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Re: [TowerTalk] Effect of element shape was: Re: InnovAntennas contact i

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Effect of element shape was: Re: InnovAntennas contact info
From: David Gilbert <xdavid@cis-broadband.com>
Date: Wed, 20 Mar 2013 10:15:55 -0700
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>

Yes. A true Moxon has less forward gain (only slightly so on a proper design) and less front-to-side than a normal yagi, but it has a really deep notch off the back. The statement that a Moxon is nothing more than a 2 element yagi with bent ends is simply false. There is a phasing component that is not purely parasitic.

73,
Dave   AB7E



On 3/20/2013 6:22 AM, Pete Smith N4ZR wrote:
But don't Moxons have something fairly close to a cardioid pattern, with a narrow deep null off the back?

73, Pete N4ZR
Check out the Reverse Beacon Network at
http://reversebeacon.net,
blog at reversebeacon.blogspot.com.
For spots, please go to your favorite
ARC V6 or VE7CC DX cluster node.

On 3/20/2013 9:06 AM, W1YW@aol.com wrote:
Yeh, you can get better gain, bandwidth AND lower sidelobes. See
'Optimization of Wire Antennas', Landstorfer and Sacher, Wiley Interscience, 1985.
  The Innova designs use end-bends to shrink the projected size of the
element. The ends do very little to the radiation pattern in the far field on
those size scales.
  Moxon's are nothing more than 2 element Yagis with end bends. There is
virtually no coupling at the voltage max's for the driven and parisitic==so the
  ends can be placed fairly close together. Same with spider beams, hex
beams,  yadayada.
  The Innova design looks like a nice offering for the ham market. The
multiband coupling is also well known: Gary Breed (who publishes Hi Frequency)
has a patent on that.
  73,
Chip W1YW
--------------------------------
    In a message dated 3/20/2013 8:48:46 A.M. Eastern Daylight Time,
n4zr@contesting.com writes:

yes, in a classic yagi with straight and parallel elements that is true... but when you bend or make the driven element not a simple half wave dipole
then it can  have an effect on the pattern by  itself.
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