Posted by
Charles Greene-2 on
Sep 10, 2005; 10:44pm
URL: http://elecraft.85.s1.nabble.com/KX1-Antenna-Idea-tp382007p382010.html
Martin,
I went up in my attic with a ruler and this is what I found for some feed
lines I made:
#24 stranded, silver plated teflon insulted, with about one twist per inch.
#26 , same type, about two twists per inch.
#28 solid, silver plated teflon insulated wire wrap wire about one twist
per inch plus a heat shrink tube about every two inches.
All are close spaced.
I also have about 1000' of #26 solid as above that would work too, or I
could use if for a near invisible antenna.
A good source of similar wires to above is eBay.
GL
73, Chas
At 10:58 AM 9/10/2005, Martin Gillen wrote:
>Hi, Chuck.
>
>I have a question about your feedline:
>
> > I have made up some feedline using #28 teflon
>insulated
> > solid wire wrap wire held together with heat shrink
> > tubing. The characteristic impedance is not
>important and
> > it is low loss. I measured some #26 twisted pair
>once and
> > it's impedance is about 180 ohms.
>
>I know that coax can be looped around 5 times to
>create
>a balun near the dipole feedpoint. Can twisted pair
>be looped around to create a balun also?
I don't see why not. You probably would want to use a plastic juice bottle
as a form, which I do anyway for coax.
> Also, what
>was
>the distance between the twists? I'm interested in
>making one to feed a dipole for my KX1 field ki
>How can you measure that a balun is being effective?
Measure impedance with an impedance meter. the Z should be roughly 10
times the impedance of the feed line. Or else check antenna handbook and
use the dimensions they give. Note that the handbook is for coax, and a
higher impedance feed line will take more turns. Impedance is proportional
to N^2.
>Thanks,
>Martin.
>
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