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[TowerTalk] halfwave verticals -Elevated

To: <towertalk@contesting.com>
Subject: [TowerTalk] halfwave verticals -Elevated
From: 2@vc.net (2)
Date: Fri, 31 Aug 2001 08:04:18 -0700
>R. L. Measures wrote>
>
>> >K7GCO wrote:
>> >
>> >I've run patterns of verticals with radials 10 or more WL long and it
>shows
>> >some promise.  I have a location where I will be able to do that.  Has
>anyone
>> >any experience with this?
>>
>> >N6RK wrote:
>> >I don't know what program you used, but I ran
>> >a bunch of simulations on NEC3-GS.  The results
>> >are fairly discouraging.  With 10 WL long radials,
>> >you need thousands to be effective.
>
>>  Since the end-feed Z of a half-wave vertical is typically c.
>> 1000-ohms, even one 1/4 wave counterpoise makes a sufficient ground.
>> OTOH, with 1/4 wave verticals, which have a thirty-something ohm feed Z,
>> an extensive ground is needed.
>
>We're confusing two different issues.  One is the
>ground radials as counterpoise, the other is
>ground radials to enhance low angle radiation.
>A half wave vertical requires virtually no
>radials to equal the gain of a 1/4 wave vertical
>with radials.  However, with either vertical, it
>requires an impractically large ground plane to get
>substantial enhancement of low angle radiation.

//  Is lower angle radiation better below 20m?

> ... 

-  R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.  
end


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