Topband: Shunt fed T

[John G3PQA]

----- Original Message ----- 
From: "Herbert Schoenbohm" <herbs at vitelcom.net>
>
> Thanks for the EZNEC model John. Are the wires in your model sloping
> down or straight as a 45 degree slope would tend to make them appear a
> bit shorter?.
>

Yes, it was assuming 45 deg slope, and all 0.1 inch wire.
However, apparently John  is using a 60ft versatower tower with 22ft 2in 
diam pole on top which has different resonant frequency of course. Am not 
experienced in tower modelling, have simply assumed 60ft x 8in diam and 22ft 
2in diam. to estimate result.  Re-running the model with this approximate 
structure loaded by 4 x 35ft sloping wires now shows resonance of about 
1830kHz.
Increasing the tophat wires to 45ft brings down the resonance to around 
1.65MHz, but little gained on feed Z because of longer foldback lowering 
effective height. Others may wish to comment on these results.

73
John G3PQA
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