Clearly I am having trouble understanding and belief of why star would
have a ten fold reduction or 20db over an equiv. shielded 2 wire. And
I appreciate your attempt as well as Walts in explaining it to me.
In further thought it makes no sense for me to buy the 2 wire version
when I like the 4 wire because of possible breaks, and maybe even the
"magic" that accounts for a noise reduction.
Right now I am preparing a parabolic presentation for a large group of
K to 12 science students. I am sure they all will have fun and
education with a group of 32" dishes and Randys math for a hands on
learning experience.
Rich
--- In "kennjava" <> wrote:
>
> --- In "Rich Peet" <>
> wrote:
> >
> > --- In "kennjava" <> wrote:
> > >
> > > The 4 conductors in the twisted "star" pattern provides more
physical
> > > symmetry of the signal-carrying conductors; this symmetry means that
> > > signals induced along the cable are more completely cancelled
out by a
> > > differential input.
> >
> > Of course you understand that there would be much more symmetry if
> > there was only two wires running directly next to each other.
> >
>
> I don't see how that could be so... (otherwise normal mic cable would
> be less prone to noise than star-quad, right?)
>
> If you consider a pair in cross-section (A and B) and noise source (N)
> like so:
>
> 1) AB N
>
> 2) A N=20
> 2) B
>
>
> Then in 2) A and B are receiving the same signal from N, but in 1) B
> is closer therefore recieving more signal from N.
>
> Isn't that the whole point of pair twist - so that over a length of
> cable the distance A to N and B to N average out to be equal... which
> means equal amounts of induced noise, which means better cancellation.
>
> And star-quad improves upon that, because it's cross-section is never
> as asymetrical as 1).
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