ABC Radio pulls plug on nighttime IBOC

[K9AF]

As of October 2, Citadel Broadcasting, the parent company of ABC Radio network, has instructed all 10 of its AM affiliates who had already converted to IBOC, to cease night time use of the digitial modulation scheme, citing many complaints from listeners. Some complaints came from listeners OF the IBOC-modulated stations, while others came from listeners of adjacent channel stations, that were being interferred with due to the IBOC bandwidth. #Citadel Director of Engineering Marty Stabbert, in a memo to his staff said, "“In response to the lackluster performance, the limited benefit and various reports of significant interference, Citadel is suspending nighttime AM HD operations at this time. Please reinstate your previous procedures for daytime-only HD operation as soon as possible.”
Stabbert says he will attempt to work with Ibiquity, the company that developed the wide-band digital AM modulation scheme to see if there is a way to #overcome the many problems encountered. # Daytime IBOC for the ABC network affiliates is not affected at this time.

[ka5piu]

Hello.

The only time I listen to AM is now at night.
IBOC sounds like a high pitched whistling sound on some AM radios.
"The only radios that seem to be having this trouble have a wide bandwidth".
This is true, however most people are not going to be happy with the idea of adding IF filters to their radios.
The last time somebody tried to enhance AM was with stereo.
Even on FM, range is reduced by as much as 30% with this HD scheme.
I give the scheme 3 years, after that it will be a minor footnote, like stereo AM and quadraphonic FM.

[KI4PEQ]

Why does the United States have to be the oddball in terms of standards for digital broadcasting? Isn't the rest of the civilized world migrating to Digital Radio Mondiale?

[ka5piu]

Hello.

DRM would make sense, that is what is wrong with it.

[W5HLH]

IBOC. DRM, or any other digital modulation scheme for broadcasting makes no sense on any frequency range where skywave propagation is a major factor. DRM tests have likewise proven a big disappointment; anything more than single-hop propagation and a low bit rate, yielding audio quality barely improved over AM, doesn't work. Sangean, the world's largest seller of shortwave receivers, recently announced cancellation of their plans to offer a DRM-ready shortwave receiver because of DRM's flaws.

Digital broadcasting might work on FM and other frequencies where skywave propagation is relatively rare, but whether there is enough consumer demand to make it a viable business proposition is another matter.

A lot of people of pushing this "digital is great and analog sucks" notion, but digital, like analog, has some real weaknesses and is not appropriate in all situations and applications. If you have a reliable path for the signal and plenty of bandwidth, digital broadcasting is great (I'm listening to XM satellite radio, a digital service, as I type this.) But that's not the case on the AM or SW broadcasting bands, and reality is showing those ranges are not suitable for digital modulation.

[n0jaa]

Good! #That is the best move ABC could make! #IBOC might be a good idea, BUT for people with analog AM receivers (which is most of them) IBOC does nothing but wipe out adjacent channels. #People who used to listen to their favorite AM station at night now find the broadcast wiped out by IBOC, which influence extends far past its bandwidth limits. #IBOC has the tendency to wipe out stations up to two channels away from either sideband.

The most significant complaints have come from low-power Class B stations who have complained that high-power, Class A clear channel stations (NOT the company of the same name) are completely wiping out their signals IN THEIR OWN LOCAL MARKETS. #Some stations have merely complained, while other Class B stations have taken the drastic step of increasing their own night-time power to levels well above their legal limit just so their listeners can hear them.

The FCC has given IBOC the same consideration that it gave BPL: #very little. #It is painfully obvious that FCC didn't give IBOC due scrutiny concerning interference before authorizing it. #I feel there are going to be a great many reprisals against FCC from local-market stations.

By the same token, I think IBOC (or IBUZ, as some opponents call it) will eventually prove to be a passing fad and slowly fade out the same way that AM Stereo withered away.

I present, for your perusal, the following excerpt from the Broadcast Discussion List about this discussion, of which most people on the list are opposed to IBOC (and most of these are broadcast engineers):

Quote[/b] ]> The public is never going to buy the idea that AM radio is going to sound
> great, it will never happen even though analogue AM can sound great, and
> why do we need digital when the only practical effects of it are that 90%
> of the stations now on the air are going to go out of business?

You've hit it Bob. I knew AM Stereo was going to bomb as well but at least
there was a glimmer of hope as there was a difference. I'm going to once
again quote a line from one of my college professors. "A difference to be a
difference must make a difference." It says a lot. In this age when people
are satisfied with listening to audio through small speakers (I'll put that
one right on the doorstep of the computer industry) and iPods and telephones
why in the world would they lay down even 20 bucks to buy a radio to hear
something from a band they consider to be there only for the reason of talk
radio. As many of us know survey's over the last couple of decades or so
have shown that people perceive the AM band as the voice band and the FM
band as the music band.

This quote dates from 2006, but the discussion continues to this day.

[ky5u]

Another "failure" of digital to live up to the hype.

[na6df]

Quote[/b] (KI4PEQ @ Oct. 03 2007,23:33)]Why does the United States have to be the oddball in terms of standards for digital broadcasting? Isn't the rest of the civilized world migrating to Digital Radio Mondiale?
If I remember correctly DRM is for shortwave stations.For terrestrial broadcasting, they have the Eureka 147 system in Europe. Eureka 147 was implemented in a new band (something like 1.4ghz ??) and was not a cobbled mess of trying to get digital to coexist with the analog carrier, like the IBOC system in the U.S.

(nope, not a big fan of the current excuse for "HD" radio, even though I'm actually in the broadcast biz)

Dave NA6DF

[k4kyv]

Quote[/b] (KI4PEQ @ Oct. 04 2007,06:33)]Why does the United States have to be the oddball in terms of standards for digital broadcasting? Isn't the rest of the civilized world migrating to Digital Radio Mondiale?
It's part of what's called American Exceptionalism (http://en.wikipedia.org/wiki/American_exceptionalism).

[K8DAD]

There are still many (CQuam) analog AM Stereo radio receivers out there in vehicles - many more than there are HD, and analog AM stereo works as far as the analog signal does - all without wiping-out their adjacent stations. I'd be in favor of the FCC mandating all AM radios to meet new quality requirements on analog - including stereo and noise blanking - IF the radio includes HD-FM!

[K7FE]

Quote[/b] (K8DAD @ Oct. 04 2007,13:45)]There are still many (CQuam) analog AM Stereo radio receivers out there in vehicles - many more than there are HD, and analog AM stereo works as far as the analog signal does - all without wiping-out their adjacent stations. I'd be in favor of the FCC mandating all AM radios to meet new quality requirements on analog - including stereo and noise blanking - IF the radio includes HD-FM!
I would be in favor of the radio manufacturing community, suppling the automobile industry to add more selectivity and an RF amp to their receivers.

I would also like the auto industry to be mindful of the RFI created by the microprocessors and other electronics they add to vehicles. The noise generated by "modern vehicles" is MUCH greater than those of a decade ago. It is becoming very difficult to listen to a ballgame or talk radio on AM broadcast band while driving. The noise also makes a mess of HF mobile operations.

My pet issues are:

1. Limited sensitivity of the receivers
2. Poor RCVR selectivity
3. Limited receiver noise reduction
4. Poor antennas (hidden)
5. Vehicle generated noise.

73,
Terry, K7FE

[KG6OPR]

The most significant complaints have come from low-power Class B stations who have complained that high-power, Class A clear channel stations (NOT the company of the same name) are completely wiping out their signals IN THEIR OWN LOCAL MARKETS. #Some stations have merely complained, while other Class B stations have taken the drastic step of increasing their own night-time power to levels well above their legal limit just so their listeners can hear them.

Thats what "Cheap Channel" had in mind from the beginning. The first thing they did was to shutdown all of their AM stereo operations knowing IBOC was down the road. KFI in LA. has pulled the plug on their IBOC. I don't the facts but I think it has something to due with their signal being cut to almost half due to the loss of their tower a few years back. http://www.qrz.com/iB_html/non-cgi/emoticons/rock.gif

[kq9j]

Perhaps this will serve as a wake up call to all the digital fanatics who keep showing up on this board complaining that amateur radio is behind the times, antiquated, whatever, for not adopting digital voice on HF. It just ain't there yet folks.

[wa3vjb]

Boston Acoustics has already discontinued its home tabletop IBOC receiver, politely explaining that the decision is part of a marketing review.

In reality, the public has simply not responded to how digital signals have been "retailed" to them.

Part of the problem for those pushing digital broadcast-band radio is that a change to digital is not mandated. The government is not taking away the AM analog service or its frequencies. We don't have to buy new receivers as with the new digital television system "HDTV."

What's in it for the public, then ? AM fidelity has already been allowed to deteriorate over the years, so there's no general complaint to "fix" it with digital or anything else. In-band, on channel digital telemetry does not answer some kind of technical malaise.

And, as the negative reaction indicates, IBOC is generating more complaints than nice impressions.

[k2gsp]

Quote[/b] (kq9j @ Oct. 03 2007,17:38)]Perhaps this will serve as a wake up call to all the digital fanatics who keep showing up on this board complaining that amateur radio is behind the times, antiquated, whatever, for not adopting digital voice on HF. It just ain't there yet folks.
You are right on the money there.

[N0FQN]

I remember the nightmare with C-QUAM. When I was Chief Engineer the owner was always harping at me that the AM stereo signal had a whine on the left channel. I listened but couldn't hear it. This went on for several years and nobody but him complained about it. I turned out that his Carver stereo system was defective. Every digital fanatic states everything but the most obvious point. #The main point I bring to the table is when they digitize it they control it. It's so much easier to scramble a digital signal and then make you pay for it. There's no free off air TV in Denmark anymore. All channels went digital and then they scrambled them and now they have to pay a fee to watch them. Same thing can be said about your personal information. You no longer have any real control of it because big brother digitized it and has absolute domination. I'm not saying you'll have to pay for digital communications on the ham bands but, the more you institute digitizing the more chance someone will come up with a way. Want to hear a real digital fiasco, listen on 3.995Mhz. A German station broadcasts 10 channels #until 11:00PM PDT. You can't use any frequency within 10khz of it on the west coast. Imagine what it's like the closer you are to it. As far as digital on HF. I wouldn't put money on it. First, you can't use VOX with it. You can't hold a informal rag chew where several people may speak at the same time. It's extremely fragile to interference. I really don't see any advantage to it but, I guess I'm old fashioned and out of date. #I don't like paying to watch damn commercials that these stations are making billions of dollars from.

[k4kyv]

Quote[/b] (K7FE @ Oct. 04 2007,21:18)]I would be in favor of the radio manufacturing community, suppling the automobile industry to add more selectivity and an RF amp to their receivers...

My pet issues are:

1. Limited sensitivity of the receivers
2. Poor RCVR selectivity
3. Limited receiver noise reduction
4. Poor antennas (hidden)
5. Vehicle generated noise.
The problem with AM receiver selectivity, both in car radios and home stereo systems, is not lack of selectivity, but the extremely poor bandpass shape characteristic. In typical receivers the audio response on AM begins to roll off somewhere about 2000 Hz, due to the narrow i.f. passband, yet adjacent channels still interfere with each other because the passband is excessively wide below about the -20 dB point. If the passband were extended out to at least 10 kHz and combined with steep skirt selectivity, analogue AM could be received with good fidelity while the receiver would still capable of separating signals that arrive on adjacent channels.

A few AM receivers manufactured to-day have adequate selectivity characteristics, but with most broadcast receiver manufacturers, the AM section is an afterthought at best.

[AC5WO]

A better name for the US digital broadcasting standard would be IBAC, in band adjacent channel. A good overview of HD radio, Hybrid Digital radio is available here.
http://en.wikipedia.org/wiki/HD_Radio

Regarding the reduced range for digital broadcasts, the digital portion of the broadcast signal is transmitted at a much lower power. 20dB lower for the FM band. To be fair, in the full digital mode with higher power, local FM band and AM band groundwave range should be pretty good.

The United States has a good tradition of ignoring European standards and instead making our own standards to meet our needs. DRM has almost zero chance of success because it requires an abrupt transition from analog to digital. Hybrid Digital radio allows broadcasters to transition from all analog, to mostly analog with some digital, to all digital, or back to analog as required by band conditions or consumer demand. I think it's a good thing that ABC could make a decision to go back to analog only broadcasting at night without getting FCC permission.

The main problem I see with both digital broadcasting and digital voice for ham radio is the end user doesn't get an obvious advantage over the analog equivalent. Think back to the advantages the audio CD and video DVD offered over their analog equivalents to see how successful digital standards work.

I think ham radio digital voice needs to be an open framework of a standard with software upgradable equipment. Ham digital voice needs channelized operation and/or really good automatic frequency control so it can be more safely tuned while driving a car. (I really hate tuning SSB.) The repeater mode needs a feedback path and automatic power control. The repeater mode could also include a feature to allow two or more separate conversations on each repeater. Integrating GPS reception could provide position information and a super accurate frequency reference for the transceiver LOs. We can do much better than DRM and D-STAR.

[W5HLH]

More about the IBOC/HD radio debacle:


http://www.fmqb.com/article.asp?id=487772

[WA3KYY]

Quote[/b] (W5HLH @ Oct. 05 2007,12:23)]More about the IBOC/HD radio debacle:


http://www.fmqb.com/article.asp?id=487772
And the commenter hits the nail squarely on the head. Unless the stations broadcasting in HD add significantly new content that excites the listeners, analog radio will be good enough, especially since no expense is required.

[KQ6XA]

Good riddance!
So-called "HD-AM" using IBOC standard is bad for AM radio.

If we could now convince all the HD-AM stations to shut down, we would be much better off.

IBOC is a marketeering slogan "In Band On Channel".

But the digital signal IBOC produces is neither "In Band" nor "On Channel".

It takes up the two adjacent channels!

Thus, it transmits directly over top of 2 other stations that could normally be heard.

Contrary to the hype being spewed by the IBOC marketeers, narrow filters cannot completely remove their digital interference from the adjacent AM channel. However, a narrow filter with steep skirts, combined with careful off-tuning, can help a lot if you are trying to listen to the 2nd adjacent channel. Most consumer AM broadcast radios have neither of these features. However, there are a few new ones in the design pipeline that have "HD-interference noise reduction" features (such as one of the new CCRANE portable radios).

[N2MDA]

It's a good thing that ABC pulled the plug on iboc. It really created a mess in the spectrum. I hope that WOR Radio in the New York Market takes note, and does the same thing too. All in all AM radio is doing just fine for the mode it's carrying,Talk radio! I can't imaging the powers that be thinking people would abandon their radios that are bought and paid for to listen to thier radios in IBOC. It's not the mode of operation, it's the programming. If you give people interesting programming they will listen. That's the way its always been, and it works.

BOB N2MDA

[k8jd]

I went out and bought a HD radio for my aging Ford Escort. Due to the lack of interest, I suppose, the price was right. What I found is the signals from both AM and FM stations have to be very strong (quite noise free to start with) before the digital mode locks in.
It's too bad the Canadian stations do not use this because our neighbors across the river have some great music programming.
The quality of the AM sound is quite satisfying when you can hear the transition from monaural to surround sound. I have heard stations that still use HD at night from quite distant cities.
On other radios I have seen the AM digital signals from local stations totally block out adjacent channels that could be heard at night easily before the advent of HD AM! since there are about half a dozen local stations using AM HD I loose another dozen potential places to listen/

[N2RJ]

Quote[/b] (KI4PEQ @ Oct. 04 2007,01:33)]Why does the United States have to be the oddball in terms of standards for digital broadcasting? Isn't the rest of the civilized world migrating to Digital Radio Mondiale?
Why do Americans keep old cars?

Because they don't want to buy new ones.

Similarly, I don't think people want to buy new radios. The public is already howling about the conversion to digital TV, which is being pushed as far back as humanly possible.

[VE3LXL]

Interesting thread. As an enthusiastic listener to AM radio, and a sometimes AM band DXer, this topic is of real interest.

I think the idea of a local digital broadcasting service is a good one, but it doesn't make any sense to try to implement it in a mediumwave band, and especially one that is already jammed full of analog signals. I think it would make more sense to simply create a third broadcasting band that would be entirely digital, which would operate alongside AM and FM. If we have to buy new receivers to listen to IBOC, then it's no greater hardship to buy a new receiver that has this third new band added.

Re "American Exceptionalism". I don't think we can use Europe's experience with transitioning to digital broadcasting as a model in North America. In Europe mediumwave broadcasting is much more centralized than it is here - it is dominated by a few large networks, many of them state-owned. In that environment is is relatively easy (or perhaps I should say relatively less difficult) to restructure the broadcasting system. But in North America there are thousands of individual stations, owned by hundreds of companies, and most carrying at least some locally-produced programming. Trying to restructure this would be a huge undertaking, and would certainly drive many of these broadcasters into bankruptcy. In our context, I think the best thing is to just leave AM radio as it is.

I wonder about the perception that AM band stations will attract bigger audiences with IBOC. Even today, analog AM band stations are capable of producing a better quality signal than most people hear, because they listen to AM mostly on cheap little radios, like clock radios. Even today listeners could get a better sound by buying a better radio, but most don't bother because it isn't important to them. I don't think IBOC will really change this fact.

My own opinion is that AM radio has a brighter future than most people think. In many large markets the FM band is now almost entirely filled, so new broadcasters will turn to the AM band simply because there's no other choice. Up here in Canada, AM broadcasters in small markets are moving to FM, but in the big cities new stations are opening up on AM because the FM band is saturated. I don't think the AM band will ever be the "main" broadcasting band again, but I'm certain it will survive as the band where stations that can't or don't need to be on FM will be found.

[2E0IMJ]

Currently in Uk we use Digital Mondial. BBC World Service use 1296khz after dark and RTL (lUXEMBOURG) 1340KHZ also. I agree the bandwith tends to cause some problems with adjacent stations. We have 9khz channel spacing, maybe we should have 10khz. There is some Mondial output on Long Wave ( Used mainly in Europe) RTE (iRELAND) 252KHZ converts to Mondial after 2200 utc. On top of that we also have DAB RADIO on 200mhz which is proving very popular hear. I have a portable dab radio here at my QTH. (Execellent quality)

[n4zou]

Quote[/b] (N2RJ @ Oct. 09 2007,07:24)][quote=KI4PEQ,Oct. 04 2007,01:33] The public is already howling about the conversion to digital TV, which is being pushed as far back as humanly possible.
It's not the public that’s howling. They don’t have a clue. It's the broadcasters that are protesting about the change in frequencies. Instead of a VHF/UHF frequency that can be received up to about 60 miles away viewers will be lucky if they can receive a free "off the air" HDTV signal 10 miles from the transmitter site. For people not able to pick up a free signal there local stations will become just another "cable" channel. Considering the poor content of broadcasters their ratings will fall even further than they are now with a corresponding reduction of revenue. I just wonder how many will survive the coming disaster about to befall them Feb 2009. I have an antenna and receive a snowy picture from a couple of them. I could pay an extra $5 a month and watch them on my satellite system but I don’t, and wont even after Feb 2009. They're not worth paying an extra $5 a month to view.

[K3UD]

Who else remembers AM stereo and further back, Quadraphonic recordings on vinyl platters? I had early equipment for both of those technologies, and as someone else put it, digital AM may well be this generations 8 track failed technology.

To put it more plainly, they take away our apple and replace it with an orange that no one really wants. Other than hearing the mess on the AM band, especially around WOR's frequency, I wonder what happens to listener ship and more importantly the advertising message that is now being covered up by adjacent AM digital.

73
George
K3UD

[VE1IDX]

I was in broadcasting when the whole digital broadcasting stuff started. What a mess. The Europeans proposed the Eureka 147 system and have had resonable luck with it. We here in Canada began tests with it as well.It uses the L band at 1.4 GHz. The USA flately refused to adopt the Eureka 147 system as they knew better. http://www.qrz.com/iB_html/non-cgi/emoticons/rock.gif One of the big roadblocks cited was the presence of military communications on L band and it was considered too big of a deal to move them off.Thus was born the IBOC system which was lauded as a failure from the beginning.I believe the future of digital broadcasting is destined to fail for no other reason than the failure to adopt the proper and most technically sound method.The same thing happened with AM stereo. Did you know that the USA waited until Canada adopted a standard before adopting one rather than the other way around which is what usually happens?More AM stations per capita in Canada were converting to AM stereo than in the USA. Yep, the inferior Motorola system was chosen based on marketing alone rather than the far superior Kahn system developed by Leonard Kahn.There were far more C-Quam receivers in use,mostely due to a deal between Motorola and GM and Chyrsler, than there were Kahn receivers. The differance in systems was night and day but in the end the better marketing agent won.In the end however what was it that they really won? AM stereo is all but dead.So shall,and should, be IBOC.