TT: I just finished putting together an equation to calculate the angle of max wind force on a Yagi. (I couldn't find it in my own TT archives, and wanted to shake the cobwebs out of my forty-somethi
I'm not at all sure that Cos Theta is a proper formula for the diminishment of drag as the shapes are turned away from full head on. It does describe the diminishment of viewed area from a point dist
Gene, You are using the wrong equation. It has been used in ham circles for a long time but is incorrect. F(max) is NOT equal to W[(boom plus bracket area)(sin theta) + (element area)(cos theta)] K5I
Guy: Thanks for the comments. I agree that flexible elements (Skyhawk) are likely to shed wind by bending a little,thereby reducing the actual force on the element/mast/tower. Would it be safe to say
Hi Gene, The direction of maximum exposed antenna area, hence maximum force developed by the antenna on the support structure, is either with the elements or the boom broadside to the wind, whichever
Hi, Kurt: If what you're asserting here is accurate (which I haven't satisfied myself that it is yet), then what you're saying is that my calculations show exactly the OPPOSITE of what I think they s
For the boom, it would. But for the elements of something like a C31, which flexes a good bit, particularly the 20 meter elements, the computation would be unnecessarily harsh. The figures would come
With both dipoles in the wind, equally sharing, the VISIBLE cross-section offered the wind is at 1.4. HOWEVER, note that the wind does NOT flow across the elements at right angles, but at a 45 degree
Hi Guys, Ok, here's the main difference between what you are thinking and what K5IU pointed out is really happening. The resultant force on a cylinder inclined to the wind is ALWAYS normal to the axi
TT: I'm feeling less and less certain that my equations are correct! Thanks to Kurt, Steve, Michael and Guy for pointing me toward previous sources. I've inquired from the sources about reprints of t