• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

iBiquity HD problems for adjacent signals?

> None the less, the reports of interference problems outside
> of protected contours are real, at least on the reserved FM
> band where short spacing and overcrowding is the norm. I
> didn't make up that report. It was reported by the CE of
> one of the stations in question. I tend to believe him.
> He has no reason to lead us otherwise, since the particular
> station in question is a NPR affiliate.

I'm curious. Unless you work for a station that's lost coverage or listen to a distant one that disappears, it's hard to tell. While I hear there are FM problems (beyond artifacts) I haven't noticed any adjacent channel interference. I'm in the Northest where there are several NPR stations and every college has a station.

Since most installations use two transmitters with high level combiners into a single antenna, what would cause this signal loss? Would it be the same if separate antennas were used? I do know the digital loss in the combiner is tremendous. You simply crank up the analog power to compensate.

Is it actual signal loss or some conflict in the sidebands that causes the receiver to be less sensitive to the signal?

In the case of AM the adjacent channel interference is severe. to the point of blotting out stations. The classic example in the Northeast is WBZ/KDKA. Between about 4 and 6pm in Winter KDKA (1020) is wiped out in Western MA by WBZ's (1030) hash. On the dot at 6pm KDKA comes bombing in when WBZ shuts IBUZ off.

I realize I'm outside both stations' protected contours. However, it seems to be a real warning about what will happen when the majority of AMs light up. That's why I propose that the FCC allow AM IBUZ operation 24/7 right now, so stations can fix interference problems before they get unmanagable.

Don't expect engineers whose companies have embraced IBUZ to have anything negative to say about it. Their jobs are at stake. All I see from them are glowing reports about how well both the AM and FM IBUZ systems perform.

I get many off list emails from managers, engineers and programmers who either can't participate or don't dare say anything publicly. Since I was one of the first to actually have a receiver to test, I seem to have become their mouthpiece with an absolute promise never to reveal their identities.

Contrary to all the hype and puffery the entire industry is not supportive of this system.

Rich
 
Re: GOOD GRIEF! The mis information continues.....

>
> <a target="_blank" href=http://www.broadcastsignallab.com/Evaluating%20Emissions%20of%20IBOC%20Transmitter.pdf>PDF URL</a>
>

Let me see if I interpret those charts correctly.
The hiss we hear on channels adjacent to stations running HD technology exists on the same frequencies that analogue sidebands are allowed to and do traverse into from time to time, just not on a constant basis.
So, if the station turns their <s>ihiss</s> digital generator off, I would hear splatter which is perfectly legal and within proper engineering practices, but on a more intermitant basis.

I hope this is correct and something which shoyuld be publicized.<P ID="signature">______________
Proud 2 B a pioneering satellite radio subs¢riber
Ai4i is always on the trailing edge of technology
______________</P><P ID="edit"><FONT class="small">Edited by ai4i on 02/28/06 03:53 PM.</FONT></P>
 
Re: GOOD GRIEF! The mis information continues.....

> The digital carriers of AM+HD Radio occupy spectra from
> about +/-10 kHz to +/-15 kHz from the AM analog carrier
> frequency. The digital carriers can cause severe
> interference to adjacent channel AM signals, which is the
> reason AM HD is not permitted at night.

From a programming perspective, either IBUZ is run on AM 24/7 or you might as well kiss off evening listening. While quality isn't normally a determining factor over content, I seriously doubt any digital listener (of whom we're told will be bazillions - it's a revolution, they say) will tolerate the drop from "FM Quality" to muddy 5KHz at 6pm. We might as well make everyone a daytimer.

Now I'm hearing that AM IBUZ is sensitive to power line noise. I thought it was supposed to get rid of all that. I'm told power line noise causes the mode to switch back to analog where you can really hear it. What's the deal? Other than low signal levels, what else will cause a receiver to drop back to analog?

Rich
 
Re: GOOD GRIEF! The mis information continues-YUP, SURE DOES!

> He has an interest in making the sale, and a quota to fill
> to satisfy his employer. The employer has an interest in
> pushing the product.
>
> Question authority, they may have an ulterior motive, or
> hidden agenda.

Or, the "authority" might be an investor in the technology.

Rich
 
Re: Wheres the proof...AGAIN

> OK we have asked you multiple times to back up your
> statements. None have shown up yet. Still waiting.......

Kent,

I realize this wasn't directed at me, but do you dispute that the FCC hasn't mandated this system? Do you dispute that they're unlikely to mandate a monopoly system? Do you dispute that the RIAA has been making noises about some kind of protection flag for digital radio? If so, you haven't been reading.

Do you dispute that, if the RIAA get the courts to mandate some kind of digital rights management, the codec or something in the receiver will have to be modified? Do you dispute the fact that receivers can't be upgraded in the field?

On another list you've participated in discussions with the Kenwood representative about their reluctance to have upgradable receivers. I know I've communicated many times with Mike Bergman at Kenwood about this issue, as well as the "layered" (WXXX-HD1, HD2) display. Mike was the guy who set up and loaned me the receiver to test. The one you suggested had a bad antenna.

I realize your company is a major participant in the HD Dominion (if not an investor in the manufacturer), so you're constrained from anything but glowing reviews of IBUZ and criticism of the critics.

I'm asking relatively softball questions so you might be able to answer without risking your job. With the current bloodbath in Calfornia I suspect that's a major concern with the company's employees.

Rich
 
> > Is it actual signal loss or some conflict in the sidebands
> > that causes the receiver to be less sensitive to the signal?
________________

If the same FM transmit antenna is used before and after adding HD, analog field strength will not be affected by HD operations. And, as most analog FM receivers have little or no response in the spectra of the HD carriers of a given FM station when tuned to its analog center frequency, its HD sidebands are essentially undetectable by an analog FM receiver.

The possible issues come from trying to tune to a weak, analog FM station in an area where a strong HD station is present on an adjacent channel. This weak station then may not be heard in areas where it was heard, prior to the adjacent channel(s) adding HD.

Frequency assignments per geographic area tend to minimize the locations where this is possible, but they are not totally eliminated.
 
Re: GOOD GRIEF! The mis information continues.....

> Let me see if I interpret those charts correctly.
> The hiss we hear on channels adjacent to stations running HD
> technology exists on the same frequencies that analogue
> sidebands are allowed to and do traverse into from time to
> time, just not on a constant basis.
______________

The digital carriers both of AM and FM HD radiate constantly on the sideband spectra of adjacent channels.

But analog FM receivers are more successful than analog AM receivers in operating with satisfactory results when tuned to an analog station on an adjacent channel from an HD station.
 
> I'm curious. Unless you work for a station that's lost
> coverage or listen to a distant one that disappears, it's
> hard to tell. While I hear there are FM problems (beyond
> artifacts) I haven't noticed any adjacent channel
> interference. I'm in the Northest where there are several
> NPR stations and every college has a station.
>
> Since most installations use two transmitters with high
> level combiners into a single antenna, what would cause this
> signal loss? Would it be the same if separate antennas were
> used? I do know the digital loss in the combiner is
> tremendous. You simply crank up the analog power to
> compensate.

Rich, I don't think the guy thought his station's analog signal strength was less. Like you I can't think of why it should be. You'd still be running at the same ERP. Is there something I’m missing?

His problem was with interference received in a not too distant town that is outside of his protected contour. It seems they used to be received OK there, at least on a car radio. Now that a neighbor has lit up IBOC, they are no longer getting decent coverage in that town. He thinks the problem is the IBOC side band.

This report came from your part of the country, western Mass, if I'm not mistaken. If I can find the old post, I'll check that out. It was posted on the PubTech Digest, which has lots of engineers from the Public Radio, NPR-PRI sector.

> In the case of AM the adjacent channel interference is
> severe. to the point of blotting out stations. The classic
> example in the Northeast is WBZ/KDKA. Between about 4 and
> 6pm in Winter KDKA (1020) is wiped out in Western MA by
> WBZ's (1030) hash. On the dot at 6pm KDKA comes bombing in
> when WBZ shuts IBUZ off.
>
> I realize I'm outside both stations' protected contours.
> However, it seems to be a real warning about what will
> happen when the majority of AMs light up. That's why I
> propose that the FCC allow AM IBUZ operation 24/7 right now,
> so stations can fix interference problems before they get
> unmanagable.

IBOC may work for many folks on the FM band, but in the case of the grandfathered short spaced stations that are common in the Great Lakes area, I think there will be problems. Hopefully, I'm wrong.

Speaking as a small station operator, we'd be dead if it weren't for the listeners beyond our protected contour. Looking at the recent Arbitron data, most of our listeners are not within our protected contour. I'm sure we are not alone. A system that works great in our protected contour, but not at all past our protected contour would be a disaster.

> Contrary to all the hype and puffery the entire industry is
> not supportive of this system.
>
> Rich

I've spoken with quite a few small station operators (mostly AM) who share that point of view. I suppose that the market will determine the outcome of all this, but I wish that radio had a better product to offer. I think we'd all like to have better sounding signals, and multicasting might be a great bonus, but this seems like a hefty price to pay.

And I'm usually an "early adopter."
 
> This report came from your part of the country, western
> Mass, if I'm not mistaken. If I can find the old post, I'll
> check that out. It was posted on the PubTech Digest, which
> has lots of engineers from the Public Radio, NPR-PRI
> sector.

I'd like to see it. Around here the stations with compelling programming on their secondaries are the non-comms. They have more programming than places to run it.

If you can find the station he was talking about I'll drive around the area and see if I can duplicate what he heard. So far I haven't experienced any of the FM interference problems that have been mentioned.

I've programmed hundreds of stations in house and via syndication, so I probably know more people within Clear Channel than those in Clear Channel. I knew them under their old companies. Most were my affiliates at ABC or WOR. I often talk to station owners who sell beyond their protected contours. Not just small markets but several in the top 10 with monster signals.

Even WOR gets enough diary mentions in the Philadelphia book to bump their total numbers through X codes and spill-in.

Rich
 
Re: Wheres the proof...AGAIN

People don't listen to the radio with their eyes and a spectrum analyzer, they listen with their ears and a radio! If they do not like what they hear, (including iBUZZ) they tune out, or turn off. This is the law of the radio jungle.
Like guns, automobiles, and most anything else, a spectrum analyzer can be a useful instrument to a knowledgable, responsable professional, and a misused disaster in the hands of a cretin.
Proof for those who truly seek it, frustration for those who ignore it:
http://worldsupercaster.blogspot.com

> OK we have asked you multiple times to back up your
> statements. None have shown up yet. Still waiting.......
>
> > The FCC has not yet given final approval to the HD radio
> > proposal. FCC MM Docket No. 99-325 (the HD Radio standard)
>
> > has not yet been approved.
> > If the RIAA has it's way HD Radio may have to change the
> > codec for rights protection. That is still being
> negotiated,
> > and may obsolete all existing HD radios.
> > The digital HD Radio signal occupies over 400 kHz. Even
> > iBiquity and the HD Radio cartel acknowledge this.
> > htp://worldsupercaster.blogspot.com
> > You are right about the misinformation coming from the HD
> > Radio cartel.
> > Question the "information" from a car salesman selling
> > Yugo's.
> > He has an interest in making the sale, and a quota to fill
>
> > to satisfy his employer. The employer has an interest in
> > pushing the product.
> >
> > Question authority, they may have an ulterior motive, or
> > hidden agenda.
> >
> > > If you are in the 100 dbu circle, commonly known as the
> > > "blanketing contour," then you may have adjacent channel
>
> > > overload....with or without IBOC.
> > > Going back to engineering 101, IF the IBOC system were
> to
> > > occupy bandwith OUTSIDE the 200 Khz channel, it would be
>
> > > ILLEGAL. AND, the FCC would not approve the system.
> > > ClearChannel, Cumulus, and God combined would/could not
> > > change this!
> > > And furthermore, why would station groups shoot
> themselves
> >
> > > in the foot by advocating a system which destroys FM
> > > receiver performance? Do you argue that the engineering
> > > staffs of these companies DO NOT UNDERSTAND?? Last time
> I
> > > looked....there's some pretty damn smart engineers in
> > these
> > > groups. And I think, if it were so obvious that IBOC is
> > > detrimental to FM performance, that these EXPERTS would
> > have
> > > killed IBOC years ago.
> > > Posting innuendo and voodoo is not helpful to the
> > > discussion. Leave the magic to the real magicians!
> > >
> > >
> > >
> > >
> > > Thats a side benefit.... and yeah, I know that if
> theres
> > a
> > > > CH6 in town there will NOT be a radio station on 88.1
> > > > UNLESS, they share transmitter sites. I also know
> there
> >
> > > is
> > > > a guard area on the NAV band....... I'm not as dumb as
> I
> >
> > > > look. They did let me into the SBE, you know...
> > > >
> > > >
> > > > Oh good grief, thats it! You got it! The companies
> > > > > investing in HD radio want to eliminate competition
> .
> >
> > > > >
> > > > > Do you really think that there is a town that has
> air
> > > > > navagation on 108.1 with a 107.9 in town?
> > > > >
> > > > > And right about the Channel six thing (NOT!). 500
> > watts
> > >
> > > > of
> > > > > HD Radio will destroy 10,000 watts of analog channel
> 6
> >
> > > > > audio. (I dont think so)
> > > > >
> > > > > Do you see your logic does not compute?
> > > > >
> > > > >
> > > > >
> > > > > > You have to understand that the big broadchasers
> > > behind
> > > > > > iniquity want this effect because it takes away
> > > > > competition.
> > > > > > Yes, you will lose whatever you hear on adjacent
> > > > channels
> > > > >
> > > > > > due to the IBOC being out of channel. It should
> > > really
> > > > be
> > > > >
> > > > > > called IBAC since it is NOT ON Channel. And if
> you
> > > have
> > > >
> > > > > > digital on 88.1 or 107.9 it will be both out of
> band
> >
> > > and
> > > >
> > > > > > adjacent channel.... I cant see ever allowing an
> FM
> >
> > > on
> > > > > > 107.9 to go IBOC because of interference to
> aircraft
> >
> > > > > > navigation equipment. Same with IBOC in a city
> with
> > a
> > >
> > > > > > channel 6 TV, the IBOC will destroy the CH 6
> audio.
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > > THE SOLUTION TO HD RADIO INTERFERENCE!
> > > > > > > SEE MY OTHER POST HERE:
> > > > > > >
> > > > >
> > >
> http://www.radio-info.com/mods/board?Post=667022&Board=hd
> > > > > > > http://worldsupercaster.blogspot.com
> > > > > > > The HD Radio interference will just get worse,
> as
> > > more
> > > >
> > > > > > > stations sign on, unless we adopt a better
> system
> > > that
> > > >
> > > > > > does
> > > > > > > not jam other stations.
> > > > > > > www.dreinc.com
> > > > > > >
> > > > > > > > In the Salt Lake City area, recently two
> signals
> >
> > > at
> > > > > 99.5
> > > > > >
> > > > > > > FM
> > > > > > > > and 98.7 FM have turned on iBiquity's
> equipment.
> >
> > > > > > > >
> > > > > > > > 99.5's has been on for a while, and their
> signal
> >
> > > is
> > > > > > > relayed
> > > > > > > > to a translator in the southern portion of our
>
> > > large
> > > >
> > > > > > metro
> > > > > > >
> > > > > > > > area.
> > > > > > > >
> > > > > > > > So now, here in Salt Lake City, it seems the
> > > > > translator,
> > > > > >
> > > > > > > > located on Lake Mountain in Utah County, is
> > dead.
> > > > > > However,
> > > > > > >
> > > > > > > > it is not - as we have received reports from a
>
> > > > > listener
> > > > > > in
> > > > > > >
> > > > > > > > that valley who can still hear it just fine.
> > > > > > > >
> > > > > > > > Does two signals both using IBOC technology
> > cause
> > > > this
> > > > >
> > > > > > to
> > > > > > > > happen to farther-away signals?
> > > > > > > >
> > > > > > > > Thanks!
> > > > > > > > -----------------------
> > > > > > > > Utah Radio News and Information
> > > > > > > > http://www.utahradioonline.com
> > > > > > > > http://www.radiogrind.com
> > > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>
 
> Don't expect engineers whose companies have embraced IBUZ to
> have anything negative to say about it. Their jobs are at
> stake. All I see from them are glowing reports about how
> well both the AM and FM IBUZ systems perform.


Not true. I have mentioned many times that I think AM "IBUZ" is flawed.


> I get many off list emails from managers, engineers and
> programmers who either can't participate or don't dare say
> anything publicly. Since I was one of the first to actually
> have a receiver to test, I seem to have become their
> mouthpiece with an absolute promise never to reveal their
> identities.

Interesting. I've never gotten any off-list emails. You must just come off as an honest guy or something. If any of you lurkers are reading, let me hear from you. My email address is easy to find. Heck, I'll give you my number and you can call me!

> Contrary to all the hype and puffery the entire industry is
> not supportive of this system.
>

I'm not sure where anyone has said otherwise.

So far, there has been plenty of puffery and bad information coming from the anti-"IBUZ" side as well. There sure seems to be plenty of experts (including yourself) that make a lot of noise while presenting very little in the way of fact. Lots of simply personal opinion.

As for you being a mouthpiece, can't argue with that one.<P ID="signature">______________
</P>
 
Re: Wheres the proof...AGAIN

> People don't listen to the radio with their eyes and a
> spectrum analyzer, they listen with their ears and a radio!
> If they do not like what they hear, (including iBUZZ) they
> tune out, or turn off. This is the law of the radio jungle.
> Like guns, automobiles, and most anything else, a spectrum
> analyzer can be a useful instrument to a knowledgable,
> responsable professional, and a misused disaster in the
> hands of a cretin.
> Proof for those who truly seek it, frustration for those who
> ignore it:
> http://worldsupercaster.blogspot.com
>
>

Nice straw man argument...good job!

One questionable spectrum shot is not proof. I have several that show otherwise.

But again, we don't expect you to provide proof.<P ID="signature">______________
</P>
 
Re: Wheres the proof...AGAIN

> > People don't listen to the radio with their eyes and a
> > spectrum analyzer, they listen with their ears and a
> radio!
> > If they do not like what they hear, (including iBUZZ) they
>
> > tune out, or turn off. This is the law of the radio
> jungle.
> > Like guns, automobiles, and most anything else, a spectrum
>
> > analyzer can be a useful instrument to a knowledgable,
> > responsable professional, and a misused disaster in the
> > hands of a cretin.
> > Proof for those who truly seek it, frustration for those
> who
> > ignore it:
> > http://worldsupercaster.blogspot.com
> >
> >
>
> Nice straw man argument...good job!
>
> One questionable spectrum shot is not proof. I have several
> that show otherwise.
>
> But again, we don't expect you to provide proof.
>


Should I screen grab from the Golden Eagle Doc?
 
> Interesting. I've never gotten any off-list emails. You
> must just come off as an honest guy or something. If any of
> you lurkers are reading, let me hear from you. My email
> address is easy to find. Heck, I'll give you my number and
> you can call me!

You don't seem to understand. I've dealt with thousands people at stations that were affiliated with my networks and syndication companies over many years. The off list emails are from people I've worked with in one capacity or another who are now captives of the HD Dominion and can't speak out. They know I won't betray their trust, so they share their thoughts. Seems logical to me.

> As for you being a mouthpiece, can't argue with that one.

I'll take that as a compliment even though I can't imagine it was intended as one. See above.

Rich
 
> > Interesting. I've never gotten any off-list emails. You
> > must just come off as an honest guy or something. If any
> of
> > you lurkers are reading, let me hear from you. My email
> > address is easy to find. Heck, I'll give you my number
> and
> > you can call me!
>
> You don't seem to understand. I've dealt with thousands
> people at stations that were affiliated with my networks and
> syndication companies over many years. The off list emails
> are from people I've worked with in one capacity or another
> who are now captives of the HD Dominion and can't speak out.
> They know I won't betray their trust, so they share their
> thoughts. Seems logical to me.
>
> > As for you being a mouthpiece, can't argue with that one.
>
> I'll take that as a compliment even though I can't imagine
> it was intended as one. See above.
>
> Rich
>


I absolutely do understand.

It's very easy to say "all these people are afraid of the big bad wolf. They agree with me but are afraid to say anything."

You don't have to prove any of that. I've also met quite a few people over the years. Guess what? Most of them admit that they don't know enough about HD to have an opinion.

I haven't gotten "off-list" messages for OR against "IBUZZ". I just find it surprising that all these people confide in you. More surprising is the "fear" that they supposedly have.

I have spoken out against AM "IBUZZ". I am still gainfully employed. I have not seen any "IBORG" black helicopters flying around my house.

And yes, it was a compliment.<P ID="signature">______________
</P>
 
WBZ/KDKA, and WOWO/WCHB

> In the case of AM the adjacent channel interference is
> severe. to the point of blotting out stations. The classic
> example in the Northeast is WBZ/KDKA. Between about 4 and
> 6pm in Winter KDKA (1020) is wiped out in Western MA by
> WBZ's (1030) hash. On the dot at 6pm KDKA comes bombing in
> when WBZ shuts IBUZ off.

My question is this: Prior to WBZ running IBOC, they probably had 10Khz bandwidth instead of 5Khz. Assuming that to be the case, was KDKAs signal clobbered by the chatter from WBZ in western MA then? If so, then we are merely substituting one type of interference for another. In a related case, somebody (I forgot his name) recorded the reception of WOWO (1190) from Lambertville, MI during critical hours while WCBH (1200) from Taylor, MI turned on their IBOC. He noted that before WCHB turned on the IBOC, WOWO was easily receivable. When WCHB switched on their IBOC, WOWO was lost in the hash. I listened to the audio clip and it sounded very convincing. However, later on it occured to me that WCBH was probably using 5khz to be compatible with IBOC. My point is this: If WCBH used 10Khz bandwidth while not running IBOC, and then swiched on the IBOC, the comparison is valid. However, if WCHB was using 5khz bandwidth while in the analog mode (which I strongly suspect), just prior to switching on the IBOC, then you are comparing apples to steaks. <P ID="edit"><FONT class="small">Edited by Len14043 on 03/01/06 02:03 AM.</FONT></P>
 
Re: Wheres the proof...AGAIN

> > > People don't listen to the radio with their eyes and a
> > > spectrum analyzer, they listen with their ears and a
> > radio!
> > > If they do not like what they hear, (including iBUZZ)
> they
> >
> > > tune out, or turn off. This is the law of the radio
> > jungle.
> > > Like guns, automobiles, and most anything else, a
> spectrum
> >
> > > analyzer can be a useful instrument to a knowledgable,
> > > responsable professional, and a misused disaster in the
> > > hands of a cretin.
> > > Proof for those who truly seek it, frustration for those
>
> > who
> > > ignore it:
> > > http://worldsupercaster.blogspot.com
> > >
> > >
> >
> > Nice straw man argument...good job!
> >
> > One questionable spectrum shot is not proof. I have
> several
> > that show otherwise.
> >
> > But again, we don't expect you to provide proof.
> >
>
>
> Should I screen grab from the Golden Eagle Doc?
>

Sure. I also just did scans of my stations with an HP analyzer...all WELL within the FM mask, as defined by the FCC. I also have one with all the other stations in the market, showing a grand total of ZERO "interference" from "IBUZ".<P ID="signature">______________
</P>
 
Re: WBZ/KDKA, and WOWO/WCHB

> My question is this: Prior to WBZ running IBOC, they
> probably had 10Khz bandwidth instead of 5Khz. Assuming that
> to be the case, was KDKAs signal clobbered by the chatter
> from WBZ in western MA then?

I'm using the analog version of the Boston Acoustics receiver. It's selectivity is pretty good. I hear no WBZ chatter when IBUZ is off. I hear no chatter between KDKA and WINS at 1010.

I've always been concerned with what comes out of the radio, not why. We're not talking about a little chatter. We're talking about being unable to receive a station that bombs in once IBUZ shuts down. That should concern all of us.

Rich
 
Re: WBZ/KDKA, and WOWO/WCHB

> I'm using the analog version of the Boston Acoustics
> receiver. It's (sic) selectivity is pretty good.

Please, Rich... I thought you were smarter than to make this mistake. :-(

> I've always been concerned with what comes out of the radio,
> not why. We're not talking about a little chatter. We're
> talking about being unable to receive a station that bombs
> in once IBUZ shuts down. That should concern all of us.

The "why" in this case is that adjacent-channel interference caused by analog AM signals is sporadic in nature, and usually has a low duty cycle. With talk radio there is lots of silence between the words, so back in their 10 kHz analog AM Stereo days, WBZ was causing interference to KDKA maybe 20% of the time. But with WBZ's IBOC hash generator on, the duty cycle of the hash is continuous, so the interference is happening 100% of the time. The result is that a signal with sporadic impairments is still intelligible, but a signal with continuous impairments is not.
<P ID="signature">______________
It's a common mistake to not use punctuation in its proper form.
<a target="_blank" href=http://www.cgl.uwaterloo.ca/~csk/its.html>Be kind to your friend, the apostrophe.</a></P>
 
Re: GOOD GRIEF! The mis information continues.....

> I didnt reaalize that translators sudden have protected
> coverage now. When did that happen?

Didn't say they did.

Regardless, the station SHOULD and WOULD be coming in crystal clear without IBUZ (I'm going to steal that term. Very appropriate.)
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom