Hello John
The most efficient shortened two element 40 meter Yagi I am aware of (the
W6NL Moxon) has a VSWR of less than 1.25:1 across all 300 KHz of 40 meters.
http://www.k3lr.com/engineering/moxon/W6NL_Moxon104.pdf
I have had two of them in the air for 5 years - the performance is
outstanding.
73,
Tim K3LR
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
john@kk9a.com
Sent: Wednesday, July 10, 2013 9:31 PM
To: TOWERTALK@contesting.com
Subject: Re: [TowerTalk] m2 40M4LLDD + 20m add on
Any efficient shortened 2el 40m beam will have over 2:1 SWR some place in
the band. Thankfully there are amplifiers that load fine into higher SWR.
John KK9A
To:Bob Gibson <w5rg@yahoo.com>
Subject:Re: [TowerTalk] m2 40M4LLDD + 20m add on
From:W2RU - Bud Hippisley <W2RU@frontiernet.net>
Date:Wed, 10 Jul 2013 12:37:25 -0400
List-post:<towertalk@contesting.com">mailto:towertalk@contesting.com>
I'm one of those guys up north. Ice and/or wet snow on the linear loading
is a
disaster; it will move the SWR at the "fair weather" minimum SWR point far
enough in either direction to activate the Alpha 99 high-SWR shutdown
circuit
and generally cause deterioration of various electrical parameters of the
beam.
That said, I'm very, very pleased with the mechanical aspects of my 40M2LL
(and by extension, the 40M3LL), so I'm hopeful the coils will be offered as
a
retrofit to existing LL owners.
Bud, W2RU
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