My version of Tim's array was installed in 1998, with 120 on-ground radials
under each element. A few years later I added an extra director toward Europe
for an additional 0.9 db gain in that direction.
It brought me up to 329 countries on 160, including JT, HS, XZ, VU, A5, BA.
After a few years I was looking for something more and came up with a
broadside/endfire array that offers about 8.5 db gain over a single vertical.
WW2Y/K2WI first used a version of this in New Jersey in the 1980s, with
Inverted L elements hung from trees. VY2ZM has one using full-size towers.
My version has a footprint of 325 feet by 146 feet, oriented to favor Europe.
One of the T-shaped wire elements (no. 12 THHN, 73.5 feet vertical, 58 feet
horizontal) is borrowed from the K3LR array, switched with relays. The other
three are hung from towers and trees. Each element has 120 on-ground radials,
about 130 feet long. A couple of bs/ef arrays are described in ON4UN's book.
If you add four more elements this becomes the 8-circle array, switchable in 8
directions (may not fit in 5 acres). N5IA (SK) built one of these in Arizona,
still in use by the NA7TB club station.
K9DX had a 9-circle array in Illinois for many years, since dismantled. More
complex but very effective.
73/Jon
Jon P. Zaimes, AA1K Tower climber for hire http://www.aa1k.us/ Cell:
302-632-2353email: jz73@verizon.net or aa1k@arrl.net
-----Original Message-----
From: Tim Duffy <k3lr@k3lr.com>
To: 'Dino Darling' <dino@kx6d.com>; 'Topband@contesting.com'
<topband@contesting.com>
Sent: Thu, Mar 24, 2022 1:13 am
Subject: Re: Topband: What antenna would you build?
Hello Dino,
Take a look in the last three editions of the ON4UN Low Band book - in the
Yagi chapter.
I have described in detail the 3 element vertical Yagi for 160 meters that I
am using. Gives over 5 dB of gain (over a single 1/4 wavelength vertical)
and the front to back is over 30 dB at the peak. Four directions. It works
good for about 40 KHz of the band (great for DX contests). I do have CW and
SSB optimum settings for the parasitic elements. W5ZN, AA1K, K9CT, NR5M and
VE3EJ have built this antenna as well. It can work omni as well. Requires
one tower 120 feet tall and a LC matching network to step up the 25 ohm
feedpoint impedance.
It is easy to build and very effective. Twice from K3LR we worked over 100
DXCC in one weekend in the CQWW CW contest - from almost Ohio...
It does require five extensive ground radial systems (one under each
element). The best DX with this antenna was JT5DX in zone 23 during the CQWW
160 meter contest and this past November, RW0A in zone 18 - in the morning
local time here!
73
Tim K3LR
-----Original Message-----
From: Topband [mailto:topband-bounces+k3lr=k3lr.com@contesting.com] On
Behalf Of Dino Darling
Sent: Thursday, March 24, 2022 12:39 AM
To: Topband@contesting.com
Subject: Topband: What antenna would you build?
If you may and you are willing to indulge me; if you were about to buy
5-acres with no neighbors or restrictions and wanted to erect a serious 160M
antenna system, what would you build and why? We can pass on the Radio
Arcala discussion; nobody's that cool.
A loaded 4-square? 1/4 wave stick (or longer)? Phased dipoles? (fill in the
blank)?
I've seen a 200' tower with three phased dipoles tilted on end. The end of
one side of the dipole was anchored and insulated at the top of the tower
and came down like guy cables. About half way down was the feedpoint, were
an isolated anchor cable continued down the same path to ground (like a guy
cable). However, the second half of the dipole was pulled back to the base
of the tower, from the center feedpoint insulator. It looked like an
arrowboard chevron or a regular dipole that was turned 90 degrees on its
side. The coax was horizontal back to the tower. There were three of these
spaced 120 degrees apart and fed with a phasing network to steer it. I
understand it works great.
So what would you build?
Dino - KX6D
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