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Tech Notes

Published by: Larry Bloomfield & Jim Mendrala

E-mail = or

December 13, 1999

Happy Holidays to all

Tech Note - 047


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 the new E-mail addresses.  To remove yourself from this list, send an e-mail to: in the subject place the word Remove.  We now have over 560 subscribers & growing.  This is YOUR forum!  Past issues are available at: WWW.SCRI.COM We also have a second site where the Tech Notes are posted now: Check it out too.


Subj:  Lets hear from more of you out there

From: Jim Mendrala

A lot of people are reluctant to write freely because of "corporate" policy.  Companies, as you know, want to co-ordinate there “public image” with their PR department and anything published has to fit the image the PR firm has set up for that company.  Consultants are a lot freer to write if they choose to do so. They, however, do not want to bite the hand that feeds them.  It sure would be nice to have freedom of speech.  But unfortunately too many people have there own agendas and the one who dishes out the bread makes the rules.  If you’ve got something to say, we will maintain your anonymity, if you so wish.

Subj: Cable Companies and DTV Programming

From: Tom McMahon

Cable companies, which carry the DTV programming, appear likely to do so only in QAM, not 8VSB. They'll do this by doing a demod (either from a terrestrial antenna or some satellite or other link) and then a QAM remod of the ATSC stream at the head end.

At the consumer end, you won't be able to plug this right into your DTV set, not for years to come, because none of the new DTV sets are cable-ready in that sense. They don't have QAM front ends and they don't know how to tune around the cable system to find an ATSC-carried signal (no EPG info available to them).

On the other side of the coin, none of the QAM digital cable boxes being deployed support ATSC. Although they DO know how to tune around the cable system, even if they knew how to decipher the Programming and System Information Protocol -- PSIP (which they don't), they wouldn't have a clue what to do with most of the formats in Table 3 when they finally inherited them.

So even if your cable company carried the Terrestrial DTV programming and figured out all of the tuning and protocol issues, you are only likely to get SDTV programs out of your new digital cable box unless the cable company takes the extra step to format-convert all DTV programming to their native CATV video format prior to distribution on their cable system. This could pretty much guarantee that you'd get all of the terrestrial DTV programming, and that it would be backward compatible with the nation's 300+ NTSC sets, since all of these cable boxes will have NTSC and S-Video outs. But HDTV
goes by the wayside.

Another option would be to make the cable box spew the ATSC transport stream out the back door over 1394 or some other home networking scheme instead of trying to decode it natively in the cable box. Of course this assumes the downstream devices all support that particular networking technology (none of them do yet). It also assumes the copy protection nonsense is worked out. It also assumes nobody cares much about watching their terrestrial DTV programming on their 36 inch Sony Trinitron - they have to buy a new (still non-existent DTV set with a network connection). It also assumes nobody cares about the value-added stuff that the cable company will be running in the digital set top box since the GUI information from those apps won't run across the network link to the DTV set.

Of course the consumer could switch between the 1394 input on their new non-existent DTV receiver and the NTSC/S-Video input on their new non-existent DTV receiver when they want to flip between the ATSC PSIP EPG and the Cable Company EPG and E-Commerce GUIs. But then they'll need two remotes to perform even the simplest channel surfing. "Let's see, Remote A: flip to NTSC input, tune Channel 3, Remote B: tune cable box to ATSC-carried channel 43 on the cable system, Remote A: flip back to 1394 input, tune DTV EPG to ATSC sub-channel 3 on DTV receiver....etc." How do you hook in DSS? DVD?

Are all of these facts a good thing or a bad thing? Would they solve your problem and make DTV not DOA?

I myself believe that cable Must-Carry solves nothing for the consumer, especially in the short term. It sounds good on the surface but won't hold up in practice. A robust terrestrial delivery system would be worth a lot. Plus, the ability to watch a sporting event or local news on a shirt-pocket device or a portable TV on a boat/train/bus would be very valuable to terrestrial DTV market development.

Tom McMahon


Subj:  Reader Response to:  Tech Note 046
From: Jeff Evans
DVD-Audio -- The discussions in HDTV Tech Note 046 show an interest in, and confusion about, DVD-Audio.  Audio Intervisual Design is sponsoring a seminar / meeting / discussion on DVD-Audio. This will be held the afternoon of December 14 in North Hollywood. If you are interested, look at our web site  for information and registration. No charge, we may all learn something.

Jeff Evans


Subj:  Equipment You’ll need for DTV

By:    Roy Trumbull

(copyright 1999 rev 12/9/1999 -- Permission is granted for non-commercial use in newsletters and for SBE websites)

The HP 8560E Spectrum Analyzer with Tracking Generator option

I use the HP 8560E spectrum analyzer with tracking generator to cover the range from 30 hz to 2.9 gig. I can’t say enough good things about it. It is very intuitive to use and I think I’ve had to refer to the instructions only twice. It has an averaging function that is essential for checking the flatness and skirts of a DTV signal. It has a number of marker functions with the delta marker being the one I use the most. It shows on-screen what the level is relative to the center span of the signal. You can pick a peak and read its frequency to a resolution of a hertz.

The tracking generator can be used to set the center point of the IOT input cavity and to adjust the bandwidth of the double slugged tuned. The tracking generator is connected to the input of the circulator feeding the IOT and the spectrum analyzer is connected in place of the circulator’s reject load.

The HP 89441V Vector Signal Analyzer (VSA)

The VSA has been available in several configurations and what I have is the same as the one used for the ATSC field measurements. I opted for less bandwidth since I could look at my third harmonic with the 8560E. I also have less input sensitivity. During the ATSC field tests, additional gain was provided by two Mini Circuits preamps. Passing on those features saved me about $15,000. The options I did buy were:

          IC2 – HP Instrument Basis

             I needed this for a measurement program written by Gary Scrignoli at Zenith

          UG7- Lan Support

             My Zenith modulator has an automatic setup program for linear and non-linear correction. The computer must be

             interfaced both to the modulator and the 89441 to analyze the signal and create the correction files.

          AY8 – Internal RF Source

             This is pretty much a required option and essential for field measurements.

The VSA can do scalar measurements much like a spectrum analyzer but it can also demodulate the 8 VSB signal and display eye and constellation patterns. The display can be set to quad configuration to show multiple measurements at the same time. It can also do a tabular chart that shows error vector magnitude (EVM), signal to noise, pilot level and pilot frequency error and much more.

The VSA has a built in floppy drive. You can save a screen as data but that requires software to make use of the resulting file. A nice alternative is that you can use the print/plot button and to create a tif file that can be opened in Windows. Thus you can save a screen and import it into documents or just print it out.  It’s also handy that a particular measurement setup can be saved and then loaded from disk.

The VSA has a feature called “Autostart” that permits you to store default settings that you want the VSA to use upon powering up. In the save/recall menu select “save more” to get to the softkey for Autostart.

I keep finding new features all the time. The ibasic software from Zenith is on the HP website. It makes both 8VSB and NTSC measurements.

The HP E4418B EPM Series Power Meter and 8482H Power Sensor

This appears to be the preferred way to measure power. The unit has an internal calibration source and reads out directly in dBm. By adding the sample port loss to the reading, the power can be computed.  The Power Sensor covers about as broad a signal range as you’re likely to encounter.

You can also measure power using Gary Sgrinoli’s program mentioned above. However, you must calibrate your test lead and add its loss plus the port loss into your calculation.

The Power of an 8VSB signal can’t easily be measured with a spectrum analyzer as the span must be increased to 100 mHz to display the peaks. Then, within that span, doing a power measurement across 6 MHz isn’t very accurate.

Instek Lab DC Power Supply PR6030

I bought this for setting up modules in my Solid State M series Larcan NTSC transmitter. It came in handy calibrating hall-effect sensors in the Larcan Landmark because it has a constant current function. Thus I could run a lead through a sensor, short it to the return, and set the current for 1 amp and calibrate a metering circuit.

The Extech 380947 clamp-on AC/DC multimeter

This is very handy for verifying focus coil current.

The Craftsman 16 gallon wet-dry vacuum cleaner

It isn’t a matter of if you will spill coolant. It’s just a matter of when.

Roy Trumbull

(ED Note:  Roy is a frequent contributor to the Tech Notes and is Asst. Chief Engineer at KRON-TV in San Francisco.)


Subj:  A Simple Master Control For HDTV 

By:  Larry Bloomfield

At the risk of sounding like a product review, it is only proper that information on new equipment be shared when it is the first or very much different than most anything else available in its class or category.  Having worked in the Master Control (MC) of a major network O&O in the nation’s second largest market, I can truly appreciate the need for simple and straight forward equipment to do the job, especially when it’s crisis intervention time.  As most MC operators know, crisis intervention can manifest itself in many different shapes and forms, besides cropping up at usually the most inopportune times.    

The Master Controls at most of the new digital stations are a complex array of equipment put together in a not too friendly way in an attempt to duplicate the efforts of the station’s analog counter part.  One thing that is conspicuous by its absence in most new digital television facilities is the capability of doing digital Emergency Alert System (EAS) messaging, much less the normal dip to blacks, dissolves, crawls etc.  Don’t look now, but the FCC requirements at a digital station are no different than they were at the good old-fashioned NTSC operations.  You’ve got to have EAS!

In a recent telephone conversation with Jay Adrick, Vice President of Systems Integration at Harris Broadcast Communications Division, he reassured the Tech Notes that Harris has been working diligently in an attempting to fill this need. Adrick says it takes typically 13 different boxes or chassis of currently available digital equipment to do all the jobs in a MC switcher that are typically done in a minimal NTSC MC switcher and you still don’t have EAS.  There should be no doubt in anyone’s mind that Harris is not the only equipment maker working on this, they just happen to be the first to put most all the trick of a digital Master Control into one box.

Right on cue, Adrick said:  “We’ve (Harris) developed the world’s first totally integrated master control module for High Definition Television (HDTV) which is a 3 input switcher; two HD inputs (1.5 Gbts) and one SD input (270 Mbts) with frame synchronizing on all inputs.”  Adrick said that the “Masterplus” system, which is the name Harris will market the new product under, not only supports the 1080i/720P/480P high-definition formats, but it is the only master control system that accommodates high-definition EAS (Emergency Alerting System) requirements and seamless closed-caption switching among program sources.”

I had to ask and yes it does have several internal generators for black and test signals in addition to having the capability of inserting the now famous watermarks or bugs in the lower right hand corner of the picture and a small still store for what ever the stations wants to use it for.  As much as the ability to bump up standard def NTSC fair to HD is a disservice to the HDTV viewer, the switcher does have that capability too along with the ability to handle the more popular flavors of audio formats and most normal MC audio transition and input requirements. 

De-embedding is a term we’ll all learn to love or hate in the wonderful world of digital.  A digital MC, weather it is SD or HD, will have occasions when the audio must be stripped from the bit stream.  Harris thought of that too and handles it well. 

You will probably be impressed as much as I was when you have the opportunity to read more about what all this HD MC switcher will do, but as I said early on, this is not an equipment profile; simply a way to let you know there is something out there that may titillate you interest, as it did mine.  For additional information, visit the Harris web page at


Subj:  Does Uncle Bill Have Big Plans For TV?

By:    Larry Bloomfield

Weather they like it or not, when the Lion roars on the Savanna, all the other animals pay very close attention. Like him or not, when Microsoft Chairman and CEO Bill Gates speaks, it pays to respond to our animal instincts, and pay attention too, irrespective weather they are a monopoly or not. 

You may not be old enough to remember the Red and Blue radio networks, but it was seen in the 1940‘s to be a monopoly.  The result of that break up is NBC and ABC.  Although GE spun off the radio part of NBC, if you take a look at ABC, they have more radio networks then anyone back in the Red and Blue network days could have ever imagined.  On the other hand NBC has sever video services.  What I’m saying is that if one big operation can come back bigger and more, Microsoft will also recover from any monopoly issues. 

In the mean time, Uncle Bill has been a travelin’ and talking about interactive TV.  While at the European Technology Roundtable Exhibition in Monaco, Gates told attendees that his company’s interests in interactive TV are very “well-placed.”

While justifying Microsoft’s interest in interactive television, Gates addressed why television will have a major roll in the future of computing:  "People can criticize Microsoft for supporting this TV thing for the past eight years, but it is a long-term bet," Gates said. "There is not any other software business that is as dedicated to the vision of
the TV and the personal digital assistant (PDA) as we are."

Curious as to what the personal digital assistant is, we contacted Microsoft and asked.  Sallie McDonald of Waggener Edstrom, Microsoft's public relations firm, told Tech Notes: “Microsoft's goal is to provide people with the power and connectivity they want anytime, anywhere and on any device. This is idea behind the Personal Digital Assistant.”  Clarifying Gates’ comments, McDonald said:  “Bill Gates didn't mean to say PDAs and the vision of TV are the same thing, they are two separate but related initiatives at Microsoft.”

Gates went on to reinforce Microsoft’s investment in WebTV saying that it has been a perfect fit for Microsoft both financially and at the human resources level.

Recognizing the lack of friendly interfaces now available to interactive TV, Gates looked into the future and said that the interface of the future will have less commands.  “We will evolve the ability of the computer to hint, which will be useful for interactive TV applications.”     Gates’ continued interest in interactive TV speaks to the point that, while in a “wait and see” posture, Microsoft has designs and plans to play as big a part in all this as they can.  Gates says that interactive TV will play a much bigger role in the living room of the future with advanced set-top boxes, digital music, digital photos, and video and the advancement of games will all soon change the home, he predicted.

Tying this together with Gates views about handheld devises as the wave for the future, perhaps Uncle Bill knows something he’s not sharing about “the possibilities” in the area of handheld TV’s like Sony’s walkman, but of a digital and perhaps interactive nature.  This could open up the whole thing about 8VSB and COFDM even more.

One thing for sure is that with all these portable and or handheld devices brother Bill see us all having in the future, it may well require Microsoft software to keep the various programs between the different devices synchronized.  Be careful!  The camel’s nose is very healthy and though possibly asleep, it is definitely in the tent and has been there for eight years by Gates’ own admission.  

  For more info, check out the Microsoft web site at:


Subj:  Spectacular In All Respects!

By:     Larry Bloomfield

The launch of a geosynchronous satellite in this day and age is nearly old hat, but when it is done at sea, now that’s a different story.  The launch pictures of DirecTV 1-R, alone, are breathtaking, to say the least.  This is also of particular interest as it may carry your station’s programming in the not too distant future.

Looking back to 1963, when the very first geosynchronous communications satellites were launched, much has changed.  Syncom-I committed suicide as it tried to make the change from “transfer orbit” to geosynchronous orbit, but Syncom-II was a big success.  Because there was no equatorial correction made to Syncom-II just after it was launched, it, Syncom-II, had a 22-degree north/south ellipse orbit, but in the spring of 1964 when Syncom-III was launched, the equatorial corrections were made and it achieved near geosynchronous orbit.  How do I know all this?  I was a part of the Syncom launch, positioning and test team.  Well, the belt around the equator at 22,300 miles in space hasn’t been the same since, with its increasingly populated neighborhood.   

Communications satellites have been launch from nearly every launching venue around the globe, but for one to be launched from an ocean-based Sea Launch platform certainly perked my interests.  DirecTV 1-R is the fourth direct-broadcast satellite built for DirecTV by Hughes Space and Communications (HSC); the two companies are literally second cousins under the Hughes umbrella, which is now owned by General Motors.  The successful launched took place late this fall and DirecTV 1-R became the first commercial satellite sent up from an ocean-based Sea Launch platform.

Hedging their bets and looking to the possibilities that they may have to deal with “must carry” obligations under the new Satellite Home Viewers’ act, DirecTV is getting the capabilities out there, just in case.  According to DirecTV, the new “bird” will have the additional Ku-band capacity to deliver local broadcast network channels to nearly 50 million homes, or about half the nation’s TV households.   

DirecTV 1-R is an HS 601HP model, with 16 high-power Ku-band transponders. The new bird will deliver 30 percent more capacity than the older DBS-1 satellites currently serving DirecTV subscribers from 101 degrees West Longitude.  DirecTV says that one of the three older DBS-1 birds will be moved to 110 degrees West Longitude to serve as back-up.

In speaking with one Hughes’ officials, he commented that with this new high-power satellite in place, DirecTV will be ready to better compete with cable and deliver local broadcast stations into local markets as soon as pending legislation is passed by Congress.  Now if that isn’t a wake up call to the cable industry, its anyone’s guess what it will take?

Having gone through the experience of losing a spacecraft (Syncom-I), it is not hard to imagine how DirecTV President Eddy Hartenstein must have felt when it was all over and he was able to commend Sea Launch, a part of the Boeing family and his corporate cousins at HSC, for the successful launch. 

The new state-of-the-art communications spacecraft will be “parked” at 101 degrees West longitude, DirecTV’s main orbital slot, along with the other older birds and will serve to strengthen DirecTV’s in-orbit redundancy.  Hartenstein said that in addition to that, the new satellite will permit, “DirecTV customers in up to 20 of the nation's key television markets to receive their local broadcast channels as well as the current
lineup of digital DirecTV entertainment and information programming through their existing set-top box and 18-inch antenna."

The satellite lifted off aboard a Sea Launch Zenit rocket from the middle of the Pacific Ocean.  After about an hour, the launch rocket left the spacecraft.  This initial phase is called the transfer orbit.  The transfer orbit is like a slingshot to get the bird out into space.  Although the spacecraft does dip back and forth between its intended orbit and earth over its 30 day transfer orbit period, the time permits the controllers to maneuver the spacecraft into circular orbit, deploy the antennas, solar arrays and radiator panels, and test the operational functions, communications payload and propulsion system.  This is a much more gentle method than employed with the first three Syncom satellites wherein they had a relatively large apogee rocket that kicked the spacecrafts into their final orbits.  A common factor is the smaller positioning propellant rockets necessary move all the birds into place and keep them there.

Range to the spacecraft is critical.  Too close to the earth and the orbit is less than twenty four hours and the satellite appears to drift; the same is true if the orbit is too far away from the earth, the orbit is more than twenty four hours and the drift is the opposite direction.   Basically by lower and raising the orbits is one method of moving or positioning the spacecraft.  DIRECTV expects to begin offering services from DirecTV 1-R sometime this month (December).

While all this was going on, the bean counters and others were at work saying that shares in Hughes Electronics are undervalued because parent company, General Motors’ focus is on the automobile industry and they’ve been lobbying for GM to spin-off Hughes and DirecTV.  Sighting EchoStar Communications’ (DISH) remarkable climb in the stock market recently, these same wolves are baying that this is one more reason to see the spin-off.  It is true that EchoStar shares have done well.  The climb has been such over the past six to eight months that twice the company split its stock.

Apparently unimpressed by this, General Motors (GM) President Richard Wagoner told reporters, while attending an automotive accessories convention in Las Vegas, that GM has no immediate plans to spin off Hughes Electronics, the parent company of DirecTV.  When pressed, according to Reuters news service, it appears that although GM's has no current plans for Hughes, Wagoner did not rule out a possible spin-off in the future.


Subj:  Another Form of Compression?

By:     Larry Bloomfield

It’s getting to the point where you can’t tell the players with out a program.  Mention the company name “Divicom” and those who have been involved in these early days of transition to digital television, will recognize it as part of C-Cube, a Milpitas, California based company, who has made their mark in digital compression and chip making.

Divicom is probably best known for its work in high-quality standards-based MPEG-2 encoding products and systems, but also have a very heavy presence in the areas of audio/video encoding, data broadcast, network management systems, consulting and integration services. Based on the MPEG-2, DVB and ATSC international standards, Divicom products have enabled digital video broadcasting over a variety of networks including satellite, wireless, fiber and cable.  

In a nutshell, irrespective of the format of digital television a station or network is working with, at some point it all has to be compressed to fit into the 6 MHz of bandwidth allotted each station by the FCC or some other form or transport media.  This is where Divicom enters the picture. 

C-Cube's Semiconductor Division makes the highly specialized digital video chips as well as the equipment for the communications and consumer electronics markets, including digital set-top boxes, VCD, and DVD.

The (approximately) 425 employees of Divicom will see a different name on their paychecks in the not distant future.  The new name will be that of a company, hardly a few off ramps down the freeway and based in Sunnyvale, California, best know in the world of cable television:  Harmonic.  Harmonic used to be known as “Harmonic Lightwave,” but the “Lightwave” got lost somewhere along the line.  Harmonic designs and markets both digital and fiber optic systems that deliver video, voice and data over cable, satellite, telco and wireless networks and they also have their foot into compression technology as well.

In speaking to several people known to me personally at Divicom, they feel very comfortable with Harmonic’s acquisition of Divicom as they explained it, it appears to be a dovetailing of efforts and will better position Harmonic as a supplier of open-systems for delivering video, voice and data over a variety of network architectures.  Our sources also say that prior to closing of this deal, C-Cube will sell or spin out all of the assets and liabilities of its semiconductor division, after which Harmonic will acquire Divicom with a merger of C-Cube into Harmonic.  This information was confirmed in the press release associated with the transaction.

To find out the Harmonic prospective, I contacted an associate with whom I’d worked on developing a report about compression technology a year ago, Ed Thompson, Vice President of Business Development at Harmonic, Inc. 

Thompson told Tech Notes, “Harmonic is in the cable business.  Divicom allows us to get into satellite and terrestrial broadcasting.  The key to our future success is in the open architecture approach both companies have adopted and practice.”  

Thompson explained that Harmonic provides fiber optic transmission capabilities for the cable television industry and their claim to fame is their TRANSend product, a video gateway system.  Thompson said they also make plug-in cards like encoders, ATM video, interactive inputs into Mpeg formats with various types of input and outputs and small compact video gateways, all for the cable industry.

In the short term, the marriage will increases Harmonic's presence in the emergence of
digital video services over cable, satellite, telco and wireless networks.  In the long run, it will increase Harmonic's participation in video transmission over emerging IP networks.

Thompson said:  “The two companies product lines complement each other with little or no overlap.”  Divicom has extremely high quality, low bit rate encoders and Harmonic has a constant bit rate encoder.  Thompson reassured me that Divicom customers can rest easy because C-Cube, as part of the deal, will support the Divicom product line for several years to come. According to Thompson, Harmonic will need C-Cube for encoder chips to run their business.  Thompson said:  “We will have the same access that Divicom had to C-Cube chip development technology and it will continue under the Harmonic banner.”

On the other side of the coin, the folks at Divicom see Harmonic’s involvement in cable as a growth opportunity, being purely synergistic, form a business point of view.

Divicom comes to the table with an impressive customer list, some very familiar: BellSouth, Cablevision Systems, EchoStar Communications, GTE, LIN Television, WGBH and US West.  Divicom was recently selected by DirecTV to provide the entire digital television compression system to its Castle Rock Broadcast Center in Colorado. Divicom says this new contract will make it DirecTV's largest supplier of compression technology.

The nuptials should all be concluded by the end of March 2000.  For more information, check the various companies websites at, and


(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.