[TowerTalk] [Bulk] Re: Rotator Choice for Larger Yagi

[john at kk9a.com]

I had a couple of Hy-Gain monobanders and they also shed element tips. 
The 7/16 tips have a very thin wall, around .030 if I remember correctly
and mate to a much larger swedged section creating a break point.  There
are much stronger element taper schedules in the ARRL antenna book.

John KK9A


To:	towertalk at contesting.com
Subject:	Re: [TowerTalk] [Bulk] Re: [Bulk] Re: Rotator Choice for Larger Yagi
From:	Bob K6UJ <k6uj at pacbell.net>
Date:	Wed, 4 May 2016 11:44:33 -0700
List-post:	<towertalk at contesting.com">mailto:towertalk at contesting.com>
I remember the rope dampers Grant. I had the same issue and resolved it
with the poly rope. I went out to my back yard and found element sections
stuck in the ground like they were
shot like an arrow.

Bob
K6UJ

On 5/4/16 11:30 AM, Grant Saviers wrote:
Which reminds me of the rope dampers in my prior TH7DX. Apparently, the
elements w/o traps were falling off due to coupling of element mechanical
resonances. HyGain/Telex came up with a clever fix by putting a 2 ft
length of polypro rope into the tips of those elements to dampen the
vibrations. A nasty property of aluminum is that it has no fatigue limit
like steel. If a certain stress level is not exceeded, steel won't fail in
fatigue. There is no such threshold in aluminum. A small stress over many
cycles and aluminum will fatigue fracture.

Grant KZ1W