[TowerTalk] 10M phased verticals

[Paul Christensen]

I just modeled a 10m four-square in 4Nec2.  I used 60 #14 AWG radials 
5/8-wave long over average soil, and 5/8 wave radiators.  The F/B is 
terrible at 1/4-wave spacing.  At best, it's about 12dB at an elevation of 
45 degrees.  As would be expected with a 5/8wave vertical, two lobes are 
present.  Maximum FS with this ground occurs at 15 degrees elevation with a 
secondary lobe at about 60 degrees elevation.  The second lobe is within 3dB 
of the primary lobe.  Reducing radial length to either 1/4 or 1/2 wave has 
minimal effect on pattern.  There may be other combinations of spacing and 
source phase with 5/8 wave verticals that yield better pattern results.

I'm not sure why anyone would want to use 5/8-wave verticals on HF.   We 
tend to equate 5/8-wave with maximum 0-degree elevation gain (usually from 
VHF/UHF antenna literature).  If someone has a compelling reason to use 
5/8-wave *vertical* radiators on HF, I would like to hear about it.

Paul, W9AC

----- Original Message ----- 
From: "Rick Karlquist" <richard at karlquist.com>
To: "Bill and Cindy" <wb0o at yahoo.com>
Cc: <towertalk at contesting.com>
Sent: Tuesday, November 29, 2011 1:06 PM
Subject: Re: [TowerTalk] 10M phased verticals


> You ask "is it worth it to make a 4 square array of 5/8 wave
> verticals?"
>
> First we need to determine if it is POSSIBLE to do that.
> I've never seen a published example of that, and my gut
> feel tells me it isn't practical.  4 square
> arrays use 1/4 wave verticals.  You can extend the analogy
> to 1/2 wave vertical dipoles fed in their centers with baluns.
> But I don't see how 5/8 wave verticals fed at the bottom
> would work that way, and it isn't clear what the optimum
> spacing should be.
>
> Rick N6RK
>
>
>
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