For those of you that think FM IBOC has no hash on the adjacents

[R.F. Burns]

WBT will resume IBOC at night after the start of the new year. So much for the claims asserted by the know it all anti IBOC people. The more I read about IBOC failing, the more ground the technology is making. Last year there was a fire near the WMCA transmitter site in New Jersey. They diplex with WNYC, which runs IBOC on 820 Khz. After the fire WNYC turned the IBOC off and the chief at WMCA specifically claimed that IBOC was gone forever from WNYC AM. I told him that I was told by WNYC that they had every intention of getting their IBOC exciter back on line. After repairs were made, WNYC is again running their IBOC exciter. They turn it off at night, probably due to antenna issues, but WNYC AM is running in IBOC mode during the day. I'm sure they are working on getting nightime IBOC to work from that site as well.

 

[Chuck]

This could make for an interesting alternative to provide relief for injured parties like Bob Savage/1040 WYSL if the FCC is going to be so stubborn about not releasing VHF Channels 5 & 6.

I’ve noticed that recently the FCC has been busy assigning LPTV stations to Channel 6. So much for doing anything that makes sense...

 

[Mike Walker]

Well that's the first actually persuasive evidence I've heard of ANY consequence from FM HD. A couple of observations.

1st-Your radio must have had an INCREDIBLY wide if filter! I have FM HD 1st adjacents (WFDD Winston Salem on 88.5, and WNCW Spindale NC on 88.7), and hear nothing like that on any analog radio I own!

2nd-I hope that's not an example of good reception once the "IBOC hash" is gone! It reinforces what I've said all along...where CLEAN FM stereo is receivable, HD usually is as well. Even after the HD switchoff, your intended station is still received in mono. It's NOT a signal I'd listen to for program content. DX, yes! But a GOOD radio, with a GOOD narrow if filter would accomplish the same thing in the presence of IBOC.

So I'd conclude "Congratulations! You've succeeded in your demonstration...IF what you were attempting to demonstrate is that you have one of the small percentage of radios so poor that it reacts this way to an adjacent IBOC station! Most don't (react that way). Not a single one in my LARGE collection does!

 

[Play Freebird]

I’ve noticed that recently the FCC has been busy assigning LPTV stations to Channel 6. So much for doing anything that makes sense...

And I'll bet most of them stay analog, transmit "FM radio" on the aural channel like the one in New York, and put up a slide -- thus wasting 5-1/2 MHz of spectrum on "video" nobody watches.

 

[Savage]

RF, what's with the reference to "know-it-all-anti-IBOC people?"

You asked for evidence that anyone other than Citadel had turned off IBOC exciters. I listed several and gave the source for that information. I'm sure that if indeed WNYC or WBT or anyone else turn HD-AM back on that will be duly noted on McLarnon's site. He reports what the status of any given station is based upon data from his sources as of a specific date. Until it happens, he doesn't report it.

If you regard an essentially status-quo IBOC station population since 9/14/07 with fewer than 2% of operating AMs using IBOC 24 hours as evidence that the system is "gaining ground," so be it.

As a footnote I will repeat that when you take away the stations owned by iBiquity's prime investors and NPR outlets and publicly-funded AMs run by schools and universities, the actual number of commercial for-profit IBOC-AM broadcasters who installed the system on "technical merit" is fewer than two dozen. I respectfully dissent from your position that the system is succeeding in the marketplace.

 

[clouseau]

Well that's the first actually persuasive evidence I've heard of ANY consequence from FM HD. A couple of observations.

1st-Your radio must have had an INCREDIBLY wide if filter! I have FM HD 1st adjacents (WFDD Winston Salem on 88.5, and WNCW Spindale NC on 88.7), and hear nothing like that on any analog radio I own!

2nd-I hope that's not an example of good reception once the "IBOC hash" is gone! It reinforces what I've said all along...where CLEAN FM stereo is receivable, HD usually is as well. Even after the HD switchoff, your intended station is still received in mono. It's NOT a signal I'd listen to for program content. DX, yes! But a GOOD radio, with a GOOD narrow if filter would accomplish the same thing in the presence of IBOC.

So I'd conclude "Congratulations! You've succeeded in your demonstration...IF what you were attempting to demonstrate is that you have one of the small percentage of radios so poor that it reacts this way to an adjacent IBOC station! Most don't (react that way). Not a single one in my LARGE collection does!

Mike, I think you are wrong. What you haven't done is spend 15 minutes to actually look at the facts about his "Demo" I was really surprised. When you dig into it, you shouldn't be...

People overall just do not understand how the contour protection and minimum spacing standards are supposed to work.

NONE of these examples are protected at his location. NONE. My favorite is the 96.9 WTKK wipes out 97.1 WQHT. Let's get real. If WQHT was the only station in the world, he could build a class "A" station on 97.1 at his house. PLENTY of Clearance. He could then go 115 KM directly TOWARDS WQHT. When he got there he could build ANOTHER full "A" station. Then he cold travel ANOTHER 120 KM towards WQHT and He would be there. No not at the Transmitter. At the edge of their protected contour. After that, you only gotta go ANOTHER 65 km and you're right there at Empire.

The WRCH station is 169 KM away from the receivers location. Twice the distance of the service area.

WXRV is a northern Boston rimshot. His location is considerably south of the city.

Even WFNX does not have a protected contour at the location received.

Later in the thread, Mr. "Right On" dude, tells us of the problems with 102.7 when travelling on "I-95" south of Providence. This would really be an issue if WRNI was supposed to reach I-95. But it isn't.

People have GOT to understand that the way the system was set up, none of this is really doing much of any harm to any significant audience. Just the DX gang.

I actually thought the fidelity of the mono sample was pretty good. Considering it came from so incredibly far away.

Clouseau

 

[Play Freebird]

Later in the thread, Mr. "Right On" dude, tells us of the problems with 102.7 when travelling on "I-95" south of Providence. This would really be an issue if WRNI was supposed to reach I-95. But it isn't.

Yes and no. The FCC commercial FM allocation system is based on an initial assumption that all stations have circular coverage areas, with each class protected to a specific distance. WRNI-FM, as a non-reserved band Class A, would normally be protected to a 28 km radius -- and if you plot that circle on a map, you'll see that it includes nearly the entire length of I-95 from the I-295 split (just south of Providence) to the Connecticut border. Unfortunately, the station is forced to transmit from a short tower on the edge of Narragansett Bay and must operate under 73.215 due to zoning issues. Rising terrain north and west of the site limits its 60 dBu predicted contour over much of the market, which is why the IBOC interference coming in from WKLB (outside the market) does a lot more harm than would otherwise be expected.

People have GOT to understand that the way the system was set up, none of this is really doing much of any harm to any significant audience. Just the DX gang.

Well, Rhode Island residents who enjoy public radio largely DON'T understand and probably never will. Most aren't familiar with the intricate details of FCC allocation policy, but when they're commuting to and from work (within a state that's smaller than many Western counties) and can't get decent mobile reception from their in-market NPR station (due to a Boston station's digital sidebands) the theoretical problem becomes quite real. At least WRNI has an AM in Providence on which to simulcast, but I understand its coverage at night (drivetime in the winter) to the south and southwest is poor.

Let's just hope the DX gang can offer some tips to Rhode Islanders on ways to improve reception of WBUR and other out-of-market public stations which they must turn to, because in-market WRNI-FM is getting clobbered!

I continue to hear rumblings about a 10 dB power increase for FM IBOC sidebands, almost as if it's a done deal. Apparently, this is this official response to broadcaster complaints about disappointing digital coverage; "Just wait until next year, you'll get a big increase, and all your problems will go away." Keep in mind that these marginal interference situations discussed in Doug Vernier's article are going to result in MAD if that ever happens.

There's also the question of whether grandfathered super-power FM stations with minimally-spaced first adjacents should be allowed full IBOC power. These are especially likely to result in out-of-market IBOC interference to in-market signals.

WHMI, an independent Class A station in Michigan, has spent a lot of money trying to fight Clear Channel's 320 kW flamethrower WBCT in Grand Rapids, but I believe the FCC denied their appeals. Anyone know the current status of that case? For background, see:

http://www.rbr.com/epaper/pdfs/021405-bounceback.pdf

 

[Mike Walker]

Well I'm not in the protected contour of WFDD (88.5), or WNCW (88.7). BOTH are clearly receivable in HD. Both are clearly separable, with no adjacent "IBOC HASH" on every analog radio I own, including my super-cheap FM Walkman (Sony SRF-M35...I'm glad I bought two of 'em when Sam Goody closed their doors!)

I've scoured adjacents to all of the IBOC FMs receivable where I live, and done it on everything from tube radios built during the Eisenhower administration, to modern units with digitally synthesized tuning, to DSP-enhanced models such as the Accurian HD Radio. I hear this stuff on NONE OF THEM!

Now talk about AM, and it's a different "kettle of fish". I can CLEARLY hear noise adjacent to BOTH of the Charlotte AM stations that are running HD (though I can't get either station to lock on to HD in my location). With AM there's no struggle to "prove the case" (of adjacent interference). Just turn on the radio...most any radio!

 

[clouseau]

Yes and no.

More like "NO"

http://www.fcc.gov/fcc-bin/FMTV-service-area?x=FM1180536.html

The FCC commercial FM allocation system is based on an initial assumption that all stations have circular coverage areas, with each class protected to a specific distance. WRNI-FM, as a non-reserved band Class A, would normally be protected to a 28 km radius -- and if you plot that circle on a map, you'll see that it includes nearly the entire length of I-95 from the I-295 split (just south of Providence) to the Connecticut border.

Not a good bit of it if it hadn't moved closer to Providence. From it's ALLOTED location, it doesn't reach it to the north.

Unfortunately, the station is forced to transmit from a short tower on the edge of Narragansett Bay and must operate under 73.215 due to zoning issues. Rising terrain north and west of the site limits its 60 dBu predicted contour over much of the market, which is why the IBOC interference coming in from WKLB (outside the market) does a lot more harm than would otherwise be expected.

What would be EXPECTED is what's on the contour map. Not what would happen if there were no NIMBY's, More towers, or better elevation. More money, better political connections or numbers of migrating sea birds are also not relevant. It is what it is. Commercially, this station was built at a fraction of full power to put it where it is. There are no secrets here. It was converted to Non Comm Status in May of '07. The quote I referenced was made by someone else who complained about issues on I-95. It doesn't REACH I-95. Woulda, Shoulda, Coulda doesn't matter. It's not supposed to go there.

People have GOT to understand that the way the system was set up, none of this is really doing much of any harm to any significant audience. Just the DX gang.

Well, Rhode Island residents who enjoy public radio largely DON'T understand and probably never will. Most aren't familiar with the intricate details of FCC allocation policy, but when they're commuting to and from work (within a state that's smaller than many Western counties) and can't get decent mobile reception from their in-market NPR station (due to a Boston station's digital sidebands) the theoretical problem becomes quite real. At least WRNI has an AM in Providence on which to simulcast, but I understand its coverage at night (drivetime in the winter) to the south and southwest is poor.

You're trying to get "6000 watts at 100 meters" coverage out of "Less than 2000 at 69". If my station could go another 60 miles, we could get into a single digit market. If Pigs had wings...

Let's just hope the DX gang can offer some tips to Rhode Islanders on ways to improve reception of WBUR and other out-of-market public stations which they must turn to, because in-market WRNI-FM is getting clobbered!

No amount of repeating it's an "In Market" station changes the facts. I would assume the station works well in it's protected contour. I have not heard otherwise.

I continue to hear rumblings about a 10 dB power increase for FM IBOC sidebands, almost as if it's a done deal. Apparently, this is this official response to broadcaster complaints about disappointing digital coverage; "Just wait until next year, you'll get a big increase, and all your problems will go away." Keep in mind that these marginal interference situations discussed in Doug Vernier's article are going to result in MAD if that ever happens.

Ya know, I've seen a couple of people refer to this. I note there is no attribution to what you characterize as "Official response". Funny how that seems to work.

There's also the question of whether grandfathered super-power FM stations with minimally-spaced first adjacents should be allowed full IBOC power. These are especially likely to result in out-of-market IBOC interference to in-market signals.

In this case, I would say you are correct. I would agree that these stations should only be allowed full HD power at theie alloted class, NOT there licensed parameters. Look, I actually agree with you.

Clouseau

 

[jlehmann]

So I'd conclude "Congratulations! You've succeeded in your demonstration...IF what you were attempting to demonstrate is that you have one of the small percentage of radios so poor that it reacts this way to an adjacent IBOC station! Most don't (react that way). Not a single one in my LARGE collection does!

Your posts never cease to amaze me. Those were recorded with a Yamaha T-85 modifield with 150 kHz IF filters. It sounds exactly the same with the Sangean HDT-1X, which is also VERY selective. If, like you say, my receiver was so incredibly wide, there's no way in hell that I'd be hearing WQHT and WRCH that well without splatter from the locals.

 

[clouseau]

Your posts never cease to amaze me. Those were recorded with a Yamaha T-85 modifield with 150 kHz IF filters. It sounds exactly the same with the Sangean HDT-1X, which is also VERY selective. If, like you say, my receiver was so incredibly wide, there's no way in hell that I'd be hearing WQHT and WRCH that well without splatter from the locals.

I think Mike's assessment, BASED ON THE SURFACE INFO YOU PROVIDED, sounds fair. What you neglected to mention was that you were looking to listen to New York FM basically in Boston. What you HAVE demonstrated is a very nice and sensitive and selective system. If he'd have known you were busting out the 300+ kilometer card, he might have reacted differently.

Anyone who understands how HD works (And I would put Mike in that group) knows it's on 1st adjacent.

BTW, you can't figure over 300 KM signal strengths using curves. The FCC calculator doesn't go that high. However WQHT at 300 KM has a 50,50 signal of

A drumroll please...

2.508 dbu. (I didin't know it would calculate that low.)

Definitely some atmosphereics in play.

Clouseau

 

[jlehmann]

Anyone who understands how HD works (And I would put Mike in that group) knows it's on 1st adjacent.

I would absolutely not put him in that group. I've seen him post say that there is no hash on the first adjacents, just based on his 88.7/88.9 situation, and nothing else. I'm guessing that he's probably using a directional antenna, and pointing it towards each station, ignoring the hash that he may get on the other station when he's pointing at the stronger one. With my APS-13, I can hear 92.3 WPRO and 92.5 WXRV fine, when I aim it in their direction.

He may be the only one that does not understand this.

And I did say in my original post that there was tropo enhancement that night allowing WQHT and WRCH to come in the way they were.

 

[kevtronics]

After repairs were made, WNYC is again running their IBOC exciter. They turn it off at night, probably due to antenna issues, but WNYC AM is running in IBOC mode during the day. I'm sure they are working on getting nightime IBOC to work from that site as well.

Are you kidding? At night, 820 WNYC drops down to 1 kW with a tight directional pattern, and they suffer heavy IBOC interference from 810 WGY and 840 WHAS. Trying to use IBOC at night on WNYC would be a complete waste. I bet even at the WNYC studios you wouldn't be able to recieve their AM signal in IBOC digital mode at night, especially due to the hash from WGY.

 

[R.F. Burns]

After repairs were made, WNYC is again running their IBOC exciter. They turn it off at night, probably due to antenna issues, but WNYC AM is running in IBOC mode during the day. I'm sure they are working on getting nightime IBOC to work from that site as well.

Are you kidding? At night, 820 WNYC drops down to 1 kW with a tight directional pattern, and they suffer heavy IBOC interference from 810 WGY and 840 WHAS. Trying to use IBOC at night on WNYC would be a complete waste. I bet even at the WNYC studios you wouldn't be able to recieve their AM signal in IBOC digital mode at night, especially due to the hash from WGY.

Well, you are just wrong here. I have no trouble receiving WNYC with no trace of IBOC from either of its naeighbors. The WNYC AM signal is fairly weak but the interference I hear is from other stations on 820 Khz. I live north of NYC. I am within WNYC's protected contour. They have poor coverage to the west and send most of their signal over Manhattan and Long Island to the east. They do however have a little bump to the north, north east over eastern Rockland and Westchester counties. I can ask but I'm sure it's antenna issues and not IBOC coverage which forces them to shut the exciter off at sundown.

 

[RadioFixerCLE]

Are you kidding? At night, 820 WNYC drops down to 1 kW with a tight directional pattern, and they suffer heavy IBOC interference from 810 WGY and 840 WHAS. Trying to use IBOC at night on WNYC would be a complete waste. I bet even at the WNYC studios you wouldn't be able to recieve their AM signal in IBOC digital mode at night, especially due to the hash from WGY.

I get very good reception of WNYC AM 82 both day and night here in New York City proper. Of course AM 82 is going to send the bulk of its signal due east, since the station IS targeting New York City.

 

[Dighton Rockhead]

While we're at it, why doesn't the USA also start using the Tropical SW band for "disadvantaged" stations? That's an honest question, I'm not too familiar with licencing on the different SW bands.

Looks like the international broadcasting commuinity has its own ideas for what to do with the Tropical Shortwave bands. Just recently, the ITU approved the use of DRM in those bands. The article in the link below provides details:

http://mt-shortwave.blogspot.com/2007/12/drm-approved-for-tropical-band.html

Hmmm......The FCC stubbornly refusing to release TV Channels 5 & 6 to help AM's digital transition (and offer relief for Bob Savage and other injured parties)... and now this development on the international scene.

Looks like it's back to the old drawing board.

 

[R.F. Burns]

Let me try to understand your logic. You want to open two VHF channels for a new radio service to replace our current AM BCB. Interesting because how many times have I read here about how terrible it is that people will be "forced" to purchase new radios and here you are suggesting just that. I'd bet the cost for the owner of putting a station on VHF channels 5 & 6 far exceed that of IBOC conversion. Imagine, that even if non directional, they'd have to erect a new tower (2 or 3 hundred foot towers aren't great for VHF use), buy a new transmitter and a DRM exciter (because no way would the commission open up new frequencies to analog transmission). and then shut down their current analog facility, which would include the expense of having their current towers disassembled (If you aren't using the towers no one wants to pay insurance on something of no value and the continuing cost of lighting the towers). So what do you think? Doesn't sound economically feasable to me.

 

[KB1OKL]

Let me try to understand your logic. You want to open two VHF channels for a new radio service to replace our current AM BCB. Interesting because how many times have I read here about how terrible it is that people will be "forced" to purchase new radios and here you are suggesting just that. I'd bet the cost for the owner of putting a station on VHF channels 5 & 6 far exceed that of IBOC conversion. Imagine, that even if non directional, they'd have to erect a new tower (2 or 3 hundred foot towers aren't great for VHF use), buy a new transmitter and a DRM exciter (because no way would the commission open up new frequencies to analog transmission). and then shut down their current analog facility, which would include the expense of having their current towers disassembled (If you aren't using the towers no one wants to pay insurance on something of no value and the continuing cost of lighting the towers). So what do you think? Doesn't sound economically feasable to me.

Channels 5 and 6 would have been advocated to either to widen the FM band or to allow a new digital band so that the AM broadcast band would not have that terrible noisy krappy hash all over it, IBOC (even though that is the worst digital system going) could go up there and not hash all over other stations as they do now. I have never heard anyone advocate the current AM BCB band be shut down, that it just be left alone as it was and iBlock can go elsewhere.
I wonder how many years it is going to take for everyone to see that this so-called digital conversion : was just a giant waste of time and money. They don't want it here and they don't want it in Europe, when are the manufacturers and this insipid know-nothing FCC going to realize that it has and will go no where, how much money is going to have to be wasted before the iBlock Alliance calls it quits, before or after radio is bankrupt?

 

[RadioFixerCLE]

Let me try to understand your logic. You want to open two VHF channels for a new radio service to replace our current AM BCB. Interesting because how many times have I read here about how terrible it is that people will be "forced" to purchase new radios and here you are suggesting just that.

More people have cheap radios capable of picking up the TV band than have IBOC-capable receivers. Let's see...a portable AM-FM-TV radio from Sony costs US$25. The cheapest HD radio costs $100. Do the math.

You can, and in fact I do, pick up normal FM broadcasts on the "TV band", since I have a couple Japanese FM sets that tune down to 76.1 MHz, and my USA-model TV band radios did pick up Tokyo FM stations when I was in Narita a couple years ago, waiting for a connecting flight.

So you'll have to either tune by ear, but it should be no big deal for the new models of radios to have a redesigned dial scale.

 

[KB1OKL]

Let me try to understand your logic. You want to open two VHF channels for a new radio service to replace our current AM BCB. Interesting because how many times have I read here about how terrible it is that people will be "forced" to purchase new radios and here you are suggesting just that.

More people have cheap radios capable of picking up the TV band than have IBOC-capable receivers. Let's see...a portable AM-FM-TV radio from Sony costs US$25. The cheapest HD radio costs $100. Do the math.

You can, and in fact I do, pick up normal FM broadcasts on the "TV band", since I have a couple Japanese FM sets that tune down to 76.1 MHz, and my USA-model TV band radios did pick up Tokyo FM stations when I was in Narita a couple years ago, waiting for a connecting flight.

So you'll have to either tune by ear, but it should be no big deal for the new models of radios to have a redesigned dial scale.

That makes too much sense, that's not the way the current FCC does things anyway, AM-FM-TV radios don't have lobbyists.