> It would be interesting to compare the 4el SteppIR and a 5
> element 10m beam with the same boom length. I think you
> would see a bigger difference on 10m, especially with F/B.
Yes, you will see a significant difference in F/R ... the five
element, 32 foot boom will provide 20 to 25 dB across 28.00 to
28.80. However the gain difference will be less than .3 dB.
73,
... Joe, W4TV
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of john@kk9a.com
> Sent: Friday, June 29, 2007 4:43 PM
> To: TOWERTALK@contesting.com
> Cc: wc1m@msn.com
> Subject: Re: [TowerTalk] SteppIR
>
>
> It would be interesting to compare the 4el SteppIR and a 5
> element 10m beam
> with the same boom length. I think you would see a bigger
> difference on
> 10m, especially with F/B.
>
> John KK9A
>
>
> To: "'Bob Maser'" <bmaser@tampabay.rr.com>,"'Joe Subich, W4TV'"
> <w4tv@subich.com>,"'Carl Smidt'" <xveoneov@primus.ca>,
> <towertalk@contesting.com>,<SteppIR@yahoogroups.com>
> Subject: Re: [TowerTalk] SteppIR
> From: "Dick Green" <wc1m@msn.com>
> Date: Fri, 29 Jun 2007 13:34:17 -0400
> List-post: <mailto:towertalk@contesting.com>
>
> I don't want to get in the middle of this, but I just ran EZNEC models
> comparing the 4-el SteppIR and Force-12 EF-420 on 20m at 96'.
> The SteppIR
> boom is 32'; the EF-420 boom is 30' (and presumably
> optimized.) Results:
>
> 4-el SteppIR Force-12 EF420
>
> Elevation at max gain: 10 degrees 10 degrees
> Forward gain: 14.36 dBi 14.29 dBi
> Front/Back: 18.12 dBi 17.35 dBi
> Front/Side: 18.12 dBi 17.35 dBi
> Beamwidth: 60 degrees 60 degrees
>
> It would be hard to tell the difference between these two
> antennas. I have
> both installed, but the EF-420 is only at 72' on a tower that
> doesn't have
> as good terrain as the tower on which the SteppIR is mounted.
> The SteppIR
> consistently outperforms the EF-420, usually by as much as 5
> dB. I attribute
> that entirely to the difference in height and terrain.
>
> I have not done models for 15m and 10m because I don't have
> data for any
> 4-el antennas for those bands. But I have compared the 4-el
> SteppIR with a
> Force-12 515 (5-el on 15m, 24' boom) and a Force-12 616 (6-el
> on 10m, 24'
> boom.) The gain figures are nearly identical, but the F/B on
> the SteppIRs is
> lower, especially on 10m (a well-known characteristic of the
> SteppIR design,
> resulting from inability to place the elements optimally on all three
> bands.) The gain being comparable suggests that optimized
> 4-el monobanders
> for 15m and 10m would outperform the SteppIR. But I don't
> know by how much.
>
> 73, Dick WC1M
>
> _______________________________________________
>
>
>
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>
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