I used to have a 20m Hy-Gain beam in addition to my stack of homebrew
Yagi's. I used no rope and it shed element tips constantly. I am not
a mechanical engineer but I believe the tips break because they are
made from very thin walled tubing and are attached to a much stiffer
swedged aluminium tube instead of using a more gradual element taper.
John KK9A
Richard Smith N6KT
I believe that the rope in the elements, specifically the element
tips, is particular to the Hy-Gain yagis, at least the 20, 15, and 10
meter designs. I have seen a Hy-Gain yagi, a 5 element 15 meter yagi,
with most of its element tips broken off by regularly occurring, but
not huge, winds. The yagi was built without the rope in the element
tips that is shown in the manual for the antenna.
I replaced the element tips in 1992, with the rope in the tips per the
instructions in the manual, and did not have any element tips break
off during the next 17 years of service at the same location.
Just sharing my experience.
73, Rich, N6KT
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