Hello Tom
It's nice to see you back on towertalk. I did a lot of modeling when I
built my P40A 20m 36' boom antenna and I decided to go with four elements.
I wanted less windload and weight. The four element had the same gain as
the five and the SWR is flat across the entire band. The only benefit that
I saw to going with a five element was improved F/B, which was not a concern
for me. Many are now using the OWA designs which use a lot of elements and
have a 50 ohm impedance. I guess this eliminates any hairpin match losses
(whatever they are), but in my modeling I have not seen the advantage to
having all of this aluminum in the air.
73,
John KK9A / P40A
To: <towertalk@contesting.com>
Subject: [TowerTalk] Yagiis
From: "Tom Rauch" <w8ji@contesting.com>
Reply-to: Tom Rauch <w8ji@contesting.com>
Date: Fri, 1 Jun 2007 21:26:20 -0400
List-post: <mailto:towertalk@contesting.com>
What's the latest thought on Yagi antennas? Is the old work
by Lawson on Yagis still considered accurate so far as boom
length, number of elements, and gain?
Or is there some newer information that casts doubt on his
work?
I'm going to play with some 34 foot boom 20 meter antennas.
They were originally 5 elements but it looks to me like I
might as well throw one element in the dumpster.
73 Tom
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|