I think you should run an EZnec model of your antenna before you put up
another one at right angles to it. You may find that a 90-degree offset
will simply result in a lot of the main lobes being duplicated (in
azimuth). You might find that a 60-degree or 45-degree orientation
would be better.
-----Original Message-----
From: tentec-bounces@contesting.com
[mailto:tentec-bounces@contesting.com] On Behalf Of Joseph Trombino Jr
Sent: Saturday, July 09, 2005 3:39 PM
To: Discussion of Ten-Tec Equipment
Cc: Rick@DJ0IP.de
Subject: Re: [TenTec] was - "Radiates like Crazy"???? No
> Carl brings up a good point.
>
> Although I do not (in general) using an asymmetrical coupler and a
balun,
> if
> you place the coupler quite some ways away from the house and insert
an RF
> choke (e.g., Radio Works or similar) between the box and the 50 ohm
line,
> then this usually works well too. It's just not a good idea to use an
> asymmetrical coupler and a balun inside the shack.
>
> The one exception I've heard of and believe works is what I call the
> "Monster Balun" and it was described to me by Bwana Bob. Since I
haven't
> yet tried it (but plan to), I can't really promise that it works,
though I
> have no reason to doubt Bob.
>
> The best thing going for remote tuners and symmetrical is not the LDG
but
> rather the tuner from Hamware: http://www.hamware.de/ (they do an
English
> translation).
----------------------snip------------------
Coax and ladderline both have their place in properly designed antenna
systems and both have their advantages and disadvantages.
I will describe an antenna system that I installed that appropriately
utilizes the strong points of both ladderline and coax.
Three years ago I installed a temporary experimental antenna system
based on
the systems we used in Government radio operations overseas.
We always had antenna tuners/couplers installed as close to the antenna
as
possible, typically on the roof of the Embassy and we controlled the
tuner/coupler via a remote control box in the commo radio shack usually
on
the highest floor of the Embassy.
We used vertical as well as center fed doublet type antennas.
Based on the above parameters, I decided to play around and installed an
experimental system that consists of the following:
180ft center fed doublet up 60 ft in the air
antenna is fed with 60ft of ladderline into a plastic box on the ground
that
connects to a Radio Works 4:1 current balun.
The output of the balun goes directly into an LDG RT-11 remote tuner.
Out of the tuner I run about 60ft of RG213 coax into the shack.
This system has been a revelation to me in terms of band coverage and
the
ability to "get out".
I can work just about whatever is out there, DX, local stuff on all
bands
from 160m-6m. The antenna loads to just about flat on all of the above
bands.
So, this "experimental" antenna system has been up for 3 years and I
don't
anticipate taking it down anytime soon:-)
I will be installing a duplicate system at right angles to the original
for
essentially 360 deg coverage.
So, in this antenna system I use ladder line properly in a balanced
system
and I also make appropriate use of coax cable in an unbalanced portion
of
the system.
Ladder line and coax are excellent transmission lines when applied
correctly.
73, Joe W2KJ
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