[TowerTalk] Elevated Vertical

[EZ Rhino]

Terry describes KN5L's field day vertical, as described here:  http://www.kn5l.net/fdantenna/
I've built this and it does work pretty good.  The link describes how to build and material list.
As I recall SWR is pretty darn flat across about all of the band (I built for 20m).  
I also built a 20/40m version with two sets of cut radials (8 total), with two vertical radiators (one is aluminum, one is wire spaced off the aluminum with insulators.)

Chris
KF7P












On Dec 24, 2011, at 15:35 , Terry G. Glagowski wrote:

I made one of those (still have it, but in storage)...
I used 4 elevated radials and had them sloped downward at 30 degrees from horizontal, and the feedpoint about 20 feet high.
SWR at feedpoint was 1:1 perfect at 7100 KHz, maybe 1.2 at the edges of the band.
The angle of the radials can be used to adjust the impedance.  Horizontal gives about 35 ohms, maybe 1.4 SWR.
73, Merry Christmas... Terry / W1TR

Message: 4
Date: Thu, 22 Dec 2011 14:23:56 -0800
From: "Tom Osborne" <w7why at frontier.com>
Subject: [TowerTalk] Elevated vertical
To: "Towertalk" <towertalk at contesting.com>
Message-ID: <443EA86127FB413BA9720F4D38FF7AE3 at Tom>

Hi All

I just put up an elevated 40 meter vertical.  The feedpoint is around 15 feet or so up and I have 8 radials on it right now.  I cut the radials the same length of the vertical section.  I have a coil of around 8 turns of coax for a choke.

It works good, as the first day I put it up, I worked some Europeans from here in Oregon.

The thing that seems strange is that at the low end of 40, the SWR is around 1.3:1.  As I go up the band, it goes up to about 1.5:1, then when I get to the top of the band, it goes back down to 1.2:1.
Is that because some of the radials are resonating at different parts of the band??  73

Tom W7WHY


73, Terry / W1TR ☺
**************

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