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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