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
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