Jack
The Inverted L or vertical at one side of your tower can work, but the most
important to make it work is the
radial system you need to have to make it work fine what understand from your
description is that
your antennas will load your tower to a lower freq than 80m, but what can see
is that the yagis can affect the SWR in your
Inv L or vertical in some positions, that happens with 2 friend that have
that
wire side of the tower and below the yagis.
Separate the wire 4 -8 ft from your tower and keep the wire with tension to
avoid wind movement
also you can include in that wire others bands like 30 and 40m or beter if
you want to have all the bands
in the other side of the tower using the same separation and same radial
system an Inverted L for 160m
just with mix 31 chokes and cables to your Rat pack for each band
those systems are working and producing a lot of DX , simple and easy to
build,
just give a try
J.Hector Garcia XE2K / AD6D
Mexicali B.C DM22fp /Heber CA
P.O.Box 73
El Centro CA 92244-0073
http://xe2k.net
________________________________
From:Jack White <m5pro@hotmail.com>
To:Towertalk <towertalk@contesting.com>
Sent: Thu, December 27, 2012 7:50:45 AM
Subject: [TowerTalk] 80M Ideas
Hi
I've been reading the ON4UN book and antenna articles online on and off for a
couple of years now but I thought I'd share my situation with some more
experienced Guys on here to see if I can perhaps find some new information and
ideas.
I have a modest HF/6 station that covers 40-6. I have a painted 3 section 60ft
Versatower (suspect v. poor electrical connection between sections) with an
Optibeam OB1-4030, Optibeam OB9-5 and 5L 6M Yagi all mounted on a 15ft stub
mast
and fed into an Array Solutions Ratpak. (Antenna pic on QRZ) The 6M Yagi has
grounded elements but the Optibeam elements are insulated from the boom and
tower. The station is working nicely now so I feel it's time to add an 80M DX
TX
antenna. I am interested in 3.5MHz CW only, so bandwidth/phone etc not an issue.
In the past I've tried an 80M coax fed inverted vee with the apex at 60ft - as
expected dynamite out to a couple of thousand miles but no good for DX. I've
ruled out the possibility of shunt feeding the tower because of the Optibeams
and the poor connection between sections. So currently I'm left with two ideas:
MFJ-1792 or Butternut HF2V mounted 50ft from the tower (landscaped gardens
prevent mounting anywhere else)
Inverted L hanging off the tower with approx 60ft vertical section.
What I guess really matters is the tower's resonant frequency, looking at the
details above, would anybody like to guess? Because the Optibeams are insulated
from the tower do they still effect the tower's resonant frequency? If it is
resonant close to 80M I guess the RF fed into a vert 50ft away would see it as
a
parasitic element?
In the worst case scenario, if the tower messed with a vertical I could always
lower it before operating on 80M but it's not ideal.
Apologies for any stupid questions and Merry Christmas to you all!
Jack G8DX
Sent from my iPhone
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