Towertalk
[Top] [All Lists]

Re: [TowerTalk] OWA Inventor?

To: towertalk@contesting.com
Subject: Re: [TowerTalk] OWA Inventor?
From: Jim Lux <jimlux@earthlink.net>
Date: Thu, 12 Dec 2013 22:48:11 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
http://www.naic.edu/~angel/kp4ao/ham/owa.html

describes the underlying concept from W3FET -> use a fat element as the driven element: fatter elements have increased bandwidth, but have higher feedpoint impedance. But in a Yagi, the feedpoint impedance is low (because of the coupling to the other elements, mostly.. it's sort of a "parallel resistor" thing)

So, if you used a fat driven element, you get the combination of wider bandwidth AND a feedpoint impedance that is closer to 50 ohms.

It's well known that putting another element close (<0.1 lambda) to a dipole is electrically very similar to a fat element, and there you have it.




On 12/12/13 10:19 PM, Jim Thomson wrote:
Date: Thu, 12 Dec 2013 15:33:08 -0600
From: Kelly Taylor <ve4xt@mymts.net>
To: Steve Sacco NN4X <nn4x@embarqmail.com>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] OWA Inventor?


##  The OWA  doesn’t use TWO driven elements.  That was a KLM concept.
The OWA only uses ONE driven element... with the 1st director closed spaced.
I bought YO  4.0 when it 1st came out.....and it would not allow you to space 
any
two elements any closer than .09 wavelength.  Thus there was no way to arrive 
at the
OWA design.  Ditto  with.... yagimax that came out aprx the same time.

##  The late VE7WJ, Henry Thel,  once gave a talk about the importance of using 
close
spacing between the single DE..and the 1st director.  That was back in the late 
70s.
N6BT came out with OWA, direct 50 ohm fed monobanders for 20-15-10-6m
I think in the early 90s.   Dunno who cooked up the original design, or which 
software
they used, but the concept works superb.  The OWA design has also been used on 
hb 5-el,
20m monoband yagis , with great success.

##  The F12 OWA, direct 50 ohm fed yagis  are killer ants.

Jim   VE7RF





Virtually every reference on Google searches to the Optimized Wideband
Antenna refers to WA3FET as the inventor. None refers to N6BT. Most also
co-credit K3LR for the OWA.

You might be able to outfox some Google search results, but not every single
one.

N6BT's contribution, which I don't mean to disparage, is a system to couple
multiple driven elements parasitically to eliminate traps in multi-band
antennas. He referred to them as multi-monoband arrays, since most of the
F12 antennas use discrete elements for each band of operation rather than
using traps to multipurpose elements.

The OWA, if I recall correctly, was around before Force12 was even a gleam
in N6BT's eyes. And, again IIRC, the OWA is a monoband antenna that uses TWO
driven elements and specific element spacing to provide consistent gain,
matching and F/B over a greater portion of a particular band than typical.

73, kelly
ve4xt
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk


_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
<Prev in Thread] Current Thread [Next in Thread>