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Old March 18th 17, 01:38 PM posted to
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Posts: 1,329
Default TV system conversion

"Graham." wrote in message
I think you've already seen this, and I must redo it sometime, now I
have built a Band I modulator and the picture is miles better.
An obsolete PC with webcam running Vidblaster and WinModelines, which
coaxes half the dual-head graphics card to output 405 lines (or 625 or
813, 525 etc.)

It's still not a real-time system converter, but I question why anyone
would want one, I am perfectly content to digitise analogue TV content
first and import the resulting digits.

Excellent bit of work.

I notice you're getting some 1Hz beating between the pictures on the TV and
your video camera for making the Youtube video. I've just looked at the
"Stats for Nerds" and I see that you shot your Youtube video at 24 rather 25
Hz, so that's why! Maybe in the interests of perfection you should use a
normal 25 Hz camcorder next time :-)

Before the National Media Museum got rid of their TV gallery (a criminal
waste to consign all the equipment that had on show to behind-the-scenes
tours only) they had three screens showing the same recorded pictures:
405-line, 720x576 SD and 1920x1080 HD. I wonder whether they used similar
equipment to you for down-scaling the HD original to 405-line mono, either
via a modulator or a direct tap into the composite video feed within the TV.

I do wonder what planet the National Media Museum are on: first they got rid
of the excellent Tim Hunkin "how TV works" demos, then the Calendar News
studio showing the petrol fire in Summit Tunnel, and all the
behind-the-scenes work to produce a live news programme, and now they have
got rid of most of the TV gallery. What will be left? The still-photography
gallery (which is still good), lots of stuff aimed at children who just like
w**king the buttons, and a few temporary and slightly pretentious galleries
of various photographers' work. Last time I went (before the demise of the
TV gallery) I was fairly underwhelmed, and I bet I would be even more so

It's a shame that when the Museum of the Moving Image on the South Bank in
London closed, more of the displays from there didn't find themselves at the
Bradford museum.