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Re: Topband: 160 Antenna

To: TopBand <topband@contesting.com>
Subject: Re: Topband: 160 Antenna
From: Joe <nss@mwt.net>
Date: Wed, 19 Dec 2018 08:02:39 -0600
List-post: <mailto:topband@contesting.com>
OK,

I ran the random wire, It was a convenient length, from the eve of the house just outside the shack with a like ten foot length of RG-58 from the tuner, and out with the wire to a tree almost due south 75 feet away.

No ground system, wire connected to center conductor of the coax. braid connected to nothing wire end, and to the tuner at the tuner end.

wire about 10 feet above ground.

It actually hears better than the center pin only vertical set up by an average of about 10 db.  And by at least 20 db when the 40 vertical ran fully connected.

Now how to improve some?  I would assume to make it longer, try to get to at least 1/4 wave,, but then it won't be straight at all. Might make tuner happy if it was longer. the tuner was able to get the swr dead flat BUT the "L" was maxed out. so I assume some more wire over the only 75 feet it has now might help that issue.

Now since it is all horizontal, not like an inverted L, I cant really add wire to the braid to make a radial.

wonder what I should do to make it better using the braid.

Thoughts?

Joe WB9SBD
Sig
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On 12/17/2018 8:31 AM, Joe wrote:
OK, as users of this band, we all have probably done this at least once in your radio lifetime.

You want to get on 160, but do not have an actual 160 antenna. So you connect the largest antenna ya have, usually a 80 meter dipole, but you just push the connector in just so only the center pin is touching, and load the whole thing up like a top capacity hat, vertical, or end fed long wire.  Hey it works.

I'm thinking of doing something similar, because a full sized 1/4 wave elevated vertical for 40 meters, works as well as a cannenna does when trying to use it on 160.

But I never thought of what might be the best way to do this. The antenna as stated is a full sized 1/4 wave elevated Vertical,  The base of the vertical is 10 feet above the ground with sloping radials that act as guy wires also to hold the base in place.

At the base of the antenna right at the feedpoint, is a large multi turn coax choke. ( Ya know the so many turns on a PVC pipe thing )

The feedline is then ran through the air for about 60 feet to the eve of the house where it runs along the eve of the house on 2 sides and finally into the shack. Total length is about 100 feet.

Now I am trying to decide without actually trying to make up connectors or whatever, what might be the best way to use this on 160.

1- As described above just the center pin, touching. I guess with the braid floating the braid gets capacitivly coupled to the power and does the radiating and receiving. YES? NO?

BUT I can see the RF actually also going and using the existing vertical because of the touching center pin. BUT, the braid signal, I'm assuming the RF is not getting past the Coax coil and using the radials.

2- Apply power to only the braid?  similiar to #1 but backwards. again no power to the radials probably?, and only cap coupled to the vertical.

3- short the center and shield together and run it that way.

Anyone have any thoughts of the best configuration any thoughts?

Or how would a end fed random wire like 1/4 wave long about 10 feet up work better?

Joe WB9SBD
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