[Antennaware] EZNEC Element Correction Factors

[Charlie Ocker]

Hi Gedas,

I am not familiar with this correction technique, so I cannot comment, 
but I do have experience with the boom *and* element clamp correction 
method employed in K6STI's Yagi Optimizer (YO) code.  It puts a "dummy" 
element of a certain length and diameter at the boom end of the element.

Subsequent modelling in EZNEC (including the "dummy" element) reveals a 
very tight correlation, and better still, building the Yagi to the 
dimensions given by YO (and verified in EZNEC) results in an antenna 
that appears to meet all the initial design criteria.

I have done this for a number of Yagi's designs ranging from 6m to 20m.

73,
Charlie  N9CO

On 1/21/2014 11:57 AM, Gedas wrote:
> Hello group.  I am trying to model a M2 2M9 for a friend for his rover
> use. I have an EZNEC model (not sure where I got it from) for the M2
> 2M12.  By looking at the PDF manual for the 2M12 and comparing it to the
> EZNEC model I have on hand, I can see that an element length correction
> factor has been applied to each element.  I.e., each element is slightly
> shorter in the model than in real life because the element passes
> through the boom.
>
> I am puzzled a bit as I noticed that the correction factor varies
> slightly from one element to another.  One element is approx 99.65% of
> the PDF manual length, another element showed up as 99.21%, while a 3rd
> element showed up as 99.38 %.  They are actually all a little different
> from each other.
>
> I guess I have two questions; is my model of the 2M12 wrong because it
> shows variable correction factors?  And, if the correction factor is
> required to be constant, what should that factor be so I can generate
> valid models for these antennas?
>
> Ok, maybe one more question, what should the correction factor be for CC
> antennas like the 17B2 where the elements are mounted with a clamp on
> top of the boom?  Thank you.
>
> 73, Gedas, W8BYA
>
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