[TowerTalk] elevated radials vertical

Tom Rauch w8ji at contesting.com
Fri Jun 8 19:11:20 EDT 2007


> Tom, have you used Elnec to model the folded unipole?

No. Not really.


> How about Professor John Mullaney's design program that is 
> specific to that antenna; have you used it? Ive been 
> trying to find a copy to no avail.

No. I really don't have much interest in the folded unipole 
since all my towers are insulated. When I did use shunt fed 
towers or folded unipoles modeling programs didn't even 
exist.

> Im especially interested in the 3 skirt wire version, 
> spacing from the tower and the 105-115 degree electrical 
> heights which Mullaney and others claim have a 
> particularly wide VSWR bandwidth..

Some shunt fed towers will do that because the skirt makes 
the antenna look very fat and the stub effect can compensate 
reactance changes to a small extent.

A vertical with a good large ground system is already 
significantly broader than of a dipole when both have 
similar diameters because the L/D is twice as favorable for 
the vertical. Even a regular 12 inch face tower, when series 
fed, has very wide bandwidth so I just don't worry about it. 
Since I don't worry about bandwidth and the efficiency is 
the same, I just never worry Carl.

73 Tom 




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