W4HV informed me that DX Blaster 80m cage dipole uses 1 meter spreaders.
These spreaders are much larger than the cage dipole example in the ARRL
Antenna book so the 400 KHz bandwidth claim is very possible without
feedline looses.
John KK9A
To: "Tower Talk List" <towertalk@contesting.com>
Subject: Re: [TowerTalk] Cage dipole alternatives
From: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 14 Apr 2009 09:15:51 -0700
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
On Mon, 13 Apr 2009 17:32:21 -0400, john@kk9a.com wrote:
>DX Blaster claims 400 KHz
>bandwidth for their 80m cage dipole. I am not sure how big their cage is,
>but it would have to be pretty large, or they have some other methode of
>obtaining this much bandwidth, assuming that they are measuring SWR at the
>antenna input.
If measured at the transmitter, losses in the feedline will significantly
reduce the apparent SWR (and increase the apparent SWR bandwidth). I use the
word "apparent" because the SWR at the antenna does not change, but drops
along the line as losses reduce the reflected power.
73,
Jim K9YC
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