[TowerTalk] Breakall short vertical

Terry Conboy n6ry at arrl.net
Fri Jun 11 15:12:36 EDT 2004


Kintronic also has a link to a more theoretical IEEE article on this antenna:
http://www.star-h.com/publications/ieee2002.pdf

In the end, this is just a permutation of a short fat vertical with a large 
capacity hat.  For short verticals, these work pretty well, but as Tom 
mentions, the ground currents are still relatively high, since the 4 wires 
all dump equal, in-phase currents into a common ground system.  If you have 
120 radials, the ground losses are quite small and the efficiency is 
good.  If you have a more typical sparse ham ground system, the losses can 
be noticeable.

I was surprised that the authors (PhDs, MSEEs, and PEs notwithstanding) of 
these papers don't seem to understand the realities of the ground 
currents.  One of them also conspired to write another paper on folded 
unipoles that propagates the same mischief.
http://www.dlr.com/dlrweb/papers/nabpaper/Nabpaper.htm

Terry


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