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Re: [TowerTalk] EZNEC- needs improvement

To: towertalk@contesting.com
Subject: Re: [TowerTalk] EZNEC- needs improvement
From: Steve Hunt <steve@karinya.net>
Date: Mon, 06 Apr 2009 15:32:58 +0100
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Paul,

I'm still struggling with your explanation. You seem to be claiming that 
if the only propagation path which exists is at a lower angle than the 
dipole's optimum take-off angle, the dipole wont hear anything. 
Obviously that's not true.

Let's take your figures for the dipole vs the vertical, and assume that 
the only viable propagation path is at 5 degrees. Even though that's way 
below the dipole's 30 degree optimum of 8.36dBi, it still has a 
reasonable response at 5 degrees (-2.94dBi). At that angle the vertical 
is 3.68dBi, so we'd expect the difference to be 6.62dB.

My point is that, even if the propagation massively favours the 
very-low-angle path, the dipole will only ever be 6.62dB behind the 
vertical. The fact that there may be other, much weaker, paths at higher 
angles where the dipole response peaks is irrelevant.

What am I missing?

Steve

Paul Playford wrote:
>
> And if you compare the 30 degree takeoff angle of the dipole to the 10 
> degrees of the vertical you will see no possibility for propagation 
> with the dipole and 14 dB above the noise and a slight chance of 
> propagation with the vertical.
>
>

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