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Re: Topband: Antenna Engineers gone wild

Subject: Re: Topband: Antenna Engineers gone wild
From: K4SAV <>
Date: Wed, 08 Sep 2010 13:27:32 -0500
List-post: <">>
Everything works.  It's just a matter of degree.  This one can easily be 
evaluated with EZNEC.  The conductivity of seawater is 5 s/m.  You can 
plug that number (in ohm-meters) into EZNEC instead of copper or 
aluminum.  It looks like that little stream he has was about 0.25 inches 
in diameter.  If you forget about the problem of matching an unknown 
length (which is randomly changing length) and just create a 1/4 
wavelength vertical of seawater, you can get an estimated of the max 
gain.  To bound this, assume no near field ground loss, and use a 
mininec ground.  For a 2 meter ground plane the gain is about -21 dBi.  
For a 160 meter antenna the gain is about -45 dBi.

But that's not the end of the story.  Theoretically this could work.  
You just need a big stream of water.  Say a stream about 20 inches in 
diameter.  That should give a gain of about -0.6 dBi for a 160 vertical, 
assuming no near field ground loss.  That push should sink most ships.  
Anyone want to calculate the thrust?

I liked the signal report the guy gave, "maximum signal 5 by 5", thru 
the repeater yet.

This is similar to the pine tree vertical where a guy tried to couple a 
signal into a tree trunk.  In that case the main radiator was the 
feedline.  That could be the main radiator in the seawater experiment 
too.  You notice there was no ground plane.  Where do you suppose the 
currents go?

Jerry, K4SAV
UR RST IS ... ... ..9 QSB QSB - hw? BK

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