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Re: [IRCA] Cable connectors
- Subject: Re: [IRCA] Cable connectors
- From: george magiros <gmagiros@xxxxxxxxx>
- Date: Mon, 6 Sep 2010 20:32:35 -0400
According to this the twisting is about preventing radiation and therefore
crosstalk.
https://www.bicsi.org/pdf/presentations/dubai2009/G%20Humbert.pdf
<http://img94.imageshack.us/i/screenshotidw.png/>
http://img94.imageshack.us/img94/8149/screenshotidw.png
On Mon, Sep 6, 2010 at 8:11 PM, <rfoxwor1@xxxxxxxxxxxxxxx> wrote:
>
> ---- Russ Edmunds <wb2bjh@xxxxxxxxx> wrote:
> > I seem to recall that 'back in the day', Gordon Nelson was concerned
> about keeping the feedlines from his loops as short as practical for the
> application. Realizing that his recommended feedline was car radio cable
> with the original center conductor removed and replaced by insulated #22 or
> so ( with the braid soldered together on each line about every foot ) I
> wonder if it is in fact possible to get what you're aiming for.
> >
> > I don't recall the specific electrical and/or magnetic characteristics of
> that type of feedline vs. coax, but perhaps that too has some relevance here
> in that he eliminated using coax for a specific reason, which alas I also
> don't recall.
> >
> > Russ Edmunds
>
> The only thing I can think of would be to lower the capacitance (per foot)
> of
> the cable itself. This is the reason that type of cable was spec'ed for
> car radios which had a compression trimmer that had to be peaked (at 1400
> kc)
> for the specific car whip being used. Now that I think about it, real
> commercial
> grade coax contains spacers to keep the center conductor equidistant from
> all parts of the shield. Running in your own #22 wire for the center
> conductor
> after removing the original wire (I guess it was too flimsy) would lead to
> the
> wire being adjacent to the shield almost everywhere. Not sure how important
> that would be. I did that once, 40 years ago, but forget the details.
>
> - Bob
>
>
>
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