Unless the wind is blowing straight on the front or back of the antennas,
the boom to mast clamps would twist the mast in the same direction no
matter which side of the mast the antenna is mounted on.
Chuck W5PR
On Tue, Mar 17, 2020 at 11:49 AM k7lxc--- via TowerTalk <
towertalk@contesting.com> wrote:
> > I have a SteppIR 3 element yagi. I want to add 40m and will probably do
> it
> with a 2 element yagi like the Shorty-40 or XM-240. And I'd like to have
> an 8 or 10 element yagi for 2m as well. I have about 17 feet of 2 inch 0.25
> wall galvanized mast to work with.
> > Just guessing that normally yagis are stacked in order of decreasing
> wind cross section. But all three yagis are pretty close in cross section
> at around 6 square feet and in weight at around 50 pounds. The Shorty-40
> has a 14 foot boom, the SteppIR has a 16 foot boom, the XM-240 has a 22
> foot boom. I'm inclined to put the 2m yagi at the top of the mast, but
> should it go between the two HF yagis?
> This won't answer your question but here's a little known tip: mount
> the 2 HF antennas on opposite sides of the mast. This will cancel out some
> of the wind vectors and wind generated torque on the mast. Dick Weber,
> K5IU, PE, published an article in QEX years ago on this topic and it makes
> a lot of sense. I'm just saying.
>
> Cheers,Steve K7LXCTOWER TECH
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