Towertalk
[Top] [All Lists]

Re: [TowerTalk] "Superloop" & other Field Day antennas

To: towertalk@contesting.com
Subject: Re: [TowerTalk] "Superloop" & other Field Day antennas
From: K4SAV <RadioIR@charter.net>
Date: Sat, 11 Apr 2009 09:25:01 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
A quick modeling job on the superloop shows that the gain in its best 
direction is very close to that of a dipole at the height of the top 
wire on both 80 and 40 (probably within 1 dB).  Maximum gain is 
perpendicular to the plane of the loop on 40 and 80.  The SWR bandwidth 
on both 40 and 80 is much narrower than that of a dipole.

On 20 meters the pattern changes to a 4 lobe pattern with maximum 
radiation at about 45 degrees to the plane of the loop.  There is a null 
broadside to the loop.  The lobes are skinny (beamwidth about 35 
degrees).  The gain in those lobes is about the same as a dipole.  The 
SWR on 20 and 15 is very high, so if you feed it with coax there will be 
a lot of feedline loss.

On 15 meters the pattern turns into lots of lobes and nulls and the gain 
of the lobes is much less than that of a dipole.  It looks poor on 15.

Jerry, K4SAV

KI9A@aol.com wrote:
> Gang-
>  
> I've googled this, and have no real answer, so, I turn to the real  
> knowledge base of the hobby--you guys!
>  
> We are planning on a FD effort, with a local club this year, and are  
> considering antennas.  We are using available trees in the 40-50' range,  and 
> maybe a simple push up pole or 2. No tower, no yagi's.  All wire.
>  
> I want something with a bit of gain.
>  
> Conventional thinking ( and good results in other years), I am thinking of  
> a simple open wire fed 80 meter dipole for all bands.  But, I am thinking  
> of building a Radioworks cloned Superloop.
>  
> Seeing that this acts as a bi-square on 40, it should show directivity and  
> slight gain off the ends.  Here is  the big question: 1) In real life,  
> does it? 2) Has anyone ever modeled this antenna? Results on 40/20?
>  
> I guess my concern is it is broadside E/W, I am in Sw Illinois, which is  
> good. But, on 40, if it fire N/S, that's not so good.  
>  
> Also, any other wire antenna ideas? I kinda want to be heard on the west  
> coast, on 40 at night, plus, be good to the east.   
>  
> 73- Chuck KI9A
> **************Worried about job security? Check out the 5 safest jobs in a 
> recession. 
> (http://jobs.aol.com/gallery/growing-job-industries?ncid=emlcntuscare00000003)
> _______________________________________________
>
>   


_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>