Hello everyone. This is not so linux related question. Have someone got usb to work 15m from computer. I have problem to get wacom drawing board work. I have used eminent usb booster cables 5m/each so three of those and then boards own cable, but thats not working. OK then i bought 4-port usb hub in the board end and tried again, but no results. I even then tried to use cat5 cable and solder usb connectors in the end, no good.

So if someone has got usb work 15meters, please could you answer and write how you did it. What cables, wich equipments

Thanks

You need something like this:
http://www.lastar.net/product.asp?cat_id=1704&sku=29341

I have not had the need to extend USB but just adding cables together or even a hub will not work. The max length of USB without an extender I believe is 5m.

I think Michaelk is right about the 5 meters.

A friend of mine, gave me an easy "remember-thingie" some time ago,
so i wouldn't forget it (smart guy but very optimistic).

It was "555" like the usual start of phonenumbers in american movies.

The maximum for usb is:
max 5 meters between pc and hub/device
max 5 meters between hubs
max 5 hubs

I found something similar than michaelk suggested. It will take few days to get those.

cable design is trickier than it seems at first. you first need to design the capacitance (C) and inductance (L) since resonance occurs at ~1/sqrt(LC). the 5m limit comes from max tolerance signal loss for the spec'd driving voltage to adequately arrive at the other end through the very specifically designed filter (wires). the error correction yielded from twisted pairs in cat5 may be useful in extending USB cables but you need to tune L and C to ensure the cable either resonates at the operating frequency or at least doesn't excessively filter out the signal before reaching the other end. Wire resistance is less important since power losses slow with increasing wire resistance [taking that from R=omega(10^(db/10)-1)]. However I have seen a spec for something like 2ohm/meter for USB.

If you want to make your own cable, scale the 2ohm/meter down by how many times you want to increase the 5m max length. then find the freq for the USB signal you want, measure the capacitance of the length of wire you want, then tune the inductance with either in-line inductors or perhaps a ferrite core.