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Old September 18th 05, 11:51 PM
David
 
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Thanks for the model, I'll try it.

What is the diameter of the elements. I understand you can also vary the
feedpoint impedance by changing element diameter ? (Zo = 276 log(2S/d)

Regards
David

Dan Richardson wrote:
On Sun, 18 Sep 2005 07:14:39 -0500, Cecil Moore
wrote:



The open stub J-Pole (Zepp) is modeled as a shorted stub
J-Pole with the source in the middle of the shorted segment.
Mine is for 53.2 MHz. On edge it looks like this:

13.5 ft.
+---------------------------------------------------
|
(S)
|
+-----------------
4.5 ft.

The sections are 0.1 ft. apart. The resonant frequency is
53.2 MHz and the feedpoint impedance is 25 ohms for an SWR
of 2:1. The feedpoint is 30 ft. high over high-accuracy
ground. The gain over ground is 6.2 dBi, omnidirectional.
Free space gain is 3.4 dBi.



You can vary the feedpoint impedance by changing (S).

73,
Danny, K6MHE

email: k6mheatarrldotnet
http://users.adelphia.net/~k6mhe/