long cables

[Tom]

Anyone know where I can get a long usb2 cable? 15-20 metres would be ideal. I've googled for usb extenders, but theyre all usb 1 devices, and I don't know if they'd support usb2.

The plan is to use usb2 to connect nearly everything on my computer from a base unit downstairs. That way, no more whirring fans etc...

 

[Doh_boy]

hmmm dunno about that BUT you should look at ebuyer or dabs for extenders and the sort. The others tend to be more limited in stock. Also maplin, if it exists they'll have it, probably.

Sorry there's no specific links but I'm desperatly trying to resurect three ancient pc's. (isa sound cards! )

 

[Tom]

Is there a difference between a USB cable and a USB2 cable?

Are USB hubs in any way incompatiable with USB2?

/edit: found this:http://www.expansys.com/product.asp?code=106114

 

[Clown]

Question:
What is the maximuim cable length for a USB connection?

Answer:
The USB standard allows for a maximum of 98.4 ft (30 m) total cable length providing there is a hub or powered hub every 16 ft (5 m). To avoid current loss using a digital camera, it is recommended that at least one powered hub be included in any chain of extended length. Hubs can be purchased through your local computer retailer.

I dunno how accurate this is, but keep it in mind until you find out taht it's bullshit.

 

[Doh_boy]

Usb is backward and forward compatible.

Usb1 devices will work on USB2 slots
USB2 devices will work on USB1 slots

Obviously, though, the speed is dependant on the slot so if you have a usb2 device it will run at usb1 speed in a usb1 slot.

 

[Xavier]

Not all cables produced for USB1 devices will support the data rates required by USB2 though. So if yoy want USB2 data rates, buy USB2 cabling - check cable manufacturers such as Belkin who offer both USB and USB2 solutions, it's not all marketing...

With regards to signalling over cable length, you don't need a hub every 5m, it's simply not true. I've got USB cables 15-20m in length and they're fine as long as they're connected between powered usb hubs. If you tried to run a lead that long from a passive port or hub then yes, you'll probably encounter some issues.

There was a guy whose company made long leads which came and posted in a similar request back in the Barrysworld days but I cant remember their name - does anyone else recall? Google will be your friend for this one I think, just keep plugging at it, they're out there somewhere.

 

[xane]

You can certainly get longish USB cables, I have a 5m one around here somewhere, and you can certainly get longish USB Extension (male-female) cables too, dont know about 15-20m tho.

 

[~Yuckfou~]

Get 5m cables and daisy chain them?

 

[Tom]

I emailed Scan about this, and they responded with:

While this would technically be possible, we don't actually have the cables necessary to do it unless you wanted to buy a bunch of extension cables for PS/2, USB, and VGA.

The only real problem would be with video - signal degradation over that kind of distance would be very bad indeed resulting in extremely poor image quality. It would be possible to use some kind of signal booster inline with the cabling but again that's not something we'd be able to sell you.

Your best bet might be to speak to some specialised cable / electronics reseller like Maplin.

Nick
Scan Computers

I've also found a supplier of self powered 5m USB2 cables, that can be daisychained. How exactly is it 'self powered'?

I'm also considering the option of putting the computer in an unused space underneath the top of my staircase. It would have the novelty of loading CDs vertically, pointing downward into my larder ceiling! At least it would save a bit of length, I might be able to get it down to 10m that way.

The VGA issue is something else though. I've read that 15 metres is about the max. Any ideas on this? Its going to be running near lots of mains/lighting cables for about 2 feet.

 

[Ardrias]

Why not use wireless equipment?

 

[Xavier]

What, a wireless SVGA connector? do you know how ropey the signal from those things is? I saw one demoed before christmas, signal over 2m was almost unreadable. At 3m the monitor thought it was disconnected.

 

[Tom]

I think the bandwidth requirements for VGA and above would far exceed what is currently available to Joe Public.

 

[Tom]

I'm wondering about the VGA signal. I have RGB inputs on the back of my monitor, I wonder if using a VGA breakout lead into 3 50ohm BNC cables would be a better way of transmitting the signal from my computer to the monitor?

 

[WPKenny]

The best I can recall seeing for the sort of thing you want is cat5 extenders. They'll carry your USB and SVGA over a fair old distance. Now if only I could remember where I saw them.....



EDIT: After a quick google (very quick) I came up with these two items but no prices yet...

http://www.42u.com/nti-usb-kvm-extender.htm

and

http://www.42u.com/minicom-smart-kvm-extender.htm

That's your USB and KVM sorted. Now you just need sound, which I'm not sure if these KVM's do but the USB one's CAN. Bitch eh? heh.

EDIT2: There's this one... http://www.42u.com/aten-ce700.htm
That does USB in the same box as the VGA but the resolution is lower (1280 as opposed to 1600 on the KVM's without VGA).


EDIT3: http://www.kvm-switches-online.com/ce700.html indicates the box above is about 300 dollars.

Hopefully with all that info you'll find a good price from a UK retailer.

 

[Tom]

Its getting more and more expensive to do what I'd like. Xav pointed me in the direction of this quiet pc technology. Most of the noise is from my 43 year old hard drives, so I might buy a new HD, and an enclosure for it, and see how things go.

Still, it would be nice not to have to look at the ugly beige metal box from hell.