USB Cable max run length?

[WalksInDarkness]

Hi All,

I need to run a USB cable 25'-30' or so. The longest cable I can find is 15', but I do see some 15' extenders too.

BUT, some people I have spoken too have said that 15' is the max before you lose significant signal strength. On the other hand some have said this is hogwash. And a few others have said I will be fine if I swap out my hub with a powered unit.

Any advice is greatly appreciated!

 

[SatinKzo]

5 meters I believe is the official spec without a powered hub or extender device.

you could try something like this, but it's only 1.1.
Active Repeater Cable

 

[DSpud]

From Wikipedia.org Universal Serial Bus - Wikipedia, the free encyclopedia

The maximum length of a standard USB cable is 5.0 meters (16.4 ft). The primary reason for this limit is the maximum allowed round-trip delay of about 1500 ns. If a USB device does not answer to host commands within the allowed time, the host considers the command to be lost. When USB device response time, delays from using the maximum number of hubs and delays from cables connecting the hubs, host and device are summed, the maximum delay caused by a single cable turns out to be 26 ns [10]. The USB 2.0 specification states that the cable delay must be less than 5.2 ns per meter, which means that maximum length USB cable is 5 meters long. However, this is also very close to the maximum possible length when using a standard copper cable.
Using USB devices over a greater length require hubs or active extension cables. Active extension cables are bus-powered hubs equipped with two maximum length standard USB cables. USB connections can be extended to 50 m (160 ft) over CAT5 or up to 10 km (6.2 mi) over fiber by using special USB extender products developed by various manufacturers.
In practice, some USB devices may work with longer cable runs than 5 meters, if the number of hubs between the host and the device is less than the maximum number allowed by the USB standard. However, using a longer cable lowers both the signal quality and the voltage provided by the USB bus below the specification tolerance limits. This may prevent USB devices from working properly or even from working at all.