On Mon, 1 Sep 2008 13:57:04 +1000, "Phil Allison"
wrote:


"Ross Herbert"
HiggsField
"Phil Allison"

: Absolute overkill, and it appears that the construction style would lead
:to HUGE capacitance levels.


** Only a complete ****** would claim 1500 pF per metre is " HUGE" for a
speaker cable.

The aim is to reduce linear inductance so that means C must go up.


Overkill doesn't come into it, although it is a ridiculous cable
construction.


** What is so ridiculous about it ?

Can you come up with a better way to reduce or eliminate cable inductance?

I've used an easier one:

Start with a hunk of the MIL-spec stranded wire, #8 or #10 maybe, the
kind with the fine silver-plated strands and very thin-skin black
teflon insulation.

Stuff that inside a tubular woven copper braid. Pull the braid to
tighten it around the inner conductor, then finish with shrink tubing.
The result is homemade coax with a very thin dielectric, which
translates to very low inductance per unit length.

I've done this for driving longish (like 10 m) runs to NMR gradient
coils, where the cable L really matters. The improvement over other
constructions, like twisted pairs, is dramatic.


John