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Re: [TowerTalk] steppIR Gain--test method

To: keith@dutson.net
Subject: Re: [TowerTalk] steppIR Gain--test method
From: k2qmf@juno.com
Date: Thu, 17 Mar 2005 10:00:07 -0500
List-post: <mailto:towertalk@contesting.com>
How can there be no difference between a
3 element SteppIR and a "2" element C3????

Seems to me that the 3 element will win every time
over a 2 element antenna......

73,  Ted  K2QMF

On Wed, 16 Mar 2005 18:32:32 -0600 "Keith Dutson"
<kjdutson@earthlink.net> writes:
> This thread about SteppIR gain has been enlightening for gain 
> figures
> published by antenna manufacturers.  I especially enjoyed reading 
> the
> enlightening posts from Tom Rauch.
> 
> I considered buying SteppIR over the past year, but decided to go 
> with a
> stack of 4 tribanders and the SteppIR price tag was just too high.  
> Also I
> had the opportunity to compare a Force 12 C-3 against the 3 element 
> SteppIR.
> There appears to be little to no gain difference on 20-15-10, but 
> the
> advantage of having WARC bands and to be able to "rotate" in seconds 
> is
> quite appealing.
> 
> Keith NM5G
> 
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of Gary Schafer
> Sent: Wednesday, March 16, 2005 5:09 PM
> To: richard@karlquist.com
> Cc: W7TMT; towertalk@contesting.com
> Subject: Re: [TowerTalk] steppIR Gain--test method
> 
> I was looking at the picture and drawing of the test setup on the 
> web site.
> They do not show any type attenuator in the drawing.
> 
> Even making a differential measurement, trying to read to 1db on a 
> log scale
> with 10db per division is not realistic. You just can't "eyeball" 
> it that close. Especially if you can't switch back and forth between 
> the two
> signals. Let alone giving tenth of a db gain specs out of those
> measurements.
> 
> Using the vernier db attenuator on the 141, if it has not been 
> calibrated
> the linearity can be off without too much trouble for making those 
> kind of
> accuracy measurements. That adds to the error.
> 
> It is also easy for the log scale on those to have errors if they 
> are not
> properly calibrated. Not saying that theirs was not but who knows.
> 
> The biggest error on the analyzer would come from trying to eyeball 
> the same
> screen position on the 10 db scale.
> 
> I assumed that they used the log scale and not the linear scale, 
> which would
> be easier to eyeball for the same spot. But since no attenuator was 
> shown
> the log scale would have to have been used.
> 
> By the way if you look at the picture of the test site closely on 
> the right
> side it looks like a set of large guy wires for a large tower or 
> power line?
> Not good for a test range.
> 
> My whole point is that giving gain specs to a tenth of a db with a 
> super
> test setup would even be iffy let alone all the obvious errors at 
> first
> glance here.
> 
> 73
> Gary  K4FMX
> [snip]
> 
> _______________________________________________
> 
> See: http://www.mscomputer.com  for "Self Supporting Towers", 
> "Wireless Weather Stations", and lot's more.  Call Toll Free, 
> 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
> 
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> 
> 
_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

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