determination.

 

[schmave]

Hah! I'm sure WBAP does sound great, if only I could null out the IBOC hash from both WGY and (I think) WCCO at the same time! Unfortunately both stations are at perpendicular directions to me. I can only null out one or the other.

WBAP caved to corporate zombies and went IBOC. Thankfully, being Citadel, they shut the IBOCr_p off at night. But they can say goodbye to their large daytime footprint. I'll take some field strength measurements in a couple of weeks to see how badly degraded they are.

WBAP still puts a decent signal into Houston during the day, even with IBOC spillover from 790 (The Sports Animal!). I can hear it under the hiss in most areas except very close to the 790 transmitter. But Bruce I am anxious to read what you find about WBAP's signal in other areas of the state.

 

[Tom Wells]

Hah! I'm sure WBAP does sound great, if only I could null out the IBOC hash from both WGY and (I think) WCCO at the same time! Unfortunately both stations are at perpendicular directions to me. I can only null out one or the other.

WBAP caved to corporate zombies and went IBOC. Thankfully, being Citadel, they shut the IBOCr_p off at night. But they can say goodbye to their large daytime footprint. I'll take some field strength measurements in a couple of weeks to see how badly degraded they are.

IBOC doesn't reduce the field strength of the analog signal. It just adds "digital carriers" (fancy term for a buzz saw) above & below the 5khz audio. IBOC makes the analog audio sound dull and adds hiss on a quality AM radio, but I don't believe you'll detect any reduction in carrier strength.

True on carrier power. The advantage of +125% modulation can no longer be indulged in, lest a clipping event occur, disastrous to decoding.
The "talk power", "punch" "pow" or whatever you call it, depends on that added power in modulation.

This may account for the sort of coverage loss being described here.

WGN 720 had HD off at 13:00 while I was having lunch. The purity and fidelity was dazzling.

 

[BobOnTheJob]

IBOC doesn't reduce the field strength of the analog signal. It just adds "digital carriers" (fancy term for a buzz saw) above & below the 5khz audio. IBOC makes the analog audio sound dull and adds hiss on a quality AM radio, but I don't believe you'll detect any reduction in carrier strength.

But I've already documented substantial loss of coverage on AM stations after the conversion. Yet one more nail in the coffin lid.

Please show this doumentation and the methodology used to make this determination.

It's called a common point current meter at the transmitter site. If you've stood in front of one of these & watched it when the IBOC carriers are turned off, you'll note that it does NOT go up in response. Verify it with any receiver with an S meter...my S meter shows higher on the adjacent channels with IBOC, but the main carrier signal is unaffected. Think about this...a 50KW station...if indeed the carrier power dropped by a barely audible 3db, that would result in an extra 25KW of power being dissapated somewhere. That might last an hour before something melted. I don't claim to be an IBOC expert, but this is the first time I have heard it suggested that the field strength of the main carrier would be reduced by the addition of IBOC. I've been wrong before...maybe I'm wrong this time too...but I don't think I am. Surely someone on here takes FI readings routinely on their station and can comment on any noted changes. Which leads me to the next point...monitor points have maximum values. If these values suddenly dropped by several db, wouldn't that result in a mass shutdown of the IBOC system? I can't see anyone taking a multi-db signal hit to run a noise generator that no one is tuned to.

Your turn...make your measurements with the IBOC carriers switched off & on. What did you actually see?

 

[Len14043]

Hah! I'm sure WBAP does sound great, if only I could null out the IBOC hash from both WGY and (I think) WCCO at the same time! Unfortunately both stations are at perpendicular directions to me. I can only null out one or the other.

WBAP caved to corporate zombies and went IBOC. Thankfully, being Citadel, they shut the IBOCr_p off at night. But they can say goodbye to their large daytime footprint. I'll take some field strength measurements in a couple of weeks to see how badly degraded they are.

Bruce, I am very familiar with the range of the signals here in the midwest such as WLW, WGN, WSCR, WJR, WIBC and many others. I assure you the range is not comprimised by IBOC. AM IBOC has many shortcomings, but analog range degradation is not one of them.

 

[Tom Wells]

OK, let's throw simple logic at this question. Anyone who's ever tried to maximize audio density on an AM knows that if you "use up" your
modulation with sound that is too peaky in one range of audio you will not be able to modulate others nearly as well.

By everything I learned about high level mod, ANY modulation sidebands added will result in less of the carrier until at full modulation, all the power (plus any added power from high-level mod) will be in the sidebands.
This isn't done for clipping's sake, but is approached as nearly as possible without clipping.


Now, if we add considerable modulation products up to 15khz, even at the very low % of power, it is still full-time, and must result in
less power for something else. The common node current won't change, and the FI readings won't either, unless you can set a passband that's really looking at only the carrier, and not adding in the energy of the sidebands, which will sum to show no net change.

Even given that the energy for the HD sideband may completely sap the equivalent coverage away from the analog signal, and it probably can be proven given what I suggest, the level to listeners is probably only -2 db, or marginally perceptible.
Most, even the cheapest radios have so much reserve gain that natural conditions account for far greater variance in signal strength.