Re: How does digital TV broadcast prevent ghosting effects?
- From: Jan Panteltje <pNaonStpealmtje@xxxxxxxxx>
- Date: Sat, 24 Nov 2007 18:49:26 GMT
On a sunny day (Sat, 24 Nov 2007 05:03:09 GMT) it happened mzenier@xxxxxxxxxx
(Mark Zenier) wrote in <fi9oqp$evh$1@xxxxxxxxxxxxxxxxxxx>:
In article <fi4tln$pao$1@xxxxxxxx>,
Jan Panteltje <pNaonStpealmtje@xxxxxxxxx> wrote:
I have heard that US did chose 8VSB because Europe had an other system,
and 8VSB would help US industry, as Europe then had the same hurdles to
market as the US.
No, they picked 8VSB (for over the air, and a different modulation for
cable) because at that time COFDM wasn't developed enough. The US
standard was defined before the European one. This stuff has been
waiting around for ages, (15 years?), and not really going anywhere.
They made it very complex with something like 13 different screen size and
frame rate combinations and the requirement to deal with incoming 1080i
with reformatting for smaller displays for decoders. That's made the
decoders too expensive and made them wait for "Moore's Law" to catch up.
Add that it's not a worldwide market so the volume is lower.
They took so long that there's no US receiver industry left to protect.
And Direct Broadcast Satellite and Cable and the Internet has left the
decentralized broadcast industry with a declining market.
Mark Zenier mzenier@xxxxxxxxxx
Googleproofaddress(account:mzenier provider:eskimo domain:com)
OK, if you say so.
But I also clearly remember the discussions in the related newsgroups at that time,
about the decision, and 8VSB versus COFDM, and an attempt by the BROADCASTERS
to force COFDM and reject 8VSB, some had alreay installed the COFDM transmitters
IIRC.
They lost (against politics).
The broadcaster very well knew 8VSB was asking for problems (multipath able chips
did not even exist at that point).
And it is exactly the development of those chips that had to be done in the US,
as Europe of course also did not have these (we do not need those).
Some related links (from google 'broadcasters 8VSB oppose'
http://www.fcc.gov/Speeches/Kennard/Statements/2000/ltwek001.html
http://www.google.nl/url?sa=t&ct=res&cd=4&url=http%3A%2F%2Fwww.ncta.com%2FDocumentBinary.aspx%3Fid%3D340&ei=zWxIR6DrDp_8wwHPpJGBDA&usg=AFQjCNHZy5daUSUfe3usS22SnBckKRd2vw&sig2=jj_chDBnXfEjXNHPYV_Waw
The Sinclair tests:
http://www.widescreenreview.com/news_exdetail.php?title=crippscomm
---------------------------
Well, I never tried 8VSB, but here COFDM is sold as 'digitenne' a small active vertical indoor antenna,
the black flat thing in this movie:
http://www.youtube.com/watch?v=A_OBURJ8Sso
Transmitters in almost all major cities, from .5 kW to max 40kW
http://home.planet.nl/~ploe2070/fmtv/dvbt/digitenne-kpntv.html
No complaints.
Now try that indoors in a city with 8VSB?
.
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