29 Nov
2006
29 Nov
'06
2:09 a.m.
Has anyone here built a gadget to take a UK PAL RF signal as input and output
a US NTSC RF signal (or output something else like composite, which can be
converted fairly easily)? I suspect that a few of the US crowd own UK machines
and may have needed to do this...
I'm thinking that the quickest way might be to homebrew something using a
scrap PC with a UK-spec TV capture card and some sort of video display card
that'll output either composite or to a US TV, but even then I suspect that
there are a few gotchas lurking!
cheers
Jules
29 Nov
29 Nov
8:35 a.m.
Did you try the following website?
http://www.epanorama.net/circuits/index.html
He has a lot of convertor circuits for TVs, VGA, etc...
Cheers,
Ram
10:43 a.m.
From: "Jules Richardson" <julesrichardsonuk at yahoo.co.uk>
I'm thinking that the quickest way might be to homebrew something using a
scrap PC with a UK-spec TV capture card and some sort of video display
card
that'll output either composite or to a US TV, but
even then I suspect
that
there are a few gotchas lurking!
Jules,
have a look at the MYTHTV LINUX package - the addition of a suitable capture
card and video out card should do the job. We've got it to do various
esoteric television standards, for a bit of a taster of what it can do, have
a look here:
http://www.g1jbg.co.uk/fothtv.htm
Most off the links you'll need are on that page.
(shameless plug for a project I'm involved in......)
Jim.
30 Nov
30 Nov
8:14 p.m.
Jim Beacon wrote:
have a look at the MYTHTV LINUX package - the addition
of a suitable capture
card and video out card should do the job. We've got it to do various
esoteric television standards, for a bit of a taster of what it can do, have
a look here:
http://www.g1jbg.co.uk/fothtv.htm
wow - that looks like it'll do the job nicely. I suppose the hardware needed
is at the point where it's almost free these days (and certainly cheaper than
a proprietary converter).
I wonder what the quality's like? Going PAL -> recoder -> NTSC obviously
won't
be as good as native NTSC device output. Or, to put it another way, is the
average PCI TV tuner card as good quality as the tuner found in a good TV set?
Or do they tend to compromise on the design in order to keep costs down? (My
limited experience of TV tuner cards for PCs has been that the output looks
awful - but that may just be a result of the output being on a good CRT
monitor rather than a TV's CRT)
(Hmm, you've got me thinking that the museum probably needs the reverse of
what I'm trying to do - something that'll take all sorts of formats as input
and output VGA or PAL...)
cheers
Jules
10:14 p.m.
On 30 Nov 2006 at 22:14, Jules Richardson wrote:
I wonder what the quality's like? Going PAL ->
recoder -> NTSC obviously won't
be as good as native NTSC device output. Or, to put it another way, is the
average PCI TV tuner card as good quality as the tuner found in a good TV set?
...a silly question occurred to me. Why bother with remodulating?
Why not just drive an RGB monitor with the demodulated output? I use
such an arrangement to view PAL-recoded VHS tapes and resulting color
is much better than local NTSC broadcast quality.
Cheers,
Chuck
2 Dec
2 Dec
2:03 p.m.
From: "Chuck Guzis" <cclist at sydex.com>
On 30 Nov 2006 at 22:14, Jules Richardson wrote:
> I wonder what the quality's like? Going PAL -> recoder -> NTSC obviously
won't
> be as good as native NTSC device output. Or, to
put it another way, is
the
> average PCI TV tuner card as good quality as the
tuner found in a good
TV set?
...a silly question occurred to me. Why bother with remodulating?
Why not just drive an RGB monitor with the demodulated output? I use
such an arrangement to view PAL-recoded VHS tapes and resulting color
is much better than local NTSC broadcast quality.
Cheers,
Chuck
There's no reason why you shouldn't put it onto a VGA monitor, except for
aesthetics - a vintage home computer looks better on a vintage TV set, much
like I try to use period programs when demonstrating the TV sets (I hide the
PC under the table). When experimenting, I use a variety of display
devices - the console drives a modern 1024x768 TFT monitor, and for the most
part, the TV ouput drives a 1970 Sony TV9-90UB monochrome TV, which is dual
standard, and will display either 405 or 625 line pictures. I have a Melford
monitor which will handle 525 and 625, and use a Tektronix 535A scope (circa
1960), with a type O plug-in for esoteric standards, but when it comes to a
demonstration, a 1950's TV set displaying a 1950's program is very
impressive. The advantage of the PC method of picture generation is that it
gives the maximum possible resolution on a set (assuming a well desinged
modulator).
Jim.
10:45 a.m.
On Fri, 01 Dec 2006 05:14:15 +0100, Jules Richardson <julesrichardsonuk at
yahoo.co.uk> wrote:
Jim Beacon wrote:
Both ATI and nVidia have really good video support these days, and Matrox have of course
been in professional equipment for many years.
have a look at the MYTHTV LINUX package - the
addition of a suitable capture
card and video out card should do the job. We've got it to do various
esoteric television standards, for a bit of a taster of what it can do, have
a look here:
http://www.g1jbg.co.uk/fothtv.htm
wow - that looks like it'll do the job nicely. I suppose the hardware needed
is at the point where it's almost free these days (and certainly cheaper than
a proprietary converter).
I wonder what the quality's like? Going PAL -> recoder -> NTSC obviously
won't
be as good as native NTSC device output. Or, to put it another way, is the
average PCI TV tuner card as good quality as the tuner found in a good TV set?
The tuners I have seen in TV cards are identical to the ones in TV sets. I suppose the
processing after the tunes is what makes the difference, and only a few years ago most PCs
were not really up to real-time video processing without glitches. I have a cheap TV- at
nywhere which works fine until they switch to DTB/MPEG4 and turn off PAL transmissions
next year.
Now that PAL and NTSC have been obsoleted by digital TV, most PCs have the processing
power needed to process PAL signals...
...
(Hmm, you've got me thinking that the museum probably needs the reverse of
what I'm trying to do - something that'll take all sorts of formats as input
and output VGA or PAL...)
VGA is acceptable for IEA-standard NTSC-M material (which has only 482 active lines and
4.2MHz video bandwidth), and I guess it is acceptable for PAL in many cases even though
you want rather higher resolution in order to show all the 574 active lines in a
OIRT-standard PAL-D signal with 6MHz video bandwidth. In both cases I think I would opt
for a 600x800 display running at 75Hz refresh instead of 60Hz 640x480 VGA. You would get
some borders around the picture, but everything would be displayed without any
interpolation artifacts.
Depending on the goals you want to accomplish, there is also a NTSC version for standard B
(625 lines 25 frames/s) and a PAL version for standard M (525 lines 30 frames/s). These
standards were used for transatlantic exchange, and in countries like Brazil which had
US-style B&W transmissions but opted for PAL for colour.
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bv＠norbionics.com -
cclist＠sydex.com -
jim＠g1jbg.co.uk -
julesrichardsonuk＠yahoo.co.uk -
RMeenaks＠olf.com