[TenTec] Zepp, zepp, zepp!

[John F.]

Here you go.....
Didn't know I'd start such a discussion.  Bob has
what I understand and have understood through
the years...

John, K4AVX
> Message: 2
> Date: Mon, 15 Sep 2014 14:04:14 -0500
> From: "Bob McGraw - K4TAX"<RMcGraw at Blomand.net>
> To: "Discussion of Ten-Tec Equipment"<tentec at contesting.com>
> Subject: Re: [TenTec] Zepp
> Message-ID: <600883B68861416DBF706D8632892FC2 at FAMILY>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> 	reply-type=response
>
> In review of the ARRL Handbook, Ed. 2014, Chapter 21.7, there are clearly
> two distinct examples of Zepp antennas.  One being 1/2 wavelength and end
> fed with open wire line and the 2nd being a center fed 1/2 wavelength wire
> fed with open wire line.
>
> On page 21.7 we find:  "Another variation, shown in Fig 21.12B, is the end
> fed Zepp, named for it original application as an antenna deployed from
> Zeppelin airships.  The feed point impedance of a Zepp is quite high,
> requiring open wire feedline and impedance matching techniques to deliver
> power effectively."
>
> The Extended Double Zepp is described as having an overall length of 1.28
> wavelengths which equates to 0.64 wavelength on each side of the center
> insulator and feedpoint.  This antenna is reported to have ~3 dB of gain to
> its broadside.  The length of the wire antenna is calculated as: 984/f(MHz)
> x 1.28 = length in feet.  The feed point impedance is ~140 ohms using wire
> elements.