[TowerTalk] Expected VSWR of antenna near the ground

[Cqtestk4xs at aol.com]

Lots of checking of antennas here.  Easiest way to check the  antenna is to 
put a pulley on the tower and then haul the antenna up  to at least 10 feet 
or so for 10-20 meters.  This will give you a rough  idea that nothing 
major is screwed up.  The SWR on most antennas will be a  little low in freq at 
this height but it should work.
 
But like John says, for a really accurate measure 30 ft is the way  to go.
 
Bill K4XS...soon to begin building on KH6
 
 
In a message dated 9/28/2015 11:16:02 A.M. Coordinated Universal Tim,  
john at kk9a.com writes:

It is a  waste of time checking an antenna near the ground. About the only
thing you  can determine is if the coax is connected. You need to pull it
up at least  30' high.

John KK9A


To:     <TowerTalk at contesting.com>
Subject:    [TowerTalk] Expected  VSWR of antenna near the ground
From:    "Doug Ronald"  <doug at dougronald.com>
Date:    Fri, 25 Sep 2015 18:16:17  -0700

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

_______________________________________________



_______________________________________________
TowerTalk  mailing  list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk