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Re: Topband: Dragon slayer

To: "Gary Nichols" <kd9sv@comcast.net>
Subject: Re: Topband: Dragon slayer
From: "Tom Rauch" <w8ji@contesting.com>
Reply-to: Tom Rauch <w8ji@contesting.com>
Date: Mon, 22 Jan 2007 17:48:16 -0500
List-post: <mailto:topband@contesting.com>
> Hi Gang, I have been thinking that perhaps an approach to 
> killing the Dragon
> might be using a small directive antenna like a pennant or 
> loop directed
> toward the noise and a beverage in the opposite direction 
> (or away from
> Dragon) to phase cancel the offending creature.  I am 
> thinking the output
> from the Pennant in the forward direction would have about 
> the same strength
> as the null of the beverage on the Dragon which should 
> make canceling a
> possiblilty.  Don't know if anybody has tried that 
> approach so far.please
> let me know.

The problem with that method is maintaining phase. What you 
would be doing is making a phased antenna with a null 
towards the offending signal out of two dissimilar antennas.

The ionosphere on 160 is constantly changing and that means 
if you use two dissimilar antennas with sharp patterns, and 
especially if they cover a large area, the signal phase and 
level will change moment by moment. We'd be much better off 
to phase two similar antennas with fairly close spacing 
between the antennas.

The ideal solution would be a blanker, but that would 
require knowing if the signal lends itself to blanking. We 
will only know that when someone gets a broad band time 
domain snapshot of the signal before it passes through 
narrow selective circuits.

**If we want a universal cure that will help everyone, we 
need to see that signal's off and on characteristics through 
a very wide filter.** Otherwise the next best choice is 
phasing two close spaced similar small antennas.

73 Tom 


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