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Battery-powered digital TVs

Dear editor:

While it is not an amateur radio issue, the role of hams in recent disasters has brought to our attention a problem that could have major consequences for the TV broadcast industry: There are no battery-powered digital TVs for people to use in emergencies.

We have looked in vain for them, but there are none. The closest we could find are a few models powered by 12V “wall warts” that might be connected to a car battery. We have been told that the chip sets in the converters draw far too much amperage for normal battery-powered applications.

Millions of people in weather-prone areas get their news and information via TV. When there is severe weather — hurricane, ice, tornado warnings, etc. — and commercial power is out, they use the small 5in, B&W sets to see the maps and get information they need to cope. Radio is helpful in this, but people prefer to see their situation whenever possible. This will no longer be possible.

The Sept. 8 transition to digital in Wilmington, NC, happens at the height of its hurricane season. Bill Morine, chairman of our national ARRL PR committee, is a resident there and is quite conversant on the topic. He has tried to bring it to the FCC's attention. You may want to contact him ( for more information.

Thank you for your consideration in this issue, and I look forward to your aid in making this issue known and resolved in some way.
Allen G Pitts, W1AGP
Media and PR manager
ARRL (The National Association for Amateur Radio)
Newington, CT

Will DTV kill over-the-air television?

Dear editor:

We in Montana are fortunate to live in the land of milk and honey. Unfortunately, every home builder in the country wants his own private piece of the Big Sky, with at least a six-strand barbed-wire fence or chain-link fence around it, and electric gates at the entrance.

Problem No. 1: These pilgrims could care less about Montana news or broadcasting. Instead, they believe a waiver to receive distant network television signals from their hometowns like Los Angeles, Chicago or Dallas is a human right guaranteed in the Constitution of the United States of America. And in no case whatsoever are they going to sully the appearance of their trophy homes with rooftop antennae to receive local television.

Problem No. 2: Nobody else is going to tolerate a rooftop antenna either. Those days began to die in 1980, when satellite service became possible.

Problem No. 3: If any homeowner has signal reliability issues, he's not going to mess around with it. Instead, he will go to programming available from direct-to-home satellite, rented movies, the Internet, etc.

Problem No. 4: After exposure to satellite TV, nobody here willingly tolerates “country TV” with (analog) sparklies, shot noise and lightning hits, or a (DTV) signal coming and going depending upon whether or not the trees have leaves, the ground is wet or dry, there is snow cover or not, the neighbor parked his car in a different location, or lightning strikes somewhere within 20mi, any of which can send his high-dollar DTV receiver falling off, resulting in no picture.

I have been assured that the math doesn't lie — that my channel 10 DTV signal with 26.1kW ERP will match or exceed my analog channel 2's 100kW signal coverage, and in a superior fashion to boot. That doesn't explain why the local analog channel 8 has run 316,000W for coverage comparable to (but not quite as good as) channel 2 in this market.

Bottom line: If it's easy, people will use it. Look at Blackberrys and cellular phones. They're easy, they're handy, and they work. If DTV doesn't provide the same level of ease, convenience and reliability, viewership will diminish. I see some hope for mobile television if a business model and technical standard can be found, but as for survival of HD and SD DTV, we'll all be much more enlightened after the first quarter of 2009.

Test Your Knowledge!

See the Freezeframe question of the month on page 6.

(Art: This first feedback item talks about how there aren't battery-powered digital TVs, which would be helpful in case the power goes out due to severe weather. So, I was thinking maybe an image that shows a tornado or really bad storm …)

AES/word clock generators

Dear editor:

In the June 15 edition of the Transition to Digital e-newsletter, you mention in “Digital audio details II” that “There are video-referenced AES/word clock generators available that accept analog video black, SDI or even trilevel HD sync to lock to and provide alarms if the video reference is lost.”

I've been looking for a long time for a device that is able to generate word clock from an SDI signal. It sounds like you found it! Can you send me the details?
Wilfried Kumeling

Russell Brown responds:

I am sorry I took so long to get back to you, but I had to research where I saw this device.

DK-Technologies makes the PT5300 sync generator that locks to SDI and generates a word clock and AES3 outputs.

In order to lock to SDI, you will need the PT8606 option as well as the PT8635 option to generate the word clock and AES3 outputs.

Here is a link to the web page for the PT5300:

I hope this helps. I know it is hard to find any equipment that locks to SDI.

Electronic version of Broadcast Engineering

Dear editor:

I was wondering if Broadcast Enginnering comes in a PDF or CD form?
Mitch Kindley
F.C. Schafer Consulting
Concord, NC

Editor responds:

Currently, Broadcast Engineering is not available in a pdf or CD form. However, we do produce a monthly Ezine, an online version of our world edition. For more information, visit: