Re:Topband: Radiation from Ends of Beverage

["CHARLES HUTTON" <charlesh3@msn.com>]

The good Doctor Beverage addressed this issue. To see what he thought, take 
a look at "The Classic Beverage Antenna Revisited" in the Jan. 82 QST. In a 
nutshell, he recommends heights no greater than 10 feet for a 200 meter 
antenna. However, the pattern distortion in that case is quite noticeable, 
and it's past what I consider acceptable.

He does say that the contribution from the vertical downleads is less than 
theory would say.

Those numbers are based on an effective height of 5 - 10%, or put another 
way the sum of the Zenneck wave tilt and arrival angle yields a 5 - 10%. 
Therefore your local soil constants and DX targets contribute to the overall 
effect of the downleads.

Somewhere in a paper I can not recall or locate, someone did the 
calculations for the effective gain of the downleads and Beverage. If anyone 
can remember where I saw this, I'd appreciate a note.


Chuck


> From: "i4jmy@iol.it" <i4jmy@iol.it>
> To: "sam.dellit" <sam.dellit@bigpond.com>
> CC: topband <topband@contesting.com>, w8ji <w8ji@contesting.com>
> Subject: Re:Topband: Radiation from Ends of Beverage
> Date: Thu, 18 Dec 2003 10:08:25 +0100
>
> ---------- Initial Header -----------
>
> >From      : topband-bounces@contesting.com
> To          : "Tom Rauch" w8ji@contesting.com,"Topband Reflector" 
> topband@contesting.com
> Cc          :
> Date      : Wed, 17 Dec 2003 16:02:29 +1000
> Subject : Topband: Radiation from Ends of Beverage
>
>
> > (8) on a more positive note, xmas came early at my shack with the
> > neighbouring sand mine
> > operator agreeing to let me use 100+ acres of their land at the rear of 
> my
> > property
> > for antennas. took me all of 3 hours to set up 500m bev at 6m on 100degT
> > right thru
> > central america. another 500m on 280degT to follow shortly. may the 
> solar
> > flux keep
> > dropping
> >
> > 73s gd dx de sam dellit  vk4zss  brisbane / tamborine
>
> Hi Sam and All,
>
> I've no time to enter into the vertical ends effect of beverages 
> discussion, but I've never felt they introduce appreciable energy to the 
> system.
> Not everything that's printed in a book or published has sense.
> In my experience effect of beverage ends is not a consistent matter in 
> practice, and simply I don't care.
> If I understand correctly You place your beverages 6m over the ground.
> In my experience, this is instead a point.
> Such an height starts to be a problem, and does affect beverage's 
> directivity.
> Season greetings and 73,
>
> Mauri I4JMY
>
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