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Re: [TowerTalk] 3 el bobtail for 80 meters

To: towertalk@contesting.com
Subject: Re: [TowerTalk] 3 el bobtail for 80 meters
From: jim Jarvis <jimjarvis@optonline.net>
Date: Sat, 05 Jul 2008 07:53:58 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
  KZ4USA wrote:


> Anyone ever take two or maybe three of these and make a 9El  
> vertical array.
>
> If you had the room would it outperform a 3El yagi for 80 meters in  
> one direction?
>
> Just wonder.
>
> KZ4USA
>
>
>
>

You will need a space of about 1200 feet to build it and a method of
accurately aiming it, 11.3 dBi gain, beamwidth 12.2 degrees.

Jerry, K4SAV

To which N2EA appended:

Assuming you could efficiently match it and deliver power to it.
Figure 3dB loss in that scheme, and you'd net out with 7 or 8 dB fwd  
gain,
and a beamwidth which won't span europe.   Plus, with 9 el, you'd have 8
rear/side nulls/lobes which were maybe 10dB down from the fwd lobe.
Yagi pattern would be cleaner.

If you were to add the price of copper into a spreadsheet model, and  
plot
$Cu/dB, you'd likely find things would optimize around 3 or 4  
vertical elements,
in  some configuration.

Unless you had a specific reason for a rifle-shot, you'd be better  
off with
something simpler to match and control.  Like putting the money in  
steel instead
of copper, and trying a pair of switchable, crossed inverted vees at  
100'?

Good question.  Good modelling.  KISS?

73/n2ea




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