VGA over CAT5e

On Sun, 5 Oct 2008 21:05:00 -0700 (PDT), BigAl.NZ.RemoveThis@gmail.com wrote:

>Hi Guys,
>
>I need to get a VGA signal from the Nav Station in my boat to the
>monitor in the bridge. I could just run a VGA cable (about 4m worth)
>but I need to pass the cable through some small holes for the looming
>(sp?) and the DB15 connectors wont fit unless I make the hole bigger.
>
>I am thinking about running the VGA singal over CAT5e, which a Google
>search seems to suggest is possible. I was wondering if anyone had any
>better ideas, keeping costs fairly low.
>


http://www.google.com/search?hl=en&q=ethernet+vga+extender

generates 257,000 hits.

http://www.google.com/search?hl=en&q=kvm+cat5+extender

generates 140, 000 hits.

Here's a few that look promising:

http://sewelldirect.com/KVMcat5extender.asp

http://www.cablestogo.com/product.asp?cat_id=503&sku=39970






>Has anyone here had any success cutting the end off a VGA cable and
>wiring on a new DB15 for example?
>

You would need the skills of a micro-surgeon and a very fine solder
tip.

BigAl.NZ.RemoveThis@gmail.com wrote:

> I need to get a VGA signal from the Nav Station in my boat to the
> monitor in the bridge. I could just run a VGA cable (about 4m worth)
> but I need to pass the cable through some small holes for the looming
> (sp?) and the DB15 connectors wont fit unless I make the hole bigger.

> I am thinking about running the VGA singal over CAT5e, which a Google
> search seems to suggest is possible. I was wondering if anyone had any
> better ideas, keeping costs fairly low.

The impedance is different enough that you will get visible reflection
at anywhere close to VGA frequencies. I believe VGA, like most analog
video signals, is 75 ohm coax (unbalanced). Matching that to 100 ohm
balanced line is not easy with passive parts. Using active circuitry
you can generate the balanced signal needed, and convert it back
at the other end. That takes a number of very fast amplifiers
(I think three video, plus two sync, but I am not so sure about sync
signals for VGA.)

I believe the boxes are commercially available, because it is sometimes
the best way to send video long distance. (The cheaper cable makes
up for the added cost of conversion.)

If you find the connectors with separate pins that you solder and
then install it isn't too hard. You still want the appropriate
multiple coax cable, though.

> Has anyone here had any success cutting the end off a VGA cable and
> wiring on a new DB15 for example?

Finding ready made cables has been easy enough, and finding the
required cable in bulk hard enough, that I haven't tried.

-- glen

BigAl.NZ DeleteThis @gmail.com wrote:
> Hi Guys,
>
> I need to get a VGA signal from the Nav Station in my boat to the
> monitor in the bridge. I could just run a VGA cable (about 4m worth)
> but I need to pass the cable through some small holes for the looming
> (sp?) and the DB15 connectors wont fit unless I make the hole bigger.
>
> I am thinking about running the VGA singal over CAT5e, which a Google
> search seems to suggest is possible. I was wondering if anyone had any
> better ideas, keeping costs fairly low.
>
> Has anyone here had any success cutting the end off a VGA cable and
> wiring on a new DB15 for example?
>
> Thanks in advance,
>
> -Al

This cable, has a round connector in the center, and is intended to make
it easier to penetrate walls. This cable is 50ft long, and claims to
support 1600x1200 (refresh rate not stated, could be 60Hz).

http://www.tripplite.com/EN/products/model.cfm?txtModelID=3351

Look for more "Easy Pull" items here. They also make DVI and HDMI
versions.

http://www.tripplite.com/EN/products/index.cfm?txtEntryID=32

In all the advertising cruft on the pages, it doesn't state
what the O.D. of the connector is. It looks like it might
be 1" diameter or so, but hard to say for sure.

It mentions pulling through 3/4" conduit here. That is, if
you trust marketing people to pull cables.

http://www.tripplite.com/shared/literature/Flyer/952906.pdf

Another brand example here. RapidRun modular cabling system. 3/4" conduit.

http://www.cablemeister.com/product.php?productid=50731

They also make RGBHV to VGA breakout cables. Such a cable
would be missing signals for DDC (used by a computer to
get resolution information from a monitor), but cables
like this are sometimes used for projector devices connected
to computers. Your application would probably be happy
with the basic RGBHV signals. RGB is color, HV are sync
signals. There are several ways to carry sync, including
sync on green. So again, the requirements can vary a bit,
and having all five RGBHV helps cover all possibilities.

http://www.ramelectronics.net/renderImage.image?imageName=products/VGA2BNC.jpg

The idea would be, you make the hole big enough, to pass
the BNC connectors one at a time. The example picture above,
has made the BNC connectors excessively fancy. A little
extra slack on the five coaxes, would probably help.
The solution is less ideal than the RapidRun, but perhaps
easier to buy locally. You can connect the BNCs with
some coax wires with mating BNCs on the end.

I suppose you could buy BNC kits, as long as they're designed
for the thin coax, and simply fit crimp BNCs on the end
of each coax. So that would be another possibility.

If soldering a VGA connector, the hard part would be
connecting the RGB coax signals. Coax and soldering
don't mix. Which is why I put so many "pull" style
solutions in the above If you visited me two hours
after giving me a soldering job like that to do, I'd
be in "full cuss mode". The insulation inside coax
melts easily.

Paul

<BigAl.NZ.DeleteThis@gmail.com> wrote in message
news:8fdab6cc-b21a-4ed7-9bac-2ed3b666c46c@x16g2000prn.googlegroups.com...
> Hi Guys,
>
> I need to get a VGA signal from the Nav Station in my boat to the
> monitor in the bridge. I could just run a VGA cable (about 4m worth)
> but I need to pass the cable through some small holes for the looming
> (sp?) and the DB15 connectors wont fit unless I make the hole bigger.
>
> I am thinking about running the VGA singal over CAT5e, which a Google
> search seems to suggest is possible. I was wondering if anyone had any
> better ideas, keeping costs fairly low.
>
> Has anyone here had any success cutting the end off a VGA cable and
> wiring on a new DB15 for example?
>
> Thanks in advance,
>
> -Al



Al

Well I was going to say different cable for different uses, but then I found
this site:
http://www.geocities.com/dougburbidge/vgaovercat5.html
The author says they've achieved 15 metres.
For the cost of the cable and solder time, worth trying.

If that doesn't work you can get gadgets that convert from VGA to RJ45 and
back again:
http://www.svideo.com/vgacat5.html

Best
Paul.

<BigAl.NZ.DeleteThis@gmail.com> wrote in message
news:8fdab6cc-b21a-4ed7-9bac-2ed3b666c46c@x16g2000prn.googlegroups.com...
> Hi Guys,
>
> I need to get a VGA signal from the Nav Station in my boat to the
> monitor in the bridge. I could just run a VGA cable (about 4m worth)
> but I need to pass the cable through some small holes for the looming
> (sp?) and the DB15 connectors wont fit unless I make the hole bigger.
>
> I am thinking about running the VGA singal over CAT5e, which a Google
> search seems to suggest is possible. I was wondering if anyone had any
> better ideas, keeping costs fairly low.
>
> Has anyone here had any success cutting the end off a VGA cable and
> wiring on a new DB15 for example?
>
> Thanks in advance,
>
> -Al


VGA cable is shielded
and CAT5 is not, so you would get some horrible ghosting.

BTW, there may still be some ghosting even with VGA cable

"philo" <philo.TakeThisOut@privacy.net> wrote in message
news:eWH7PX6JJHA.468@TK2MSFTNGP06.phx.gbl...
>
> <BigAl.NZ.TakeThisOut@gmail.com> wrote in message
> news:8fdab6cc-b21a-4ed7-9bac-2ed3b666c46c@x16g2000prn.googlegroups.com...
>> Hi Guys,
>>
>> I need to get a VGA signal from the Nav Station in my boat to the
>> monitor in the bridge. I could just run a VGA cable (about 4m worth)
>> but I need to pass the cable through some small holes for the looming
>> (sp?) and the DB15 connectors wont fit unless I make the hole bigger.
>>
>> I am thinking about running the VGA singal over CAT5e, which a Google
>> search seems to suggest is possible. I was wondering if anyone had any
>> better ideas, keeping costs fairly low.
>>
>> Has anyone here had any success cutting the end off a VGA cable and
>> wiring on a new DB15 for example?
>>
>> Thanks in advance,
>>
>> -Al
>
>
> VGA cable is shielded
> and CAT5 is not, so you would get some horrible ghosting.
>
> BTW, there may still be some ghosting even with VGA cable
>

STP CAT5e or CAT 6 would do the trick, and at these lengths the cost
difference isn't an issue.

-John O