Most HDTV broadcasting in Australia is on VHF! Is Australi..

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"HireMe.geek.nz" <mikehack@u.washington.edu> wrote:

> Is Australia an exception, or do several countries intend on using
> VHF heavily for HDTV?

The US is broadcasting H/DTV on both VHF and UHF. They will likely use
a *lot* of highband VHF for H/DTV after analog is shutoff. Currently,
the only US city that is nearly all VHF-DTV is Las Vegas.

Lowband VHF DTV suffers from impulse noise interference problems.
However the US 8VSB system is more immune to this problem than COFDM,
if sufficient transmitter power is used. :-)

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not@127.0.0.1 wrote:
> "HireMe.geek.nz" <mikehack@u.washington.edu> wrote:
>
>
>>Is Australia an exception, or do several countries intend on using
>>VHF heavily for HDTV?
>
>
> The US is broadcasting H/DTV on both VHF and UHF. They will likely use
> a *lot* of highband VHF for H/DTV after analog is shutoff. Currently,
> the only US city that is nearly all VHF-DTV is Las Vegas.
>
> Lowband VHF DTV suffers from impulse noise interference problems.
> However the US 8VSB system is more immune to this problem than COFDM,
> if sufficient transmitter power is used. :-)

Band I channel A3 (60-66MHz) isn't working very well in Chicago...
(http://www.avsforum.com) Then again, local interference from analog
stations in Wisconsin and Michigan (both roughly 200km distant) might be
the real problem.

My employer is using Band III channel A10 (192-198MHz) VHF for digital
transmission with considerable success.
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

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Doug Smith W9WI wrote:

>
> Band I channel A3 (60-66MHz) isn't working very well in Chicago...
> (http://www.avsforum.com) Then again, local interference from analog
> stations in Wisconsin and Michigan (both roughly 200km distant) might be
> the real problem.


200 km ... who not use real measure, that's about
120 miles, is also the distance of our local Channel
three here in central Illinois.

The problem with Ch. 3 in Chicago is not
distant interference, it is too-low power, pure
and simple.

A low DTV VHF station should be about 50 kW ERP
(digital measure) absolute minimum, ideally 100 kW.
This is necessary to get around impulse noise in
cities. Also, the antennas used on low channels
are never very good.

Doug McDonald