[Xastir] Portable Digipeater Antenna?

[Jim Shorney]

On Sun, 01 Jul 2007 14:42:41 -0500, Gerry Creager wrote:

>3.  If you were to expand the braid and double it back over the jacket 
>of the coax, you'd achieve the decoupling you're trying to get with the 
>(effectively HF) choke.  A similar decoupler can theoretically (meaning, 
>I've not tried this yet) with a piece of 1/2 in pvc and aluminum or 
>copper tape bonded (electrically) to the shield and also .52 wave long.
>
>This is a good idea for a short-term, temporary, quickie antenna.


What you're talking about is basically this:

http://athensarc.org/sleevedipole.asp

The feed needs to be offset from the center because of the end effect of the
dipole element interacting with the coax.  They can be made with coax as you
describe above, I've seen them called a "coaxial dipole" in the past.



-- 
Jim Shorney      -->.<--Put complaints in this box
jshorney (at) inebraska.com
Ham Radio NU0C
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