Most hams dont have that benefit Peter but I'll bet that a screen at the
base will still improve the efficiency. Something like a 2x4" grid "rabbit
fencing" with all connections welded, then hot dip galvanized, and then
dipped in plastic.
With 60+ 60-150' radials for a 100' shunt fed tower for 160 with a 4el
Christmas Tree top load, which resonated around 1520 KHz, I was many layers
down in working any DX with 1200W. Adding 4 spokes of 4' x 50' mesh and
interconnecting everything I was cracking pileups on one call many times and
blew thru DXCC in one season. The ground was glacial sand with a fresh water
table about 4' down....totally useless.
When I moved here on top of the hill at about 550' higher, I didnt even
waste time trying radials on the ground since solid granite was only about
1-2' down. Elevated radials were the key. Im up to 98 DXCC with 5W and 18
with 100 milliwatts on Topband and over 300 total.
Carl
KM1H
----- Original Message -----
From: "peter chadwick" <g8on@fsmail.net>
To: <amps@contesting.com>
Sent: Friday, February 21, 2014 3:18 AM
Subject: Re: [Amps] QRO operation into a 80 meter vertical
Carl said:
It still needs radials<
That depends on what the ground is. I use a 60 foot tower topped off with
a 4 ele Steppir, with the directors and reflectors strapped to the boom
to give a better capacity hat, and fed as folded unipole. No radials
because adding them made no change to the feed impedance and no current
could be detected in them - BUT the ground is thick heavy wet clay - even
in the middle of a dry summer. The tower is grounded to 4 ground rods.
It was described as 'Loud' into the US last Sunday morning in the ARRL DX
CW contest
73
Peter G3RZP
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