[TowerTalk] QST switchable antenna

[Guy Molinari]

No, it is a completely different design.    I have it scaled for 80M with the slope angle changed from 30 to 45 degrees.   The F/B is about 10 dbi and gain is about 8.
 
73,
Guy, N7ZG
 

> Date: Fri, 18 Nov 2011 20:36:28 -0500
> From: K8RI-on-TowerTalk at tm.net
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] QST switchable antenna
> 
> On 11/18/2011 4:50 PM, Jim Lux wrote:
> > Well, I've got part of the model in. Copied the dimensions from the QST
> > article and the developer's MA presentation..
> >
> > Not getting a good match yet, nor the F/B... but it's probably some
> > little fiddling needed with dimensions, etc.
> >
> Check the antenna handbook. There's been one of these in there for 
> years although I don't know if it was in the last one or not. I'll have 
> to check.
> 
> IIRC they bring the individual feed lines back to a remote antenna 
> switch mounted on the mast. The feedlines are a quarter wave with an RF 
> Choke just before the antenna switch. I don't remember if they ground 
> the connections other than the active one or not.
> 
> 
> 73
> 
> Roger (K8RI)
> >
> > CM QST switchable
> > CM Ashraf Abuelhaija design
> > CM dimensions taken from slides Vortrag_MA_Abuelhaija_Ashraf.pdf
> > CE 20m
> > SY L = 5.3'wire length
> > SY DR = .00021 ' wire radiu (0.14 mm2)
> > SY Hc = 7 ' height of center
> > SY HE = 4.35 ' height of wire ends
> > SY Y=4 'distance to side of antenna middle elements (fore aft Y=0)
> > SY X1=4.62/2 'distance fore/aft for middle elements
> > SY X=4
> > SY CL = 120 ' pf Load
> > GW 999 1 0.05 -0.05 HC 0.05 0.05 HC DR 'feedpoint
> > GW 10 50 0.10 0 HC X 0 HE DR 'wire #1
> > GW 950 1 -0.05 -0.05 HC -0.05 0.05 HC DR 'loaded element feed
> > GW 20 50 0.05 -0.05 HC X1 -Y HE DR
> > GW 30 50 -0.05 -0.05 HC -x1 -y HE DR
> > GW 40 50 -0.10 0 HC -x 0 HE DR 'wire #4, directly aft
> > GW 50 50 -0.05 0.05 HC -x1 y HE DR
> > GW 60 50 0.05 0.05 HC x1 y HE DR
> > GE 1
> > LD 5 0 0 0 58000000
> > LD 0 950 1 1 0 0 CL*1e-12
> > EX 0 999 1 0 1.0 0.0
> > GN 2 0 0 0 13.0 .005 0.0 0.0
> > FR 0 1 0 0 14.15 0.0 0.0 0.0
> > EN
> > _______________________________________________
> >
> >
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk at contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> 
> 
> _______________________________________________
> 
> 
> 
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk