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A monthly newsletter by Society of Broadcast Engineers Chapter 48

January 1999


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Contents

Chapter 48's Next Meeting
1998 SBE / SMPTE / SCTE Meeting Schedule
Year 2000 - What's all the hubbub, bub
Members Get Discounted NAB Registration Benefit Again
Thermally Compensated Waveguide Filters
Harris/PBS DTV Express Comes to Salt Lake City
Monthly HAMnet Brings Sbe To Remote Areas
A Look at NWS
Industry News From Chapter 3
Clay's Corner
The End User
More Recommended Reading
Chapter 48 Photo Gallery
Etc.

Chapter 48's Next Meeting...

Will be held on January 20, 1999 at 12:00 noon. Dennis Roundtree of Industrial Power Systems will speak to the gruop about back-up power systems. The meeting location is to be announced.

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1998/1999 SBE / SMPTE Meeting Schedule

WEDNESDAY - 20 January - Dennis Roundtree of Industrial Power Systems will cover back-up power systems. Location TBA

(Tentative) February VAC (Video Accessories Corporation) new facility in Louisville tour. Time TBA.

14 July - World Famous Annual Picnic on Lookout Mountain.

Elsewhere around the country:

33rd SMPTE Advance Motion Imaging Conference, Orlando, FL, February 25-27,1999

Broadcast Education Association 99, Las Vegas, Nevada, April 16-19, 1999

The NAB99 Conferences Apr 17 1999 - Apr 22 1999.

SCTE/Cable-Tec Expo, Orlando, FL, May 25-28, 1999

SBE Leadership Skills Seminar, Indianopolis, IN, June 7-11, 1999

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Year 2000 What's all the hubbub, bub

Rich Kaelberer, Chapter SBE 41

Year 2000 issues are important to all of us. Computers and microprocessor based controllers have become insidious. They are everywhere. They're in your microwave oven, your car, even your alarm clock. Not the least of the places you may find them is in many of your pieces of Broadcast Equipment, and even in your building security system(s) and climate control systems.

The problem(s)? There are actually two. The first centers on the fact that for storage utilization efficiency, years ago, system programmers used only two digits to represent the year. The century was assumed to always be 19. So when the clock rolls from December 31, 1999 to January 1, 2000, we have a problem - 12/31/99 to 01/01/00. Will your system interpret 00 as 1900 or 2000?

Many programs that sequence things by date store the date in the form Year, Month, Day - thus 98/21/31 - or 981231 and 00/01/01 - or 000101. The problem should be obvious: Which is larger (or which should come first) 981231 or 000101? All new systems you purchase should use a 4 digit representation for the year. The second problem revolves around leap year calculations. Most programmers, in fact most people, know that every fourth year is a leap year (any year evenly divisible by 4 is a leap year). Unfortunately, the rule does not stop there. It goes on to say that Century Years (evenly divisible by 100) are exceptions and are NOT leap years. This is where a lot of programmers stopped. BUT, the rule goes on even further to say that a Century Year evenly divisible by 400 is an exception to the Century Year rule. Thus 2000 IS a Leap Year. The rule actually goes even further than that, but personally, I'm not going to worry about that break-point which is out around years evenly divisible by 1600. If your systems do not correctly handle this mess, you could easily be in trouble not only once, but twice (once on Jan 1, 2000 and again when you go from Feb 28, 2000 to March 1, 2000 instead of Feb 29, 2000).

Another potential problem has recently been brought to my attention. This occurs on September 9, 1999. This is, of course, 9/9/99. Some programmers used the 'all nines' as a special case to represent dates when there was no information available to be placed in the data field. As you can see, this can cause a few potential headaches. Additional problems may be encountered with reports that must calculate information that crosses the critical dates (9/9/99, 12/31/99, 1/1/00, and 2/29/00). Problems may also arise with events and functions that automatically re-schedule their execution (such as recurring automatic backups of your system, recurring automatically generated reports, etc.) if they do not individually handle the critical dates correctly. Don't delay - start looking into this NOW!

Test your equipment now and avoid those annoying calls at midnight. There are several good test programs out there that are available for free.

Try: Test2000 available from www.rightime.com and ymark2000 from www.nstl.com.

Recommendations I have heard are to run both of these programs since they each have their strengths and weaknesses. Remember, these will not test application programs, only system components, bios, and operating systems. You need to test your report and analysis programs yourself. For those using Microsoft products, there is rather extensive information on Y2K compliance for their products available on their web site.

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Members Get Discounted NAB Registration Benefit Again

Again in 1999, SBE members will be able to take advantage of discounts to the NAB Convention in Las Vegas. SBE members will get the NAB Member rate discount for the full conference fee. This is a savings of $300! More than five times the cost of one year of SBE dues! Registration forms will come direct from NAB, and you probably have already received one or more of the mailings. But if you don't get one in the mail by the end of January, call NAB Conventions at (202) 429-5419 and request one be sent to you.

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Thermally Compensated Waveguide Filters

By Dr. Paul D. Smith
Reprinted with permission from the December 1998 Micronews.

Thermal stability of RF filter responses has become increasingly important in television broadcast systems. The primary reason for this heightened requirement is spectrum crowding, which reduces the available transition bandwidth for mask and adjacent channel combining filters. For instance: if a given filter application allows a maximum of 700 khz in which to transition from passband to stopband and if the filter is expected to drift 300 kHz, then that filter must transition within 400 kHz at any given temperature. The necessity of accommodating thermal drift just forced the RF system solution from a sixth order filter to a tenth order filter!

Another motivation for developing temperature stable filters is to facilitate group delay correction. Adaptive group delay pre-correctors monitor RF system outputs and impress equal but opposite distortions upon the signals at the system input. This robust solution allows for the possibility of a time varying RF system response. On the other hand, transmitters equipped with fixed pre-correctors rely on the assumption that the RF system response is constant. Fixed pre-correctors impress an approprite pre-distortion to the input signal as long as the RF filter response does not drift with ambient temperature and applied power.

The thermal drift of waveguide filter responses is simple to understand. A waveguide filter is a cascade of precisely coupled cavities which all resonate at a single frequency that is inversely proportional to the cavity dimensions. As cavity temperatures rise, the metals expand proportionately and very predictably. This in turn results in a very predictable downward frequency shift in the filter response with increasing temperature. This frequency shift can be reduced either by using more stable materials or by adding an inverse frequency drift compensating device to each cavity.

MCI has a long history of building high power, temperature stable filters with great success by constructing the filter ccavities of Invar, a highly temperature stable nickel-iron alloy. This metal expands so little with increasing temperature that filters constructed from it remain essentially stable. However, Invar is not always the optimal solution. Invar is expensive and heavy, and it does not lend itself well to the construction of in-line Chebyshev waveguide filters. MCI has therefore developed a thermally compensated filter as an alternative to Invar filters.

MCI Thermally Compensated Waveguide Filters have frequency tuning probes in each of the cavities that, by themselves, raise the resonant frequency with increasing temperature. These tuners are precisely engineered to impart frequency shifts that are equal and opposite to the natural downward shift in frequency due to thermal expansion of the aluminum cavity. Conceptually simple, the real challenge in designing these filters is to determine the exact dimensions that are required to get the job done. Once this is acccomplished, the final result is a very solid, very repeatable high power filter that is temperature stable. These filters will cost a bit more than their uncompensated counterparts, but once you have one, you can forget about how much power you are going to run through it and how hot or cold the filter may get.

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Harris/PBS DTV Express Comes to Salt Lake City

From Chapter 62

This February 16th - 19th, KUED in Salt Lake City will be proud to host the HARRIS/PBS DTV EXPRESS, a national educational program that can help you with the transition, challenges, and opportunities of digital television. This innovative and in-depth seminar series has been developed with the knowledge of industry experts from over 45 leading technology companies to highlight the key business and engineering changes for you and your television station.

Business managers will participate in a full day seminar and discussions that highlight the DTV technology - in a business context - as well as new service opportunities and critical transition issues.

Engineering managers will participate in a two and a half day seminar and workshop to cover the changes in the transmission and studio elements of the broadcast operations. Each participant will receive a workbook to continue learning and share information with others at your station.

You will be able to see working demonstrations of the services and DTV equipment you'll need, participate in hands-on demonstrations (for engineers), and experience what the DTV world will look like to your viewers at home. Each seminar participant will experience an informational - and entertaining - tour through the high-tech 66-foot DTV express vehicle.

Registration costs are $200 for the business track and $250 for the technical track. These costs go directly to PBS Express for the operation of the truck and seminars. NONE of it goes toward KUED or the University of Utah.

To sign up for the seminars, please visit the DTV Express web site at http://www.dtvexpress.org

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Monthly HAMnet Brings SBE To Remote Areas

At 20:00 EST, 0000 GMT, on the second Sunday of each month, SBE Chapter 73 takes to the air. Hal Hostetler, WA7BGX, of Tucson, Arizona, is the control station for the "meeting". Updates on SBE activities are given each month and participants can discuss technical issues and visit. HAMnet was originally begun to help serve members who lived too far to attend meetings of any regular chapter, but any amateur operator is welcome and encouraged to participate. Look for HAMnet on 14.205 mHz.

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A Look at NWS

Chapter 124

Our recent tour of the Portland area NWS office was very interesting. The current Weather Radio system is a DOS program that runs on a PC, and the audio is recorded with a telephone handset! That explains the ghastly lack of quality. The infamous bell that announces the Portland forecast sits right there in the same cubicle. The new "Weather Radio 2000 Console Replacement System" looks very slick, but the DECtalk text-to-speech synthesized voice that is supposed to have the highest quality and accuracy (used by Stephen Hawking), sounds dated ("it will be sun-knee"). At least they can program the correct local pronunciations, and the new system sports a headset with an actual non-carbon microphone for the recording of announcements. They will also be able to stick to a "format" clock, so that the most popular forecasts will play at the same times every hour. By the way, the NWS owns a Sage Endec system, and they hope to interface it with Weather Radio 2000 next year.

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Industry News

Chapter 3

Clear Channel has scored another coup in a merger with Jacor Communications which will top out at over $4.4 Billion of stock swap, and $1.26 Billion in Jacor debt. Clear Channel will be the surviving company and will count at total of 454 U.S. radio stations in 117 markets, and 12 TV stations. Clear Channel already owns 171 foreign radio stations and 220,000 billboards world wide.

Scientists have discovered small gaps in the aurora borealis. They have found gaps in the light when it was thought none should be occurring, and have no explanations. The gaps appear between 7 PM and midnight, and about 10 to 20 minutes before and sometimes after the onset of a magnetic storm. The northern lights are shaped in an oval ring shown in a time lapse picture from an ultraviolet imager aboard the Polar spacecraft.

Scientific Atlanta has announced a range of products designed to support the national rollout of HDTV in November. Of particular interest to broadcasters are SA's solutions to the problem of 8VSB over cable systems. The model SP-1D signal processor enable cable operators to deliver broadcast DTV programming over cable. The unit can translate any 8VSB off-air signal to any designated cable channel in the 50-890 MHz range. The units are available now.

Lockheed Martin Global Telecommunication, in conjunction with a leading group of broadcast service providers, laboratories, and development facilities, successfully demonstrated "the first real-time MPEG-4 over satellite link" recently. With MPEG-4, "the customer's television set has the ability to match its processing power to the incoming video information. The new standard enables content providers to design feature-rich programs that let customers with lower bandwidth choose the elements they most desire such as the audio from a signal, or a central image (of a tennis player, for example, without background), or just the overlay text services of any given program."

In an effort to reduce the number of requests for extensions of CPs, the FCC will extend station construction time from 2 years for commercial and 1.5 years for all others to 3 years for all stations. The move to the Portals is finally underway. I would suggest you save copies of any documents or filings you make with the FCC for a while, and mail them registered with returned signature option. Some of the previous FCC moves have resulted in lost documents causing repeat work.

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Clay's Corner

Clay Freinwald, Chapter 16, Seattle

One of the major findings of this past year came only recently... the discovery that Duct Tape is good for everything but DUCTS! After all this time we have been led to believe that this wonderful gray stuff was really being misused. Apparently the heat from using it on ducts caused the adhesive to dry out and it falls off. I wonder if the world will discover Gaffer's Tape next; I carry a roll around in my truck.

From the department of Nifty Gizmo's... the Kirkland firm, Absolute Software, has developed a little program that you load into your software. If someone steals your laptop and connects it to a phone line this little bit of code calls them and reports where the PC is located. In the event you reported it stolen they call the cops with the phone number from where it called home. Pretty cool. Now if they would do the same for stolen Cellular Phones.

IBOC moves ahead... well at least to the point that one of the proponents has asked the FCC for a rule making. In their petition some interesting statistics about our FM band are revealed....

The reason for this showing is that IBOC (In-band-on-channel) Digital operation will put a considerable amount of stress on adjacent channels, creating a very complicated dynamic. Just when you thought that AM was bad.

Harris is finding success with their new Z-Series of solid state FM transmitters... to the point that they are dropping three of their lower powered tube final FM rigs. Their 10 kW tube final transmitter will also be dropped from the catalog in mid 1999.

Looks like CD radio is ramping up. They've been selling stock, awarding contracts for their Up-link (Globecomm) and building a studio complex in New York that will house the digital studios for their some 100 stations. If all goes well they plan to hit the air with some 50 channels of commercial free programming for about 10 bucks a month. Wall Street likes it... we will see. It sounds to me to be more of a competitor to CD and Tape players than Radio.

Are you having a problem with RF from your Cellphone? Perhaps you need RAYAWAY. Check this one out at www.rayaway.com. According to their site they have a chip that can be applied easily to all portable hand mobile telephones that will provide protection against electromagnetic fields... AND... EARTH RAYS!

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The End User

Richard Jones, CPBE, Chapter 16

About two years ago, as the Internet was taking off, many old-timers and "newbies" were beginning to jam the information superhighway and predictions about its future were just as prevalent. Most of the predictions had it that the infrastructure could not support the growth rate that was taking place. At that time it was believed that the cost of providing service would rise and many Internet providers would go out of business leaving just a few to charge higher rates for access. This in turn would drive many users back off the Internet.

It appears that the exact opposite has occurred. In fact, there are more Internet providers than ever before and more are coming aboard. Not only are there big players such as the various phone companies but many smaller "mom and pop" operations as well. All are competing with one another and quite successfully at that. Predictions of dire consequences have not happened. It was once believed that online prices would skyrocket. In fact, they have plummeted. Many providers that once charged $19.95 for unlimited access have lowered their rates to $16.95 and some as low as $14.95 for unlimited access. Whether this will continue remains to be seen as the laws of supply and demand appear to be working well at this point in history.

Most of this is for standard telephone/modem access but in addition to that are newer high speed connections. Digital Subscriber Line (DSL) is now being marketed that allows for connection rates of 30 to 50 Mbps -- blazingly fast compared to today's standard connect rate of 33 to 56 Kbps.

The question remains: can the Internet keep up with all of this activity? Many have speculated that the Internet would eventually collapse under all of this weight -- and that may have been true if the Internet were a standard centrally-based network. But it's not. It's more of a web with independent connections that do not rely on other parts of the web for communications. Nevertheless, there are just a few trunk areas where the whole system could bog down if too much traffic tries to jam its way through. Seems that modem speeds don't always guarantee fast access.

Now there's talk -- in fact, more than just talk -- of an "Internet 2", which would connect universities and government agencies; something the original Internet was created for. This new Internet is still in the exploration stage but expect to hear more about it in the future.

For years the FCC was denying that they were considering a "modem tax" on users who connect to the Internet. It's not a modem tax but a reciprocal tax that would be imposed on Internet service providers. It would be a per-minute fee to, essentially, refund money back to the phone companies because they apparently lose money when users fire up their modems and connect. Whenever the connection crosses over state lines to another phone company that phone company loses money on the connection. It would be a kind of reciprocal long distance charge that the Internet Providers may have to pay the phone company- -which, in turn, would be passed on to the consumer. The FCC denies that they are imposing a "modem tax" and that this is an urban myth that recurs every few years. However, there does appear to a consideration of new rules for the phone companies regarding interstate fees charged one another to help balance out costs resulting from Internet access.

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More Recommended Reading

Chapter 26

A Technical Introduction to Digital Video
Charles A. Poynton
Published by John Wiley & Sons
Publication Date: January 1996
ISBN: 047112253X

The publisher, John Wiley & Sons:

Poynton, who has won awards for his work integrating video and computing, has written an interesting and enlightening reference on the basic concepts and processes essential for successful design and development of digital video projects. Featuring 200 line drawings and photographs as well as 12 pages of four-color artwork, this book will prove indispensable for technical people who are not video experts. Synopsis:

Not a programming or a recipe book, this is a complete reference that presents the fundamental concepts and processes development of digital video projects. This book is designed for technical people not already video experts who need to design, build and program--hardware and software--systems that include video.

If you would like to get more information regarding these books or make suggestions for books to add to the list, please send your comments to sbe26@broadcast.net

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Chapter 48 Photo Gallery

If you have any old photos of Chapter 48 events, we can put them into an electronic "photo gallery" on the Chapter 48 Web Page. Send your photos, with a brief description to:

Eric Schultz
National Digital Television Center
4100 E. Dry Creek Road
Littleton, CO 80122

If you would like your photos back, please send along a self-addressed stamped envelope.

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Society of Broadcast Engineers
Chapter 48

2950 South Birch Street
Denver, Colorado 80222


SBE Officers

Chairman
Andre' Smith (303)556-3549
asmith@carbon.cudenver.edu

Vice-Chairman
Fred Baumgartner (303) 486-3946
Baumgartner.Fred.M@tci.com

Secretary/Treasurer
Bill Harris (303) 756-4843
BHarris4@IX.netcom.com

Certification Chairman
Fred Baumgartner (303) 486-3946
Baumgartner.Fred.M@tci.com


SMPTE Officers

Chair
Fred Baumgartner (303) 486-3946
Baumgartner.Fred.M@tci.com

Secretary/Treasurer
Rick Craddock (719) 634-2844

Managers
Myron Olinger
Dick Phannenstiel
George Sollenberger

SMPTE Govenor (National Liason)
Rome Chelsi


Newsletter Committee

Bill Harris.......(303)756-4843 email: BHarris4@IX.netcom.com
Garneth M. Harris..(303)756-4843
Andre' Smith.......(303)556-3549 email: asmith@carbon.cudenver.edu

Views expressed herein do not necessarily reflect the official positions of the Society, its officers, or its members. We regret, but are not liable for, any omissions or errors. The Denver SBE & SMPTE Newsletter is published approximately twelve times per year. It is prepared with a combination of text and graphic data. Submission deadline is 10 days before the last day of each month. Other SBE chapters are permitted to use excerpts if attributed to the original authors, sources, and/or the Denver SBE Newsletter.