Interestingly one of the reasons I asked this question was that, whilst its=
a commonly held belief, the aluminium threads used for mic cable shielding=
costs manufacturers the same & sometimes more than copper.
--- In "Avocet" <> wrote:
> > Q: even at high cost some cables use braided copper shield & some
> > use braided aluminium shield. Does anyone know what the actual
> > difference is between the two in a practical sense ?
> Aluminium is cheaper. If there is a slight difference in conductivity,
> this should still be well within the cable impedance spec.
> The cable to avoid with long runs is helical screened which can puch
> up RF interference from medium wave transmitters etc. That is the
> reason for braiding.
> I've got 100 and 150 metre cables and I went for cable designed for
> permanent installations which was foil screened with a copper
> conductor. This cable is not designed to be flexed frequently but I
> use it in long semi-permanant runs into woodland.
> The only problem I have had with my long cables was when I had two
> double runs in opposite directions during a storm. My 11,000 volt
> electricity supply line was arcing over, and I got fizzle when both
> lines were plugged into my mixer, but that was extreme conditions.
> I've also used conductive plastic screened cable for short cables but
> have doubts about using it where flexibillty is not a requirrement,
> but it works. The doubts are mainly financal. :-)
> The other cable parameter is microphony but it is rarely given. Try
> tapping cables without an input and at high gain. Conductive plastic
> screening can be bad, but most helical screened types are quite low.
> Microphony is not important with studio or music work but with
> wildlife recording, if movement is involved, it could be a problem.
> Sorry to waffle but avoid helical and go for cheap cable. :-)
> PS. My cable drums are garden hose drums which are light and cheap and
> I screwed in clips for the XLR's. They easily take 300 metres of the
> foil screened cable. I use coloured heatshrink to identfy plugs.
> David Brinicombe
> North Devon, UK
> Cogito cogito ergo cogito sum - Ambrose Bierce