SBE CHAPTER 40 NEWSLETTER
AUGUST 1998
SAN FRANCISCO
Roy Trumbull - Editor roy547@netcom.com
Bill Dempster - Artist
Advertisers for this month's newsletter are:
Zack Electronics - (800) 998-3947
Advanced Marketing - Frank A. Santucci - (650) 365-3944
Riggins Electronics Sales - George Riggins - (662) 598-7007
Orban - Rick Sawyer - (360) 715-1913
MARCOM - Martin Jackson - (408) 768-8668
William F. Ruck, Jr. Broadcast Engineer - (415) 995-6969
Communications Law Center - Philip M. Kane - (650) 369-7373
RF Specialties of California - Bill Newbrough - (888) 737-7321
Hammett & Edison, Inc. - Dane E. Ericksen, P.E. - (707) 996-5200
LeBLANC - David A. Hill - (650) 574-4600
Pacific Research & Engineering Corp. - William Hopkins - (760) 438-3911 Keith Davidson & Company - Keith Davidson, CSBE - (707) 648-0412
Improbable Missions Fource - Mike Schweizer - (888) 4-ISDN4U
Svetlana Electron Devices - George Badger - (800) 578-3852
TFT Inc. - Jesse J. Piatte, Jr. - (408) 727-7272 x504
Audio Accessories - Rosie Alexander - (510) 787-3335
Brill Electronics - Marcie Mearns / Field Sales - (510) 308-1248
Brill Electronics - Larry Shore / Inside Sales - (510) 834-5888
Scala - Michael Wm. Bach - (541) 779-6500
Scala - Everett E. Helm, CPBE - (541) 779-6500
Harris - Ed Longcrier - (800) 315-7285
Anixter - Judy Conner - (510) 489-7430
 

BABES/SBE LUNCHEON ON WEDNESDAY AUG 26TH
This month our program will feature the new monitoring equipment from Tektronix for over-the-air digital television.

As usual our luncheon will be at Sinbad's. Sinbad's is just south of the Ferry Building on the Embarcadero near the foot of Mission Street. Please RSVP to Karen Prasek at Zack's: 408-324-0551 x126 as we've been running out of tables and chairs. We meet at 11:30 and are seated at 12:30.

Future Meetings
DTV IS MTV
The M stands for Merrill as in Merrill Weise. He's the engine driving many a standards committee and one of the best people to know in the shifting world of digital. During the recent Model Station meeting in DC I learned from Merrill about a new phone service which is known as 270 MHz overlay. It's a way to transport serial digital video. It doesn't suffer from the outage specs of DS3 or its pricing. When you buy a 2-way telco service it winds up being equated to the number of POTS it could provide and you are charged accordingly. The 270 overlay is a one-way transport and cheaper than DS-3.

We are trying to setup an evening meeting with Brad Medford of Pacific (Taco) Bell to bring us up to speed on this new service that will be available next year.

WAFFLE IRONS AND DRY SUPPLIES
Those of us putting in DTV transmitters found out that we have to make room for a ten foot + long wavequide lo-pass filter known as a waffle iron filter. It has all manner of ridges internally. The basic problem, other than harmonics, is that you don't want to radiate anything on the GPS frequency.

While wet beam supplies have been the norm for UHF, it looks like the dry supplies are coming. Some of the supplies at Sutro will be switching power supplies capable of 35,000 volts. They'll mount in a standard rack. The advantage is that you can achieve really fine control of the voltage but then damp down quickly when an arc starts. Only prototype units are in the field presently and the supplies at Sutro should come from the first production run.

MASTERCONTROLLER FOR WINDOWS
I just started using the Windows version of Moseley's software for the MRC2 remote control.

The new software is based around a computer functioning as a server that is looking at all your sites. Users are networked to the server.

Screens can be constructed with meters, pushbuttons, LEDs, spreadsheets, and text boxes. Moving elements around and sizing them is still a bit crude but there is an alignment feature. Still needed is the ability to specify spacing of elements and to draw lines between text boxes for diagrams.

I really like the spreadsheet feature. I have four amplifiers that each have 9 identical alarm functions. With the spreadsheet I was able to list the alarms in a vertical column and list the amplifiers across a horizontal header row. The spreadsheet intersections contain the channel status messages.

All of the site and channel information is entered into a MS Access database that is linked to the program.

BILL RUCK'S FATHER DIES
Bills father died the morning of Aug 12th after a short illness. In lieu of flowers, the family suggests contributions to the Roy Esposto Library Fund, Hanna Boys Center, P.O. box 100, Sonoma, CA 95476

FRANK FOGE INJURED
Frank Foge received a concussion at Monument Peak after being hit on the head by a hose fitting. He is in San Jose Hospital.

EMAIL ADDRESS
If you have an email address, please contact Warren Reese at radions@jps.net. Warren is in charge of our email list, which we use when we need to notify members when something has happened between newsletters.

WEB PAGE
Webmeister Tim Pozer has the current newsletter plus newsletters all the way back to 1996 at: http://www.lns.com/sbe

AFTER DEADLINE
After laying out and printing the newsletter, something always comes to light and the web page gives me a chance to follow-up. It turns out no one at Sutro intends to take delivery of a "dry" supply at this time.

AUDIO MYSTERY
We assume that the networks will use some form of "light" compression to take 1.5 gig video down to 270 MHz or even 45 MHz for transport. What will they do with the audio? There's not a simple way to transport 5.1 channels of sound other than encoded as AC3. That creates a problem when decoded audio is used with "lightly" compressed video as there will be a loss of sync.

If a network sends out surround sound sometimes and AC3 others, there isn't a simple way to detect the difference and adjust the audio/video rubber band to set sound sync.

A Dolby AC3 encoder will recognize surround sound but it must be set in the appropriate mode to do so. There is no standard for "lightly" compressed video.