Is the IBOC hash more excessive lately?

[The Youngest Oldie]

I notice when the signal should be clear WBCB/WKDN/ and 880 out of NY really seems to be heavy on the static. I normally pull all three in very well.

 

[MoldaMania182]

As much as I love kicking IBOC when it's down, it's not so much IBOC (though it is partly to blame) as it is our other habits in general. Every year our own electromagnetic interference from a plethora of devices hurt AM transmissions. Situation will only get worse with time, not better. Beyond all the business noise (pun intended) it's the biggest reason AM is dying in general, just too much (legal) interference.

 

[WhotonyD]

What is this iboc hash?

 

[HGN2001]

What is this iboc hash?

A: The noise created by radio purists who are upset that they can no longer hear out-of-town signals as clearly as they used to.

 

[ddsparxx]

It's the adjacent sideband interference that sounds like the whooshing noise on AM, a bit more buzzing-like on FM, it's caused by the HD radio transmission by the station that's using it.

 

[rtetro]

Naturally occuring noise generally increases on AM in the Spring and Summer. I have noticed the annual increase lately, but I haven't noticed anything that might be related to IBOC, at least not in the Philly area.

That being said, I notice that WWDB produces an incredible amount of noise and splatter for about 30-40 kHz either side of their 860 carrier. No matter where I am in central and eastern Montgomery County, the splatter makes it nigh to impossible to listen to WCBS 880. Even WEEU 830 takes quite a hit from WWDB. As soon as 860 cuts the carrier at sunset, BINGO!, WCBS comes in clean. I've wondered for a while if there is a problem with their audio processing or transmitter? If the NRSC-2 mask is working properly, it is usually pretty difficult to hear a station's sideband splash more than 10-20 kHz removed from the carrier, even when you are fairly close to the transmitter. I know that in my own situation, once I get more than about 1/2 mile from WNTP's 990 transmitter, I can hear 1010 WINS with no problem. Same with WFIL 560 and WHP 580.

Even with stations running IBOC, I can usually listen to stations that are 20-30 kHz away. For instance, it is easy to pull in a fairly clean signal from WNJE 1040 once you get a couple of miles away from KYW. Likewise when WPEN-AM was running IBOC, I had no problem hearing WCHR on 920, even with a strong 950 signal.

 

[Tom Wells]

AM iboc can develop weird "sparkly" emissions outside the defined iboc bandwidth.
KFUO St. Louis had a case of this, and more recently WSCR in Chicago.

The engineer at KFUO said his sparkly signal would not decode and he turned off the iboc.
I have no idea whether KFUO still runs it, but WSCR did drop the iboc, which for them always created a weird buzzy lisp
on modulation peaks as heard by standard radio listeners. It did always decode for me in HD when I checked.
I have two HD radios, but one in a car that I dont use, and the other too cloddy to try to use (RS Accurian) much.
WSCR chased the problem away 2 or 3 times but it always came back.

There are also different AM method revisions, the earliest ones were quite awful as to hissing.
WTMJ 620 in Milwaukee still has one of the death-flame thrower jobs...

 

[satech]

That being said, I notice that WWDB produces an incredible amount of noise and splatter for about 30-40 kHz either side of their 860 carrier.

Have you checked your radio recently? 860 WWDB is not transmitting IBOC (HD Radio) anymore, and has not for over a year now. In central NJ, I can pick up the weak signal of 850 WAXB from CT just fine with 860 WWDB right next door on the dial.

 

[Steve Green NEPA]

I originally didn't read any IBOC into RTetro's claim of the 860, SaTech. (Since your post I read it through twice, too :- )
It's just a splattery signal by where he listened.

A legendary Brooklyn NYC AM DXer known to many in the hobby, the late Ernie Cooper, who had logged an incredible amount of stations, moaned almost weekly about not being able to hear WERA 1590 from its quite nearby New Jersey site.

Because of WWRL 1600.
WWRL must have sent their main power lobe not just down Flatbush Avenue at Ernie, but probably right into his apartment and up his snortch.
WERA Plainfield NJ could not have existed much more than 25 miles from this iconic DXer's den. Yet, 'ERC' could not get anything on 1590 during the day -- WERA signed off at sunset -- because of splatter from WWRL. And he had a great radio, from what I remember.
Our little DXing throng lived a bit east of 'ERC' and his Hammarlund radio -- even farther from WERA -- and we could get this new station with little problem. Cooper must have DXed from the exact bearing of WWRL's main laser beam.

There were reports in the 1960's from near Chester PA that WWRL 1600 did not come in -- but their splash on 1610 DID come in there!

All this was long before the days of IBOC.

 

[Tom Wells]

I originally didn't read any IBOC into RTetro's claim of the 860, SaTech. (Since your post I read it through twice, too :- )
It's just a splattery signal by where he listened.

A legendary Brooklyn NYC AM DXer known to many in the hobby, the late Ernie Cooper, who had logged an incredible amount of stations, moaned almost weekly about not being able to hear WERA 1590 from its quite nearby New Jersey site.

Because of WWRL 1600.
WWRL must have sent their main power lobe not just down Flatbush Avenue at Ernie, but probably right into his apartment and up his snortch.
WERA Plainfield NJ could not have existed much more than 25 miles from this iconic DXer's den. Yet, 'ERC' could not get anything on 1590 during the day -- WERA signed off at sunset -- because of splatter from WWRL. And he had a great radio, from what I remember.
Our little DXing throng lived a bit east of 'ERC' and his Hammarlund radio -- even farther from WERA -- and we could get this new station with little problem. Cooper must have DXed from the exact bearing of WWRL's main laser beam.

There were reports in the 1960's from near Chester PA that WWRL 1600 did not come in -- but their splash on 1610 DID come in there!

All this was long before the days of IBOC.

Being in a maxima lobe is hell on any radio. I am in the max pattern of a 1590 directional about 3 miles away, and my pt 15 AM 1620 gets clobbered pretty bad in their direction, particularly if the receiver has no rf preselector stage.

 

[ajc_trw]

What is this iboc hash?

A: The noise created by radio purists who are upset that they can no longer hear out-of-town signals as clearly as they used to.

B: The cheese grater hash heard primarily in the treble region when listening to an AM-HD station in digital. It's like listening to an old vinyl record with a thrashed stylus or on a system with a blown tweeter. Didn't they used to call this distortion? ;D

 

[Tom Wells]

It is the Veriest definition of distortion, of a sort not even imagined when "traditional" types of distortion were defined.

It's a combination of of phase, amplitude, harmonic and frequency distortion, once upon a time honestly called "sounds funny".

PS-- Cylinder records sometimes have very similar artifacts on the highest reproduceable notes, and as they are vertically modulated, it
may be a case of needle reasonance on the Edison cyls, but I don't know what to the call the ibiquity sizzzz.

 

[JerseyShor]

B: The cheese grater hash heard primarily in the treble region when listening to an AM-HD station in digital. It's like listening to an old vinyl record with a thrashed stylus or on a system with a blown tweeter. Didn't they used to call this distortion? ;D

I have an HD radio in my car and must disagree, to me AM-HD digital stations sound MUCH clearer and intelligible than their analog counterparts. For example KYW sounds like a totally different station in HD compared to analog.

Of course AM HD signals are so fussy that they go in & out even well inside the 10 mV/m contour of the stations but that's a whole other problem... (KYW on 94.1HD2 has about 3x the coverage as KYW's HD on 1060 in my experience!)

 

[Tom Wells]

B: The cheese grater hash heard primarily in the treble region when listening to an AM-HD station in digital. It's like listening to an old vinyl record with a thrashed stylus or on a system with a blown tweeter. Didn't they used to call this distortion? ;D

I have an HD radio in my car and must disagree, to me AM-HD digital stations sound MUCH clearer and intelligible than their analog counterparts. For example KYW sounds like a totally different station in HD compared to analog.

Of course AM HD signals are so fussy that they go in & out even well inside the 10 mV/m contour of the stations but that's a whole other problem... (KYW on 94.1HD2 has about 3x the coverage as KYW's HD on 1060 in my experience!)

Any "radio" which decodes HD is so far removed from any "true" analog demodulation that such comparisons are moot.

Compare to some proper pure AM MW analog receiver with 15 khz audio bandwidth say...circa 1963 with variable IF bandwidth.....

Incrediblly good sounding "hi-fi" local AMs including WGN, WLS, WIND, and WNuthinNuthin Nuthin, all sond like MUD on
any of our HD radios. It's all a sham, saddling AM radio with a 3khz audio bandwidth and then calling it "lame".
This is hucksterism, a special manner of presentation that accomplishes conversion of the (unwitting) undecided by deceitful presentation.
Look the word up.

 

[rtetro]

I originally didn't read any IBOC into RTetro's claim of the 860, SaTech. (Since your post I read it through twice, too :- )
It's just a splattery signal by where he listened.

Exactly. I was not speaking of IBOC hash but good old sideband splatter. It is often caused by mis-adjusted or defective audio processing, transmitter problems, or antenna issues. Since the noise is more of a wideband whooshing than merely high-frequency splatter, I would suspect a transmitter issue.