[NLRS] Stacking distances for loopers

[Mike King - KM0T]

Glen, good questions.  I too asked the same thing many times.  How much does 
it matter?  It depends :)

If you have not seen it, check out this link on my website...shows stacking 
distances of loopers and diagrams of the rough appertures.

http://www.km0t.com/pages/june2001.htm

I decided to minimize apperture interaction with other antennas on my tower 
as well as the roof of N0DQSs rover roof.  There are diagrams of both.  Some 
are a bit comprimised on the tower, but years of operation has indicated 
that they work pretty well.

I think if you get them too close, you know they will give reduced gain as 
the patterns will be messed up.  How much, well that would have to be done 
on the antenna range while installed in the real world application, unless 
you have the antennas modeled for one of those antenna programs.

Sorry, but not much concrete help, I just know that Gene's antennas on the 
roof of his rover work extreamly well on all bands.

73 and GL

Mike - KM0T


----- Original Message ----- 
From: "Glen Overby" <goverby at charter.net>
To: <nlrs at mailman.qth.net>
Sent: Thursday, May 24, 2007 8:49 PM
Subject: [NLRS] Stacking distances for loopers


>
>
>
> When preping for the recent SBMS 2ghz+ contest, I got looking at the 
> stacking
> distance specs for Directive's loop yagis.  I've been ignoring these specs 
> and
> put the antennas directly on my roof rack (about 4" from the metal roof).
> It's easy, but lately I've been wondering how bad that has hurt me?
> Directive's page on stacking dis-simmar antennas talks about how much you 
> can
> squish antennas together, but not about possibly cutting off the bottom
> portion of an antenna's aperature.
>
> Here's the list of stacking distances:
>
>                        Band    #       Boom    Beam    Stacking Distance
>                                Ele     Length  Width   E(Horiz)H (Vert)
> Directive 3318LYRM      902     18      72"     30      24      21 1/2
> Directive 2324LYRM      1296    24      72"     27      21 3/4  19 1/4
> Directive 1345LY        2304    45      81"     16      15      13
> Directive 945LY         3456    45      60"     16      9.8     9
>
> Directive's advice on stacking antennas says to use half of the stacking
> distance for an antenna when calculating stacking distance between
> dis-simmilar antennas.
>
> So, my car roof is definately in the aperature of all of these, but how 
> much
> does that matter?
>
> Glen, kc0iyt.
>
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