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Dear Guy,

CAM D DIGITAL RADIO IS THE ANSWER

This article is in response to a recent story published in Radio World (Nov. 3, 2004) about the positive aspects of Ibiquity's IBOC (In Band On Channel - HD Radio)
The Anonymous article in Radio World Engineering Edition called "Guy Breaks Down the Anti-HD Radio Arguments" (Oct. 27, 2004)

Following are nine points:

First Point - HD Radio is not in-band as it causes interference to adjacent channels with a hissing sound, thus causing reception to be degraded on those stations. This interference should not be tolerated by the F.C.C. We are required presently to stay on our assigned frequency. If we stray from our band, F.C.C. inspectors would fine us. Even a harmonic can get us in trouble. It should be no different with HD Radio.
This interference can be detected even at great distances in other cities. Of course, if all the 50 KW stations install HD Radio it could wipe out thousands of lesser powered stations across the U.S. Already Canada has voiced concerns about the interference to their stations.

Second Point - Clear Channel and Ibiquity are championing a reduction to 5 KHz band width. Their reasoning, though they deny it, is to give more room for HD Radio. Also, they claim that no radios are capable of wide band above 5-6 KHz. This is incorrect, and there are radios capable of wide band (G.E. Super Radios, Grundig and others). I was always under the impression that AM Radio was to reach par with FM Radio at 15 KHz. Also, the analog stations would not be able to broadcast in stereo. It will be years before IBOC even approaches 10% of the 800 million radios. Meanwhile, all the AM analog stations would be handicapped with inferior broadcast systems. Talk about a disaster!

Third Point - The cost of conversion to HD Radio requires spending thousands of dollars on new equipment, etc. Even the required erection of new towers and purchasing new transmitters will be beyond the ability of thousands of stations to convert. That's not the end, though, as a license fee must be paid every year it is in use. A fee will be assessed on transmitters (HD). Estimated costs can range from $ 150,000 to $ 400,000 or more.
Fourth Point - The IBOC System cuts down sky wave distance at night. There are listeners other than DX'ers that are tuning in to distant stations. In Salt Lake City,
KSL-AM's 50,000 watt signal is heard all over the west. Many people listen at night. With IBOC the signal will be impaired, and what does get out will be jumbled and not listenable. On top of that, the hissing interference will affect adjacent channels 1140, 1150, 1170, & 1180.

Fifth Point - The digital processing delay from mike to your speaker can range up to 8 seconds. A listener at a sporting event will see the action but the play by play will be delayed. But IBOC has a plan; they will go back to analog during sporting events. (This is progress?).

Sixth Point - The IBOC signal does not work well with directional antennas. There are hundreds of directional antennas in the U.S. that will be frustrated in this installation of HD Radio. Already consulting engineers are trying to solve this problem.

Seventh Point - HD Radio's signal gets interference from high power electrical lines. Find an HD Radio station in your town and check it out.

Eighth Point - Coverage of the station's signal will be cut down and not reach as far. Management will have to re-do their coverage maps. On the fringes of coverage with HD Radio, the radio receiver will switch back to analog. It will be quite a trick to balance out volume levels while it pops back and forth between HD and analog.

Ninth Point - The IBOC system is proprietary, that is it is not an open market system. The backers are the large chain broadcasters and manufacturers that will require an annual fee forever.

There are other points that I can make, but they say don't criticize others work unless you have something better to offer. I believe that something better is the Kahn Communications CAM-D Digital Radio Broadcasting System.

1. The Kahn Communications, Inc. CAM-D is up and doing what it promised on KDYL-AM 1060 in Salt Lake City. Tests on the spectrum analyzer show that it has a clean digital signal.
2. We are delighted to be the first in the world to have this new digital modernization for AM Radio. Unlike the old IBOC System, CAM-D will not interfere with adjacent channels.
3. CAM-D dramatically increases, and does not limit, sky wave coverage.
4. CAM-D is fully compatible with the more than 800 million radios in America.
5. CAM-D more than passes NRSC Standards with + or - 8 KHz bandwidth.
6. CAM-D will utilize the several data channels that will alert the listening public about storms, road conditions, and national defense.
7. The installation cost to broadcasters is minimal compared to HD Radio. It does not require purchasing new transmitters, tower antennas, or processors.
8. There is no time delay from mike to speaker in your car, home or business.
9. Interference from high power electrical lines is eliminated almost completely. The signal remains strong when going through road underpasses.
10. CAM-D will work to improve the AM band, not take it backwards to 5 KHz. More wide band digital radios are on the horizon that will make AM even better.

The question has been posed by some why Leonard Kahn waited so long to come up with his new digital radio system. It was only when he Leonard saw what the Ibiquity System was going to do to degrade AM Radio that he went to work on an alternative digital system.
In my estimation, Mr. Kahn is a genius who was an adjunct professor of engineering at Polytechnic University of New York, holds nearly one hundred patents, and has worked under contract at Bell Labs and R.C.A Labs.

All I ask is that stations look before they leap and not install something that will take the AM Band backwards. Call me at 801 268-8181 or Leonard Kahn at (212) 983-4765 for more information.

Ralph J. Carlson
President, Carlson Communications, Intl.

Guy Wire responds here.

Its annoying that people like "Guy Wire" say things like "Put away your buggy whips, boys, and accept the reality of 5 kHz AM."

The fact is that promoting 5kHz audio is itself a reversion back to circa pre-1936 performance!!!!! Now who is selling buggy whips?

You can look it up in old radio manuals and radio engineering textbooks that many console radios of the late 30's included a bandwidth or fidelity switch that adjusted the reciever IF bandwidth!!!. You could select Narrow/Sharp or Wide/Hi-Fidelity on many of these classic radios.

Granted that most network programs back then were probably not "high-fidelity", the major stations would have local programs with wide audio, and many AM receivers were not that bad until perhaps the point that Stereo FM began to be signifant force. The receiver manufactures stopped putting much effort into the AM section and concentrated on FM performance. The Stereo equipment salesmans pitch was that FM sounds better, thus the radio had to sound signifantly better on FM than it did on AM (easy to do if the AM section of the tuner he is trying to sell you is without any treble) when demonstrated in the showroom.

I'll bet that most major AM's had with wide audio (wider than 5kHz) for local programs, DJ programs, etc all the way thru 40's 50's 60's 70's 80s and 90's!!!!!

Now the new HD sales pitch is the same, except that you "sell" IBOC by artificially increasing the quality contrast between it and analog reception. If all stations are limited to 5khz analog, then youv'e got your sales demonstration ready to go. The only way the customer is going to hear good "AM" audio is now on the IBOC receiver.

Guy responds:

> Its annoying that people like "Guy Wire" say things like "Put away your
> buggy whips, boys, and accept the reality of 5 kHz AM ".
>
> The fact is that promoting 5khz audio is itself a reversion back to circa
> pre-1936 performance!!!!! Now who is selling buggy whips?
> You can look it up in old radio manuals and radio engineering textbooks
> that many console radios of the late 30's included a bandwidth or fidelity
> switch that adjusted the reciever IF bandwidth!!!. You could select Narrow/Sharp
> or Wide/Hi-Fidelity on many of these classic radios.

Just because some of the classic console models had this feature hardly means the majority of users even noticed it or used it. AM reception has always been plagued by noise and adjacent channel interference. Reducing the bandwidth always helped listeners overcome those sources of interference. It's just that there is more of it in the modern era. Those who persist in hanging onto the notion that AM was and continues to be a high fidelity medium and cite the existence of a few receiver models that have a wideband option completely miss the point that the public didnt care or even notice back then. And they still don't.

> Granted that most network programs back then were probably not "high-fidelity",
> the major stations would have local programs with wide audio, and many
> AM receivers were not that bad until perhaps the point that Stereo FM began
> to be signifant force. The receiver manufacturers stopped putting much effort
> into the AM section and concentrated on FM performance. The Stereo equipment
> salesmans pitch was that FM sounds better, thus the radio had to sound
> signifantly better on FM than it did on AM (easy to do if the AM section of the
> tuner he is trying to sell you is without any treble) when demonstrated in the
> showroom.

Equipment salesmen didn't need 3 kHz AM to show off the difference. Even with the "wideband" AM mode engaged on any radio that had it, the difference between 5 or even 8 kHz mono performance on AM over the full stereo 15 kHz of FM was dramatic and profound. Any radio salesman didn't have to work very hard at all convincing anybody that FM was so much better and lightyears ahead.

> I'll bet that most major AM's had wide audio (wider than 5khz) for local
> programs, DJ programs, etc all the way thru 40's 50's 60's 70's 80s and
> 90's!!!!!

Stations may have been transmitting wide audio but all that did for most listeners was create more interference. When stations started running heavy processing and aggressive preemphasis, it was merely throwing gasoline onto a burning fire. High Fidelity AM was toast.

> Now the new HD sales pitch is the same, except that you "sell" IBOC by
> artificially increasing the quality contrast between it and analog reception. If
> all stations are limited to 5khz analog, then youv'e got your sales
> demonstration ready to go. The only way the customer is going to hear good "AM" audio
> is now on the IBOC receiver.

There are so few folks still listening to music on AM that such a demonstration would not mean anything to today's consumer or even be worth doing. Check out Arbitron and you'll find the vast majority of those who use AM radio do so for news, talk and sports programming. Listening to and understanding speech is actually easier and more efficient in a bandwidth limited environment. That's today's defacto reality for AM. When HD delivers full 15 kHz stereo for AM stations, music formats will again become a viable choice to attract meaningful audiences.

Dear Guy,

The current IBOC iBiquity system does not meet FCC engineering standards for AM or FM broadcasting. It causes more interference to existing service then the small benefit it might provide to a few who will immediately trash all the old radios they have around the house and run out and buy expensive new IBOC radios for every room, car, and workplace. There have been successful High Definition digital broadcasting systems on the air for years, (DRM, Sirius, XM) and people who want them and have them are perfectly happy, so there is no need to destroy the current system of AM and FM. Better, perhaps digital, detectors in radios could provide much of the same benefit with no changes to the broadcasting system. The reason these haven't appeared is the reluctance of most consumers to pay high prices for replacement radios with what they perceive as little benefit. The slight increase in fidelity is not perceived as warranting the inconvenience and large expenditure.

Many AM directional antenna systems can not be easily, effectively, or cheaply be broad banded as required for proper digital IBOC.

The iBiquity claim that "It's all free for consumers," is a lie. The costs are: destruction of and interference with the current AM and FM broadcasting system, excessive cost, inconvenience, little benefit to the average user.

The slow digital TV sales and adoption by consumers is a strong message to the radio community. Radio is largely content driven. Put something on the air that people want to hear, and they will listen, as long as they can pick it up on their current radios. Most people don't listen to technology, they listen to content, and could care less about the delivery system except when it involves inconvenience and excessive expense.

Jeff Littlejohn's (Clear Channel) claim that what is wrong with analog AM is that the fidelity is too good and needs to be cut in half by a brick wall filter, reduces AM to near telephone quality audio.

Guy Wire's claims that those that are against IBOC are stuck in the past is untrue. Most advocate even more advanced all digital systems such as 5.1 and even 7.1 digital surround sound (not IBOC) that doesn't destroy any AM or FM coverage or abandon, inconvenience, or interfere with current listeners. Dolby 5.1 and 7.1 digital surround sound is already here and could be easily broadcast on channels that are all digital, not in the current band on top of AM and FM stations. He is right when he said 5.1 surround sound could be the "killer app." DRM, digital broadcasting which has been worldwide for years is currently being adapted to 5.1 and even 7.1 all digital surround sound, XM and Sirius are sure to follow. IBOC can hardly squeeze in 2 channel stereo, and even then causes noise, interference, reduced coverage and fidelity loss to current listeners.

The large broadcasting and recording trusts are terrified by their impending loss of control over what people can view and hear. They might not be able to monopolize digital delivery of all sound and video. They fear competition, restrict access by less powerful potential competition, while claiming to be for a free market. Unfortunately Teddy Roosevelt is no longer with us to protect our freedom and liberty.

Community broadcasting should be encouraged and provided a reasonable, inexpensive place in the AM, FM, digital, and TV bands.

Sometimes I find a simple, old fashioned, soldering iron will do the trick even though laser welding has been invented. Not everything needs to be laser welded. The availability of inexpensive, convenient, easy to use soldering irons without the bulky laser welding attachments, should be continued and not impeded.

Sincerely,
Richard Franklin
Super Sound Studios,
WNAR-AM

Guy responds:

Richard,

Thanks for responding and for your concern about the future of traditional radio. Most of your points are straight out tof the generic anti-HD playbook of talking points. Let me answer each one so nothing gets missed.

>>>The current IBOC iBiquity system does not meet FCC engineering standards for AM or FM broadcasting. It causes more interference to existing service then the small benefit it might provide.

To the contrary, iBiquity has worked extraordinarily hard to make both the AM and FM HD systems fit within existing mask limits for both services to reduce interference to existing analog as much as possible. When HD systems are properly adjusted and optimized, complying with the "FCC engineering standards" you claim are being violated is not that difficult. What you probably think is "illegal interference" is the constant level of low-level digital "hash" in the sidebands of HD signals picked up by analog receivers. Especially for AM HD where it appears to be more annoying for many who perceive it as interference than the usual high fequency analog splatter on first adjacent channels. This is not much of a problem at all for FM HD since the modulation limits of allocated FM channels do not overlap into first adjacent channels like AM does.

>>> There have been successful High Definition digital broadcasting systems on the air for years, (DRM, Sirius, XM) and people who want them and have them are perfectly happy, so there is no need to destroy the current system of AM and FM. Better, perhaps digital, detectors in radios could provide much of the same benefit with no changes to the broadcasting system.

DRM is hardly a system that has been "on the air for years" that enjoys a large audience of happy listeners. Receivers are barely available to the public. HD has been up and running in many markets for several years in this country. Except for a few reports of critical hours interference problems for AM and a few fringe coverage situations affecting "rim-shot" signals, very very few reports of any station's coverage being "destroyed" have emerged or reported to the FCC or to the trade press to my knowledge. Receiver manufacturers see no real future in spending lots of R&D money and time developing digital bandaids for analog radios to gain marginal reception improvements. They know the future is digital. And for the USA, that means HD.

>>>Many AM directional antenna systems can not be easily, effectively, or cheaply be broad banded as required for proper digital IBOC.

According to the studies I've seen done by blue-ribbon consulting firms like dLR, the inventory of existing AM DA's that will be challenged to be able to deliver acceptable HD performacne number less than 50 stations. And most of those are nighttime arrays. The vast majority can be easily treated with modern broadbanding techniques, using passive component modifications or additions and retuning to achieve acceptable performance. Most stations that need any optimization effort at all merely require a simple phase rotation maneuver to present a balanced load to the transmitter and they will work just fine on HD. Yes that may involve some expense, but if a station truly has an economically viable future, it should be able to easily justify this.

>>>The iBiquity claim that "It's all free for consumers," is a lie. The costs are: destruction of and interference with the current AM and FM broadcasting system, excessive cost, inconvenience, little benefit to the average user.

As with any other major technological improvement to a consumer electronics appliance, the first ones to appear will be pricey. As more units are sold and critical mass distribution is acheived, costs will have dropped rapidly. Witness HDTV. HD radio will be no different. I've already addressed the totally specious claim there will be "destruction of.....the current AM and FM broadcasting system". But I'll expand on it some more below.

>>>Radio is largely content driven. Put something on the air that people want to hear, and they will listen, as long as they can pick it up on their current radios. Most people don't listen to technology, they listen to content, and could care less about the delivery system except when it involves inconvenience and excessive expense.

The point you are completely missing here is that virtually everyone who wants to keep using existing radios to hear the content they like now will be able to do so for at least the next ten years or more. Those who dont want to buy a new HD radio dont have to if all they're interested in is one channel of simple audio programming. HD offers more than that. Much more in generation 2 and beyond HD radios. By the time those folks get around to buying a new car and start discovering the advantgaes of HD, many will be looking to replace old analog radios so they can have the HD features, whether it be 5.1 surround sound, a second audio programming channel on many stations, better reception in noisy areas, or whatever. As time goes on, finding analog only radios on store shelves or in cars in the future will become more difficult.

>>>Jeff Littlejohn's (Clear Channel) claim that what is wrong with analog AM is that the fidelity is too good and needs to be cut in half by a brick wall filter, reduces AM to near telephone quality audio.

Telephone response over most POTS circuits and phonesets is typcially 300-3000 hz at best. Cellphones are even less, maybe 500-2000 hz.If you listen to talk radio and don't hear a big difference between the quality of the host and the callers, you must be unable to hear above 3khz and need to get your hearing checked. Those who lament reducing effective AM transmission bandwidth from 10 khz to 5 kHz claiming half the fidleity is being destoyed just don't realize 95% of AM receivers are rolling off the audio between 3 and 5 kHz anyway. Wake up and smell the radio.

>>>Guy Wire's claims that those that are against IBOC are stuck in the past is untrue. Most advocate even more advanced all digital systems such as 5.1 and even 7.1 digital surround sound (not IBOC) that doesn't destroy any AM or FM coverage or abandon, inconvenience, or interfere with current listeners. Dolby 5.1 and 7.1 digital surround sound is already here and could be easily broadcast on channels that are all digital, not in the current band on top of AM and FM stations. He is right when he said 5.1 surround sound could be the "killer app."

In case you havent noticed, HD with 5.1 surround sound is already being tested on a number of existing FM stations quite successfully. Check it out with the folks from Harris Corporation. The HD bitstream easily accomodates 5.1 encoding, especially the watermarked-based system like the Neural Audio Neustar system.

>>>DRM, digital broadcasting which has been worldwide for years is currently being adapted to 5.1 and even 7.1 all digital surround sound, XM and Sirius are sure to follow. IBOC can hardly squeeze in 2 channel stereo, and even then causes noise, interference, reduced coverage and fidelity loss to current listeners.

There you go again. I'm guessing you have not yet heard HD on any existing FM station. You're just parroting the anti-HD talking points again. Give it an honest listening test on a Kenwood car radio and HD adaptor and get back to me. (check out www.crutchfield.com) I've heard it in maybe 4 different markets on dozens of stations. It works very well indeed. On FM, I have yet to hear any meanigful interference at all to second adjacent channel stations. The first adjacent situations were already unlistenable with analog interference on most receivers long before HD came on because of receiver limitations.

>>>The large broadcasting and recording trusts are terrified by their impending loss of control over what people can view and hear. They might not be able to monopolize digital delivery of all sound and video. They fear competition, restrict access by less powerful potential competition, while claiming to be for a free market. Unfortunately Teddy Roosevelt is no longer with us to protect our freedom and liberty.

Spare me the old Bull Moose Libertarian rhetoric. Over the air broadcasters have always been by far the most regulated of all mass media outlets and have had tons of competition for years. I guess you've never had dish TV, cable TV, internet access, satellite radio or even an iPod. The large "broadcasting trusts" have been up against all of these and are just trying to remain competitive by providing a sustaining digital product for the future within the constraints of existing FCC channel allocation rules. The "recording trusts" are fighting for their very survival in the face of music pirating and digital copying. I'd say the free market is very much alive and well as a myriad of electronic entertainment choices out there compete for consumer's money and attention.

>>>Community broadcasting should be encouraged and provided a reasonable, inexpensive place in the AM, FM, digital, and TV bands.

Channels in the exsiting bands are a very limited and scarce resource, especially in population centers. Like anything in a regulated free market, prices and values increase dramatically when demand far outstips supply. The LPFM and LPTV services are out there and not all that inaccessible or expensive for service to smaller communities. And ofcourse there are public access cable channels always looking for community oriented content of worthwhile interest.

>>>Sometimes I find a simple, old fashioned, soldering iron will do the trick even though laser welding has been invented. Not everything needs to be laser welded. The availability of inexpensive, convenient, easy to use soldering irons without the bulky laser welding attachments, should be continued and not impeded.

Nothing wrong with simplicity Richard. But I dont think HD radio is a laser welder compared to analog radio's soldering iron. Technology advances almost always make a new consumer electronics product or invention a lot more user friendly and affordable in a rather short period of time. Even the simple soldering iron is now much more efficient and effective with automatic temperature control. Dont forget that radios were considered rather complex and difficult to use devices when they were first introduced. The HD radio you will see in the marketplace in the next few years will knock your socks off, not to mention your eyes and ears. And it will be quite affordable.

Dear Guy,

Hi, Guy!

Looks like you're going to be on the hot seat for a change with your recent HD radio column.

Thank you for stating exactly what I have been stating since WOR signed our HD operation on 2 years ago.

Thomas R. Ray, III, CPBE

Dear Guy,

The article "Ibiquity Charts a New Course" contains the following statements about DRM:

"Digital Radio Mondiale was invented as an all-digital replacement for international analog AM broadcasting below 30 MHz." ... "Nor does it offer a hybrid digital/analog mode to allow analog to remain useable."

This statement is factually incorrect, since DRM does indeed have a "simulcast" mode which has both analogue and digital components.

The article also contains the following statement:

"While it could be done, DRM provides no information about that on its Web site or any other public communications."

As the following sample links from the DRM website show, this statement is also factually incorrect:-

http://www.drm.org/newsevents/faqs/faq-053.htm
http://www.drm.org/newsevents/faqs/faq-054.htm
http://www.drm.org/newsevents/faqs/faq-055.htm

The RW Online website will be widely read within the US radio industry and a statement such as this is likely adversely to affect the perception of DRM as well as misinform your readership. I'm sure you'll wish to publish a correction, particularly as you surely pride yourselves on the accuracy of your reporting.

Best wishes

Carey
http://www.wohnort.demon.co.uk/DAB/

Guy responds:

Carey,

It's always good to hear from merry old England, especially on matters of DAB.

Your cited claims of incorrect information regarding my review of the DRM hybrid or "simulcast" mode are technically accurate. I thought I had researched this issue carefully. The DRM simulcast mode does exist and apparently is still being tested, but it's hardly a significant part of the system specification. The DRM website (www.drm.org) makes no mention of it whatsoever in system specifications, preferring instead to make only passing mention of it in 3 brief answers buried among 60 FAQ's in the News & Events section.....which you cited and which I unfortunately missed. But I have to ask, if this were truly an important mode for DRM, why would it be almost invisible on the website and elsewhere throughout the trade press?

Clearly the reason is that DRM was conceived as a complete digital replacement technology for analog AM below 30 MHz, primarily in WARC regions 1 and 3. The inventors chose to focus on that instead of a fully developed hybrid compatible mode as Ibiquity has proposed to allow the preservation of existing analog transmission and reception. The 3 FAQ's you cite indicate that the DRM simulcast mode was being tested and that further information would be forthcoming. Curiously these were last updated in June, 2002, almost 16 months ago.

FAQ 54 suggests that the DRM simulcast mode contemplates SSB or asymmetric/vestigial SB operation to reduce interference but at the expense of increased distortion. Further research seems to indicate that the 10 kHz DSB simulcast mode of DRM would not fit in the NRSC bandwidth mask limitation for our AM band. If this mode is to be useful in the US as an alternative to Ibiquity's AM HD-R, a lot more tweaking, testing and revelation is needed.

The context of my remarks on DRM come out of the reality that Ibiquity has rigorously tested, demonstrated, and proposed as a standard their hybrid model which does fit in the NRSC mask and as such is a real and valid product. Yes there are some interference issues that will have to be dealt with, especially for nighttime operation. While DRM may have a hybrid mode that is being quietly evaluated behind the scenes, it still appears to me that it's nowhere close to being a contender that could offer performance equal or better to Ibiquity's HD-R for the US AM broadcast band.

-- GW

Dear Guy Wire,

I read with interest your points on "Fixing the HD Radio Breakdown" and would like to put forward a few thoughts for consideration.

My first point relates to the fundamental aspects of auditory masking and psycho-acoustic based compression algorithms, in particular AAC, PAC and earlier versions of MPEG i.e. Layer II and Layer III. It has been well documented over the past 10 years, that having a number of destructive psycho-acoustic based algorithms in the audio broadcast chain would introduce artefacts. Implementation of a low bit rate algorithm for the final leg of HD Radio was always going to accentuate any problems that already existed (in addition to introducing new artifacts).

As such, whether AAC or PAC is used for HD Radio is largely an academic argument. Sure, one "tweaked" algorithm may offer a very slight incremental improvement (which is largely dependent on the source material i.e. talk or music) but to fundamentally confront the problem, broadcasters need to address the complete broadcast chain.

We at APT - Audio Processing Technology (http://www.aptx.com) have been recommending that broadcasters take more care of their content. By this we suggest a reduction in the number of psycho-acoustic passes in the broadcast chain and where compression is required use a non-destructive gentler ADPCM compression algorithm i.e. apt-X(tm). Although you have touched on this subject i.e. channel level imbalances, frequency and phase response errors etc, the terrible effects of multiple MPEG/AAC/PAC passes should be highlighted.

As an aside, the apt-X(tm) algorithm has been in existence for 15 years and in addition to using a non-destructive compression technique, broadcasters also have an added benefit of a low latency i.e. sub 5 milliseconds. Many broadcasters have adopted the apt-X(tm) solution through our OEM / Business Partners i.e. Harris Intraplex, Scott Studios, Computer Concepts, Moseley and TFT. The largest success to date is DTS cinema's i.e. every DTS equipped cinema uses the apt-X(tm) algorithm for 5.1 playback.

My second point concerns "Applying the big fix" where the AM HD Radio output appears in the form of gritty, unnatural-sounding voices. It is stated that most listeners may not notice these artefacts, however artefacts at any level eventually result in Listener-fatigue. This in turns leads to "the tune-out factor" and listeners flicking across the dial. In the world of commercial radio this ultimately equates to a loss of revenue when salesmen have to go to their customers after the listener figures are published.

To summarise in the form of an analogy, if a house has got serious cracks in the wall, then papering over the cracks will not solve the problem. Only by looking at the foundations of the building will the problem be addressed. Until broadcasters take ownership of the cascading and concatenation issue and reduce the number MPEG passes, then all investments in HD Radio will have a very poor return.

Jon McClintock
Commercial Director
APT

Guy responds:

Always good to hear from our Apt friends in Belfast. Jonny, I've often wondered why the Apt-x lossless codec did not make more friends and win more contracts when first introduced. It just makes sense that the non-destructive approach would be preferrable and work better. Maybe its all about NIH syndrome. (Not Invented Here). I can personally attest to how well Apt-x works on the Intraplex and Moseley STL gear.

Now that Ibiquity is being forced to re-examine the codec issue with HD Radio, you might just have a narrow window of opportunity to get on their radar screen. Call Bob Struble and ask for a meeting and demo. I've heard that they're actually considering switching to MPEG AAC+. How serious or likely that could happen is questionable since bailing out of PAC puts a huge dent in their business plan, not to mention their pride and ego.

"Until broadcasters take ownership of the cascading and concatenation issue and reduce the number MPEG passes, then all investments in HD Radio will have a very poor return."

I would not go that far out on the limb and predict HD radio will fail because of cascading MPEG passes. I've heard too many stations with standard MPEG-2 256 compressed music running with both PAC and AAC on HD-FM that sound just fine. Listeners and engineers alike cannot hear any degradation of significance. As stations convert to linear audio storage, the problem diminishes further. The bigger problem that will linger longer will be satellite fed programs and MP3 commercials. Let's face it. The audio consumer is adaptive and forgiving. MP3's sound just a good to them as CD's. It doesn't have to be perfect audio all the time. Just almost perfect most all of the time seems to be more than adequate.

-- GW

Dear Mr. "Wire",

Transmitting digital signals on the AM and FM radio bands is an admirable concept. However, experience over the past decade has proven time and time again that the AM band is simply unsuitable for the use of "hybrid" digital/analog signals. The huge number of stations occupying a limited bandwidth and the presence of nighttime skywave propagation all severely limit the real-world success of any such system.

At first glance, the current IBOC system seems to have overcome this challenge. However, it only does so by purposely taking advantage of the loopholes in broadcasting standards that were never designed to accomodate digital signals (such as the NRSC AM bandwidth mask), which comes at a price of causing large amounts of interference to both the IBOC signal itself and to neighboring stations on the dial... all for what? To deliver digital audio that sounds as bad as a RealAudio internet stream coming through a 28.8K modem?

The rest of the world figured out long ago that there are basically two viable choices: either to commence operation of digital-only AM signals, throwing compatibility with existing analog receivers out the window -- or to allocate digital broadcasts to a new dedicated spectrum space, and leave the existing analog radio services as-is.

Comitting the AM radio band to analog broadcasts indefinitely is by no means a death sentence. In fact, the technology used has little to do with the impending success or failure of AM radio. People aren't listening to AM radio as often as they used to, not just because typical AM receivers deliver low-fidelity monaural audio and the band has become more prone to electrical interference, but also because many AM stations just don't offer programming that listeners find attractive anymore. If somebody doesn't like Rush Limbaugh or Dr. Laura, they're not going to listen to these programs no matter if they are available with hi-fi CD-quality stereo digital audio.

With the standardization of C-Quam AM Stereo and introduction of the NRSC technical standards, AM radio stations set the playing field for high-quality broadcasts over a decade ago. But just because the typical AM receiver cannot live up to this level of quality doesn't mean that analog AM, and indeed AM Stereo, should be scrapped entirely. That's like saying all stereo TV broadcasts should be cancelled because more than three-quarters of TV sets in use are still monaural-only!

Companies like Motorola, Blaupunkt, and Omega Reception Technologies are on the right track -- to use today's digital technology to provide the best possible quality from today's *analog* AM and FM radio signals. Indeed, IBOC has yet to live up to the quality that any good analog AM Stereo or FM Stereo receiver can deliver, and as your article explained, this is a problem that will not be easily or completely resolved. So, why not make the best of proven analog broadcasting methods? That would be win-win situation for everybody -- broadcasters and listeners alike.

Kevin Tekel
kevtronics@yahoo.com
Webmaster of The AM Stereo Web Site
http://www.AMStereoRadio.com

Mr. Wire responds:

Kevin,

OK..... I'll admit it, AM Stereo does sound pretty good. It was worthy technology when introduced, but even you would have to admit it got buried by legal complications and marketing confusion. It never had a fair chance. We need to move beyond old technology and embrace a digital future for this industry.

"...experience over the past decade has proven time and time again that the AM band is simply unsuitable for the use of "hybrid" digital/analog signals."

I'm not sure that the experiences of testing early versions of the AM hybrid mode over the past decade tell us how the system will ultimately perform as ongoing improvements to both the transmission and reception ends of this equation evolve. It comes down to balancing the overall improvements to the listening experience that AM HD will deliver versus the toll that increased interference might inflict on existing listening. So far, daytime HD testing appears to deliver dramatic improvement compared to the minor increase in adjacent channel noise that impacts a very small percentage of fringe signal listening. Admittedly there is some increased interference at night factoring in skywave. But if you accept the results of the Glen Clark study, the number of actual AM nighttime listeners affected is still ridiculously lower than the number of listeners who will continue to be able use existing analog radios to enjoy their chosen stations without problems. As HD radios penetrate the marketplace, they'll be able to enjoy noise free high fidelity stereo on AM for the first time. The AM band will truly be reborn.

"......(AM HD) comes at a price of causing large amounts of interference to both the IBOC signal itself and to neighboring stations on the dial... all for what? To deliver digital audio that sounds as bad as a RealAudio internet stream coming through a 28.8K modem?"

You're stuck in a time warp from impressions formed a number of years ago. Recent over the air AM HD tests have demonstrated that its stereo fidelity even using the PAC codec at 36 kb/s is robust and impressive. Light years ahead of what any music format on analog sounds like on a typical AM radio, even in a new car. After the codec artifact issues are resolved, there won't be much to complain about in this contest.

"The rest of the world figured out long ago that there are basically two viable choices: either to commence operation of digital-only AM signals, throwing compatibility with existing analog receivers out the window - or to allocate digital broadcasts to a new dedicated spectrum space, and leave the existing analog radio services as-is."

Just because the rest of the world thinks these are the only viable options, it hardly means the US must be constrained by them. We invented radio here. We are now inventing and perfecting a digital radio solution that fits our needs for the future. Our structure of 14,000 stations serving 280,000 folks in hundreds of thriving communities spaced out across a huge area exists nowhere else on the planet. Both the industry and the government concluded long ago that a separate band was neither politically available nor economically desirable.

"........the technology used has little to do with the impending success or failure of AM radio. People aren't listening to AM radio as often as they used to, not just because typical AM receivers deliver low-fidelity monaural audio and the band has become more prone to electrical interference, but also because many AM stations just don't offer programming that listeners find attractive anymore. If somebody doesn't like Rush Limbaugh or Dr. Laura, they're not going to listen to these programs no matter if they are available with hi-fi CD-quality stereo digital audio. "

The NAB tracks AM vs. FM listening closely. While the AM numbers slowly declined over many years they have leveled off since 2001 at 19%. Almost all of that is news/talk/sports programming attracting very good ratings in the money demos. There may be fewer successful AM stations than FM but claiming this will not change with the advent of only better fidelity on HD ignores the destructive impact of noise in the existing analog environment. I'm sure you've tried but failed to listen to your favorite liberal talk show on AM inside a building or even at home where impulse and amplitude noise wipes out the entire AM band.

"Companies like Motorola, Blaupunkt, and Omega Reception Technologies are on the right track -- to use today's digital technology to provide the best possible quality from today's *analog* AM and FM radio signals."

What traditional AM and AM stereo enthusiasts like you have a hard time accepting is the superior noise suppression performance of digital receivers decoding digital modulation. Analog and even the digitally assisted receivers you mention that decode amplitude modulation are at huge disadvantage. Noise is the most menacing enemy of AM listening. Not lower fidelity or bad programming. And it only gets worse with every passing year. That's why analog AM needs to prepare for a just and honorable burial in the not-so-distant future. All digital clearly best serves the long term interests of the grandfather band. It's just getting there that will be a little painful.

If the hybrid transition proves to be too disruptive for AM, the FCC can always adopt my suggestion posited over a year ago: Roll out FM HD now but skip the AM HD hybrid mode. At least for those stations that cause significant interference. Then when enough receivers are in the marketplace, mandate that all AM stations switch to all-digital together. This can be done with plenty of forewarning with a hard deadline. Probably about 8 to 10 years in the future.

"Indeed, IBOC has yet to live up to the quality that any good analog AM Stereo or FM Stereo receiver can deliver, and as your article explained, this is a problem that will not be easily or completely resolved."

Again, you either haven't been paying attention or haven't heard HD perform in the real world on real stations. Take a quick trip to NYC and have Tom Ray demo WOR AM-HD. Or go to LA and have Scott Mason show you how well KROQ FM-HD covers the huge LA metro and how impressive it sounds. Fixing the codec problem might be difficult, but it does not appear to be an insurmountable challenge.

-- GW

Dear Guy,

I think you are correct. XM will provide the coast to coast broadcast capability for "regular radio" when the statios start broadcasting digital. But I hopel like hell XM keeps at least 50 of the stations they presently offer. The present subscription package is unlike anything I've ever experienced on radio. This is a new kind of listening experience, not really comparable to regular radio.

Also agree, Sirius is toast. From what I gather, they still don't have a decent chip to build into equipment. And XM's seems to work "flawlessly".

I have two XMs. One in the car, one in the office. Have been a subscriber for about a year. Honestly, I have not listened to old timey FM since. And I really thought I would, on occaision. XM is that good. It's fascinating to have all those choices, with only the occaisional ad. And the sound quality is undistinguishable from CD.

What is interesting is that I am now becomming very familiar with music that I was never before exposed to and never thought I would like. I mean, I know my Coltrane and Miles Davis now. Before getting XM, I was just happy for the occaisional Pearl Jam or Neal Young song stuck in with the endless annoying parade of ads on FM.

What I'm saying is XM is not like old timey FM. XM is a brave new world of music and information that is changing what people listen to and what they like. XM is broadening horizons and offering a far more satisfying listening experience. I really do think XM is hear to stay.

Thanks for your article, it was interesting.
Just one person's take on things,

Beatrix Jacob

Guy replies:

Tis hard to disagree the variety found on the SDARS services is compelling, particularly for those like you who are looking for it and are willing to pay for it. In the end, if it survives, the costs will be higher for both users and advertisers. But like everything else in the world that carries a "premium service" menu, that's nothng new.

-- GW

Dear Guy,

It is my understanding that a tower worker was burned during the KDOC antenna installation. It was a worker from John (Russ) Hignite's tower crew. Apparently, as I'm told, the suit he was wearing started to "take off" in temperature and landed him in the hospital with 2nd degree burns. Naturally, the tower crew would remain silent about this, since this is their backyard. The complaint to the commission was made anonymously. Now I realize that this is a rumor, and I want it treated strictly as such. I must remain anonymous, as I still like to be able to work at facilities such as this mountain top. Perhaps this information will help to dig out the real story. It is also possible that the suit was old, and of an inferior type. My source says that the early suits are not too good and can fail. Wear and washings can also contribute to this. There was also mention made of a TV station in the proximity of the tower crew not turning down their power. Again, only a rumor. I do not have the desire to dig into this as it will impact my future as an engineer. I want this treated solely as a potential story lead that might help reveal the truth. These things must not occur in the future. I was at the mountain working on a facility perhaps 1000' away at the time when the commission showed up. They were quite friendly. It was the following day that the CE's from many stations were alerted. Even guys with neckties were there. Unusual for a transmitting plant.

Regarding the "open gate," it was really a chain that covered a large gap in the fence. There was no RF sign on the chain and it was lying on the ground anyway. Since the public has access to this mountain top, my best guess is that there will be a gate installed very soon so that little Johnny can't wander into an RF field.

This also brings up the point that there is a double standard. Why do we have a 1000uW/cm2 standard and the public a 250uW/cm2 standard? Are we impervious to RF? We typically spend far more time near fields than the public.

BTW, do you want any pictures of the KDOC antenna or other parts of the farm? Again, I must remain anonymous.

Sincerely,
(Name Withheld On Request)

Guy replies:

Thanks for sharing this response. We clearly understand your concern being closely involved with the Mt. Wilson incident and your desire to retain anonymity.

We know how difficult it has been to get reliable information from responsible sources on these cases. While the FCC investigations are ongoing, nobody wants to come out in the open.

Regarding the apparent "failure" of the RF suit worn by one of the workers: I have never thought these devices were reliable or appropriate and could actually make a hazardous situation potentially worse, as it may have done here. While they are intended to be metallic shields to RF energy, the older "hotsuits" were clearly not predictably effective in certain conditions or at certain frequencies and can actually cause more absorption that reflection.

The technology is improving, however and newer designs apparently offer better protection. IMHO, a properly calibrated RF sensor worn by all tower workers with a well co-ordinated effort by engineers on the ground to prevent accidental re-energizing of transmitters is a better approach. Many sites now
have RFR plans that are very simple: No work on the tower is done at all unless ALL transmitters are shut down. PERIOD. The attorneys like that plan
the best.

The so called "double standard" you refer to regarding public versus worker exposure limits is purely precautionary and is based on assumption. The standards setting bodies that came up with this justify it by citing the fact that workers are assumed to be more knowledgeable and aware of the risks and manifestations of RFR over-exposure while working around it. The public is assumed to totally clueless and could more easily subject themselves to potentially harmful over-exposure without any idea of what they were doing or what the risk might be.

Share your pictures of the Mt. Wilson site with us and we'll post 'em here. (Note: And here you go!)

-- GW

Dear RW,

Good to see Guy is seeing the light regarding Ibiquity. And I agree with his conclusion that, by default, IBOC is US radio's best shot to go digital. But with friends like these, who needs conversion? Why spend all the time, trouble and money on a format that is likely to fail? Maybe analog will do just fine for radio *transmission* and receivers can add digital technology for audible improvement and marketing parity. (See my upcoming May 22, 2002 "The Big Picture" column in RW for more on this approach.)

I will take issue with one other bit of spin that Guy and others have used lately, however, which is the comparison of Ibiquity's software licensing fee to "Microsoft's" or the general computer software industry's practice of charging for software. There is a simple but critical distinction here: Computers are designed as *general purpose platforms*, which can run a variety of operating systems and applications. They are like engines without the gas until the software is added, and the software can be changed or new software added to provide different functionalities on the device. The hardware and the software are both valuable products in their own right, and each can be made by a variety of manufacturers thanks to agreements and standards of interoperability. On the other hand, an Ibiquity exciter is *dedicated hardware* designed to provide one function -- the generation of a complex waveform intended for subsequent RF amplification, radiation and reception by standardized receivers. The exciter cannot run other manufacturers' software and thereby provide radically different functionality. In other words, that hardware is of no value without that particular software and vice versa. It is a single-purpose pairing, not an interoperable, multi-purpose environment. So where is the added value of the software in this case? Why is it sold (licensed) separately? Yes, it can be updated, but this is the case for many of today's *hardware* devices in broadcasting, which base their operation on field-replaceable firmware or downloadable software. This cost for this software is initially bundled with the hardware, the upgrades are either provided free or sold with a nominal fee as a maintenance package. Such upgrades may expand the device's functionality somewhat, but they will not change its fundamental application from a dedicated, single purpose.

Therefore the allusion to the precedent of an established industry practice for separately licensed software does not apply here. In fact, the truly applicable established practice (for dedicated broadcast hardware such as an IBOC exciter) has just the opposite tradition. EAS encoders, digital STLs or digital audio processors are all good examples, in which upgradeable proprietary software is used, and not licensed separately from the hardware it is exclusively written to control.

Finally, consider what's really going on here: The Ibiquity software is being licensed on a sliding fee scale based on market size and class of service (i.e., proportional to potential audience size), while the hardware is sold at a flat rate (as always). Maybe it would make sense to do so, but long-established market practices render it impossible for today's transmitter manufacturers to charge different fees to different customers based on such graduated criteria as Arbitron ratings or FCC license fees. Yet because the concept of levying of separate software license fee for transmission equipment has no established tradition, this new idea of a sliding scale could be tried. In fact, it's just a way to penalize a major market station for transmitting at the same bandwidth and power as a smaller market station, with Ibiquity reaping benefits they could not receive if a traditional licensing arrangement to manufacturers was used.

RF should be RF. Equipment costs should be based on technical performance. Keep the audience-related fees to the business side of the operation.

Skip Pizzi
Fairfax, VA

Dear Guy,

I am baffled as to why you don't think that the EAS system is a good system. The radio stations that I engineer at we have the EAS system setup to were it will automatically drop whatever programming is on the air, and immediatly put the national weather service on the air, as we monitor them as well as our local lp1 and lp2 stations. (Primarily because we can never seem to get them in!) I have read about the A.M.B.E.R. program, but I don't really understand it. I am confused at whether they expect the lp1 and lp2 stations to transimtt these, or will it fall back on a outside agency, for example State Police? I am also a little confused about the status on the current EAS system. The reason that I am confused is that I subscribe to many different engineering newsgroups, and in a couple of them they say that an outside company (I can't remember their name, off the top of my head) developed the original EAS system and are now trying to require a licensing fee? They said that the FCC is thinking of dropping the EAS system and developing something different? Why doesn't the government just invoke their right of eminent domain and take it away? If there is something we don't want, it is another change! I appreciate your reply on this!

Jeffrey Oestreich
admin@oestreich.net
Asst. Chief Engineer

Guy replies:

Jeffrey,

If you auto-forward all NWS EAS tests and alerts on your stations, I pity your listeners and your ratings. Based on all the questions you are confused about, I think you have answered your first question as to why EAS is not a very good system.

The SAME digital coding format used by EAS was allegedly developed by a private company before the Feds employed it for EAS. They are asking for royalty payments for its use by EAS. Invoking eminent domain to claim private property by a government entity works for real estate, but not for patented inventions.

-- GW

Dear Guy,

I do not urge that "we stay with analog..." as per your reply to my original email on this subject. I _do_ urge that we fully understand the real-world performance of analog FM and FM IBOC systems before committing to FCC endorsement, and to the cost of the hardware changes necessary to implement IBOC (or any other broadcast standard).

In your reply, you wrote "We can't control what stations do with their audio processing...", and later, that FM IBOC will produce "dramatically reduced noise." Let's carry on a bit with those ideas.
It is highly likely that much of FM IBOC audio will be processed to have the same loudness, or modulation density as analog FM does. Why? Because listeners will expect a uniformly loud audio level as their IBOC receivers switch between stations, and toggle between digital and analog modes of operation. They will not want the annoyance of riding the volume control to accommodate changing audio levels every time the receiver switches stations or modes.

The audio processing used with analog FM allows for little dynamic range, in most cases. This is the result of "loudness wars" that have evolved among competitive stations, and the need for the program to remain audible under the high acoustic noise levels common in the automotive receiver environment. This low dynamic range at near-100% constant modulation means that analog FM audio is far, far above the electrical noise level of the system (source+studio+ tx+rx), and that for most locations the analog FM system noise floor already is far, far below audibility.

When FM IBOC program audio is processed to provide loudness parity with analog FM, not only will there NOT be "dramatically reduced noise" compared to analog FM, but system noise actually will INCREASE due to the digital compression artifacts that are always present in FM IBOC program audio. And that added noise will be heard throughout the coverage area of the digital signal, not just in fringe areas.

In closing, the issue of the FM capture ratio performance of automotive FM receivers is another subject beyond the control of the broadcaster. Receiver OEMs need some incentive to produce them. Certainly the end users will not be the source of that, because the benefit of a good capture ratio is unknown to them. With a few exceptions, receiver OEMs have judged that ~10 dB capture ratio performance is good enough. Industry pressure, and/or FCC mandates for good (<1 dB) FM capture ratio would be needed, but the resulting receivers would do much toward eliminating "multipath distortion" in auto receivers. And the added cost per receiver would be small compared to adding FM IBOC to the receiver -- not to mention the money saved at the transmission end of the chain.

Richard Fry
rfry@adams.net

Guy replies:

>> I do not urge that "we stay with analog..." as per your reply to my
>> original email on this subject. I _do_ urge that we fully understand
>> the real-world performance of analog FM and FM IBOC systems before
>> committing to FCC endorsement, and to the cost of the hardware changes
>> necessary to implement IBOC (or any other broadcast standard).

Richard, With all due respect, it sounds like you don't trust the NRSC or the combined judgment and backing of all the key players that are part of the iBiquity partnership. I guess that's to be expected from a theoretician and design guy like you. However, I also have BIG reservations about the costs of implemetation. Not so much the hardware costs, but the licensing costs for broadcasters.

>In your reply, you wrote "We can't control what stations do with their
>audio processing...", and later, that FM IBOC will produce
>"dramatically reduced noise." Let's carry on a bit with those ideas.
>
>It is highly likely that much of FM IBOC audio will be processed to
>have the same loudness, or modulation density as analog FM does.
>Why? Because listeners will expect a uniformly loud audio level as
>their IBOC receivers switch between stations, and toggle between
>digital and analog modes of operation. They will not want the
>annoyance of riding the volume control to accommodate changing audio
>levels every time the receiver switches stations or modes.
>
>The audio processing used with analog FM allows for little dynamic
>range, in most cases. This is the result of "loudness wars" that have
>evolved among competitive stations, and the need for the program to
>remain audible under the high acoustic noise levels common in the
>automotive receiver environment. This low dynamic range at near-100%
>constant modulation means that analog FM audio is far, far above the
>electrical noise level of the system (source+studio+ tx+rx), and that
>for most locations the analog FM system noise floor already is far,
>far below audibility.

I really think broadcaster's attitudes towards audio processing are changing. With satellite and CD competition, it's no longer business as usual. Old style loudness wars that feature the modulation monitors staying glued on 100% seem to be abating a bit. Digital processors are getting better and smarter, allowing stations to sound full and loud but yet dynamic. I'm seeing increased use of less overall gain reduction and compression in favor of much smarter look ahead clipping and limiting to create loudness. Many PD's I talk to see an opportunity to run their DAB audio less squashed and more dynamic to compete with CD and satellite. DAB audio processing needs that to be worthy of the "digital" label in the consumer's mind. Dynamic range and lack of interference and noise are more impressive improvements than you give them credit for. Matching the analog and digital audio levels will be very important ofcourse. We'll see what happens.

>When FM IBOC program audio is processed to provide loudness parity
>with analog FM, not only will there NOT be "dramatically reduced
>noise" compared to analog FM, but system noise actually will INCREASE
>due to the digital compression artifacts that are always present in FM
>IBOC program audio. And that added noise will be heard throughout the
>coverage area of the digital signal, not just in fringe areas.

Your definition of "noise" in this context is mostly academic and does not translate as such for the consumer. Digital compression artifacts that become audible as noise are typically well below the threshhold of untrained ears to hear any, even at the 64 kbps compression rate that XM uses, let alone the 96 kbps used by FM IBOC. If this were not the case, XM would have never put their product out there in the form it is, with the backing of so many experts and investors. They use a fleet of Omnia processors adjusted with appropriate processing levels for each format. My PD's have all listened to XM and think that technically, it sounds "great" and they're not real happy about that. If you don't believe this, ask a dozen consumer listeners yourself who have XM. Your trained ears are looking for nuances that average listeners just don't hear of care about.

You could be partially right though about digital distortion artifacts, in the sense that if some stations insist on traditional heavy processing that is not well tolerated by IBOC with clearly audible artifacts, it might force at least some of the "loud at all costs" PD's to back off on both the analog and digital processors. There could well be a silver lining in there.

>In closing, the issue of the FM capture ratio performance of
>automotive FM receivers is another subject beyond the control of the
>broadcaster. Receiver OEMs need some incentive to produce them.
>Certainly the end users will not be the source of that, because the
>benefit of a good capture ratio is unknown to them. With a few
>exceptions, receiver OEMs have judged that ~10 dB capture ratio
>performance is good enough. Industry pressure, and/or FCC mandates
>for good (<1 dB) FM capture ratio would be needed, but the resulting
>receivers would do much toward eliminating "multipath distortion" in
>auto receivers. And the added cost per receiver would be small
>compared to adding FM IBOC to the receiver -- not to mention the money
>saved at the transmission end of the chain.

I really think if reducing the capture ratio to less than one db were that impressive of an improvement overall, it would have been done long ago. Even if it were, it's simply too late for receiver manufacturer's to get excited about adjusting their capture ratios. Just like it was too late for any of them to get excited about AM stereo in the 1980's, when the ballgame for music on AM was already over. The world is ready for a digital solution for both radio bands.

-- GW

Dear Guy,

you wrote: "... similar to how the new Windows Xp connected to the Internet updates itself automatically."

Wow! What an example. A crashy bloated operating system for which most updates are security patches or fixes for things that weren't done right the first time. I hope IBOC receivers aren't like this or IBOC is doomed.
Actually, the process for this already exists in some early models of the US military software defined radios. New modes, modulation types and even encryption codes can be sent from one radio to another or one to many. The operator may not even need to do anything or know it happens. He just knows that now his Army unit can communicate with that Navy unit. Yesterday they couldn't.

Otherwise I agree with your analysis. I hope the FCC drives the adoption by picking a standard and mandating implementation. Even then, I'll be chafing at the bit to hear IBOC audio coming out of my radio.

Regards,
Stephen Ickes
Webmaster,
The AM Window
www.amwindow.org

Guy replies:

Stephen,

By using this comparision, I was merely suggesting that the updating process was similar, not that IBOC code would be bloated and full of bugs like windoze. If you haven't tried it, Xp actually works pretty good, considering its pedigree and need to be backward compatible for windoze based software. The licensing and registration process is a whole new monster however.

--GW

Dear Guy,

The statement from your Radio World paper "Deriving the Real IBOC Equation" points to the truth of the alleged superior audio quality of FM IBOC. If FM IBOC provided a worthwhile and significant improvement in audio quality, it should be apparent to the average listener when an IBOC receiver transitions between analog and digital.

Audio processing and data compression largely determine the audio quality perceived by the listener. Analog FM using exciters with digital modulators can transmit 16-bit digital audio quality with no data compression artifacts. IBOC _will_ have compression artifacts. With the same processing philosophy, analog FM is capable of lower distortion and a lower noise floor than FM IBOC can provide. And analog FM "multipath distortion" could be greatly reduced if mobile FM receivers had sufficiently low FM capture ratio (<1 dB instead of ~10 dB or more) -- which would cost far less to implement than will FM IBOC. These points appear to be overlooked, suppressed, or perhaps unrealized by the proponents of FM IBOC.

If few will notice the difference between analog FM and IBOC, what is the benefit to the listener? And what will the motivation be for the average listener (or broadcaster, for that matter) to spend the money needed to convert to IBOC?

Guy Replies,

Richard,

Many engineers and purists like you argue that existing FM analog performance capabilities are much better than offered with IBOC. Because of that, you urge we should stay with analog and just get receiver manufactureres to tweak their capture ratios to solve the multipath problem. If it were really that easy, receiver manufacturer's would have embraced and implemented this trick long ago. You guys are too far inside the forest to see the trees. XM commercials are touting "sound quality out of this world" and most of their new converts thoroughly agree. Even Skip Pizzi seems to think XM at 64 kbs sounds better than IBOC at 96 kbs or even analog FM. How could that be? Well, Richard, it's because the perception of analog FM quality has been spoiled in the mind's ear of the public by heavy processing, noise, interference, and multipath. Coding compression is now smart enough to get by them completely. They are responding mostly to expanded dynamic range without noise and inteference. A simple lesson largely ignored by most in our industry. We can't control what stations do with their audio processing, but IBOC should be a lot closer to XM and the CD player than analog FM could ever hope to be.

The typical audio consumer does not listen to radio like you and I do. They will not be looking for a big jump in quality during the quick transition from analog to digital after IBOC is first acquired. What they will experience is dramatically reduced noise and interference as they drive around during long periods of listening. They may hear the analog becoming noisy near the point of failure after the digital is gone, but that's OK. Graceful degradation is what they are used to, signalling that it's time to change the channel.

The quality improvements that digital technology has brought to consumer electronics as with cassette and LP records giving way to CD and with VCR to DVD will translate in broadcasting for both DTV and IBOC DAB. It's only a matter of time.

--GW

Dear Guy,

Well you are mostly right but PLEASE do not suggest a fix for EAS. EAS isn't needed period. I too believed the concept might work when it was first introduced but I soon wised up. When EAS was first introduced I had a contract engineering firm. EAS cost me many kilo-bucks training my engineers, making changes because the FCC changed their minds or didn't know what the rules were, and hours spent in meetings. I've written procedures and trained jocks but it never seems to end. Engineering just can't keep up with all the personnel changes. All the time spent training does cost money, ya know. I have five stations at this location and our EAS system runs fine -- we just will never use it for anything other than test, test, test. We have too many other better ways to get the word and disseminate it.

Keep up the good work, Guy

Ray Uberecken
Chief Engineer

Guy Replies..

While I completely empathize with your position, Ray, the reality is that we're stuck with EAS. Period. Rather than just keep blasting it for being flawed and ineffectual, technology advances have now made it possible for rational human beings to come up with a scheme that could work much better than it does now. Most of the solution will be the result of political give and take. And that takes time, of course. It's a concept worth perfecting, but that can only happen by evolving the present system into something better. It's a dirty baby and so is the water, but the cleanup is doable.

- GW

Dear Guy,

<< I really wonder about your conclusion that terrestrial broadcasters should plow ahead with IBOC. I guess we should because it's the only card we have to play. I must admit grave concern that 'legacy broadcasters' have aimed so low with IBOC that it may end up being nothing more than a footnote in some future history, beside AM Stereo, RDS, Dolby FM, FMQuad etc. >>

IBOC is the only digital card this country's radio broadcasters will indeed have to play. We have no choice but to play it. Without a digital equivalent to satellite that cures many of the traditional interference problems that have plagued our analog transmission modes, we will lose more ground more quickly to satellite. When its clear to the receiver industry that the majority of existing stations will implement IBOC, multi-mode receivers will be a big seller. - GW

<< IMHO the last major change in consumer behavior involving radio was the embrace of FM in the 60s/70s. Will any future technology put the shine back on terrestrial radio's apple? >>

No doubt that satellite is the most significant improvement for radio since FM. But don't forget that FM took maybe 20 years to really catch on. It won't take digital anywhere near that long with the satellite choice sitting in the same radio. Especially considering XM works well and sounds good out of the box.FM didn't have that luxury in car radios for many years.

-- GW

Dear Guy,

I did not see in your article where you tested the XM radio. What city, and how much driving you did on the open road, or in the city.

Could you elaborate on these reception issues?

Guy Replies...

If I told you, I'd have to kill you. You never saw the Lone Ranger ever take off his mask did you? Let's just say I've been playing with my new XM toy in several major markets, one with only moderate blockage problems and two others with considerably more terrain and urban challenge. Its doing pretty doggone good, especially in the car. In the markets where the terrestrial repeaters are not yet established, inside reception only works near a
favorably facing window.

-- GW

Dear Guy,

As you, I do see AM as a bigger beneficiary of IBOC than FM. IBOC is nice, but it would have been really nice for it to have come along before satellite. If a consumer just invested in a satellite capable radio, why would they want to turn around and spend money to replace it again...just to get the same over consulted terrestrial programming digitally?

Guy Replies...

No question about it Greg. The next few years will be the great shakeout period for receivers. Only early adopters and fans of high tech are likely to pay the big bucks for single mode only receivers. WIth XM, Sirius, and iBiquity all using different transmission protocols, there won't be cross compatibility until some clever and resourceful company produces an affordable multi-mode model. My guess is the satellite boys will settle on a single company and platform before iBiquity gets rolling. Then we'll see receivers appear that can play both digital modes plus traditional AM/FM.

-- GW

Dear Guy,

Amen!

I remain unconvinced that digital--either IBOC or in a separate band, will be a significant improvement over a moderately processed, clean, FM signal.

I see the value of IBOC for AM, where any method of transmission that is immune to the all-pervasive electrical/computer noise will be a welcome improvement. Skywave reception is irrelevant--all those old line clear channels I used to listen to growing up in Ohio are either buried in the rumble of daytimers(who forgot to switch) or Cuban jammers.

"M Street" claimed someone is pushing for Channel 6 for DAB/radio. I would suspect a Eureka-type system would need about 2 TV channels to accommodate any significant number of channels, but this would cure a lot of problems they seem to be running into in Canada up in the centimeter bands.

However, the real, unspoken fear of many small U.S. broadcasters to any scheme to move FM to a digital signal in a new band is the FCC and Congress will put the band up for sale to the deepest pockets. Consider the fuss made in Washington about "giving away spectrum" to digital TV. The handwriting is on the wall--any scheme to open up a new band using Eureka or other digital technology would require all of us to pony up big dollars to protect our right to exist. End result will be a new band owned and operated by megamedia conglomerates.

So we are stuck with IBOC. What we need is a little blue light in the car radio that lights up and says "Digital" whenever it picks up a 57 KC subcarrier...

Tom Taggart
WVVW/WRRR-FM
St. Marys, WV

Guy Replies...

Dear Tom,

If the IBOC proponents are to be believed, the new IBOC FM medium will at best not only sound better (20 khz is so much better than 15 kHz....especially for the under 21 crowd and dogs), but will dramatically clean up annoying multipath. On the other hand, many others fear a much less robust and forgiving medium, with a higher incidence of drop-outs and interuptions, especially in fringe and shadowed areas and interference zones.

The truth is probably somewhere in between. We should know the answer next year when real world test results are finally released. There's no question about IBOC DAB dramatically improving the lot of AM listening. Achieving 15 khz stereo performance and break-through noise reduction will give AM virtual full parity with FM. The big sticks will benefit profoundly. Which signal would you rather have in a DAB world? WLS-FM which covers a radius of about 50 miles, or WLS-AM which covers much of six states (daytime) and half the country at night.

Forget Eureka making any headway here in the US. The mega groups and the NAB would never stand for it. Any plan which opens up a whole new band invites a whole new slew of competitiors. Notice how fast the CEMA MMDS plan of importing Eureka onto a few sparsely populated UHF TV channels went away. The Congress snuffed out that possiblilty almost before the plan got any real publicity.

-- GW

Dear Guy,

Gee, "Guy" you haven't coordinated with your esteemed (or is it half-baked) RW editor who thinks LPFM is better than home-delivered pizza. I agree with you about 85%. Of course this whole thing is political-- Bill Kennard realizes that under lame-duck Bill Clinton he will be a "Canard Morte" unless his patron Al Gore gets elected. LPFM is all about a phot-op for the VP at the sign-on next fall of a new 100 watter that's just been granted to (fill-in favorite minority group that votes Democratic).

As a practical matter, most of these LPFM's will be snapped up by the major religious broadcasters, operating through "prayer partners" or affiliated churches as the straw-man applicants. Who are these folks? Look who is applying for the majority of the translators these days. I am aware that the rules require a certain amount of locally produced and originated programing, but that could be gospel music loaded up on the hard disk and cranked out overnight. The rules don't say when this locally produced programing runs. Also, while an LPFM can't "translate" it can run "network" programing.

True, most open channels will be in rural areas and small cities, but I checked one web site that has a program, purportedly linked to the new rules, that indicated a 100 watter was available in suburban Columbus. (I used the coordinates of Otterbein College's WOBN, in Westerville). Columbus, is, I believe, the 34th market.

I suspect you are right about policing these stations. I remember an infamous Class A in NW Ohio that ran for years with a 10 KW transmitter into a 3 bay antenna (it was supposed to be 1 bay). I translated the minimum distance table into miles--for a class A these things could be 42 miles away co-channel, 35 miles away first adj. and 18 miles second adjacent. In hilly terrain like SE Ohio, a 100 watter 18 miles away on the second adjacent can put quite a hole in a Class A's audience. Unless the NAB gets a stay from the DC District Court of Appeals, I expect the Commission to go full speed ahead on taking applications as soon as they can. After all, the courts will be more reluctant to take action when the Commission has several thousand applications in the hopper.

Given the present level of incompetence at the Commssion, this will also mean that most other routine broadcast applications are on hold until after the election; since the mass media staff will be shunted over to process through the "favored" (e.g., politically correct) LPFM applicants.

Then again, once the FM band is destroyed, we can all switch to satellite DAB.

Doesn't Clear Cahnnel get an interest in one of those companies through its purchase of AM/FM? I suspect the government likes that better anyway. One programer is easier to control, and those big companies all have PAC's.

Tom Taggart
WVVW/WRRR-FM

Guy Wire responds:

The esteemed RW editor has his column and I have mine. He figures the more broadcasters there are, the more copies of RW can be sold and read. Canard Morte or not, I worry about killing the golden goose, and her too many eggs already in the nest. Why hatch a bunch of little ugly ducklings that'll just mess the nest up even more?

-- GW

Dear Guy,

You've GOT to be kidding! Any time I see the phrase "Grand Alliance" I positively CRINGE! Look at the DTV "joke" the TV "Grand Alliance" gave us. Another 40 or so years as the only country in the world with AM TELEVISION!!!

GW: It's still way too early in the game to write off DTV and the wisdom of the Grand Alliance. We all knew this conversion would take time and money. It's like changing the oil in thousands of cars while they're driving down the freeway at 60 mph. You've got to start somwhere with a carefully co-ordinated effort and timetable. A Grand Alliance for digital radio was desperately needed to avoid the kind of thing that happend to AM stereo.

This country will soon be the only country OUT of step insofar as DAB is concerned!! Know why? Simple. The 'big guys' (Clearchannel, CBS/Infinity, etc.) DON'T WANT DIGITAL RADIO!! They're quite happy with the monopoly they have NOW.

GW: If the US is so far out of step with the rest of the world on DAB, why is Eureka having such a hard time getting off the ground in Europe and Canada? The truth is, the rest of the world is waiting for US to pave the way for digital radio. The consuming public wants simple to use and affordable radios. Quality of the audio is really quite secondary. Content is King. Radio engineers like you who bitch about the lower quality of IBOC DAB versus Eureka just don't see the Big Picture and have never accepted this crucial point. "Entertainment quality" achieved by analog FM radio has been proven to be very acceptable for the vast majority of radio users. Yes AM needs help, but getting it out of the noise plagued analog domain with DAB will launch AM listening into a whole new renaissance for radio. IBOC DAB on existing channel allocations will allow the easiest and most cost effective transition into digital by far, for both the public and the broadcast industry.

Let's take a look at how behind our country is due to monopolies like this. First, If I recall, ISDN arrived in the U.S. about 15 years after it was commonplace in Europe. Our digital phone system (cellular, PCS, etc.) is years behind even the eastern bloc's. They have many more features and theirs works much better. France has had terminals on their phones over 10 years ago.

GW: When I travelled across Europe some years ago, the most memorable comment made by the locals was how bad their local phone service was and how superior the US phone system was, for those who had had the pleasure of using it. Yes a few countries had ISDN before us, but while it may have added a few user features and embellishments, it has yet to provide the universally simple, reliable, and available everywhere service that we have enjoyed in this country for many many decades. Sure, there are exceptions in areas of some of the more advanced countries like France and Germany. The rest of Europe and the world in general is woefully behind us, IMHO. Many of the "eastern bloc" countries you refer to have had the advantage of starting with brand new wireless infrastructures in comparatively very small geographically sized countries, where the old wired systems were merely ignored. Much of it continues to be provided by American companies using American technology.

Europe has had FM television for almost 25 years. Now, they're about to eclipse us with L-band DAB! When will we learn? When the government gets the 'balls' to make a decision and stick by it without bowing down to the lobbyists of the NAB! Look at AM stereo. The FCC adopted a perfectly usable system (Magnavox). The broadcasters whined: "let the marketplace decide", so they did. Where'd AM stereo wind up (and music on AM band with it)? In the DUMPSTER!

GW: AM stereo did not fail because Magnavox was replaced by Motorola. It failed for a host of other reasons, but mainly because FM had come into its own and sounded much better on all types of radios for the vast majority of listeners. Talk and all news radio is the only reason AM has survived at all.

Get with it, Guy....as long as big business is involved in decisions, they'll BE no decision...no innovation. They simply want to squeeze every last dime out of what they have until they are forced to change, kicking and screaming all the way!

-- Dana Puopolo

GW: Oh boy. Another brain-washed anti-business liberal. The NAB and all radio group owners very much want to embrace a digital future. Competition is clearly forcing the issue. But you want the government to make all the decisions without the input the broadcast business community? Without healthy businesses that make a profit there can be no sustainable marketplace where products can be invented, manufactured, marketed, and sold to consumers. New ideas and innovation will never be stifled in a free marketplace where plenty of competition insures more products at lower prices. If a new idea is truly worthy, the marketplace will quickly determine that. Econ 101.

Most all of the technological inventions and innovations which have launched the digital revolution were born and raised in this country. The rest of the world in general stands in envy of American ingenuity along with our economic and political structure, not to mention our broadcast industry. Why do you suppose so many countries write their constitutions modeled on ours? "Big" business has plenty of government imposed regulations to keep diversity and competition alive and well for a long long time.

-- GW

Dear Guy,

You've GOT to be kidding! Any time I see the phrase "Grand Alliance" I positively CRINGE! Look at the DTV "joke" the TV "Grand Alliance" gave us. Another 40 or so years as the only country in the world with AM TELEVISION!!!

GW: It's still way too early in the game to write off DTV and the wisdom of the Grand Alliance. We all knew this conversion would take time and money. It's like changing the oil in thousands of cars while they're driving down the freeway at 60 mph. You've got to start somwhere with a carefully co-ordinated effort and timetable. A Grand Alliance for digital radio was desperately needed to avoid the kind of thing that happend to AM stereo.

This country will soon be the only country OUT of step insofar as DAB is concerned!! Know why? Simple. The 'big guys' (Clearchannel, CBS/Infinity, etc.) DON'T WANT DIGITAL RADIO!! They're quite happy with the monopoly they have NOW.

GW: If the US is so far out of step with the rest of the world on DAB, why is Eureka having such a hard time getting off the ground in Europe and Canada? The truth is, the rest of the world is waiting for US to pave the way for digital radio. The consuming public wants simple to use and affordable radios. Quality of the audio is really quite secondary. Content is King. Radio engineers like you who bitch about the lower quality of IBOC DAB versus Eureka just don't see the Big Picture and have never accepted this crucial point. "Entertainment quality" achieved by analog FM radio has been proven to be very acceptable for the vast majority of radio users. Yes AM needs help, but getting it out of the noise plagued analog domain with DAB will launch AM listening into a whole new renaissance for radio. IBOC DAB on existing channel allocations will allow the easiest and most cost effective transition into digital by far, for both the public and the broadcast industry.

Let's take a look at how behind our country is due to monopolies like this. First, If I recall, ISDN arrived in the U.S. about 15 years after it was commonplace in Europe. Our digital phone system (cellular, PCS, etc.) is years behind even the eastern bloc's. They have many more features and theirs works much better. France has had terminals on their phones over 10 years ago.

GW: When I travelled across Europe some years ago, the most memorable comment made by the locals was how bad their local phone service was and how superior the US phone system was, for those who had had the pleasure of using it. Yes a few countries had ISDN before us, but while it may have added a few user features and embellishments, it has yet to provide the universally simple, reliable, and available everywhere service that we have enjoyed in this country for many many decades. Sure, there are exceptions in areas of some of the more advanced countries like France and Germany. The rest of Europe and the world in general is woefully behind us, IMHO. Many of the "eastern bloc" countries you refer to have had the advantage of starting with brand new wireless infrastructures in comparatively very small geographically sized countries, where the old wired systems were merely ignored. Much of it continues to be provided by American companies using American technology.

Europe has had FM television for almost 25 years. Now, they're about to eclipse us with L-band DAB! When will we learn? When the government gets the 'balls' to make a decision and stick by it without bowing down to the lobbyists of the NAB! Look at AM stereo. The FCC adopted a perfectly usable system (Magnavox). The broadcasters whined: "let the marketplace decide", so they did. Where'd AM stereo wind up (and music on AM band with it)? In the DUMPSTER!

GW: AM stereo did not fail because Magnavox was replaced by Motorola. It failed for a host of other reasons, but mainly because FM had come into its own and sounded much better on all types of radios for the vast majority of listeners. Talk and all news radio is the only reason AM has survived at all.

Get with it, Guy....as long as big business is involved in decisions, they'll BE no decision...no innovation. They simply want to squeeze every last dime out of what they have until they are forced to change, kicking and screaming all the way!

-- Dana Puopolo

GW: Oh boy. Another brain-washed anti-business liberal. The NAB and all radio group owners very much want to embrace a digital future. Competition is clearly forcing the issue. But you want the government to make all the decisions without the input the broadcast business community? Without healthy businesses that make a profit there can be no sustainable marketplace where products can be invented, manufactured, marketed, and sold to consumers. New ideas and innovation will never be stifled in a free marketplace where plenty of competition insures more products at lower prices. If a new idea is truly worthy, the marketplace will quickly determine that. Econ 101.

Most all of the technological inventions and innovations which have launched the digital revolution were born and raised in this country. The rest of the world in general stands in envy of American ingenuity along with our economic and political structure, not to mention our broadcast industry. Why do you suppose so many countries write their constitutions modeled on ours? "Big" business has plenty of government imposed regulations to keep diversity and competition alive and well for a long long time.

-- GW

Dear Guy,

I was beginning to think no-one else read your column, but now your mailbag is full. I am replying not to your comments but to the comments about your IBOC comments.

Eureka-based DAB in the L-band was conceived, I am sure, as the response of the government run broadcasters (In Germany, these are run primarily by the Lander , or states, instead of the Gederal government) to the growth of private broadcasters. L-band bears some resemblence to cellular telephone, in that each transmitter carries a (finite) number of channels, but is designed to cover only a small area.

I have traveled in Europe, too, and for an Ohioan it is always enlightening on how small and close together the European countries are, and how densely populated many countries are. For example, the city of Berlin, supposedly one of the largest cities in area in Europe, has 3.4 million people in an area (about 345 sq. miles) smaller than Franklin County (Columbus) Ohio. Outside of the beltway in Berlin--you're in the country, outside the beltway in Columbus and--you are in Delaware County,where everyone who works in Columbus lives. For that matter, the former "states" of East Germany (including Berlin) are the same size as Ohio, but with 5 million more people.

Hence, limited coverage L-Band can work quite well over such a small densely populated, areas. The same is true for the rest of Germany, Switzerland, northern France, and the Benelux.

I just put on a new station that is 90 miles from where I live. Look at the Benelux countries, where a trip of 75 to 100 miles can not only take you out of one country into another but also into a different dialect area. The new Church of Christ minister in little St. Marys WV is from a town near Brugge, Belgium, right on the language divide. He's trilingual--but one can see that there would not be