VGA over CAT5e

[BigAl.NZ]

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

 

[PeeCee]

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.

 

[Paul]

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]

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


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

I am liking the ethernet idea. I found these mounts I could use which
have sealed end caps for when not in use:

http://au.farnell.com/1254803/connectors/product.us0?sku=amphenol-pcd-rjfrb71

This way it has a fighting chance of surviving in the marine
enviroment!

-Al

 

[Tomi Holger Engdahl]

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.

How about cutting the connector from one cable end, pulling
the cable and then soldering a new one to the end.
Or building entirely new VGA cable the length you want
by soldering the connectors yourself to both ends.
The soldering the cable consisting of several mini
coax condictors and many other conductor DB15 VGA connector
is not the easiest job, but doable if you are good
at building cables. I have done that kind of soldering
myself when I have needed some custon VGA cables for
some applications.

I am thinking about running the VGA singal over CAT5e, which a Google
search seems to suggest is possible.

Runnign VGA over CAT5e is possible.
There are commercial active adapters that do the conversion
"right" and work even for some longer distances. Those
cost money but work quite well.
Then in Internet there are some simple plans to run
VGA over CAT5e cables. When you use a shielded CAT5e cable
and not too long distances, those hacks can work quite well
but might not give perfect "crystal clear" picture like
a real VGA cable or commercial converter would give.
Running VGA signal on unshielded CAT5e cable with simple
DIY passive adapters is not a vry good idea: the image
quality will get worse and your cable will radiate
out considerable RF interference which could interfere
for example with boat radios.

I was wondering if anyone had any
better ideas, keeping costs fairly low.

I just gave you several ideas.

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

Yes. I have done this several times.

 

[philo]

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

 

[JohnO]

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

 

[Rick Jones]

It might be worthwhile to think-out a bit beyond the size of the hole
though which you want to pass this signal. Stuff like "what will
hold-up best when I'm at the bridge, in a storm, near a rocky shore
and I really need to know where I am?" I say that only half in jest.

rick jones

 

[Mike Hall - MVP]

It might be worthwhile to think-out a bit beyond the size of the hole
though which you want to pass this signal. Stuff like "what will
hold-up best when I'm at the bridge, in a storm, near a rocky shore
and I really need to know where I am?" I say that only half in jest.

rick jones

How about these two products..

http://www.terralogic.co.uk/

PLUS

https://www.mightyputty.ca/spark/index.php?tag=mpcaedg100tm

... and a wireless connection.. no holes required..


--
Mike Hall - MVP
How to construct a good post..
http://dts-l.com/goodpost.htm
How to use the Microsoft Product Support Newsgroups..
http://support.microsoft.com/default.aspx?pr=newswhelp&style=toc
Mike's Window - My Blog..
http://msmvps.com/blogs/mikehall/default.aspx

 

[Bod43]

It might be worthwhile to think-out a bit beyond the size of the hole
though which you want to pass this signal.  Stuff like "what will
hold-up best when I'm at the bridge, in a storm, near a rocky shore
and I really need to know where I am?"  I say that only half in jest.

I have worked with commercial solutions using this technology.
Was about 5 or 6 years ago.

I forget the name of the product.

One serious problem was that by *design* (as I understand it)
the various different pairs in the cat5 cable have different
twist rates. This results in different cable lengths and
produces different delays for each of the
RGB and Sync. The solution overcame this by having
user adjustable delays controlled by DIP switches
at the remote end.

(or is sync on one of the RGB?) doesn't matter - is still broken.

NIGHTMARE - in the event of any moves or changes.

Not sure of your proposed length would run into this or not.
I suspect it would since the frequency required to drive
a display is rather high.

In the case I observed the differential delay issue
was *very* significant over two floors of
a narrow buillding.

There of course may be commercial solutions available now that
avoid the problems entirely. Perhaps by combining the
signals into one pair.

Composite Video?

 

[BigAl.NZ]

Not sure of your proposed length would run into this or not.
I suspect it would since the frequency required to drive
a display is rather high.

Length in this case 4m absolute MAX!

-Al

 

[Tomi Holger Engdahl]

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

Thethe wrong cable impedance and lack of shileding between
RGB signals will not cause ghosting. Most ghosting will
be caused by the impedance mismatches.

The lack of shield in cable will cause that that cable
will pick up more easily external interference
and will radiate out more RF interference and properly
shielded VGA cable.

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

True. The VGA cables vary in quality. The good ones are good
but there are also bad ones. One thing to keep in mind
in VGA connections is that it is a good idea to keep the
number of VGA connectors along the link minimum (ideally
only at source and destination), because the VGA connector
impedance is not exactly 75 ohms as the system is designed
for, and having many such wrong impedance connectors on
the way will cause impedanc mismatches that cause
reflections. For VGA cables is best to use a correct
length cable in the beginning, and avoid using
orignal cable + extension cable combinations.

 

[PeeCee]

I used to make up VGA cables for control room applications. 15M using
individual screened conductors was about the recommended limit

mmm wouldn't surprise me.
I've seen VGA extension cables as short as 2M exhibit ghosting.

P.

 

[Tomi Holger Engdahl]

mmm wouldn't surprise me.
I've seen VGA extension cables as short as 2M exhibit ghosting.

There are well built VGA extension cables (use 75 ohm mini coax cables
at least for RGB signals). Those work generally well.
Also there are those crappy cables built just from general purpose
computer cable with lots of wires inside one outer shield. Those
cheap cables have typically wrong impedance and considerable
crosstalk between signals -> ghosting problems

Then the used resolution + refresh combination has effect.
Almost any crapphy cable works for 640x480 60 Hz resolution
but for 1280x12o4 and higher resolutions the quality of the cable
starts really slow up.