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[TowerTalk] 40M FD Antenna

To: <towertalk@contesting.com>
Subject: [TowerTalk] 40M FD Antenna
From: n4kg@juno.com (n4kg@juno.com)
Date: Tue, 26 Jun 2001 22:08:31 -0600
A current fed Long Wire is an OK antenna, but probably NOT at 20 ft.  
There will be DEEP NULLS broadside to the wire and lesser nulls
off the ends of the wire.

I installed a 2L wire beam composed of an inverted VEE plus 
Reflector with 150 degree apex angles and 21 ft of separation
supported by a rope boom  between two 50 ft high light poles
for adjacent baseball fields.  The ends were tied off 200 ft from
the center of the antenna.  This beam was aimed due NORTH
from North Alabama (K4BFT 5A AL).  Performance was AMAZING -  
we had W1's answering CQ's an hour before sunset and VE1,2,3,
5,7, KL7, and even a few Europeans after dark.  With a single inv vee
we usually work far fewer W1's and VE's.  For the West Coast,
we use a vertically polarized Delta Loop which is usually about 
6 dB stronger to W6 / 7 after 11 pm.  It was interesting to note
that we still had many Tex, NM, Ariz, CA stations call after
CQing on the 2L wire beam aimed North.  Some FL stations
were somewhat weak but still called in and were worked off
the back of the beam.  We have used this antenna for the last
2 years and both times beat the 20 / 80 CW station for the first
and second time.  Peak 10 QSO rate was 140, our best ever.

BTW, we also used the 40M wire beam on 15M and worked all 
over the country, jumping from W1/2 to W6/7 to W4. A 3/2 WL current
fed Long Wire (e.g. 40M straight dipole used on 15M) has 6 lobes.
If the ends are dropped SLIGHTLY (15 to 30 degrees), the nulls
are filled in.  If the ends are dropped too much (45 degrees) it
becomes much less effective.

K4BFT  40 / 15 / 10 CW station results using 100W output:

40M  CW  QSO's  738     2L40 Inv Vee + Vert Polarized Delta Loop
15M  CW  QSO's  355   40M Inv Vee
10M  CW  QSO's    15   40M Vertically polarized Delta Loop)

Total station QSO's  1108 


On Tue, 26 Jun 2001  EDT N4CW@aol.com writes:
> Out of curiosity, what antennas were truly outstanding during Field 
> Day this > year? I used a full-wave, fed a quarter wave from one end
(up 20 
> feet!) and  it performed "just okay", judging by how long it took me to
get 
> responses to  my CQ's.
> You can E-mail your responses directly to me to save on bandwidth. 
> 73, Bert N4CW (N4CW@AOL.COM)
> 

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