thank you, Tom - great info!
> From: w8ji@w8ji.com
> To: rodenkirch_llc@msn.com; tshoppa@wmata.com; topband@contesting.com
> Date: Mon, 5 Nov 2012 12:37:34 -0500
> Subject: Re: Topband: Further discussions on EWEs
>
> > Tom, et al: is there data that nail down the horizontal wire to vertical
> > wire ratio? I see in that write up by wa1on mention of 2.25:1 h to v
> > but...is that some rule that can't be violated or.../
> >
> > For instance, assuming a vertical section height of 10' I could run a
> > longer horizontal section but don't know if that gains me anything.
>
> I can't imagine why there would be some set rule or guideline, except with
> many qualifications. I'm sure there is some general range of lengths vs.
> height for various configurations. The ideal shape would be rectangular with
> source and load centered in the shorter vertical wires, which is the
> equivalent of a base-fed EWE over perfect ground.
>
> The horizontal part or component of the antenna works best when it behaves
> most like a transmission line with a velocity factor of unity (ideally
> faster than light). The longer it is and the wider it is spaced, and the
> poorer the earth below the antenna, the more the system responds to unwanted
> signals in the horizontal mode.
>
> The vertical component of the antenna wires acts like two verticals, and is
> the desired signal response.
>
> You can see the obvious conflicts. If the vertical section is taller,
> horizontal spacing is wider and that response increases. If the length along
> earth is longer, the verticals are separated more and this increases
> sensitivity of the verticals (until they are 1/4 wave apart) but it also
> makes undesired horizontal sensitivity increase.
>
> There are a half dozen things that can make one thing better while making
> other things worse. Everything, including characteristics of the earth and
> things around the antenna, would interact.
>
> If you really wanted to optimize an antenna like this, you would have to
> make it two short verticals that are phased. After all, that is all the
> antenna actually is.
>
> 73 Tom
>
> _______________________________________________
> Topband reflector - topband@contesting.com
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Topband reflector - topband@contesting.com
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