[sdiy] non shield cable

[harrybissell]

Czech Martin wrote:

<snip>

> Oh, you can do it the other way as well:
>
> Use unshielded wire, and shield you room.
> Wire netting material should do the trick
> up to several MHz, but not for low freq. H fields.

No problemo. You just have to shield the room with Mu Metal (a nickel, iron,
copper
and molybdenum alloy),  Even a thin, continuous wrap around the whole room
should do it.
Of course it would be tough to get inside the room after that, so maybe two
concentric
rooms, with the material aligned at 90 degree axis might be more practical.

Failing this, good old steel could be used. In the past I've found even 12ga
(heavy) steel
is not totally impervious to those pesky H fields.... But its a start...
<bfg>

Maybe a better solution would be to build your studio underground in an old
iron mine ???

(just kidding folks... Mu metal is great stuff... but very expensive and you
can't bend it
easily around corners without destroying the effectiveness of the shielding
unless you
heat treat afterwards.   Once I tried to shield an ARP Avitar pickup with
mu-metal.
BIG mistake... the magnetic field was SO well reduced that the internal
magnets did not
sense the strings anymore... Live and learn :^)

H^) harry

>
>
> Yes, I'm very picky about noise.
>
> m.c.
>
> > -----Original Message-----
> > From: owner-synth-diy at dropmix.xs4all.nl
> > [mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Fernando de
> > Izuzquiza
> > Sent: Mittwoch, 8. Oktober 2003 23:50
> > To: synth-diy at dropmix.xs4all.nl
> > Subject: [sdiy] non shield cable
> >
> >
> > Hi all,
> >
> > Wondering about risks of using non-shielded cable for patching.
> > Crosstalk? EMI? RFI?, where is the "danger"?
> > Planning to use 4mm banana cabling but not shure of potential
> > problems,
> > mostly for audio signals but also for CV.
> >
> > Imagine a 3 or 4 rack frames modular, each 12U, so lots of
> > modules. Heavily
> > patched. Cords interpatching frames too. One PSU per frame at
> > about 1 meter
> > away in the floor.
> > What happens if all cables are 4mm banana patchcords? (except
> > output cables
> > to amps)
> >
> > How much will the audio and CV signals suffer, degrade or be prone to
> > interference, etc?
> >
> >
> > Thank you,
> >
> > Fernando
> >
> >
> > <br><br>
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