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Component video really need 75 ohm cable?

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Anonymous
May 4, 2004 4:42:38 PM

Archived from groups: rec.audio.tech (More info?)

Hi Folks,

I just upgraded to a new "progressive" DVD player and of course the salesman
tried to sell me a $50 component video cable to connect it. So for now I'm
using a regular three-wire RCA cable meant for composite video and
Left/Right audio, and it works, but I'm wondering if I really would benefit
from better cables.

Thanks for any advice.

--Ethan
Anonymous
May 4, 2004 8:00:16 PM

Archived from groups: rec.audio.tech (More info?)

Here is a website that seems to be a reasonably accurate answer to
your question:

http://members.aol.com/ajaynejr/compon.htm

One thing that you might do is to plug in just the yellow cable to the
yellow jacks. The resulting image will be monochrome but will show the
maximum bandwidth (sharpness) possible. When plugging in the P'b and
P'r, do you see a loss in image detail and are there color distortions
in the fine detail? If so, the audio cables may be degrading the color
information. The above website suggests that you are not likely to
have a significant problem and with good reason: The color channel
bandwidths are signficantly lower than the luminance component. The
human visual system has much better spatial resolution with respect to
luminance than to color.

Of course, you might also consider a DIY cable set. Given your
absolutely outstanding technical qualifications, this would be a
trivial (but annoying) undertaking! :-)

"Ethan Winer" <ethanw at ethanwiner dot com> wrote in message news:<wLWdnbcvZfmcVQrdRVn-ig@giganews.com>...
> Hi Folks,
>
> I just upgraded to a new "progressive" DVD player and of course the salesman
> tried to sell me a $50 component video cable to connect it. So for now I'm
> using a regular three-wire RCA cable meant for composite video and
> Left/Right audio, and it works, but I'm wondering if I really would benefit
> from better cables.
>
> Thanks for any advice.
>
> --Ethan
May 4, 2004 8:55:52 PM

Archived from groups: rec.audio.tech (More info?)

Ethan Winer wrote:
> Hi Folks,
>
> I just upgraded to a new "progressive" DVD player and of course the salesman
> tried to sell me a $50 component video cable to connect it. So for now I'm
> using a regular three-wire RCA cable meant for composite video and
> Left/Right audio, and it works, but I'm wondering if I really would benefit
> from better cables.
>
> Thanks for any advice.
>
> --Ethan
>
>

Why do you think the "regular" cable is not 75 ohm?

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
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Anonymous
May 4, 2004 8:55:53 PM

Archived from groups: rec.audio.tech (More info?)

CJ,

> Why do you think the "regular" cable is not 75 ohm? <

Well, I know what RG59 looks like, and the thin RCA cables I'm using now
ain't them. :->)

Seriously, the component video looks okay, and is slightly better than the
composite output. Mostly the colors are better and less washed-out looking.
I was also expecting a meaningful improvement in overall sharpness and
clarity, and I'm not getting that. Hence the question as to whether cables
in this particular application really do matter. I *know* that cables don't
matter most of the time even though audio stores try to convince you they
do.

Thanks.

--Ethan
Anonymous
May 4, 2004 9:53:50 PM

Archived from groups: rec.audio.tech (More info?)

Ethan Winer wrote:
> Hi Folks,
>
> I just upgraded to a new "progressive" DVD player and of course the
> salesman tried to sell me a $50 component video cable to connect it.
> So for now I'm using a regular three-wire RCA cable meant for
> composite video and Left/Right audio, and it works, but I'm wondering
> if I really would benefit from better cables.
>
> Thanks for any advice.

It's all about length. One meter? No sweat! 50 feet? 75 ohm seems to be in
order.

BTW, I wouldn't be so sanguine about impedance mismatch if this was high
res, high-refresh computer video.
Anonymous
May 4, 2004 10:36:54 PM

Archived from groups: rec.audio.tech (More info?)

"JWV Miller" wrote ...
> Here is a website that seems to be a reasonably accurate
> answer to your question:
>
> http://members.aol.com/ajaynejr/compon.htm
>
> One thing that you might do is to plug in just the yellow
> cable to the yellow jacks. The resulting image will be
> monochrome but will show the maximum bandwidth
> (sharpness) possible.

Actually it will show you *exagerated* artificial sharpness
because the color subcarrier will make edges look sharper
than they would if you were looking at just the Y
(monochrome) signal.

Agree that "industrial" 75 ohm cables are quite sufficient.
If you went to the studios that produced that video, do you
think you would find them wired with "Monster" or other
boutique cable? Not bloody likely.

If you really want "the good stuff" use Belden 8281 precision
video coax. (Except that is so darn stiff and requires special
connectors.)
Anonymous
May 4, 2004 11:52:58 PM

Archived from groups: rec.audio.tech (More info?)

On Tue, 4 May 2004 13:47:42 -0400, "Ethan Winer" <ethanw at ethanwiner dot
com> wrote:

>Hence the question as to whether cables
>in this particular application really do matter.

Using quality 75-ohm coax could help, yes. But you don't have to buy any of
those "premium" videophile cables: get some serious industrial stuff.
May 4, 2004 11:52:59 PM

Archived from groups: rec.audio.tech (More info?)

There are reasonably priced 3-up 75 ohm RCA connector cable sets for
component video. I've seen some from GE or maybe it was RCA for around $15
if memory serves right.


the "video" cable in your composite video/stereo cable set is likely 75 ohm
already. the audio channels may or may not be, same for the connectors.
Look for ghosts or lines parallel to edges in the image. These would be
indicative of reflections caused by impedance mismatch. Cheap lossy cables
could also cause a loss of sharpness of the image.

Don't buy monster cables. Very excessive profit there. The GE or RCA ones
are fine at a good price.


"Fran├žois Yves Le Gal" <flegal@aingeal.com> wrote in message
news:c2mf905qu9ec956ircqdne3tc8ovfko07b@4ax.com...
> On Tue, 4 May 2004 13:47:42 -0400, "Ethan Winer" <ethanw at ethanwiner dot
> com> wrote:
>
> >Hence the question as to whether cables
> >in this particular application really do matter.
>
> Using quality 75-ohm coax could help, yes. But you don't have to buy any
of
> those "premium" videophile cables: get some serious industrial stuff.
>
>
Anonymous
May 4, 2004 11:53:00 PM

Archived from groups: rec.audio.tech (More info?)

Rocky,

> around $15 if memory serves right. <

Yeah, that's more like it. The store I deal with is not big into wire
gouging, and the video cables they offered were $50. But I know full well
that "even" $50 is excessive, which is why I refused.

> Don't buy monster cables. Very excessive profit there. <

Believe me, I'm quite aware of that, and I spend a lot of time explaining to
folks that heavy enough lamp cord is every bit as good as $1,000 speaker
cables. But I'm new to high-res video and it makes sense that 75 Ohms may
really be needed. NOT expensive cable! Just 75 Ohms.

If I weren't so darn lazy I'd just make the cables myself...

Thanks.

--Ethan
May 5, 2004 2:08:24 AM

Archived from groups: rec.audio.tech (More info?)

Ethan Winer wrote:

> CJ,
>
>
>>Why do you think the "regular" cable is not 75 ohm? <
>
>
> Well, I know what RG59 looks like, and the thin RCA cables I'm using now
> ain't them. :->)

Well, RG59 isn't the only 75 ohm cable made.

>
> Seriously, the component video looks okay, and is slightly better than the
> composite output. Mostly the colors are better and less washed-out looking.
> I was also expecting a meaningful improvement in overall sharpness and
> clarity, and I'm not getting that. Hence the question as to whether cables
> in this particular application really do matter. I *know* that cables don't
> matter most of the time even though audio stores try to convince you they
> do.
>
> Thanks.
>
> --Ethan
>
>


--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
Anonymous
May 5, 2004 2:08:25 AM

Archived from groups: rec.audio.tech (More info?)

CJT wrote:
> Ethan Winer wrote:
>
>> CJ,
>>
>>
>>> Why do you think the "regular" cable is not 75 ohm? <
>>
>>
>> Well, I know what RG59 looks like, and the thin RCA cables I'm using
>> now ain't them. :->)
>
> Well, RG59 isn't the only 75 ohm cable made.
>

Right. If you are going some distance, RG6 with copper core would be more
appropriate. If the environment is noisy, double or triple shielding might
be in order.

BTW, none of this stuff costs serious money. Markertek would cut and
terminate for a reasonable cost.
Anonymous
May 5, 2004 11:12:33 AM

Archived from groups: rec.audio.tech (More info?)

What color subcarrier? NTSC/SECAM/PAL use a color subcarrier but this
is component out from a DVD so there is no reason to encode color
information with a subcarrier.

"Richard Crowley" <rcrowley7@xprt.net> wrote in message news:<109gh9lrqu66a8e@corp.supernews.com>...
> "JWV Miller" wrote ...
> > Here is a website that seems to be a reasonably accurate
> > answer to your question:
> >
> > http://members.aol.com/ajaynejr/compon.htm
> >
> > One thing that you might do is to plug in just the yellow
> > cable to the yellow jacks. The resulting image will be
> > monochrome but will show the maximum bandwidth
> > (sharpness) possible.
>
> Actually it will show you *exagerated* artificial sharpness
> because the color subcarrier will make edges look sharper
> than they would if you were looking at just the Y
> (monochrome) signal.
>
> Agree that "industrial" 75 ohm cables are quite sufficient.
> If you went to the studios that produced that video, do you
> think you would find them wired with "Monster" or other
> boutique cable? Not bloody likely.
>
> If you really want "the good stuff" use Belden 8281 precision
> video coax. (Except that is so darn stiff and requires special
> connectors.)
Anonymous
May 5, 2004 12:21:07 PM

Archived from groups: rec.audio.tech (More info?)

These cables are over priced. Production facilities normally buy this cable
by the spool, cut off what they need, and put on their own connectors. You
can use any standard 75 ohm rated RCA video type cable, and it will not be
critical for your player.

I would not use audio cable, because you will loose its response. If you
shop around at the local electronics parts distributors, they will most
likely have cables for about 1/2 of what you were quoted.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Ethan Winer" <ethanw at ethanwiner dot com> wrote in message
news:wLWdnbcvZfmcVQrdRVn-ig@giganews.com...
Hi Folks,

I just upgraded to a new "progressive" DVD player and of course the salesman
tried to sell me a $50 component video cable to connect it. So for now I'm
using a regular three-wire RCA cable meant for composite video and
Left/Right audio, and it works, but I'm wondering if I really would benefit
from better cables.

Thanks for any advice.

--Ethan
Anonymous
May 5, 2004 1:35:45 PM

Archived from groups: rec.audio.tech (More info?)

Folks,

> http://members.aol.com/ajaynejr/compon.htm <

Thanks JW, that's a great link.

And thanks to all the rest of you for clarifying this for me. I'll go buy
some cheap, but correct, cables today.

--Ethan
Anonymous
May 5, 2004 6:37:59 PM

Archived from groups: rec.audio.tech (More info?)

"Ethan Winer" <ethanw at ethanwiner dot com> writes:

> Hi Folks,
>
> I just upgraded to a new "progressive" DVD player and of course the salesman
> tried to sell me a $50 component video cable to connect it. So for now I'm
> using a regular three-wire RCA cable meant for composite video and
> Left/Right audio, and it works, but I'm wondering if I really would benefit
> from better cables.

Practically all analogue consumer video interfaces are designed top use
75 ohm coaxial cable. This is the right cable to use in all those
applications and gives guaranteed performance. If you use something
else, then the results you cet can vary from good performance to poor
performance depending the cable used, cable length and sometimes
even on equipment used. Usually with showr wires od few meters
the "normal RCA cables" do not cuase problems on normal TV signals.
But when cables get longer or you have higher resolution signal
(progressive video from DVD, HDTV signal, computer VGA signal),
problems are more easily seen.

The cable you used most propably is designed to have two
different types of cables it.
RCA terminated video cable is generally 75ohms.
The audio wires are general purpose shielded audio cable,
that can have considerably different impedance than 75 ohms
and has generally considerable higher attenuation than
video coax cables (bnecause of different insulation material used).
I have also seen video + audio cabls where all three wires
are all the same general purpose audio cable type..

Depending on the distance from the video source to display
device distance, you might or might not benefit from the better
cables. If your cables have length of one meter or so, then
changing cables most propably do not have any noticable effect.
If your cables are 10 meters long, you most propably can
see some difference.

--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/
Anonymous
May 5, 2004 11:43:30 PM

Archived from groups: rec.audio.tech (More info?)

"JWV Miller" wrote ...
> What color subcarrier? NTSC/SECAM/PAL use a color
> subcarrier but this is component out from a DVD so there
> is no reason to encode color information with a subcarrier.

By "the yellow jacks" I was assuming you were refering to
the composite video output. Otherwise, it might be less confusing
to actually define the signal rather than the color of the connector.
!