🚀 go-pugleaf

Any cable w/ a ferrite core should do the trick.
--
jeff brady
www.iamnotageek.com

"Louis Banens" <louis.banens@xs4all.nl> wrote in message
news:acvl78$2j3$1@news1.xs4all.nl...
> Hi,
>
> Can anybody tell me what the maximum length is of an Analog Video Cable
for
> a CRT monitor and DVI Cable for a TFT monitor ? I have a TFT monitor with
> both Analog and Digital input. Distance to my computer is around 10 meter
> (30 feet). Anybody knows which cable to use ?
>
> Thanks,
>
> Louis
>
>

"Jeff Brady" <jeffbrady@dmait.com> wrote in message
news:3cf39c22$0$46454$45beb828@newscene.com...
> Any cable w/ a ferrite core should do the trick.
> --

Not true.  The purpose of a ferrite core on the cable is to help in reducing
radiation to meet FCC Part 15 rules requirements.

As the cable gets longer the capacitance between the video leads and ground
increases and will degrade the video response if the cable exceeds a
critical length.

Depending on the cable construction, usable lengths will differ.  I doubt if
you will find any commercially available cable that will allow acceptable
performance at 30 meters.

Now if you installed amplifiers along the way you could attain a distance of
30 metesrs,












> jeff brady
> www.iamnotageek.com
>
> "Louis Banens" <louis.banens@xs4all.nl> wrote in message
> news:acvl78$2j3$1@news1.xs4all.nl...
> > Hi,
> >
> > Can anybody tell me what the maximum length is of an Analog Video Cable
> for
> > a CRT monitor and DVI Cable for a TFT monitor ? I have a TFT monitor
with
> > both Analog and Digital input. Distance to my computer is around 10
meter
> > (30 feet). Anybody knows which cable to use ?
> >
> > Thanks,
> >
> > Louis
> >
> >
>
>
>
>

Al Peterson wrote:
> 
> "Jeff Brady" <jeffbrady@dmait.com> wrote in message
>
> > Any cable w/ a ferrite core should do the trick.
> 
> Not true.  The purpose of a ferrite core on the cable is to help
> in reducing radiation to meet FCC Part 15 rules requirements.
> 
> As the cable gets longer the capacitance between the video leads
> and ground increases and will degrade the video response if the
> cable exceeds a critical length.
> 
> Depending on the cable construction, usable lengths will differ. 
> I doubt if you will find any commercially available cable that
> will allow acceptable performance at 30 meters.

Good cables are actually several coax lines, with a characteristic
impedence (which is related to the ratio of inductance to
capacitance per unit length) and look resistive, usually around
100 ohms.  A line will attentuate higher frequencies, but the
losses will not be significant at medium lengths.  It is important
that such lines be driven from a matching driver, and terminated
in their characteristic impedance, otherwise you will get ringing
and other nasties.

At frequencies below the cutoff frequency the principle effect of
the line is to delay a signal, and it will also attentuate it
(depends on the resistance per unit length).

So the effects depend highly on the quality of the cable.  You
could probably replace the chroma carrying portions (three colors)
by lengths of RG58, or whatever is the right match to the end
impedances, and function perfectly well over fairly long
distances.  Small dimensions (such as the multiple lines in your
cable) generally mean poorer quality lines.

The important thing is matching impedances.

-- 
Chuck F (cbfalconer@yahoo.com) (cbfalconer@worldnet.att.net)
   Available for consulting/temporary embedded and systems.
   <http://cbfalconer.home.att.net>  USE worldnet address!

"Al Peterson" <none@none.net> wrote in message
news:uf7kikerfem0cf@corp.supernews.com...
>
> "Jeff Brady" <jeffbrady@dmait.com> wrote in message
> news:3cf39c22$0$46454$45beb828@newscene.com...
> > Any cable w/ a ferrite core should do the trick.
> > --
>
> Not true.  The purpose of a ferrite core on the cable is to help in
reducing
> radiation to meet FCC Part 15 rules requirements.

My mistake if I'm wrong. I've just seen 100ft VGA cables, and the only
big difference was a ferrite core.

> As the cable gets longer the capacitance between the video leads and
ground
> increases and will degrade the video response if the cable exceeds a
> critical length.
>
> Depending on the cable construction, usable lengths will differ.  I doubt
if
> you will find any commercially available cable that will allow acceptable
> performance at 30 meters.
>
> Now if you installed amplifiers along the way you could attain a distance
of
> 30 metesrs,
>
>
>
>
>
>
>
>
>
>
>
>
> > jeff brady
> > www.iamnotageek.com
> >
> > "Louis Banens" <louis.banens@xs4all.nl> wrote in message
> > news:acvl78$2j3$1@news1.xs4all.nl...
> > > Hi,
> > >
> > > Can anybody tell me what the maximum length is of an Analog Video
Cable
> > for
> > > a CRT monitor and DVI Cable for a TFT monitor ? I have a TFT monitor
> with
> > > both Analog and Digital input. Distance to my computer is around 10
> meter
> > > (30 feet). Anybody knows which cable to use ?
> > >
> > > Thanks,
> > >
> > > Louis
> > >
> > >
> >
> >
> >
> >
>
>

Try www.blackbox.com.

They list VGA cables up to 100 ft.

Before I retired, I purchased a lot of cables among other things from
them and they had excellent tech support.

Louis Banens wrote:
> 
> Hi,
> 
> Can anybody tell me what the maximum length is of an Analog Video Cable for
> a CRT monitor and DVI Cable for a TFT monitor ? I have a TFT monitor with
> both Analog and Digital input. Distance to my computer is around 10 meter
> (30 feet). Anybody knows which cable to use ?
> 
> Thanks,
> 
> Louis