The char impedance of the cable = sqrt(L/C) at high frequencies so if
you know the impedance then the inductance is easy.
However. the inductance does increase slightly as frequency increases
due to skin effect. IIRC its about 5% increase at some frequency
dependent on the size (& shape) of the conductor.
Also the impedance at high frequency may not be known. It's likely to
be ~120ohms or so but does depend on the geometary etc. 600ohms is a
low frequency value if you see it written anywhere - and is more in
line with the old overhead wires than with modern twisted pair.

Or you could just use the value of 0.5mH/km as a _very_ approximate value.

RP

On 10/11/05, David Van Horn <dvanhorn@microbrix.com> wrote:
> > a real test with a simulated line? If the latter you are probably best
> to
> > get a reel of cable from the local radio Shark or similar store, and
> find
> > the inner end, and connect both ends to your circuit.
>
> I've seen it done with lumped constants, but I'm having trouble
> remembering which book it's in.
>
>
>
>
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