[sdiy] grounding sheilded wire?

[Dave Krooshof]

>But I wonder
>how I am supposed to ground the sheild, do I just connect one end to ground
>and leave the other end floating?
Ideally, each module of your synth is grounded in only one way.
This means that if you connect the shield of your wire to
ground on both ends, that your likely to have more then one
ground lead, simply because you'll probably connect more then one
lead to a module, and you might have chosen to connect it to ground
internally as well.

What you can do, is to make a central ground somewhere in the
middle of your box. Then you connect each module's ground to that.
(like a star) The female connectors of your modules are grounded
to the modules ground.

Then your wires. In a jack plug, I'd connect the shield to one connector.
I'd leave it unconnected on the other side. This way, you won't
connect two "beams" of the "star". I might be wrong, but a banana plug
doesn't have a ground ring, does it? What I call a banana plug is a
one-tip-only thing.

I do not know is shielding is of much use then. It might even work as
a small capacity... Do you happen to have any hum/hf problems
that make you want to shield?

>is it ok to just have wires
>tapping ground with loose (ie not connected to anything) ends?
>or does it need to go in some sort of continuous loop?
Synths differ from "guitars with effects" in the fact that
guitarist tend to patch modules in a line...
guitar-->fuzz-->wah-->flanger-->chorus-->amp.
They connect the shielding to earth in the amp, so everything
inline is grounded.

...and synthesizer players tend to build networks, in which their
modules can be connected in more then 2 ways. If you'd choose
to ground all shieldings of your wires on both ends, you'd make
loops in the grounding. Ground-loops are a problem because they
behave like a dynamo: The alternating magnetic fields of
electricity in your house will generate some current flowing
in your groundloop (a simple coil). Hummmmmmm....


Dave


BTW in the studio-control room, I can patch the mixerconsole
to either the studio, the theater, or the dance theatre. I
measured their grounds... 4 volt AC. I decided to connect a led.
I glowed! In the building are 3 rods in the ground to ground
the building. The Amsterdam soil is a battery...