HD Interference Case #1 (FM)

[Chuck]

So has there been showings that an adjacent channel IBOC system has interfered with a stations protected contour, or that there has been an increase in interference in the stations secondary contour?

Sorry if this has been explained already...it was a little difficult to follow the thread...

I monitor a user group called "PubTech Digest." It is mostly made up of NPR affiliates. There have been a few reports of IBOC interference among them. WEOS in Geneva New York, was one that I recall having problems. I’ve also read of problems these stations are having with their translators, which are quite common with that type of station. Most of these stories come from the New York and New England areas. Keep in mind that these stations are typically short spaced in the non-com band.

Typically, the small station is the one who is having problems. How bad those problems are, I don't really know. They are simultaneously launching a new satellite delivery system called Content Depot. Currently, debugging it, and switching to a new satellite seems to be their largest priority.

 

[IBOCRocks]

So has there been showings that an adjacent channel IBOC system has interfered with a stations protected contour, or that there has been an increase in interference in the stations secondary contour?

Sorry if this has been explained already...it was a little difficult to follow the thread...

I monitor a user group called "PubTech Digest." It is mostly made up of NPR affiliates. There have been a few reports of IBOC interference among them. WEOS in Geneva New York, was one that I recall having problems. I’ve also read of problems these stations are having with their translators, which are quite common with that type of station. Most of these stories come from the New York and New England areas. Keep in mind that these stations are typically short spaced in the non-com band.

Typically, the small station is the one who is having problems. How bad those problems are, I don't really know. They are simultaneously launching a new satellite delivery system called Content Depot. Currently, debugging it, and switching to a new satellite seems to be their largest priority.

Gotcha. That makes sense...I imagine translators and low power non-comms have the largest potential interference issues. The question I have is if the interference is on their protected contour or not? Not to pass judgement or not, just more curious than anything...admittedly some of the protected contours of these stations are tiny.

 

[SayNoToIBOC]

IBOCRocks wrote: "Gotcha."

"CPB Seeks Applications for HD-R Interference Study"

http://www.rwonline.com/dailynews/one.php?id=8963

"HD RADIO INTERFERENCE MUCH WORSE-CLEAR CHANNEL SENIOR ENGINEER"

http://worldsupercaster.blogspot.com/2006/04/hd-radio-interference-much-worse-clear.html

"HD/IBOC Radio Pioneer Hears the Call of Interference"

http://www.mediageek.net/?p=1420

Are you waiting for me to logoff, before you post/reply ?

 

[Chuck]

Gotcha. That makes sense...I imagine translators and low power non-comms have the largest potential interference issues. The question I have is if the interference is on their protected contour or not? Not to pass judgement or not, just more curious than anything...admittedly some of the protected contours of these stations are tiny.

Can't say I know, but I'll hazard a guess that it is beyond the protected contour. Even so, in that particular case, the station's engineer was very unhappy that they were no longer receivable in a nearby town, where they’d very definitely had listeners in the past. Wouldn't you be unhappy if it was your station? Those listeners were disappointed, regardless of whether or not they had a legal right to expect reception. They'd always listened before, and this is going to be perceived as losing something.

As I've mentioned before, the high power stations probably have nothing to worry about. It's the smaller stations that have a problem. I also have no idea how this works with translators. Let's say you have a 100 watt translator that does a decent job of covering a town of 10-20,000 people. With an IBOC signal that is 20 db down, that is a one watt digital signal. I know that is more then your cell phone, but is it enough to do any good? Somehow I doubt it.

How many times have you had to go outside, or stand next to a window to get your cell phone to work? I have to do it all the time. I can't see this being much more robust.

At this summer's TAB convention, I asked how this works with translators. The rep from Harris said that Rice University had a translator on campus since they couldn't get good reception from their transmitter site which is evidentially some distance from campus. Without going into details about why they couldn’t pick up their main signal with reliability on campus, he said that the HD translator did "a good job of covering the campus." That's not a very big space....

 

[IBOCRocks]

Gotcha. That makes sense...I imagine translators and low power non-comms have the largest potential interference issues. The question I have is if the interference is on their protected contour or not? Not to pass judgement or not, just more curious than anything...admittedly some of the protected contours of these stations are tiny.

Can't say I know, but I'll hazard a guess that it is beyond the protected contour. Even so, in that particular case, the station's engineer was very unhappy that they were no longer receivable in a nearby town, where they’d very definitely had listeners in the past. Wouldn't you be unhappy if it was your station? Those listeners were disappointed, regardless of whether or not they had a legal right to expect reception. They'd always listened before, and this is going to be perceived as losing something.

As I've mentioned before, the high power stations probably have nothing to worry about. It's the smaller stations that have a problem. I also have no idea how this works with translators. Let's say you have a 100 watt translator that does a decent job of covering a town of 10-20,000 people. With an IBOC signal that is 20 db down, that is a one watt digital signal. I know that is more then your cell phone, but is it enough to do any good? Somehow I doubt it.

How many times have you had to go outside, or stand next to a window to get your cell phone to work? I have to do it all the time. I can't see this being much more robust.

At this summer's TAB convention, I asked how this works with translators. The rep from Harris said that Rice University had a translator on campus since they couldn't get good reception from their transmitter site which is evidentially some distance from campus. Without going into details about why they couldn’t pick up their main signal with reliability on campus, he said that the HD translator did "a good job of covering the campus." That's not a very big space....

I absolutely understand what you are saying. I would certainly be upset that it's my station! Have they done any signal analysis to 100% show that it's an adjacent IBOC causing the problem? I'm not trying to discount any reports, but it's just like the old story of the guy who put up the new tower that was empty. Even though the neighbors didn't know there was nothing on the tower they blamed it for every interference problem they had!

I think these are interesting issues that need to be investigated...it just seems that nobody is really stepping forward, other than to give anecdotal evidence. There may be real easy (or not so easy) solutions to the problems.

 

[Chuck]

I'm not sure if there are any easy solutions. It seems the station that was interfering had just gone IBOC. I never figured out if the smaller station was IBOB or not. My impression was that they were not. The good news is the two are friendly neighbors, both owned by nearby colleges. I haven't heard how it worked out, or if anything has been resolved.

I suspect that the real problem is there is a point of diminishing returns for any signal. When the power gets below a certain threshold, this may not work. I did notice that Armstrong is marketing an IBOC enabled translator. I'd be very interested to see how it works. I just can’t imagine that a maximum 2.5 watt digital signal is worth bothering with. Maybe I’m wrong.

Since the FCC received 13,400+ translator applications in the last filing window, this may be a huge problem if they get on the air. Most of those applications are for the commercial band. Of course, the process is frozen right now due to the possibility of unethical behavior on the part of some of the "mega filers." The Commission may just throw out all the applications that have not been granted. Then again, they may not. If 1/3 of those applications are approved, things are going to get a lot more crowded. And now NAB is proposing that 1 KW daytime AM's be given FM translators. I don't know where they are planning on putting them.

I have no bone to pick with the idea digital radio, or even IBOC, assuming it can be made to work without interfering with your neighbors, but this exercise looks to me like they are trying to cram 10 pounds of sh*t into a one pound bag.

It would be fun to go talk this out over a few beers....

 

[IBOCRocks]

I'm not sure if there are any easy solutions. It seems the station that was interfering had just gone IBOC. I never figured out if the smaller station was IBOB or not. My impression was that they were not. The good news is the two are friendly neighbors, both owned by nearby colleges. I haven't heard how it worked out, or if anything has been resolved.

I suspect that the real problem is there is a point of diminishing returns for any signal. When the power gets below a certain threshold, this may not work. I did notice that Armstrong is marketing an IBOC enabled translator. I'd be very interested to see how it works. I just can’t imagine that a maximum 2.5 watt digital signal is worth bothering with. Maybe I’m wrong.

Since the FCC received 13,400+ translator applications in the last filing window, this may be a huge problem if they get on the air. Most of those applications are for the commercial band. Of course, the process is frozen right now due to the possibility of unethical behavior on the part of some of the "mega filers." The Commission may just throw out all the applications that have not been granted. Then again, they may not. If 1/3 of those applications are approved, things are going to get a lot more crowded. And now NAB is proposing that 1 KW daytime AM's be given FM translators. I don't know where they are planning on putting them.

I have no bone to pick with the idea digital radio, or even IBOC, assuming it can be made to work without interfering with your neighbors, but this exercise looks to me like they are trying to cram 10 pounds of sh*t into a one pound bag.

It would be fun to go talk this out over a few beers....

I would absolutely love to talk about this over some beer! There are other fun RF things down the pipe, such as the proposal for "smart" radios that would use "unused" (yeah, right!) TV channels, other radios using GPS to determine what frequencies/power levels to operate on, and of course those pesky FM Modulators that seem to have better coverage than some translators!

Anyway, I agree. The RF noise floor just keeps rising. Interference is going to happen, and the questions are many:

What are the sources?
Who is impacted?
How do we mitigate it?
How much is acceptable?

Contrary to what others say here, I have no vested interest in the success or failure of IBOC. If the world decides that IBOC shouldn't happen, so be it. On the other hand, I don't want to just see it shut down because somebody has a problem with it. No matter what you do, someone will find something wrong with it. Let the tests continue and the discussions roll on. Only with that kind of dialog will things change.

 

[Chuck]

No matter what you do, someone will find something wrong with it. Let the tests continue and the discussions roll on. Only with that kind of dialog will things change.

Almost everything is a trade off. I'd just like whatever we do to have as little collateral damage as possible. That's why I think there may be room for more than one digital system to coexist peacefully, just as they do in the land of HDTV.

Incidentally, on the same PubTech news group, one station is currently playing with FMeXtra. They reported that it was seamless to at least their 60 dbu contour, and still usable in most locations to their 50 dbu contour. IF that is true, that is a huge improvement over the Ibiquity version.

Yes, I know there aren't any FMeXtra radios, but truthfully, there aren't that many HD radios either. I really can't see why you couldn't make a radio that decoded both, as well as conventional analog signals. It’s all software. The basic DSP chips are not that unusual. Of course Ibiquity would have to participate, and thus far, the jungle drums say they are not interested. It seems it is all or nothing as far as they are concerned.

Most significantly, as you pointed out, if programmers fail to use these technologies in a manner that is appealing to the public, the whole thing is doomed for failure. I hope they get that message. Unfortunately, I think a lot of folks in radio are more concerned with technology than content. People will listen on a tin can and a string if it is something they want to hear.

I think I’ll have that beer now…

 

[IBOCRocks]

No matter what you do, someone will find something wrong with it. Let the tests continue and the discussions roll on. Only with that kind of dialog will things change.

Almost everything is a trade off. I'd just like whatever we do to have as little collateral damage as possible. That's why I think there may be room for more than one digital system to coexist peacefully, just as they do in the land of HDTV.

Incidentally, on the same PubTech news group, one station is currently playing with FMeXtra. They reported that it was seamless to at least their 60 dbu contour, and still usable in most locations to their 50 dbu contour. IF that is true, that is a huge improvement over the Ibiquity version.

Yes, I know there aren't any FMeXtra radios, but truthfully, there aren't that many HD radios either. I really can't see why you couldn't make a radio that decoded both, as well as conventional analog signals. It’s all software. The basic DSP chips are not that unusual. Of course Ibiquity would have to participate, and thus far, the jungle drums say they are not interested. It seems it is all or nothing as far as they are concerned.

Most significantly, as you pointed out, if programmers fail to use these technologies in a manner that is appealing to the public, the whole thing is doomed for failure. I hope they get that message. Unfortunately, I think a lot of folks in radio are more concerned with technology than content. People will listen on a tin can and a string if it is something they want to hear.

I think I’ll have that beer now…

All very good points! I have been following FMeXtra, and am interested in seeing where it goes. I think that be it IBOC or FMeXtra or whatever, digital radio is the delivery method of the future for terrestrial radio. Of course, it'll be the content that really decides the fate of any of this stuff.

 

[SayNoToIBOC]

IBOCRocks wrote: "digital radio is the delivery method of the future for terrestrial radio."

There are no facts to back up that statement - just take IBOC, as an example of a miserable attempt. Actually, the Bridge Ratings show analog terrestrial radio, well out into mid-century (still over 200 million analog listeners).

 

[audiophile.]

No matter what you do, someone will find something wrong with it. Let the tests continue and the discussions roll on. Only with that kind of dialog will things change.

Almost everything is a trade off. I'd just like whatever we do to have as little collateral damage as possible. That's why I think there may be room for more than one digital system to coexist peacefully, just as they do in the land of HDTV.

Incidentally, on the same PubTech news group, one station is currently playing with FMeXtra. They reported that it was seamless to at least their 60 dbu contour, and still usable in most locations to their 50 dbu contour. IF that is true, that is a huge improvement over the Ibiquity version.

Yes, I know there aren't any FMeXtra radios, but truthfully, there aren't that many HD radios either. I really can't see why you couldn't make a radio that decoded both, as well as conventional analog signals. It’s all software. The basic DSP chips are not that unusual. Of course Ibiquity would have to participate, and thus far, the jungle drums say they are not interested. It seems it is all or nothing as far as they are concerned.

Most significantly, as you pointed out, if programmers fail to use these technologies in a manner that is appealing to the public, the whole thing is doomed for failure. I hope they get that message. Unfortunately, I think a lot of folks in radio are more concerned with technology than content. People will listen on a tin can and a string if it is something they want to hear.

I think I’ll have that beer now…

All very good points! I have been following FMeXtra, and am interested in seeing where it goes. I think that be it IBOC or FMeXtra or whatever, digital radio is the delivery method of the future for terrestrial radio. Of course, it'll be the content that really decides the fate of any of this stuff.

The DRE and DRM are truly IBOC systems.

 

[Chuck]

The DRE and DRM are truly IBOC systems.

True. DRE makes a lot of sense to me. It's a simple idea. I like simple.....

 

[autopaint-1]

BUT each requires their own bands. Neither is compatible with existing spectrum and the FCC is not assigning new spectrum for broadcast radio.

 

[I.B. Iquity]

There is no new spectrum available for DRM to be implimented. Actually I beleive DRM has been around longer and find itself behind IBOC as far as radios manufactured and there are some countries which have left the DRM fold and chosen to go IBOC instead.

 

[1q2w3e]

No matter what you do, someone will find something wrong with it. Let the tests continue and the discussions roll on. Only with that kind of dialog will things change.

Almost everything is a trade off. I'd just like whatever we do to have as little collateral damage as possible. That's why I think there may be room for more than one digital system to coexist peacefully, just as they do in the land of HDTV.

Incidentally, on the same PubTech news group, one station is currently playing with FMeXtra. They reported that it was seamless to at least their 60 dbu contour, and still usable in most locations to their 50 dbu contour. IF that is true, that is a huge improvement over the Ibiquity version.

Yes, I know there aren't any FMeXtra radios, but truthfully, there aren't that many HD radios either. I really can't see why you couldn't make a radio that decoded both, as well as conventional analog signals. It’s all software. The basic DSP chips are not that unusual. Of course Ibiquity would have to participate, and thus far, the jungle drums say they are not interested. It seems it is all or nothing as far as they are concerned.

Most significantly, as you pointed out, if programmers fail to use these technologies in a manner that is appealing to the public, the whole thing is doomed for failure. I hope they get that message. Unfortunately, I think a lot of folks in radio are more concerned with technology than content. People will listen on a tin can and a string if it is something they want to hear.

I think I’ll have that beer now…

All very good points! I have been following FMeXtra, and am interested in seeing where it goes. I think that be it IBOC or FMeXtra or whatever, digital radio is the delivery method of the future for terrestrial radio. Of course, it'll be the content that really decides the fate of any of this stuff.

Great conversation guys!

From what I have heard about FMeXtra, it runs on the SCA channels, and that the bandwidth moght not be enough to meet the expecations of a decent digital signal. People are already complaining about the "limited" bandwidth of HD. FMeXtra would be even worse.

I would like to have the opportunity to try FM eXtra though.

 

[SUPERCASTER]

No matter what you do, someone will find something wrong with it. Let the tests continue and the discussions roll on. Only with that kind of dialog will things change.

Almost everything is a trade off. I'd just like whatever we do to have as little collateral damage as possible. That's why I think there may be room for more than one digital system to coexist peacefully, just as they do in the land of HDTV.

Incidentally, on the same PubTech news group, one station is currently playing with FMeXtra. They reported that it was seamless to at least their 60 dbu contour, and still usable in most locations to their 50 dbu contour. IF that is true, that is a huge improvement over the Ibiquity version.
Yes, I know there aren't any FMeXtra radios, but truthfully, there aren't that many HD radios either. I really can't see why you couldn't make a radio that decoded both, as well as conventional analog signals. It’s all software. The basic DSP chips are not that unusual. Of course Ibiquity would have to participate, and thus far, the jungle drums say they are not interested. It seems it is all or nothing as far as they are concerned.

Most significantly, as you pointed out, if programmers fail to use these technologies in a manner that is appealing to the public, the whole thing is doomed for failure. I hope they get that message. Unfortunately, I think a lot of folks in radio are more concerned with technology than content. People will listen on a tin can and a string if it is something they want to hear.

I think I’ll have that beer now…

All very good points! I have been following FMeXtra, and am interested in seeing where it goes. I think that be it IBOC or FMeXtra or whatever, digital radio is the delivery method of the future for terrestrial radio. Of course, it'll be the content that really decides the fate of any of this stuff.

The public does not seem to have a problem with analog terrestrial radio and the several sources of digital audio and radio they already have.
As far as choices and trade offs, at least FMeXtra www.dreinc.com is compatable with current FM assignments, has final approval, is much simpler, less expensive, has better coverage, equal sound quality, and causes no harm. In my mind, it is probably the better choice. It requires no final approval of "masks" to hide behind, adjacent channel saddlebags, or jamming of the "stations between the stations".
I want a competent, unbiased, independent, comprehensive, technical engineering analysis as to which system (FMeXtra or HD Radio) harms the least and performs the best. Why does that infuriate HD supporters?
If HD Radio was even 10% as good as they claim they would have nothing to fear.

 

[calstymes]

SUPERCASTER proclaimed:

The public does not seem to have a problem with analog terrestrial radio and the several sources of digital audio and radio they already have.

Even extra terrestrial radio is better than HD! ;D

I want a competent, unbiased, independent, comprehensive, technical engineering analysis as to which system (FMeXtra or HD Radio) harms the least and performs the best. Why does that infuriate HD supporters?

Didn't you know? Because when the likes of the broadcast professionals in the #1 market say that FMeXtra is dead, then it really must be. If you don't believe that then YOU must be mistaken and YOUR thinking is deficient and dangerous. This kind of thinking is infuriating to the pro-IBOCers who believe that Ubiquitous is the guiding light (sorry CBS) and we must all follow blindly into HD-nirvana.

If HD Radio was even 10% as good as they claim they would have nothing to fear.

Now there's a thought! I'm aghast that it might not be that good. Will the free world as we know it survive without HD? Tune again tomorrow, same IBOC-time, same IBOC-channel... oh wait! That's only if you have a Receptor that works!

 

[I.B. Iquity]

"Even extra terrestrial radio is better than HD!"

Not if you are professional broadcaster trying to compete with new competitors, such as XM & Sirius. Radio is a business not a hobby.


Didn't you know? Because when the likes of the broadcast professionals in the #1 market say that FMeXtra is dead, then it really must be. If you don't believe that then YOU must be mistaken and YOUR thinking is deficient and dangerous. This kind of thinking is infuriating to the pro-IBOCers who believe that Ubiquitous is the guiding light (sorry CBS) and we must all follow blindly into HD-nirvana."


As mentioned above IBOC has better audio quality than FMeXtra, doesnt make use of an analogue subcarrier and the FM IBOC stations are not causing intereference with any stations protected contours. You can go out today and purchase several IBOC capable radios. Not so for the competition. Are there any major market stations broadcasting FMeXtra at the moment?

 

[Chuck]

BUT each requires their own bands. Neither is compatible with existing spectrum and the FCC is not assigning new spectrum for broadcast radio.

FME (FMeXtra) does not require any new band. It works on the existing FM band using your subcarriers.

 

[Chuck]

As mentioned above IBOC has better audio quality than FMeXtra, doesnt make use of an analogue subcarrier and the FM IBOC stations are not causing intereference with any stations protected contours. You can go out today and purchase several IBOC capable radios. Not so for the competition. Are there any major market stations broadcasting FMeXtra at the moment?

Have you actually heard them side by side, or is this hearsay? I’d be very surprised if you have heard it in any A-B comparison.

I have not heard FMeXtra, but I have heard IBOC. I can't see any technical treason why FMeXtra shouldn't sound very good. As I understand it, FMeXtra uses AAC+ encoding, which can sound pretty good at 32 kbs. You don't have to run it at that low a rate, but it's nice to know you can.

Reports I've heard from some public broadcasters who are experimenting with this system are very encouraging. Since these guys are long term engineers from stations that tend to be fairly "tweaky," I tend to respect their opinions.

I've also noticed that most kids are very happy with 64 kbs (or smaller) mp3 files. Lots of people are still OK with the sound of AM. The fact of the matter is if you give people something really worth listening to, they will be content with a tin can and a string. Audio quality is important, but it is not why 99.9% of all people listen to radio.

At this point, it really doesn’t matter how many HD radios have been sold. The number isn't that great. The real issue is money. Large broadcasters have dumped a lot of cash into IBOC and they would like to see their investment returned many times over. That is the real reason why you have opposition to possibly better technology. It has noting to do with quality. It has everything to do with money.