VGA cable

[Mike Tomlinson]

En el artículo , ARWadsworth escribió:

I wouldn't. VGA connectors are a nightmare to solder neatly. If you possibly can, get the cable pre-made to the right length. There are several firms that make cables to order - I can recommend one (would need to look it up at work) - if interested, let me know.

Or install Cat5 and use these:

AdderLink X100 and X200 also carry sound, which you asked for.

I use the AdderLink XL at a remote site with a ~40m run and it works fine. Be warned that although the link connection uses Cat5 and RJ45 connectors, the protocol is *not* ethernet and it must not be connected to network devices.

[Pete Shew]

I run VGA, 1024x768 IIRC maybe more for about 10m through Cat5E with no baluns and no sign of degradation for a text based display. It should be fine for CCTV I would think.

I can't remember the exact site with the info but it may have been or

Pete

[tony sayer]

OK so you have a BALUN at end A then "x" metres of CAT 5 cable then a BALUN and end B and this looses signal or drops out every so often?...

And nothing else in circuit anywhere?..

[Mike Barnes]

tony sayer :

Nope.

I'm as baffled as you seem to be.

BTW "x" is about 15 in each case.

[Dave Plowman (News)]

I've got a long VGA cable feeding a monitor on the other side of this room. Came from Ebay - and wasn't pricey. 5 metres, IIRC. Appears to work just fine.

[Dave Plowman (News)]

Of course. In a pro situation, composite video was sent over far greater distances than any likely to be encountered here. But using the correct cable. Certainly not a co-ax with a diameter of a couple of mm.

[charles]

I've used 20m on a regular basis.

[tony sayer]

In article , Mike Barnes scribeth thus

Shouldn't really be a problem. None of the associated equipment is intermittently faulty at all?..

[The Natural Philosopher]

interference mate. CAT5 is not desiged for low level analogue signals at high frequencies.

[Andy Dingley]

Then WTF do you _think_ it's designed for?

[Graham.]

I know of an installation that uses these, a server and 5 workstations all housed in the server room and effectively dumb terminals using adderlinks. The stated reason was lack of room at the workstations but that wasn't really true. There was a separate patch panel.

Stupid idea really, no advantages for the user, and it makes the site difficult to support.

The video quality on the monitors is very good and the only thing that gives it away is a lateral shift to the right of the lo-res windows logo while the machines are booting up.

[Adrian C]

CPC does kit for this, good for 300m 1920x1200 resolution using dedicated straight Cat5e/6 cable.

Contains powered line drivers, not Baluns.

PRO SIGNAL - PSG03502 - VGA + AUDIO OVER CAT5 KIT

+ vat etc....

[tony sayer]

Ummm .. beg pardon but we've used this technique over hundreds of feet for Vision bandwidth signals and one of the good things is its balanced operation with common mode rejection which makes good for interference rejection.

And that in some every Electro-magnetically noisy areas....

I'm sure there is something else going on here somewhere but remote diagnosis is rather difficult sometimes...

[Mike Barnes]

tony sayer :

That's what I thought, too. But if so, multiple equipment has exhibited the same fault. I changed the PC a year or two ago, from a Dell desktop to a Tranquil silent PC. I've tried probably five different types of VGA/CAT5 adapter. I've tried three types of monitor. I've swapped all the patch leads of course. I've re-made the connections on the back of RJ-45 wall plates. Still the same fault exists on two separate circuits.

Perhaps the house is haunted.

Seriously, though, it's reassuring to know that I'm not using some flaky technology and expecting too much of it. Thanks for your input. I shall keep on trying before calling in the exorcist.

Thinking on, I haven't tried replacing the wall plates. I think that will have to be the next step.

[John Rumm]

Probably stating the bleeding obvious, but, have you checked that the wall plates are wired to the proper standard (i.e. EIA 568B etc)? Because otherwise its possible to get the correct end to end connectivity, but to not use the twisted pairs in the intended configuration, which would knacker the noise immunity.

[Mike Barnes]

a confusing area due to the two standards and no clear idea as to why there are two standards and which I should be using. For unrelated reasons I can't go and check the wiring now, but I can tell you that the colours of the wires certainly match the colours of the paint blobs on the connectors, which to me suggests that the pairs are correctly paired IYSWIM. I've also tested the circuits end-to-end with a device that steps though pins 1-8 in turn, and the ends match. The only suspicious thing is that the tester has lights for 1-8 and GND, and though the 1-8 lights come on in sequence, the GND light never does. I don't know whether this is anything to be concerned about, or perhaps just a consequence of using UTP wiring.

[Andy Burns]

So long as you use the same standard at each end, it isn't an issue which standard you use, in practice the UK tends strongly towards using "B".

[John Rumm]

As they say; the nice thing about standards is that if you don't like one, there will always be another along in a moment.

The reality is it does not really matter which you use, as long as its the same on both ends.

568B is the more common one these days.

Yup, you are probably right. There are some connectors out there marked with only one standard's colours and if you mix and match the wrong combination then problems arise...

Chances are you are fine - just thought I would mention it in case. Note however that stepping through the "pairs" does not usually test (on basic testers) that the two wires used are actually twisted together - only that the connectivity is correct.

Yup, GND is probably testing the screen continuity on STP.

[Mike Barnes]

Prompted by this exchange I've carried out more tests. The problem is

*very* intermittent, and fortunately at the moment it's in an every-few- minutes phase rather than every few days.

I've managed to get the problem to manifest itself with a monitor connected directly (one 50cm lead) to the PC, so there's none of my wiring and no VGA extenders in the circuit. Ditto, kind of, with a completely different monitor, but the picture merely flickered rather than blanking for a few seconds, and I'm guessing that that difference is just a quirk of the monitors concerned.

I've also established that when I have two monitors connected to the same PC, they both blank out at exactly the same time.

So it seems pretty likely that, unless I'm looking at multiple faults, it's the PC that's the problem. But not just one PC: two completely different PCs, running different versions of Windows. Some would no doubt say that Windows is the obvious common factor. :-)

[tony sayer]

Not using the same "connector" at all