Archived Tech-Notes 
Published by: Larry Bloomfield & Jim Mendrala      The following are our current e-mail addresses: 
E-mail = hdtvguy@garlic.comor 
 We have copied the original Tech-Notes below as it was sent out.  Some of the information may be out of date. 

North West Tech Notes

 % Larry Bloomfield & Jim Mendrala521 Forest Grove Dr.

Bend, Oregon 97702

(541) 385-9115

Email =



September 7, 1997


NWTN - 008



This effort will be successful ONLY with the assistance of those who help by contributing  information to us and have the professional desire to keep us all on the cutting edge of this technology.  We need you to share your experiences, knowledge or anything else relating to DTV, HDTV etc.  We will share what we get from you. This is a work of love.  We see a need and we're doing this solely with the idea of keeping ourselves and our associates informed.  We ask no compensation for our efforts, just the latest information you may have on what's going on.  We will not pass on anything that cannot be verified or the source cannot be identified. If we inadvertently pass on erroneous information, we will make every effort to get it corrected as soon as possible.  The above disclaimer is for obvious reasons. 


Who will we send these issues to?   We will make every effort to share this effort with our fellow broadcasters: Anyone interested!.  Just e-mail us your request to be added to the mailing list and it's done!  Feel free to forward this on to your associates, but let them know that you've done so and it's not directly from us.  If we've sent this to you and you're not interested, just let us know and we will take you off the mailing list. 


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Sorry it has taken over a month to get another one of our Tech Note out to you.  As we've said above, this is a labor of love and love sometimes has to wait on work and vacation.


From: THE CGC COMMUNICATOR (Electronic Edition)  #181

            Monday, August 18, 1997

            (Used by permission)         




ABC Television and Sinclair Broadcast Group are backing away from the high definition television (HDTV) format.  Instead, Preston Padden, president of Walt Disney's ABC network, said ABC  is leaning toward broadcasting several lower resolution channels

simultaneously, including the ABC-TV feed.  Separately, Baltimore-based Sinclair said it has already made the decision to forgo HDTV.   Sinclair is one of the largest TV station operators in the country.  For the full story, see Wall Street Journal, August 13, 1997, p. B5.


Thanks, Mike Worrall, ABC.COM


From: THE CGC COMMUNICATOR (Electronic Edition)  #183

            Monday, August 25, 1997

            (Used by permission)        




Brooks Boliek, in the Hollywood Reporter, quotes an aide to Rep. Billy Tauzin, R-La., as saying, "If broadcasters abandon HDTV, they can expect a fight in Congress over the use of the new channels."   "It's going to fuel that criticism that this is a giveaway all along." recent comments by ABC and Sinclair Broadcasting executives that HDTV is a non-starter are raising lawmakers' eyebrows even during their August recess.


  (Mary Shea)


From:     Larry Bloomfield


      With the above freshly in mind, we want to add that during a recent conversation with a CBS engineering manager, he told this NWTN writer that his company is seriously considering the same tact;  that is CBS is also "leaning" toward broadcasting several lower resolution channels simultaneously, including their feed. 


      From what I got out of the conversation with my associate at CBS and other conversations I've had with other engineering managers around the country, I can't help but wonder if HDTV won't go by the wayside......,  for a while at least, in favor of the multiple channel approach.  It is interesting to speculate if the gentleman from congress above is a lone cry in the political  arena or would other representatives echo his thinking. Playing the devils advocate, I have to ask why would congress get up set?  They gave us the ability to choose.  We keep hearing the cry:  "Let the market place set the standards."  Like it or not, isn't that what's happening?  Admittedly the market place has consistently chosen unwisely.  We ended up with VHS tape in our homes instead of Beta and the Motorola AM stereo system instead of the Kahn system.  I could go on but I think you got my point?


      I don't see or hear much about HDTV in Japan, where it has been around for almost a decade.  I have heard reports of an HDTV station going dark in Europe for lack of interest.  I also wonder what the set manufacturers will give us.  I believe that will sure make the broadcasters take a look at what to broadcast.  As we've said in this column before:  "If the transmitter will pass a respectable bit stream, it could care less if it is HDTV, multiple channel or a combination of both.  Having worked in the Project Implementation departments at several places, I believe this is where all this will have the greatest impact. 


      One more comment about Congress.  With what I heard during the various hearing on this subject matter and the the way things have gone so far,  it wouldn't surprise me if Congress's only interest in all this is to get the bucks when the FCC is able to sell the spectrum.


      Please don't get me wrong.   I'm in favor of any improvements that can be made in what our industry can deliver to the public.  The first time I saw HDTV was many years ago at KCET-TV Channel 28 in Los Angeles where one of several systems was being demonstrated.  I was impressed then and continue to be impressed each time I see it.  I do believe, however that it will take much longer for it to "catch on" than within the time frame we have been given, so in the mean time we will continue to dole out  the same old stuff -----  be it one or several channels all within our newly allocated 6 MHz digital broadcast slot.  One thing we all, most likely, will agree on and that is no one can rush Americans into doing anything, especially if it is new and different.  It took RCA many years of demonstrations and the broadcasters many years of perseverance to get COLOR to it's current level of acceptance.  These are my views.  Let's hear yours.




From: THE CGC COMMUNICATOR (Electronic Edition)  #183

            Monday, August 25, 1997

            (Used by permission)        




The text on this item (complete with footnotes and all) is now available on the web in html format at:


(NWTN Ed Note:  This might be a blessing in disguise.)





Driving home last night I saw installers building a fake palm tree in Orange at the 22 Fwy @ Glassell Street.  It is within 80 feet of an existing undisguised LACTC tower and within about 1/3 mile of an undisguised AirTouch tower.


  Paul H. Sakrison,


(NWTN Ed Note:  We've seen several reports of this type.  We wonder how this interacts with the local zoning issues addressed above?)


From: (Charles A. Pantus)

Hello recipients of North West Technical Notes.


Though you might be interested in a recent Opinion paper by me, Charles

Pantuso, Founding Partner & Director of Engineering, HD VISION, Inc. The

title is "The Emperor's New Digital Clothes". The paper can be found on the

HD VISION web site, URL:

Please let me know what you think:


Also, I was recently part of four seminars held at Bjorn's Audio-Video in

San Antonio, TX, where each group of about 30 people listened to a seminar

that fairly presented the views of their local cable company (Paragon), a

satellite broadcaster (Dish-TV), a local TV station (CH-12, ABC), and a set

manufacturer (Mitsubishi), as well as a few comments from my perspective

(HDTV Production). They were then shown real HDTV images on a 10'-wide

Stuart screen, using a Runco projector with playback from an HD-D5 machine.

Interestingly, at least in this group of relatively-affluent early

adopters, over 97% said that they were not interested in more

NTSC-DirecTV-quality signals and they wanted real HDTV or they were not

willing to buy new sets or decoders. If only broadcasters would do some of

this research before making their decisions.






Subj: Area Code Change & more


Dear Friends:


PacBell has changed the area code for San Mateo County in California.  The new area code effective August 2, 1997 is 650.  The old area code (415) can still be used until the end of the year during the changeover period.


TEL:  650+347-9700       FAX:  650+347-1772 


LARCAN now has a web site:  LARCAN.COM which allows me to add an e-mail address:


 So you can e-mail me at :   <or> 


Also several people have asked me about Digital STL's for DTV.  You might want to note the following address.  This was passed on to me by Carl Guastaferro at Microwave Radio. <A HREF="">Converting from Analog to Digital Video STLs</A>  and also the following home page where there is a wealth of knowledge <A HREF="">Microwave Radio Communications -- Analog and ...</A>


Trust all goes well.

Kind regards,


Dave Hill


Subj: Rabbit Ear Reception

From: (Sears, Don (NBC))


Speaking of "rabbit ear reception", has anyone really tried one of these

"Turn your home wiring into an antenna..." devices?  Do they work?

Everything I learned in school says they won't.  But then again, I

sometimes get the best reception when my rabbit ears are in a

configuration that is not supposed to work.


Now for DTV:  Will rabbit ears work better for DTV than analog?  Will

they work at all?  Will we need a new (expensive) outdoor antenna?  Will

Radio Shack sell us a 16x9 antenna?  And what will happen to the "home

wiring" devices?


- Don Sears


        Because e-mail can be altered electronically,

        the integrity of this communication cannot be guaranteed.



Subj: Digital TV seminars

From: (Oscar)


Every year, the Texas Association of Broadcasters and the Society of

Broadcast Engineers (in Texas) get together and host the second largest

trade show and convention (behind the NAB).


As this years technical seminars coordinator, I have placed a major

emphasis on the transition to DTV.  If you feel it is appropriate, you

might want to send out the information.


The seminars will be held on October 30, and 31st (Thursday/Friday).


A list of the confirmed seminars follows.  Cost of the seminars is $45 - $65 for engineers.  The convention & trade show will be held in El Paso, Texas this year.  El Paso area information can be found at:


To be added to the mailing list for the convention, interested parties

should e-mail Oscar Rodriguez at


Oscar Medina

Technical Seminars Coordinator TAB / SBE Convention & trade show


Here's the schedule of seminars:



 Presenter: Steve Schott of Harris Broadcast


As both a factory field service engineer and a transmitter salesman,

I've seen that many engineers are afraid of transmitters because it

"seems" complicated.  This program explains a transmitter in easy to

understand language and simplifies the tuning procedures.






Presenters: Dean Stone, Systems Integration Manager, Sony

Randy Brigham, Advanced Technology Specialist, Sony


This seminar is designed to help the broadcast engineer transition from

the analog world to the world of digital and familiarize him with the

various compression techniques.  We will be discussing the

characteristics of the 601 sampling standard, various compression

techniques, and the effects of multiple compression on the video stream.




Presenters:  Reese & Associates and The Austin Company




Presenter:  Tektronix Corporation


This presentation takes a brief look at the 8VSB Modulator, with and

explanation of the various coding schemes, and the relationship between

the 8VSB signal and an analog NTSC signal.  The presentation explains

the mathematical relationships and how the signals coexist with general

information about (generic) 8VSB transmitters and how to test and align






Presenter:  James Rooney, System Engineering Manager for Microwave Radio



This paper will explore considerations in planning for the transport of

the digital television signal from the studio to the transmitter via

microwave radio. The issues include interfacing with the studio

equipment, interfacing with the transmitter, differences in path

profiling and system engineering for digital vs. analog microwave

systems, and approaches to adding DTV STL where new RF channels are

constrained or not available.



SURVIVING THE DIGITAL TRANSITION - Thursday, 9:30 a.m. - 11:30 a.m.

Presenter:  combined session with GMs



Subj: Engineers and the Bean Counters

From: (James Mendrala)



I am not an expert in TV finance, but I have some thoughts on how the

broadcaster can afford an HDTV facility.


It seems like DTV, at this time, is in a stalemate.  Most TV Engineers, with an

eye for the future, say that DTV (Digital Television) should go to HDTV

(High Definition Television).  The "Bean Counters" say let's stay with SDTV

(Standard Definition Television). The public hasn't seen HDTV and doesn't

have a clue as to what it is all about. Station management probably doesn't

have any idea what HDTV is either. Some say it's only a slightly wider

screen so why the fuss.  HDTV means screens up to 4 1/2 x 8 ft. with a

picture so sharp one could sit 3 screen heights away and see a flawless

picture. That's Big Screen for the home!


Table 3 of the FCC standard, passed in April of this year, say's you can have greater

than 18 different types of program sources. From SDTV on up through HDTV,

24 fps (frames per second) to 60 fps,  interlaced or progressive, 640 x 480

pixels up through 1920 x 1080 pixels.  Aspect ratio's of 16:9 down to 4:3.

What's not obvious is that the display is independent of the frame rate.

For example, if the IRD (Integrated Receiver/Decoder) is feeding a CRT type

of display, then a 24 fps transmission would display each frame 3 times a

second for an effective 72 times a second image. Therefore, no flicker! A

25 fps program would be displayed by the IRD at 75 times a second. Again no

flicker!  For a 30 fps program, the IRD would probably display that picture

at 60 times a second and a slight amount of flicker on bright scenes would

probably be seen. In the movie theater, 24 fps film is displayed on the

movie screen with two applications of light per frame and it has a flicker

of 48 times a second.


So why do the "Bean Counters" say let's stay with SDTV?  I believe it's because their

thinking is off.  They seem to think that because they are making revenues

for the station now with one program channel that they should be able to

make up to five times more revenues with five channels.  This really will

not be the case as SDTV does not represent any improvement over what we have

today.  The audience will still watch the station, but having more programs

to watch, will be divided.  It's like the old DOS PC's before the

introduction of  Windows.  A viewer can only watch one channel at a time if

she/he is interested in what they're watching.  They generally will never

watch more than one program at any point in time.  So how can the station

say they have more viewers and generate more revenues?  The station would

still have the same number of viewers but would have to have up to four

more program sources to run those five channels. Where will the extra

revenues come from?  The broadcaster will still have basically the same

number of viewers but the advertising would be divided up on the five

programs. The advertiser would probably save money but the broadcaster

would have to find income from other sources.  A town for example of, let's

say, 100,000 people, of which 60% watch the only channel in town, now would

get about a 60% share of the audience.  If the same audience is broken up

for the five additional channels, the same number of viewers will watch the

station's five DTV channels.  Therefore, it is almost a wash, as far as the

station is concerned and the station would have to have and operate more

equipment with more personnel (negative cash flow) to accomplish this.  The

only one who gains is the advertiser.  The viewer will still have TV as we

have now. Only the picture would be more like what we see on todays studio

monitor. The station's income will stay the same but with more costs.


But if the station converts to HDTV, the station then could, because of its

much higher quality, demand a higher premium for that televised image.  It

will carry, in the beginning, a higher premium because it is different. It's

equivalent to:  would you rather have 3 identical Chevy cars in your garage

or would you prefer a single Rolls?  Five STV's or one HDTV.  Remember

viewers can only watch one thing at a time.



DTV is not the same as HDTV but includes HDTV.  DTV is very flexible as

Table 3 points out.  These are transmission standards and have little to do

with the display device. Until the TV set manufactures start shipping the

new DTV sets, we can only guess as to what the consumer of today will go

for tomorrow.





The NWTN is published for broadcast professionals who are interested in DTV, HDTV etc. by Larry Bloomfield, Chief Engineer, KTVZ, Bend, Oregon and Jim Mendrala, Consulting Engineer, Val Verde, California.  We can be reached by either e-mail or land line (541) 385-9115, (805) 294-1049 or fax at (805) 294-0705.  News items, comments, opinions etc. are always welcome from our readers; letters may be edited  for brevity.




NWTN articles may be reproduced in any form provided they are unaltered and credit is given to the North West Technical Notes and the originating authors, when named.


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