[TowerTalk] Expected VSWR of antenna near the ground

Doug Ronald doug at dougronald.com
Fri Sep 25 21:16:17 EDT 2015


I have assembled my 19 element LPDA with the front 12 elements about 3 feet
off the ground and parallel to the ground. The back elements are laying on
the ground, but electrically connected in the usual LPDA way. Today, as a
check before I erect it, I swept with a VNA, the antenna from 1 MHz through
32 MHz. The VSWR is horrible! It has peaks and deep dips at the low end, and
then at 14 MHz or so, rises to over 5:1 and stays there.  Now I didn't
expect even 2:1 over the range, but I expected the VSWR on the high end to
be at least reasonable, because the front shorter elements are off the
ground.

 

Anyone care to weigh in with an opinion? I hoping an expert says this is
perfectly normal for an antenna just a few feet off the ground. If not, I'm
kind 'a stuck as I have checked all the connections with an ohm meter, and
they are all okay.

 

Thanks,

W6DSR



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