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[Towertalk] Need Antenna Advice!

To: <towertalk@contesting.com>
Subject: [Towertalk] Need Antenna Advice!
From: stevek@jmr.com (Steve Katz)
Date: Mon, 16 Sep 2002 07:08:37 -0700

> Hi Steve.  I have the steppir, but I'm clueless about modelling 
> antennas.  Only one question.  Did you do the 6 M model for 3 or 4 
> elements.
> 
        Three elements, the standard configuration.  I realize there's a
stationary 4th element available for the 6m configuration, but don't know
where they put it...will try to find out.  -WB2WIK/6


>  The optimum Steppir configuration is for 4 elements using the 
> 180 degree setting. I'm told the stationary parasytic is better spaced 
> in this configuration...  Try it and let us know the results.  (or maybe 
> you already did?)
> 
> Always willing to learn.
> Gil, W1RG
> 
> 
> Steve Katz wrote:
> 
> >
> >  
> >
> >>>The StepIR is an optimized 3L beam AT
> >>>ALL FREQUENCIES.
> >>>      
> >>>
> >>That depends on how you define the word "optimized," eh?  I don't call
> >>fixed
> >>element locations on the boom optimized on more than one band.
> >>
> >>Mark, N5OT
> >>
> >>    
> >>
> >     [Steve Katz]  Mark, I have to agree.  Unless this antenna defies all
> >the modeling programs, using a 16' boom and fixed element locations
> provided
> >in the SteppIR manual, and modeling using NEC, if I adjust the element
> >lengths in 1" increments indefinitely, to try every combination of
> element
> >lengths there is from 10" to 432" per element using (N+1...) algorithms,
> I
> >cannot come up with any combination that provides more than about 6dB F/B
> on
> >six meters, for example.  The original claims for F/B on "all bands" is
> >"20-50 dB, depending on frequency" for the 3L model, but I can't use any
> >modeling integers that indicate that, at any element lengths or any
> height
> >above ground.  If the inventor/manufacturer can provide us with some new
> >data on this matter, I'd love to receive it!   Better still, I'd like to
> >know what the exact element lengths are to provide max F/B on each band,
> >based on the 16' boom length and fixed element spacing.  Then I can scale
> it
> >1:10 and stick the model in our RF anechoic chamber here at the lab, and
> >take actual (empirical) data.  I'll be happy to provide the test report
> in
> >this forum, if I can get the data to make the model. -WB2WIK/6
> >
> >
> >  
> >
> >>_______________________________________________
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> >>    
> >>
> >_______________________________________________
> >Self Supporting Towers, Wireless Weather Stations, see web site:
> http://www.mscomputer.com
> >Call 888-333-9041 to place your order, mention you saw this ad and take
> an additional 5 percent off
> >any weather station price.
> >_______________________________________________
> >Towertalk mailing list
> >Towertalk@contesting.com
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> >  
> >

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