[TowerTalk] 402cd

[JayTerleski]

If you really want to "improve" the antenna add a helical hairpin to the
feedpoint.

This will give you a 1.0:1 SWR and probably add 75-100 Khz to the 2:1
SWR plot.

7 turns 3 inches in diameter of #6 wire will do it. Just put it at the
feedpoing in parrallel with the balun system.

I did this to my M2 shorty 40 stack years ago and got a great match and
the whole band back.

If anyone wants one or two M2 shorty 40m antennas give me a call.


Jay, WX0B

alsopb wrote:
> 
> Marc,
> 
> Just for kicks I ran EZNEC for a full sized 2 element beam (24' boom)
> at 24 and 28 M height.
> 
> 24 M    SWR =1.306  IMPEDANCE =38 -1.8j
> 28 M    SWR =1.519  IMPEDANCE =33 -0.5j
> 
> Interesting that the impedance actually decreases rather than
> increasing with height as the dipole impedance plot vs height
> predicts.
> 
> I don't have a model for the 402CD.  It would be interesting to
> actually run such a model at the two heights.
> 
> Of course, these values are at the feedpoint.  What the reading would
> be at the shack end of the coax is unknown.
> 
> 73 de Brian/K3KO
> 
> List Sponsored by AN Wireless:  AN Wireless handles Rohn tower systems,
> Trylon Titan towers, coax, hardline and more. Also check out our self
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> 
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-- 
Jay Terleski
Array Solutions - RME Filters
Phased Arrays - Horizontal and Vertical
RF Switches, Antennas & Towers
www.arraysolutions.com

List Sponsored by AN Wireless:  AN Wireless handles Rohn tower systems,
Trylon Titan towers, coax, hardline and more. Also check out our self
supporting towers up to 96 feet for under $1500!!  http://www.anwireless.com

-----
FAQ on WWW:               http://www.contesting.com/FAQ/towertalk
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com