Hello John.

12 Jul 04 22:48, you wrote to all:


 JT>   I only wish I could have a portable version for use at client's
 JT> offices,

you could use a pocket sized oscilloscope, but it'd no longer be al-cheapo.

 >>  JT>   Again in theory, if you had a long enough cable length on one
 >>  JT> (or both) ends, the system should still work, because there are
 >>  JT> no reflections, thus no corruption of signal. What you would
 >>  JT> need is a cable length long enough at the ends that the
 >>  JT> inevitable reflections are degraded enough by the time they
 >>  JT> come back, that they offer little or no effect on the closer
 >>  JT> valid signals. --
 >>
 >> or that they take long enough to come back that the original has
 >> already reached it's destination :)

 JT>   Er, that's not one of those 'if a tree falls in a forest' or the
 JT> 'sound of one hand clapping' question is it?

the maximum cable lenght spec used for ertherenet isn't due to signal loss
but due to having the cable short enough that a collision can be
detected by all stations.

 >> I wonder how much loss you get in 100m of that cable at 10Mhz.

 JT>   Easily calculated.  Cable specs state loss at specified freqency
 JT> use, you just add it up for your length of cable.

I don't have any specs handy, do you?

Jasen

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