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Old March 15th 07, 07:48 AM posted to rec.radio.amateur.antenna
Owen Duffy Owen Duffy is offline
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First recorded activity by RadioBanter: Dec 2006
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Default Best HF Vertical

David Ryeburn wrote in
:

In article ,
Jet_Li wrote:

best is any vertical from Force 12 - I got one on 75 meters that
beats everything else I have put up.
got one on 40 meters from Force 12 - beats everything else I have put
up.


I went to the Force 12 website and clicked on the "Flagpole antennas"
link http://force12inc.com/F12-flagpole-ants-003.htm.

I read the "New 40 Meter Coil" portion of the page with interest --
sounded too good to be true. A moment's use of the calculator showed
that the VSWR figures and the quoted feed point impedances were very
inconsistent -- orders of magnitude wrong. The claimed SWR of 16 for
the unloaded antenna worked out really to be about 850 -- close enough
to infinity for me!


Ah, but you calculated the VSWR at the load end. They calculated the much
lower VSWR at the source end of the line.

If you were Force12, you probably wouldn't want to publicise the extreme
VSWR that users of the standard flagpole experience in this scenario.

Owen