[TowerTalk] Element taper change

[Charles Morrison]

Thanks JOHN
It was on K8CU website  realhamradio.com
-Charlie N1RR

On Thu, Aug 20, 2020 at 10:32 PM <john at kk9a.com> wrote:

> W6QHS/W6NL created a Lotus ELEMENT spreadsheet that has a taper algorithm.
> The last time that I saw it on the internet it was free and was easy to
> convert to Excel. You can use this spreadsheet to determine the resonant
> frequency of each designed element and then input your tubing diameters
> while adjusting the tip length to obtain the same frequency. I doubt that
> there will be much length difference but it is worth checking.
>
> John KK9A
>
> Charles Morrison N1RR wrote
>
> I'm duplicating a few yagi elements made from European diameter tubing.
> I want to get it as close as I can but I dont want to model .
> I'll compensate at the tips.
> .
> Question: Which will get me closest to determining the correct
> 'equivalent'.
>    Area of the cross section of the element:      L X W
> -or-
>    Volume of a cylinder:     2 pi r h + 2 pi r^2
>
> Half-element Example
> EU:
> Diameter   1.18"    0.987"   0.787"
>                     43"       51"       32"
> US
> Diameter   1.125"   1.00"   0.875"
>                     36"       68"       X"
>
> Stated another way: LAWSON's Yagi Element Equivalent is closer to a surface
> area approximation or a cross-sectional area approximation ?
>
>  -Charlie N1RR
>
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