Hi guys... more questions! I'm thinking looking at putting an A4S and and some kind of 40M yagi on the same mast. I plan to rotate the 40M yagi 90 deg from the A4S to minimize interaction. I'm thin
Gary, You may want to go with 11.0 figure. You need to factor in "moment of force" (aka torque). This may help you sleep better on very gusty days. Good luck in your choice. Semper Fi, Tommy - K6YE D
A tube looking end on has a drag much more than the cross sectional area of the tube. Also consider what happens when the wind is at a 45 degree angle.. But.. let's for a minute assume that the drag
Shoot... using the .707 figure for 45 deg I'm back right at the worst case scenario. Where does the .707 come from? I was using a simplified version of windload calcs from the force 12 web site th
It's the sine and cosine of 45 degrees..... Al AB2ZY Shoot... using the .707 figure for 45 deg I'm back right at the worst case scenario. Where does the .707 come from? I was using a simplified versi
cosine (45 degrees) That's the projected area in the direction of the wind coming from 45 degrees off axis. That's probably not a very valid approach. Some sort of "projected area" is more valid, but
Unless you're a Sam Harris disciple (if it stays up more than a year it was over designed), it's hard to be too cautious when you consider the possible combination of factors such as ice and wind, re
If you access to Leeson's "Physical Design of Yagi Antennas" (or something close to that) it covers this topic and how to "fix" it. Shoot... using the .707 figure for 45 deg I'm back right at the wor
This is a very complicated subject for us non-engineers. One complication I ran into years ago was that Rohn was quoting their windload figures by one standard, while most antenna manufacturers were
You also can use Yagi-Mech software from DX Engineering to check Yagi wind and ice load stresses. It's a little confusing about how to enter sleeved sections, but other than that it has an ok Windows
Thanks to all for your info on this. My main thought was that maybe I could gain a little windload room by rotating one of the yagis 90 deg from the other, exposing one on its maximum windlload si