Steve,
There is an optional fixed 6 meter director available for the SteppIR
that is suppose to greatly improves the F/B ratio:
http://www.steppir.com/
Look under the "products" tab for the "6 meter passive element kit".
The list price is $79.95, but you could probably make your own easily
enough (it looks like nothing more than a piece of tubing and a U-bolt).
Of course assuming this is a director, you probably lose the ability to
do instant 180 deg switching on 6 meters with this installed.
73 de Mike, W4EF.....................................................
----- Original Message -----
From: "Steve Katz" <stevek@jmr.com>
To: "'Mark Beckwith'" <mark@concertart.com>; <towertalk@contesting.com>
Sent: Friday, September 13, 2002 3:39 PM
Subject: RE: [Towertalk] Need Antenna Advice!
>
>
>
> > >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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> > http://www.mscomputer.com
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an
> > additional 5 percent off
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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.
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>
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