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Tech Notes

Published by: Larry Bloomfield & Jim Mendrala

E-mail = or

November 2, 1999

Tech Note - 043


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

Our Mission: Sharing experiences, knowledge, observations, concerns, opinions or anything else relating to Electronic Cinema, DTV, etc., with fellow engineers and readers. We do hope that everyone will participate with comments, experiences, questions and/or answers.  Please note Jim Mendrala's new E-mail address. Phone numbers and other stuff that used to be up here is now at the end of this newsletter. We now have over 500 subscribers & growing.                  This is YOUR forum! 

                                   Past issues are available at: WWW.SCRI.COM


Subj:  Reader Feedback


From:   Dianne Edwards - BARCO Communication Systems --


I come from the Newspaper industry....UPI not being available amazed me since I remember pulling off stories from AP and UPI years (obviously) years ago.....I hadn't heard this, so thanks for the update....Wow, the news reporting business has really changed, hasn't it?



To Tech Notes:   I didn't get the Tech Note, only a nearly empty text file (it contained "T", nothing else).  Could you resend it to me please?

Also, I have been participating in trying to help breath life into a web based HDTV Forum to exchange information with those interested in the topic.  It is located at  Pay it a visit and give me any suggestions you might have.  Also, would you be willing to promote it in an upcoming Tech Notes?

Thanks, Lee A. Wood, Director of Engineering -- KOIN-TV -- Portland, OR  97201


(Ed Note:  If anyone else is having problems, please advise.)


Subj:  Second Wave of DTV stations coming on line, maybe.

By:     Larry Bloomfield

With only a few days remain for the 80 stations in the second wave to be on the air by November 1st only a hand full will make it, according to an FCC status report.  28 affiliates of the four major TV networks are requesting extension in an effort to resolve their individual problems.  At least these stations had the insight to file for their construction permits (CP), but most have asked for extensions until May 1, 2000 to get things done and begin broadcasting in digital.  One factor is in the international arena.  A number of these stations need to coordinate their activities with the Canadian and Mexican governments.  Again, according to the FCC, eleven of these second wave stations are on the air with their digital broadcasts. 

Reasons for the delays range everywhere from tower site problems, equipment deliveries, to, in some case, petitions to change their DTV channel allocation. 

The markets No. 11 through No. 30 markets slated to come on line are: Houston, Seattle-Tacoma, Cleveland, Minneapolis-St.  Paul, Tampa-St. Petersburg, Miami-Ft. Lauderdale, Phoenix, Denver, Pittsburgh, Sacramento-Stockton-Modesto, St. Louis, Orlando-Daytona Beach-Melbourne, Baltimore, Portland, Indianapolis, San Diego, Hartford-New Haven, Charlotte, Raleigh-Durham and Cincinnati.  Digital TV stations are on the air in Houston, Cleveland, Miami, Pittsburgh, Indianapolis, Hartford, Charlotte and Cincinnati. 


But this is not where the biggest concern lays.  Here it is the last few days in October.  There are a total of 1599 "full-power" television stations serving these United States.  Broken down, that's 1229 commercial and 370 non-commercial stations.  Discounting the affiliates of the four major networks in the top 30 markets who should all be on by Nov. 1st or have extensions (total of 120), that leaves 1109 full power stations that must have on file by November 1st a construction permit.  With 23 of the 24 stations in the nation's top 10 markets that volunteered to be on the air by last November, who are transmitting digitally, that still leaves nearly a thousand who will have had to file for their CPs by November 1st.  It should be noted that eight of the 40 stations in the 10 largest TV markets required to be on the air by May 1 have sought extensions until 2000.  According to the latest info from the FCC only about half of the remaining stations who need to do something in the way of filing for their CB had done NOTHING!!!!!!

It’s no secret that the launch of DTV here in the US has been anything but smooth, with nearly a fourth of all stations as signatures to the Sinclair Broadcast Group’s petition to the FCC to reopen the US terrestrial standard in hopes of changing or broadening the vestigial sideband transmission spec or giving broadcasters options to use other proven modulation techniques.  NxtWave and Motorola say they have the solution to the multipath problems with their new chip sets, which address, they say, these issues and will solve ghosting and other reception problems.  This has yet to be demonstrated.

It seems like the industry is fighting the move to digital, in a number of instances, by either ignoring it or putting little or no effort into it, while others are putting forth a Herculean effort.   Broadcasters are programming the “good stuff,” in most cases, in time slots long after consumers can go to a TV store to see them.  Case in point is the Tonight Show and many of the primetime fair on CBS and ABC.  And what’s with FOX?  Good morning FOX, are you folks taking part in any of this HDTV stuff?  I think there should also be a law that prohibits anyone form running any one of those stupid two to three hour tape loop of the same thing over and over.  If you wan to sell HDTV to the consumer, don’t ever let them watch anything that’s been up converted.  That has got to be one of the greatest disservices we could do to them.  All these things considered, it’s not hard to understand why set makers are also complaining about a lack of digital broadcasts needed to spur sales and lower receiver costs.


Subj:  The Zenith 8VSB Modulator

By:     Roy Trumbull – (ED Note:  Roy Trumbull is the Assistant Chief Engineer at KRON in San Francisco and their transmitter supervisor)

The Zenith Modulator is being used by those transmitter manufacturers who decided not to re-invent the wheel by building their own. My understanding is that in future years some of the companies will actually manufacturer the modulator under license to Zenith.


The modulator is a rack-mounted unit with horizontal plug in cards. It takes a SMPTE 310M input and can use an external 10 mHz reference. The output is at 45 MHz IF and typically goes to the transmitter manufacturer’s upconverter. If a 10 MHz reference is used it must be supplied both to the Zenith and the upconverter. The Zenith has an RS232 port.


The HP 89441 Vector Signal Analyzer has a GPIB port that is connected to a GPIB card in the user’s computer. The Zenith modulator’s RS232 port is connected to Com 1. Zenith supplies a CDROM disk that contains a program to use for generating correction files.


The program typically should be used with a sample from the output of the mask filter. The program has three user functions. One configures the HP VSA to act as either an 8VSB monitor or a spectrum analyzer. The 8VSB monitor can be activated with a variety of equalizer taps to simulate how a receiver will respond to the signal.


The linear correction program calibrates the HP VSA and uses signal error data to generate a graph and a numeric indication of EVM (error vector magnitude) or S/N. It then iterates correction values giving you better and better numbers. When the values get to the point where they are simply varying within a small range, you click on the converge button and the correction file is completed and stored in the Zenith.


The last function is the nonlinear correction. It creates a correction file that mainly works to correct for those distortions produced by the transmitter. It takes a few minutes to auto-range the input signal and activate and converge the VSA equalizer before gathering data. It then generates corrections and stores them in memory. The user must initiate moving that file to nonvolatile memory. That move takes about 5 minutes.


The linear correction mostly effects the flatness of response within the channel. The nonlinear correction extends the skirts. The software does it all. There are no pots to tweak or coils to tune.


How successful the program is, is highly dependant on the linearity of the driver and the match between the driver and the IOT. In transmitters using the EEV IOT there is a double-slugged tuner between the driver and the IOT input. Its position impacts the match, the flatness and the skirts. Using the Zenith monitoring program to put the VSA in spectrum analyzer mode, you can observe that the position of the slug assembly effects signal flatness. The position between the slugs adjusts the balance of the skirts, and any change at all will impact the match. Heck of a balancing act. If you get it right, the linear correction will just gallop along and resolve to a low EVM within a few minutes. If you have it wrong, it will take a long time to see much improvement and the final value won’t be all that great.

My experience has been that once corrections are generated that they remain stable for weeks. There really isn’t any reason to continually redo corrections in a stable system.


Subj:  Cable Labs - A Ray of Hope   

By:    Larry Bloomfield


Television broadcasters have been moving into the digital television arena with considerable caution and trepidation as alarmists and soothsayers predict any number of not so positive scenarios.  Remember, according CEMA, about eighty percent of Americans get their television service via cable and reports have it that little has been accomplished to establish standards.  With a July 1, 2000, deadline established by the FCC and not knowing when the cable television industry will get their collective acts together, its no wonder that broadcasters can only hope the efforts of "OpenCable," the CableLabs-managed project in the Denver suburb of Louisville, Colorado, will be successful in meeting the deadline. 


CableLabs spokesperson Mike Schwartz is not the least bit hesitant in talking about who his organization is or what they do.  Schwartz says: "OpenCable is the project that seeks to facilitate the development of advanced digital devices from multiple suppliers that will communicate, or interoperate, with one another."  The really important part of what Schwartz has to say is: "The project is working to achieve a retail available set-top box (STB) or integrated television set that employs a point-of-deployment (POD) module interface specification."   


With literally hundreds of manufacturers each making a specific part of the puzzle, CableLabs is the place where they all come together to see if their part fits or not.  By sharing relevant technologies, CableLabs acts as a clearinghouse to provide information on current and prospect projects to others within the cable industry.  With member support, CableLabs is also able to plan and fund research and development projects that are mutually beneficial.


Lisa Lee, director of OpenCable project told The Tech Notes: "The consumer will have many innovative products available as a result of many industries working together to make OpenCable a reality."  Acknowledging the cooperative efforts within their current project, Lee said: "Significant accomplishments, such as the completion of the hardware specifications and the incubator phase of testing, have been made possible by the teamwork across industries. These accomplishments would never have been possible without the contributions of General Instrument, Scientific-Atlanta, Divicom, SCM Microsystems and the consumer electronics Industry."  "We are very lucky to have these companies as our partners in this endeavor," Lee concluded. 


CableLabs recently completed its first wave of OpenCable interoperability testing.  Subscription management systems (SMS) and conditional access (CA) play a big roll in most every cable system.  Broadcasters may well employ some or all of these techniques, as multicasting becomes more popular as a way to offer pay per view (PPV) or near video on demand (NVOD) services. The focus of these first tests were on removable security cards that would work in conjunction with SMS, CA, PPV, NVOD and other such features.


A name familiar to Tech Note readers, Microtune participates and benefits from a relationship with CableLabs.  Microtune demonstrated capability of its single chip tuner to perform both analog video and QAM 256-modulated digital data in an integrated environment.


As the term, Integrated Receiver Decoder (IRD) implies, these devices, the STB, draws on several disciplines from diverse areas: Tuners, decoders, filters and even encryption techniques, along with other such technologies.  These are but a few of the may part which go into making up only the simplest of STBs.  Some manufacturers plan on including hard drives and other such feature rich items, as the consumers determine their own needs and the markets develop. 


Not only cable companies will benefit from the efforts of CableLabs and the OpenCable work, but Broadcasters, as well will stand to play a big roll as the areas of interactivity evolve and other uses of the data parts of digital television.  Broadcast engineers will have to become familiar with this technology as you can bet your life when the General Manager finds out there is another source of revenue through this technology, he'll be ganging at the Chief Engineer's door wanting to know how soon he can get it installed. 


Certification of a product is the goal and pride of participants.  CableLabs is not a "Good old Boys" organization who passes out the certifications indiscriminately.  Compliance to the letter of the specification is an absolute must.  Once certified, consumers can rest assured of quality performance.


In reviewing material for this story, modem suppliers were the topic of one bit of information.  In researching the subject, it was found to be indicative of participation. The modem suppliers whose products have been certified by CableLabs reads like a whose whom in the cable and broadcast industries.  For more information on participants in this effort and CableLabs themselves, they maintain several web sites:;;;; and  And Microtune can be reached at


Subj: D-Cinema Picking Up Steam
by Jim Mendrala

At Show East D-Cinema was the one of the big topics under discussion. In addition to a panel on The Advent of Digital Cinema there also was a SMPTE Task Force on Digital Cinema meeting convened by Ioan Allen, Dolby. Curt Behlmer was appointed chairman of the SMPTE Task Force On Digital Cinema.

Topics discussed by the Show East Panel included Conditional Access (Encryption) Theater needs for D-Cinema, D-Cinema from a Studio Perspective and How Kodak sees D-Cinema.

The feeling is that D-Cinema is right around the corner but has yet to be defined. Several digital projections were shown but it was also said that as good as the movies displayed where they were not up to yet what Hollywood has in mind. They were certainly "good enough" to start the D-Cinema rolling though.

Since George Lucas announced at Show West back in March that Lucas Films was to release "Star Wars - The Phantom Menace" in Digital Cinema a lot has happened. Miramar's "The Ideal Husband" and Disney's "Tarzan" has been shown in D-Cinema both on the West and East coasts. Even though film was the backup in case the D-Cinema failed it did not have to be used. The D-Cinema projectors racked up over 1,000 hours of flawless performance.

The next D-Cinema to hit some 20 screens will be Disney's "Toy Story 2" in November. Like Tarzan the D-Cinema will be just that digital. No film used in going from the animation done on computers to the motion picture screen.


Subj: Duopoly Makes For Strange Bedfellows 


With the ink hardly dry in the FCC's recent ruling that allows a company to own two television stations in the same market under certain circumstances, you can bet the broadcast corporate legal types and bean counters are scheming and conniving to figure out ways to maximize their holdings.  The new ruling opens the way for cost savings and programming flexibility's not heretofore available to owners of television stations. As a result it didn't come as any big surprise when media giants CBS and Viacom announced last month that they were putting their corporate heads together.   The marriage will not come, however without its own set of unique problems, but not insurmountable problems. 


For openers, the FCC also says that no one television station owner can hold title to stations whose viewership would exceed 35 percent of the total US TV market.  The big problem with this corporate knot tying is that CBS is almost there with 15 television stations, and the acquisition of one more is in the mill. Viacom brings to the table 19 stations of its own.  With the acquisition of CBS by Viacom there is not only duopoly in Boston, Dallas, Miami, Philadelphia and Pittsburgh, but the 35 percent limit would be exceeded.     


The post Labor Day announcement by was billed as "the largest media transaction ever." The newly merged companies will carry the name Viacom.  Their combined assets make them, if not the biggest, one of the biggest entertainment organizations in the world.  Talk about your one stop shop, the new Viacom is capable of producing, promoting and distributing nearly every conceivable kind of entertainment, news, sports and music, and all under one roof. The trade names of their services and products are readily identifiable, well respected and strongly patronized.

In case you don't know, heading up the new media giant will be Sumner Redstone, who will retain the title of Chairman and CEO of the new Viacom.  All operations in the newly combined company will, however report to Mel Karmazin, former President and Chief Executive Officer of the CBS Corporation, will become the new company's President and Chief Operating Officer. Needless to say it will not all happen overnight.  In addition to certain closing conditions, federally imposed waiting times, FCC approval and other governmental regulatory agency approvals, the nod must still come from CBS Corporate shareholder before the final seals are set.  All this should take the new company well into the first half of next year.


Obviously, business has not gone on as usual.  The CBS acquisition of King World Productions, Inc has been put on the backburner for a while as was a King World's shareholders meeting.  No word was mentioned about the possible departure from the fold by Blockbuster, but the merger of Viacom and CBS has many a tongue a waging. This deal involves not only a list of companies, anyone of which is impressive buy itself, but involves the lives, fortunes and destiny's of many thousands of employees around the globe.


Here's just a partial list of what is involved in the Viacom-CBS merger: 


In the filed of Cable television there are a number of cable networks that include: MTV, Nickelodeon, VH1, TNN, CMT, MTV2, TV Land, Home Team Sports and Midwest Sports Channel; pay channels Showtime, The Movie Channel and FLIX, and interests in Comedy Central, Noggin and Sundance Channel, and other cable programming operations outside the United States;

In broadcasting they now own a sizeable chunk of Infinity Broadcasting Corporation, a radio and outdoor media company; The have, arguably, the largest aggregation of television properties in the nation, including the CBS Television Network and stations in all top ten markets, with 18 of the top 20 markets covered as well;

They're in the motion picture business with no less a name then Paramount Pictures who has a library of more than 2,500 titles including some of the like Titanic (the highest grossing motion
picture of all time);

There production and syndication operations include:  CBS Productions, Paramount Television, Eyemark Entertainment, Viacom Productions and Spelling, not to mention possibly King World, previously mentioned. 


They own the book publishing company, Simon & Schuster, the video tape rental company Blockbuster Video, who has over 6,000 stores in 27 countries and Five theme parks,

With other recent exchanges for advertising time, they now have a significant and growing Internet presence, on some of the best-known sites on the Web, including,,,,, and

Even with this list of "what we've got's" from  both CBS and Viacom, it's hard to sort out who has what. Viacom has another relationship which, to say the least is interesting.  They, with Chris-Craft Industries, who owns 10 stations, began the UPN Network. Chris-Craft also controls BHC Inc. and United Television Inc., both of which own television stations. The new FCC duopoly rules make the Chris-Craft properties much more valuable, but it's hard to say when and if any of the principals involved will call, fold or bust.


At first thought, one could not help but wonder how this and other mergers might impact the DTV migration and build-out schedule.  In speaking with John Morgan of the FCC, he said; "The CBS-Viacom merger will not have any impact on any of their respective stations.  Those determinations were made a long time ago." 


But Viacom and CBS are not the only companies who have exchanged notes and this will not be the last of the "new big deals."  The new duopoly ruling has thrown open the doors of possibility and you can be assured that many other broadcasters have entered similar kinds of dialogue. The companies who have not done some talking would be more the exception than the rule. 
More than one NBC executive has suggested over the past year that GE would like to spin off the Peacock network and her stations, but inquires about such a move have all been treat with derision.  Under these new set of rules, there is little doubt, based on GE's track record, that anyone with the right pocket change could have them, but yet they might try to grow with the flow. 


Other smaller group owners and lessor networks are more likely to find the "lets get together" conversation one that will be come as familiar as a schoolboy chatting with his bevy of girlfriends.  One recent report in the Hollywood trades suggested that Berry Diller, the Chairman of USA Network, has been in conversation with Disney's ABC with merger on his mind.

The biggest concern to engineers is that nothing will remain constant.  With these new duopoly rules, the chances of consolidations and staff reductions are very real.  The only thing broadcast engineers can do is to make themselves move valuable to their employer is by broadening their knowledge base and marketable skills.


It is interesting to note that since this story was originally written about a week ago, according to Broadcasting & Cable: “The Senate antitrust committee will hold a hearing to examine the antitrust implications of the proposed merger of Viacom and CBS.  Tentatively scheduled to testify are Viacom's Sumner Redstone, CBS' Mel Karmazin and public interest advocate Andrew Schwartzman.”  May the deepest pockets win!


Subj: An Affordable DTV Set-top Box

By:     Roy Trumbull


Affordable is a relative term. Up until now the STBs on the market have been the far side of $1300. Some have had a narrow input signal window and had severe trouble handling modest amounts of multipath. Changing channels was an act of faith and rather bumpy. All that is about to change. Expect to see ads promoting a STB that handles NTSC, DTV and DSS, bundled with a 36” monitor at a price in the neighborhood of $3000. The stand alone STB will list at $650.


The box puts out NTSC video and audio, modulated NTSC on ch 3-4, S-Video, and multipin HD. The chips and their programming are far more robust than anything on the market now. Locations where channel X can’t be received, this STB will receive it. I know because I’ve had one to try since July. I just sent it back for brain surgery because they’ve gone through three software releases in the meantime.


If you pull the power plug and then restore power it will come back to the state it was in prior to the interruption. Whatever channel you were watching, that’s what it will come back to. If you’re watching on an NTSC receiver you can set the picture to be 4:3. There is an on-screen signal strength reading you can use to peak your antenna. It has two antenna inputs plus DSS.

This STB is the RCA DTV100 by Thompson. For more details look under new products at


(Ed Note:  We got an e-mail from an organization that plans to put on a digital audio seminar.  We had to nearly pull teeth to find out the “who, what, where and when” about it.  The only reason we are mentioning it here is that several of the advertised instructors or moderators are well known professionals in the industry and may well be worth your time to look into it.  We, therefore, are passing on the web page for your information with any endorsements what so ever.  The event is The Surround 2000 Conference to be held on Friday and Saturday, November 5th and 6th, at the Beverly Hilton in Beverly Hills, CA and is being put on by the TMH Corporation, 3375 South Hoover St, Suite J, Los Angeles, CA 90007 who can be reached at 213-742-0030.  Don’t be surprised if the answers to your questions are as vague as we got when we called. for more information.)


(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.     

From: Des Chaskelson, Research Director, SCRI International (

Re: New Website with Industry Press Releases Plus New HDTV Survey


Check out the SCRI web site, where the Tech Notes are published, for some really great information on industry trends and other very valuable marketing information, trade news and current television events.  SCRI is currently in preparation of our latest survey, analyses and report.  Stay tuned!


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.