[sdiy] Shielded Cable

[harrybissell]

its a pop fly... I got it :^P

Use the shielded cable where you are likely to pick up noise (audio inputs to
high gain
circuits like VCF, VCA...) or where you need to run cables parallel to each
other, some
of which are likely to couple noise (like sawtooth and pulse which have lots of
fast rise
time edges) and other cables where such noise will be obvious (like a sine
wave).

I usually tie the shield at one end, whichever end has the best ground. Usually
you tie the
shield to the end of the circuit that is driving (force the noise to return to
the source) but
some folks might have the opposite opinion.

For single ended cables, I usually use one inner conductor, and ground the other
one along
with the drain (bare) wire.   If its differential (like a balanced mic input)
use both center conductors
for signal and ground the drain wire.

Most CVs don't need to be shielded in most synthesizers (there can be an odd
exception here and there

H^) harry

Pat Kammerer wrote:

> Hi all,
>
> I had the good fortune to stumble upon maybe 100 ft of Belden 8451 shielded
> cable today while dumpster diving.  I was pretty happy about this, since I
> have just started putting together my first true VCO (Rene Schmitz's 4069
> VCO, with Scott Gravenhorst's add-ons).  What a find!
>
> I've used shielded wire (low quality, salvaged) in only one project, which
> was a circuit bent keyboard that would howl unless you used sheilded on
> certain sections.  The thing is that I don't know if I used it right.
>
> I know that many of you have expressed that you use belden cable for
> internal connections, but what connections do you recommend using it on?
> Also, does the sheild get connected to ground, or to nothing?  This cable
> has a foil shield, as well as a stranded lead next to the shield, as well as
> two wires (red,black).
>
> If anyone can give me crash course in sheilded cable in relation to SDIY, I
> would be in debt to you.  I have googled by the way, and only came up with
> people selling cable and the like, but very little in the way of useful
> information.
>
> Thank you!
> Pat