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Dave Plowman (News) Dave Plowman (News) is offline
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Default Composite video via RF modulator, negative image?

In article ,
Michael A. Terrell wrote:

"Dave Plowman (News)" wrote:

In article ,
Michael A. Terrell wrote:
"Dave Plowman (News)" wrote:

In article ,
Michael A. Terrell wrote:
Composite video has negative sync.

Not as transmitted; tip of sync is peak output power.

That was done so that any 'snow' in a weak picture was white,
instead of black dots.

Quite the reverse, actually.


Really? Show us a valid cite for NTSC Visual modulation that
agrees with you. (Type M) An old term in the US TV industry for
sync was 'Blacker than Black'. If the modulation is inverted, any
loss of signal strength causes sync to be affected before the video.
I've read the NTSC documents and arguments that were published at
the time the system was created.


PAL as used in most of Europe uses negative modulation - and one
reason was precisely that interference is less noticeable being black
flecks rather than peak white.



NTSC uses 'Negative Modulation' as well, and for the reasons I've
stated.


'Snow' due to poor signal tends to be random noise - with the white parts
showing more. And of course with a weak signal interference is more
likely.

Did you even look at the URL I posted?


http://en.wikipedia.org/wiki/NTSC


No. Wiki is in no way a reliable reference source.

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