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Re: Topband: contesting in a field

To: topband@contesting.com
Subject: Re: Topband: contesting in a field
From: <k3ky@radioprism.com>
Date: Tue, 15 Nov 2011 22:15:04 -0700
List-post: <topband@contesting.com">mailto:topband@contesting.com>
I like resonant, voltage-fed verticals for their simplicity. For field
ops,
they can be a very quick way to deploy a working antenna. On 40 meters,
for example,  you're only dealing with 70ft- or 35ft if bent like an
"L",
Half Square, Bobtail, etc.

If you could catch Murphy on vacation, and if you can raise a large
enough balloon to support ~268ft of smaller gage wire, you can go with
a voltage fed half wave using an LC tank to tune it. Tap up the coil
from the ground end with your coax for a 1:1 SWR (assuming your LC is
properly resonated) Your farm isn't near any airports, is it? OTOH if
it's windy, this could be a rather frustrating event. (technically,
you're 'pushing it' a little with anything over ~200ft in height)

You don't need much of a counterpoise, feeding this way- roll out
however much chicken wire or wire cloth as you care to- or think
'radials', if that is your preference. A denser, shorter radial field
or counterpoise ought to work pretty well.

Having the current max up 134ft couldn't hurt. It ought to play
reasonably well. As always, more ground is better ground. I like
the roll(s) of chicken wire approach.

73, David K3KY


>The last thing I need is a reason to generate flammable gasses in bulk :)
>
>We homeschool, so maybe that would fit the stereotype everyone expects.
>"And then they did a chemistry experiment and blew up their garage."
>
>I've thought about an inverted L at home, I have just short of an acre, I
>think the above ground part wouldn't be a problem its the radials. I'm
>assuming in the wide open spaces at the farm I can pursue the same elevated
>radials I would for a kite/balloon vertical? The elevated vertical thing
>seems to be the best bang for the effort, and in some ways less effort
>especially for temporary ops like this.

Chris

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