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Tech Notes

Published by: Larry Bloomfield & Jim Mendrala

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December 9, 1999

Tech Note - 046


Talent does what it can, but genius does what it must!

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Subj: Tech Note #045 - Increasing Optical Media Densities

Feed back from: Garry Margolis, Director, Technology Liaison, Philips Entertainment Group

CD-Audio discs will not change sampling rates or bit depths, because any such change would be incompatible with the upwards of 600 million CD players in the field.

There are two new next-generation audio formats, which will provide high resolution and multichannel, audio: Super Audio CD and DVD-Audio.

Super Audio CD has been developed by Philips and Sony and provides the capability of a CD-Audio layer as well as a high-resolution layer with separate two-channel and six-channel program areas. SACD utilizes Direct Stream Digital encoding, a delta-sigma one-bit digital signal operating at 2.8224 megabits/second/channel. Lossless data packing developed by Philips can be used to increase the storage efficiency by factors greater than 2:1, depending on the characteristics of the program material.

Two-channel SACD players and discs are now on the market; Philips has announced the release of multichannel players and discs in the second half of next year. The Philips players will also handle DVD-Video and DVD-Audio (see below) discs.

DVD-Audio is an extension of the DVD-Video specification and has been developed by Working Group 4 of the DVD Forum. It can contain up to six channels of full-bandwidth audio in PCM format, with sampling rates of up to 192 kilobits/second (two-channel only) or 96 kilobits/second (up to six channels) with bit depths of up to 24 bits. It does not allow backward compatibility with existing CD players, as it does not

contain a CD-Audio layer. Lossless data packing developed by Meridien is part of the standard to allow increased playing time.

No DVD-Audio players or discs are currently available. The last announced ship date is after the first of next year. The Matsushita players announced last September will play both DVD-Video and DVD-Audio discs -- it will reproduce the CD-Audio layer of an SACD, but not the high-resolution layer.

Hageman said: "I realize that if they change the CD technology it would not be compatible with all CD layers already in the field. When color TV came out one of the requirements was that it was compatible with the black & white system, so all those people could still use their old sets. The CD technology is not really compatible with that restriction. It would be nice if it was."

Margolis: That's exactly the point of the hybrid capability of Super Audio CD. The same disc can play in any existing CD player and in a next-generation player.

A blue laser is used for recording a DVD master. It is not necessary, fortunately, to have a blue laser for playback, because it is very expensive and has a short

life. The required laser for reading a DVD has a shorter wavelength than the one used for CD.

Garry Margolis


Subj: Tech Note #045 - Increasing Optical Media Densities

Feed back from: BILL HOGAN - Sprocket Digital -

The information contained in the article is totally wrong.

Hageman: Well, as you know the DVD was made possible by the blue laser diode.

Hogan: No, As I know and most of the world knows the DVD does not use a blue laser diode. It uses a slightly different wavelength red diode for the DVD read out. Some high-end DVD players that of course also read CDs use a different diode for the read out of CDs. This two-diode approach optimizes the reflectivity of the different CD and DVD reflectivity.  This helps when reading CDR and CDRW disks.

Hageman: An application of this technology and as a side note, when are they going to increase the sampling rate on audio CD's? 44.1KHz is not fast enough to properly reproduce the complex harmonics generated by classical, jazz, and other music styles.

Hogan: I guess he has had his head somewhere because it seems that he has not heard of DVD-Audio or Sony/Philips SCCD. The DVD-A allows sampling up to 192

kHz and also at 92 kHz. Also at 88.2 kHz. This should be high enough for the dog whistles to be recorded.  The Sony/Philips system is a one-bit system that samples and records at many megahertz-sampling rate.

Best Regards, Bill Hogan


Subj: Tech Note #045 - Increasing Optical Media Densities

Feed back from the author: Kurt Hageman -

I was not aware of the new CD technology. That is good, but I was hoping for an even higher sampling rate than 192KHz. Is not the 1 bit system he is talking about basically a single-slope A to D converter? If so, is the ramp actually at several

MHz? Let me know, I am interested. (Please respond directly to Hageman)

  The DVD issue, how are they able to pack all the data in that tight of space. What then is the limiting factor in data density? I did read about the use of blue laser diodes in the DVD field. DVD is still aluminum flashed on the Lexan disk with the bit

pattern on it and then laminated. I have watched this first hand at Ron's CD-DVD factory in Hollywood.

I am talking to Garry; he is straightening me out. Blue lasers are for recording DVD's only. I thought they were needed for playing too. Ron has them in his new CD-DVD factory he just built in Hollywood. Below is what Garry sent me back.

I am not completely wrong on this. I got this statement from the following web site.

Optical storage is touted to be the application for blue laser diodes due to the shorter wavelength of the light. The storage density for optical storage devices can be raised by a factor of about two or four compared to the commercially available red or infrared

laser diodes, respectively (High Density CD-ROMs, holographic storage devices). In home-entertainment systems it will be possible to store a movie in high-resolution HDTV quality together with several audio-channels in HiFi-stereo and digital surround

sound on a small HD-CD (DVD). Multimedia applications such as interactive databases or video-animated computer games would also be greatly enhanced.

I am not completely screwed up.

Blue diode lasers have very short wavelengths, which means that they can be used to pack data more densely than red lasers, in storage media such as CDs.

A blue laser, the key component needed to jump the capacity in various fields, is essential for next-generation disk systems that can store high-definition movies and a mandatory light source for high-resolution printers and large-capacity optical communications

Well, I have learned something too. Also apparently the limiting factor still relates to the wavelength of the light. I thought blue light was used in the playback process. I was wrong but that's OK I have been wrong before.



Subj: DOD Video Working Group Recommends Public Debate on Digital Modulation Systems

From: a press release dated: November 29th, 1999

The Chairman of the Department of Defense /Intelligence Community / United States Imagery and Geospatial Services (DOD/IC/USIGS) Video Working Group (VWG) has raised concerns about potential problems with the "8VSB" digital television modulation standard mandated in the FCC "Fourth Report and Order." The VWG

Chairman requested that the FCC consider conducting open, public debate on the question of continued use of the 8VSB-modulation standard. The FCC was also

requested to consider an additional digital modulation system known as COFDM be allowed for use in the United States.

The Chairman of the VWG has concerns about our national capability to employ digital television broadcast systems to communicate with the public during civil and defense emergencies. There is growing evidence that digital television receivers using 8VSB may require large, highly directional, outdoor antennas for adequate signal reception. Large outdoor 8VSB antennas may be the first things destroyed in adverse weather conditions, natural disasters, or other hostile propagation environments.

The COFDM digital modulation system appears to be a robust modulation system, which would significantly improve the ability to guarantee reception in routine and national emergency environments. It has been implemented by a majority of other countries around the world and provides digital television broadcast capability, including the ability to use small, portable and mobile antennas.

It is a fundamental DOD mission to provide domestic support in times of national emergency (such as natural disasters, and National Security incidents). The existing US analog NTSC transmission system currently has the ability to operate in poor signal conditions.

The VWG Chairman said that technical improvements have been recently announced to improve 8VSB receiver designs. Any such improvements are welcome and encouraged. Improved 8VSB receivers should be fairly evaluated as part of the proposed open, public debate.

The Department of Defense/Intelligence Community/United States Imagery and Geospatial Services (DOD/IC/USIGS) Video Working Group (VWG) was chartered to establish video imagery and related standards for the DOD, the IC and the USIGS.


Subj: Update on FCC deliberations

From: Mark E. Hyman, VP Corporate Relations - Sinclair Broadcast Group

We completed a second round of visits at the FCC regarding the DTV modulation standard. The meetings went very well. Commissioners and staff have been very receptive and engaged on this issue. While I am certain no one at the Portals is overjoyed that a significant problem with the ATSC standard has been identified, it is what it is, and they realize it must be addressed. They also realize that a solution is at hand.

The Commission must still place the broadcaster's petition on public notice for comment. Very small minorities of groups with financial interests in 8VSB and/or the status quo have lobbied against placing the petition on public notice. However, several hundred stations have filed in favor of the petition and a few hundred more have taken the public position that the DTV modulation standard warrants further review. If you and your organization are uncertain of your position, but believe that this matter is deserving of public scrutiny, then I urge you to immediately notify the FCC that you support a public comment period. It is only then that the hallway discussions and the secret-handshake meetings will end and all parties will have to "put their cards on the table," go on the public record and back up their claims with technical data and hard facts.  We have been in contact with various groups, which are awaiting public notice before they file comments on this matter. Unfortunately, there are some groups with self-interests that are not aligned with free, over-the-air broadcasting that would prefer to have this matter swept under the rug.

As one Commissioner told us, "You deserve your day in court and for that reason I will vote to place your petition on public notice." We believe this is the proper approach, as NO ONE WANTS THIS MATTER DECIDED IN THE COURTS OR IN CONGRESS.

A few more groups have recently gone on the record in support of the petition with more to come.  Broadcasters are realizing that it is time we reclaim the leadership of broadcasting's future and not leave it to trade associations not aligned with our best

interests, Washington lobbyists who oppose our industry and a minority of manufacturers whose entire future is invested in a single product that does not work.

Thank you. Mark E. Hyman


Subj: Tech Note #045 - E-cinema maybe not

Feed back from: Peter Krieg former Dir. of the Babelsberg High Tech Center a digital film and production center outside of Berlin.

I am afraid Larry Bloomfield is wrong. 35 mm film camera negative in 16:9 aspect ratio is considered the equivalent of 4.096 pixel (4K) vertical resolution (equivalent because film is analog and has no pixel structure like digital media). Once this camera film is copied to Interneg and finally to exhibition print stock, resolution has dropped to about 2 K in the cinema. Tests have shown that for practical purposes 2

K in a digitally generated image is absolutely equivalent to the analog camera original. This is the reason why all CGI for 35 mm today is done at 2 K vertical resolution. (for compositing life action footage with CGI the camera neg. is scanned at 2K and later recorded back to film at the same resolution. 4K scanning is only used for Imax and 65mm (70mm exhibition format) film.

So in fact we are comparing a 2,048 by 1,152 (16:9) film standard with a 1,920 x 1,080 HDTV digital cinema standard.

If you consider that digital film has no jitter like a projected film, no grain, dust, dirt or scratches, you can expect the quality of the digital cinema image superior to the eye of the viewer than the projected film image. The key here is the projector and the

problems of digital projectors are not so much resolution (this will "grow naturally" with better chips and technologies currently evolving) but rather with contrast. Contrast ratio in film is between 1:6,000 - 1:10,000, while contrast in digital high-end

projection is just entering the 1:1,000 range. (office video projectors currently are between 1:100 and 1:300) I personally consider a projector that does 1,920 by 1,080 resolution at 1:2000 contrast ration as absolutely fit for digital cinema.

footnote: George Lucas has included secretly (so the tale goes) some 1,920 vertical resolution digital images into Phantom Menace, using the prototype Sony 24p camera. None of the critics noticed or complained.

Best- Peter Krieg can be reached in Berlin Germany.


Response: The information was gotten from Kodak out of the SMPTE Journal, Nov. 1999, page 753, as stated, so "they" must be wrong. I did convert the pixel equivalent to the aspect ratio that is nominal for wide screen. Jim Mendrala, our resident expert in E-cinema will be responding to this in our next issue. Larry


Subj: Translators and other DTV anomalies that have not been addressed.

From: (John J. Webber)

The opinions expressed here are strictly my own and do not reflect the opinions of KTVQ Communications, Inc., and probably won't sit well with a few others either,

but here goes!


As we discussed, our interconnect between stations all around Montana (Billings, Bozeman, Butte, Great Falls, Missoula, Kalispell) is nearly all 7 GHz and all long

paths. The longest is over 100 miles, most are over 70 miles. The speculation on the robustness of digital microwave runs from "it won't work past 30 miles" to the over-water 130 mile frequency/space diversity experiment in Hawaii. We'll see, but the wait makes for difficult long-term planning.


CBS does not provide a Mountain Time zone feed, so we have to do it ourselves. Will they provide a DTV time shift? If not, and because our interconnect is unlikely to successfully pass digital, each station will have to invest in a DTV delay system of some kind. OK, maybe a server will provide a 1-hour delay, but what about one-day, 3-day, and one-week turnarounds for syndicated programs? You're starting to talk about some serious storage, and serious cash. ...for each station...


Each of our stations has to lay out money for a digital system of some kind. An $800K transmitter costs the same in Billings as it does in New York. The difference is that $800K in New York is some fraction of the annual capital expense allotted, and a small fraction of annual cash flow. Here in Billings (or other small markets), that total represents the entire annual capital allocation for several years, it

represents a SUBSTANTIAL percentage of annual cash flow, and all you have is the transmitter. That's no microwave replacement, no studio equipment, no tower

and antenna, no field gear. That's a bunch of cash, which many small market television stations will be unlikely to produce. The result? I expect many stations to go dark because they simply can't afford DTV. The survivors may be able to siphon off the dark stations' network contracts and multicast or cherry-pick them. So much for minority and female ownership. The big will just get bigger. How will FCC's Mr. Kennard counter this problem of ownership concentration....a low-power TV initiative like his ill-conceived low-power FM project?


I'm going to quote you some figures supplied by Nielsen (Nov 1998) for the Billings television market:

Market Ranking - 169

DMA Counties - 18

Cable Penetration - 54%

Metro Households (served directly by our transmitter,

or by microwave to cable

headend) - 49,760

Total Viewing Area Households - 105,720 (end of quote)

Now, you do the math: total viewing area households minus Metro households roughly equals the number of households served by translators, either by the viewer

having his own aluminum up in the air, or by the local cable headend carrying a translator signal to distribute KTVQ. My TI-30 says it's about 55,960 households (around 53%) that we will not cover with DTV because of the inability of existing microwave to carry a DTV signal, and because there are no provisions in the DTV scheme for translators. Unless translator/microwave provisions change, we will

definitely and completely lose these households if and when NTSC goes away.


Fox and NBC have demonstrated clearly and startlingly that the old order.... network delivery to local affiliate.... is a concept undergoing relentless attack. Have you ever wondered why the networks have been conspicuous by their silence on revisions to the Satellite Home Viewer Act? It's simple: their goal is to have eyeballs, by any means. Whether it's through my transmitter or through EchoStar's satellite is immaterial to them. For now, local stations have to live with reduced network compensation, then zero network compensation, and finally, paying the network

for programming and services that are no longer exclusive to the local affiliate. Throw in the expense of DTV, and you'll see a lot of local television go down for the count.


From my isolated vantagepoint, the whole DTV issue looks driven by flatlanders who believe real mountains and deep valleys exist only in fairytales, in Tibet, and on post cards. No, the world is not all like what's inside the Beltway, geographically or otherwise, and if those folks on the inside think Pennsylvania is a big state, reflect carefully on the fact that you can park two Pennsylvanias inside Montana, leaving room for several national parks. We can hide a number of New England states within the borders of some counties out here!

The DTV issue is also driven by the egos of people who want to leave a lasting mark on broadcasting, preferably with their names etched on the same marquee as Colonel Armstrong for FM and David Sarnoff for television They are using DTV to achieve that goal.

We're having DTV crammed down our throats by electronics concerns trying to generate revenue streams through legislative obsolescence of video and RF equipment. Why not the same transmission standard as used in Europe? Corporate welfare for US industries. (So explain why Kathrein, a German outfit, got the DTV antenna contract in Salt Lake City over Harris and other US firms?) Perhaps the most lame-brained of all, Congress thinks DTV is a good idea because they expect to reap $500-billion off sales of the old analog spectrum, and to use that cash to balance the federal budget. What constipated Congressional (or Administration) accountant worked that one out with a pencil?

The DTV issue is NOT being driven by the one segment that counts.... The consumer. Save for the few "golden eyes" out there, for which money is no object, there is no clamor by the public for this stuff. Yeh, they may see the PBS HDTV transponder in their local high-end television store and maybe come away impressed (especially with the cost), and what?  Obviously, very few outside the industry can see the stepped gradations in existing DTH video, or we'd have heard about it plenty by now. Why would these people suddenly find themselves conducting a high-definition feeding frenzy if the only real difference their untrained eyes can observe is a 16:9 aspect ratio?  People just want to watch clean pictures with no snow or ghosts and hear sound (stereo, thank you very much) and be entertained or informed. Technology has not and never will make good television... that's the job of content providers.

DTV proponents continually point to the development of color television as their model for the rate of public acceptance of DTV. Their model is without merit; my grandmother's 1956-vintage tube-type television set will still receive KTVQ just fine today, in monochrome. My own 1996-model RCA color set will never ecode DTV. There is no upgrade path here, no downward compatibility, and only complete system replacement.  And forget set-top box technology as a migration route, unless the box allows the user to completely control the set, including channel AND audio level, from a SINGLE remote control (read, "stereo modulator" with gain control, full interactivity, closed captioning, etc.), just like the DirecTV boxes, AND sell for under $100.

The current Satellite Home Viewer Act problems we are all suffering through point out just what the consumer wants:

1. Consumers do not want antennas on their roofs. To the consumer they look bad; they are a hazard to install, frightening to maintain, and one more thing to keep out of the neighbors' yards in windstorms.  

2. Serious (and real) safety issues and potential liability concerns arise in my mind when I deny a satellite waiver for someone who has no experience installing or maintaining antenna systems.  

3. 18-inch satellite dishes are sexy, they're status symbols, and expressly permitted in any zoning or covenant I've seen to date. (Never mind they are protected by Section 1.4000, along with television antennas...)

4. DTH penetration in Montana as of mid- 1999 was over 33%, versus 10.90% for the total US as of November 1998. Montana's DTH penetration is the highest in the nation. In the Billings DMA, satellite penetration in May 1996 was 8.81%. In November 1998 we were up to 17.63% (Nielsen Station Index). For Missoula, MT,

14.24% in May '96, up to 26.97% in November '98. For Butte-Bozeman, MT, May '96 was 16.67%, up to 25.38% in November '98. What do you suppose happened to these numbers in the past year? Can anybody see a trend here?

In this environment, how is terrestrial DTV going to make a dent? How are consumers going to be convinced to dump a pile of money on a new television set (in

whatever form), install an antenna on their roof, and make advertisers happy? Great programming? Nope.. too many other outlets for that. Answer.. it ain't gonna happen. How am I, a small-market television station, ever going to recoup the cost of the DTV transmission system I'm forced to have on the air by mid-2002? I'm not going to get any more eyeballs with it... in fact, I stand to eventually lose half of my present audience altogether because of the current NON-plan for DTV translator service. At best, I'll simply fragment my existing analog audience. Start broadcasting digital

data services? Maybe, but Senator McCain (and others) believe broadcasters were handed "free" spectrum, and by God, we had better show our gratitude by broadcasting high definition programming, or else Congress will personally see to it that we do. So much for wideband Datacasting in prime time. It's pretty tough to be a

profitable data carrier under those conditions; in data/internet/etc., if you're not ALWAYS there, you're not there at all.


I believe that as NTSC goes, so goes terrestrial free over-the-air broadcasting, and DTV has no hope whatever of succeeding unless the following conditions are met:

1. DTV sets of reasonable size (equivalent to 27" sets today, NOT set-top

boxes) sell for under $500.

2. A single digital transmission standard is adopted.

3. Cable systems, willingly or otherwise, carry DTV.

4. DTH also goes fully and compatibly DTV. Even then, the odds for success don't look good.

Eventually, I believe there will be a lot of mountaintop real estate for sale that once was the home of high-power television transmitter and translator sites. We television stations will still be

here (at least some of us that survive the DTV buildout few consumers will watch), we'll still be in the entertainment, news, and advertising business, but the delivery system will be DTH. Free over-the-air television, if it exists, will be a gaunt shadow of

its former self, serving very few. There are too many looming RF spectrum issues, power consumption and operating costs, audience fragmentation problems,

irrational radiation scares, zoning difficulties (Denver and San Francisco come to mind), loss of skilled technical talent (read, "RF and antenna") to jobs that pay better and provide better working conditions, and other resource issues to allow the

current system to go on forever.

The miracle of technology the DTV proponents believe and pray will rescue their problem child from oblivion (like, the next generation of decoder ships, or the latest forward error correction scheme) is the same technology miracle that will make DTV obsolete before it takes firm root: Technology will resolve Local-to-Local satellite capacity, and we who survive the DTV buildout will have shut off our transmitters

because we will be on satellite. And don't talk to me about serving the poor who can't afford satellite dishes... A precedent has been set for this in the form of minimum telephone service and minimum cable service price tiers. The same will happen with DTH, mandated by law if necessary. I've dealt with too many waiver requests from self-professed old-retired-on-fixed-income-can't-afford-a-rooftop-antenna-and-I'm-crippled folks who somehow are able to subscribe to DTH, and are damned upset that I won't grant them waivers to watch the East Coast network feeds so that they can get to bed by 8PM!

DTV has an ominous resonance with that 1980's train wreck, AM Stereo. No single transmission standard was decreed in the end for AM Stereo. (Sound familiar?) AM

broadcasting continued to lose market share not just because of its inferior performance compared to FM, but because programming sucked! At least AM Stereo was downward compatible with 1955 Studebaker radios.

Not DTV. It's still a non-compatible over-the-air transmission pipe dream, and it will never measure up to the performance of satellite or (some) cable-delivered video, except when you're close enough to the DTV transmission antenna to hit it with a rock.  Some would also hold that network television programming sucks today. All the more reason to pay close attention to the lessons of AM Stereo.

Montana is rural, without a doubt. I grew up 50 miles from Billings watching skip interfere with Channel 2, but I was used to it and didn't mind it too much at the time. One waiver requester recently called this "country television". Today, everyone on the

continent can retrieve sparkling clean pictures with a very small, rugged, unobtrusive and inexpensive antenna. Rain fade or an occasional wet snow is about the only thing to cause a problem for these systems. I'm afraid the genie is out of the bottle... Pandora's box is open... they've tasted the good clean stuff off satellite and VHS and DVD, and will never again settle for marginal television performance. I am one of those who won't. I suspect the same is true in metropolitan areas as well. DTV is dead at the gate, and over-the-air television's future is no longer endless, no matter what happens to DTV.

To quote a recent country song, "That's my story, and I'm sticking to it".

John Webber - Chief Engineer KTVQ TV


(Ed Note: The Editors and Publishers of the Tech Notes wish to thank Des Chaskelson, Research Director of SCRI International for his generosity in posting the Tech Notes on the SCRI web site.

Subject: FREE HDTV Report for US TV Station

From: Des Chaskelson , Research Director, SCRI International

The following report is available FREE to US TV Stations only who respond to SCRI's new HDTV online survey at:

<<< >>>

On completion of the survey, you will receive via email "The Millennium Report - The Migration To Digital Television," an 80 page report compiled by Larry Bloomfield, publisher of DTV Tech Notes and writer for Broadcast Engineering Magazine.  Results of the survey will again be published in Broadcast Engineering Magazine.


The Tech Notes are published for broadcast professionals, and others, who are interested in DTV, HDTV, Electronic Cinema, etc., by Larry Bloomfield and Jim Mendrala. We can be reached by either e-mail or land lines (408) 778-3412, (661) 294-1049 or fax at (419) 710-1913 or (419) 793-8340. (Please note Larry's new e-mail address). The Tech Notes are sent (BCC) directly only to those who have asked to be on the mailing list, however feel free to forward them, intact, to anyone who you think might be interested.  There is no charge for this Newsletter, no one gets paid (sigh), there is no advertising and we do not indorse any product or service(s). The ideas and opinions are those of the individual authors. We still administer everything manually. We don't use any "majordomo" automatic servers. News items, comments, observations, opinions, etc. are encouraged and always welcome. We publish when there is something to share. Material may be edited for brevity, but usually not. Tech Note articles may be reproduced in any form provided they are unaltered and credit is given to both Tech Notes and the originating authors, when named. If they are to be used by a publication that normally compensates their writers, please contact us first.