[TenTec] 450 Ohm feedline

[Robert & Linda McGraw K4TAX]

If one remembers seeing the many "signal lines" that ran along beside of the
RR tracks, they had a insulator arrangement with a metal support in the form
of an X which was used to swap the conductors.

Bob, K4TAX

----- Original Message ----- 
From: "Bwana Bob" <wb2vuf at qsl.net>
To: <tentec at contesting.com>
Sent: Friday, April 16, 2004 9:22 PM
Subject: Re: [TenTec] 450 Ohm feedline


> Yes, even before bundled cable, when long parallel lines were run on the
> telephone poles, the wire positions on the poles were periodically
> interchanged. One wire was dropped under the other and crossed over to
> its opposite side by means of a "drop bracket".
>
> Hey! Maybe this is the solution to BPL interference: Make the power
> companies twist the power lines!
>
>
> 73,
>
> BoB WB2VUF
>
> JAMES HANLON wrote:
> >
> > Bob wrote:
> >
> > > Regarding twisting the feed-line, why do you suppose the phone company
> > > called it "a twisted pair"?  Answer: because that what it was and it
was
> > > used to maintain symmetry and thus reduce induced voltage from
overhead
> > > power lines.  Same applies here.
> > >
> >
> > I'm an old Bell Labs engineer, and I can recall being taught in our
"CDT"
> > (Communications Development Training) courses that the pairs were
twisted to
> > cut down on the cross talk from other pairs bundled into the same cable.
> > I'm sure it helped for power line induced voltage as well though.
> >
> > Jim, W8KGI
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>
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