composite to VGA

B

b

Guest
just seen this,
http://www.isec-solutions.co.uk/P/CCTV-VGA-to-BNC-Converter(296).htm

never tried sending composite to VGA before, but it would mean making
use of lots of old PC monitors! How exactly do these things work?
(scan rates etc)
B.
 
Though VGA has the same number of scanning lines as composite (US) video,
it's an RGB system. Composite won't work. How do you intend to generate the
primaries from the composite?
 
"b" <reverend_rogers@yahoo.com> wrote in message
news:8b8568a3-6525-49d0-8e24-f89dfcb6e694@f19g2000yqh.googlegroups.com...
just seen this,
http://www.isec-solutions.co.uk/P/CCTV-VGA-to-BNC-Converter(296).htm

never tried sending composite to VGA before, but it would mean making
use of lots of old PC monitors! How exactly do these things work?
(scan rates etc)
B.
Click to expand...
What the mother fuck does this have to do with electronics repair you
spamming jerkoff?
 
b wrote:
just seen this,
http://www.isec-solutions.co.uk/P/CCTV-VGA-to-BNC-Converter(296).htm

never tried sending composite to VGA before, but it would mean making
use of lots of old PC monitors! How exactly do these things work?
(scan rates etc)
Click to expand...
(1) They need to extract RGB from colour composite,
(2) They need to scan-convert from ~15KHz (PAL/NTSC) to at least 30KHz
for VGA.


--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
 
Bob Larter <bobbylarter@gmail.com> writes:

b wrote:
just seen this,
http://www.isec-solutions.co.uk/P/CCTV-VGA-to-BNC-Converter(296).htmff
never tried sending composite to VGA before, but it would mean making
use of lots of old PC monitors! How exactly do these things work?
(scan rates etc)

(1) They need to extract RGB from colour composite,
(2) They need to scan-convert from ~15KHz (PAL/NTSC) to at least 30KHz
for VGA.
Click to expand...
Unless it does a full scan conversion, not going to work on any
VGA monitor less than perhaps 15 or 20 years old as they don't
support scan rates below normal 640x480 VGA at around 31 kHz H rate.

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
 
On 30 mar, 15:18, s...@repairfaq.org (Samuel M. Goldwasser) wrote:
Bob Larter <bobbylar...@gmail.com> writes:
b wrote:
just seen this,
http://www.isec-solutions.co.uk/P/CCTV-VGA-to-BNC-Converter(296).htmff
never tried sending composite to VGA before, but it would mean making
use of lots of old PC monitors! How exactly do these things work?
(scan rates etc)

(1) They need to extract RGB from colour composite,
(2) They need to scan-convert from ~15KHz (PAL/NTSC) to at least 30KHz
for VGA.

Unless it does a full scan conversion, not going to work on any
VGA monitor less than perhaps 15 or 20 years old as they don't
support scan rates below normal 640x480 VGA at around 31 kHz H rate.

--
sam | Sci.Electronics.Repair FAQ:http://www.repairfaq.org/
Repair | Main Table of Contents:http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ:http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites:http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
Click to expand...
thanks Sam and Bob. getting RGB from composite and upping the scan
rate seems no easy task, which is why I was surprised to see these
things so cheap. Presumably they use buffers, processing power etc. A
few years ago it would have been pretty much unthinkable I suppose.
B
 
b <reverend_rogers@yahoo.com> writes:

On 30 mar, 15:18, s...@repairfaq.org (Samuel M. Goldwasser) wrote:
Bob Larter <bobbylar...@gmail.com> writes:
b wrote:
just seen this,
http://www.isec-solutions.co.uk/P/CCTV-VGA-to-BNC-Converter(296).htmff
never tried sending composite to VGA before, but it would mean making
use of lots of old PC monitors! How exactly do these things work?
(scan rates etc)

(1) They need to extract RGB from colour composite,
(2) They need to scan-convert from ~15KHz (PAL/NTSC) to at least 30KHz
for VGA.

Unless it does a full scan conversion, not going to work on any
VGA monitor less than perhaps 15 or 20 years old as they don't
support scan rates below normal 640x480 VGA at around 31 kHz H rate.

--
sam | Sci.Electronics.Repair FAQ:http://www.repairfaq.org/

thanks Sam and Bob. getting RGB from composite and upping the scan
rate seems no easy task, which is why I was surprised to see these
things so cheap. Presumably they use buffers, processing power etc. A
few years ago it would have been pretty much unthinkable I suppose.
Click to expand...
There are single chips nowadays to do scan conversion but you would need
to confirm that in fact the $30 device actually does it.

I remember when they took up a 19 inch rack space and cost $10,000!

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
 
In article
<cf36688a-1a18-4dea-a6ad-a28fbd7c5bac@o36g2000yqh.googlegroups.com>,
b <reverend_rogers@yahoo.com> wrote:
thanks Sam and Bob. getting RGB from composite and upping the scan rate
seems no easy task, which is why I was surprised to see these things so
cheap. Presumably they use buffers, processing power etc. A few years
ago it would have been pretty much unthinkable I suppose. B
Click to expand...
I've got two convertors designed to allow a VGA monitor to run a broadcast
video signal and neither work particularly well. The newest one about 2
years old and cost quite a bit. I wanted to have one monitor in my
workshop that would accept pretty well any signal. In the end I bought a
TV with a VGA input and that does work just fine.

--
*Nostalgia isn't what is used to be.

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
Dave Plowman (News) wrote:
I've got two convertors designed to allow a VGA monitor to run a broadcast
video signal and neither work particularly well. The newest one about 2
years old and cost quite a bit. I wanted to have one monitor in my
workshop that would accept pretty well any signal. In the end I bought a
TV with a VGA input and that does work just fine.
Click to expand...
One of the big problems I found with these is they didn't react well to
unstable video signals. You may *think* that's uncommon, but it's not
-- the signal from a typical VCR has a lot of sync jitter, for example.
This tends to cause LCD monitors to continually black out and attempt
to auto-sync.
 
In article <66adnevNGfTek0XUnZ2dnUVZ_rHinZ2d@speakeasy.net>,
David Brodbeck <gull@gull.us> wrote:
Dave Plowman (News) wrote:
I've got two convertors designed to allow a VGA monitor to run a
broadcast video signal and neither work particularly well. The newest
one about 2 years old and cost quite a bit. I wanted to have one
monitor in my workshop that would accept pretty well any signal. In
the end I bought a TV with a VGA input and that does work just fine.

One of the big problems I found with these is they didn't react well to
unstable video signals. You may *think* that's uncommon, but it's not
-- the signal from a typical VCR has a lot of sync jitter, for example.
This tends to cause LCD monitors to continually black out and attempt
to auto-sync.
Click to expand...
I never tried it with a VCR - just FreeView (UK terrestrial digital) And
one of my main dislikes was that that computer monitors tend to as you say
auto sync to fill the screen - not much use with a mixture of 16:9 and
4:3, as you get here.

--
*I have my own little world - but it's OK...they know me here*

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
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