Mark:
Notwithstanding all the prior commentary ....
You do not say anything about your tree layout, such as spacing, height,
etc. Without knowing any of that I think one alternative that you might
consider is an OCF antenna.
I am using two of these at my QTH, on is a 40M (69') using a 70/30 split
ratio and the other is an 80M (137') using an 80/20 split ratio. I have a
good 4:1 balun at the feedpoint, augmented with an additional 1:1 choke just
below the balun (to try to clean up any current on the feedline).
I get decent SWR on all the bands (including WARC). I use a little LDG tuner
in the shack, although if your radio has an internal tuner you could use
that.
Lots of people don?t like the idea of OCFs, but they do work and I think
they are a good compromise if you want to cover multiple bands with a
minimum of fuss. The fan dipoles are nice, but are really difficult to deal
with if you don't have good clear openings between your trees/supports.
This is just something to think about.
-------------------
Wes Attaway (N5WA)
(318) 393-3289 - Shreveport, LA
Computer/Cellphone Forensics
AttawayForensics.com
-------------------
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Wes
Stewart
Sent: Tuesday, July 17, 2018 3:19 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Auto tuners, Baluns and open wire feeders
The man wants a simple, single wire antenna. How the heck is choking at the
input end of a short length of open wire significantly better that doing it
at
the feedpoint?
I know you and Dean are buddies, but don't get me started about him. Since
he's
using his software which has been shown to be in error in the past,
"Introducing
an Improved Version of Transmission Line for Windows Software" QST, Jun
2014,
p.39, I wouldn't make bank on the conclusions. Plus he continues the
fallacy
that a balun on the input of a tuner is better than one on the output.
Shown to
be wrong by W7EL, W8JI, W9CF among others. ARRL's publication of such an
unbalanced tuner and pretending it's balanced is a disservice to the
community.
I agree with your recommendation of fan dipoles, but that is beyond the
scope of
the OP's desires.
Wes N7WS
On 7/17/2018 11:32 AM, Jim Brown wrote:
> On 7/17/2018 11:00 AM, Wes Stewart wrote:
>> If your open wire is short, why bother? Replace it with low loss coax,
put a
>> decent common-mode choke at the feedpoint and tune it. Sometimes the
effort
>> to use open wire simply isn't worth it.
>
> Caution on this. See JUN 2015 - QST (PG. 30) "Don't Blow Up Your Balun"
> by Dean Straw, N6BV
>
> Dean's work clearly shows why it simply is not practical to choke a
> non-resonant antenna. And, because receive noise is such a major issue for
> most of us, it's why I don't recommend antennas like this. The random wire
and
> off-center fed wires were great ideas for 30 years ago, but terrible ideas
today.
>
> Fan dipoles are a FAR better choice.
>
> 73, Jim K9YC
>
> _______________________________________________
>
>
>
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