It would be silly to not install dampening rope. I place dampening rope in
all my elements, even when not called for in the instructions. It is good
insurance and easy to do when the antenna is on the ground. Try and avoid
having to remove the antenna to fix a broken element. Remember you buy
insurance hoping never to use it.
Use the same rope as suggested by Bob. I fold the braid over the element,
slide on a cap, place heat shrink over the cap followed by wraps of
electrical tape. This ensures the cap will not come off.
Doug
"Political correctness is a weapon used to silence people who tell the
truth" - Ayaan Hirsi Ali
-----Original Message-----
Hi David,
Two suggestions....
For the rope, I suggest braided polypropylene - it is easy to pull apart the
braid and spread it out evenly over the element so that it fits under the
element cap without "lumps". The polypropylene is also resistant to
moisture. You also might want to consider delicately taping over the
element cap with Scott's 33 or similar quality electrical tape. This
prevents moisture from getting into the element cap from any spaces between
the rope and cap and the element.
I also do not use drainage holes in the element caps. I don't want moisture
or spiders and /or other nesting critters getting into the element, which a
drainage hole allows them to do.
Two additional suggestions....
I balance each of the Hygain antennas at the boom to mast clamp so that when
held by the clamp the antenna will not dip. It is MUCH easier to control in
the wind this way and puts far less stress on the rotator because it does
not have to deal with turning an unbalanced antenna. I balanced the antenna
by the following method:
I bought malleable rolled up lead sheeting and cut off pieces and put them
at the end of the boom so that both sides of the antenna balanced at the
boom to mast clamp. I then drilled through the underside of the boom and
the lead sheeting and screwed in a thick stainless steel eyebolt and bolted
it to the bottom of the boom and inside the boom above the lead sheeting
with 5/8" SS bolts so that it would not move. Then after the eyebolt and
sheeting is secured you waterproof the whole in the boom by using silicone
bathtub sealant and let dry for a few hours. Now you have a completely
balanced Hygain antenna! It takes another 1 - 2 hours to do this properly
but you will never have to worry about fighting the wind with an unbalanced
antenna! I can't tell you how much easier this technique makes it when you
are dealing with long-boom antennas.
On the 15 and 20 meter Hygains, I also made a homebrew truss, mounted next
to the boom to mast plate. The truss consists of drilled 3/8" aluminum
plate about
9" x 12" which is drilled for 2 galvanized hoseclamps vertically and
horizontally to which I insert a 3' piece of steel 2" od mast. On the top
of the mast, I have two stainless steel eye-to-jaw turnbuckles that attach
to the end of two galvanized muffler clamps. From the turnbuckle I use
phillystran rope that is cable clamped at three points on the near end and
at the far end where it attached through another stainless steel eyebolt
that attaches ~ 18" from the end of the boom through a hole drilled in the
top and bottom of the boom and then waterproofed with silicone seal.
When the antenna is mounted on the tower or mast, I then turn the
turnbuckles on each side and tighten them to leave just a tiny bit of sag.
The additional mast and truss adds about 15-20 lbs to the antenna and takes
about 4 - 5 hours of time to make it and install it but it makes the antenna
rock solid. It is the only thing that has kept the booms from breaking in
ice storms and violent winds. I highly recommend this technique for any
long boom antenna. I don't use it on my 10 meter Hygains but it would
probably be helpful. On the 15's and 20's it is essential at a heavy wind
and/or ice prone location.
73 and GL!
Bob KQ2M
From: David Aslin G3WGN
Sent: Wednesday, June 21, 2017 11:06 AM
To: Bob Shohet, KQ2M
Subject: RE: [TowerTalk] HyGain 155CA dampening rope
Thanks Bob! Good thinking IMO. We've had some 90mph gusts here (only owned
the property for a few months) so anticipating some wild Atlantic weather
coming our way in the fall/winter. Even though the antennas will be on
telescoping towers, it's still a PITA to fix a broken antenna, so I'll be
copying your method to the letter! Had already ordered the all-stainless
clamps. Now just need to source new end caps and suitable rope, which
should be straightforward.
See you in the piles,
73, David G3WGN M6O
From: Bob Shohet, KQ2M [mailto:kq2m@kq2m.com]
Sent: 21 June 2017 15:49
To: David Aslin G3WGN <david@aslinvc.com>
Subject: Re: [TowerTalk] HyGain 155CA dampening rope
Hi David,
I have used the dampening rope in every single element of my 11 Hygain Yagis
(105CA/155CA/205CA) at my extremely windy hilltop qth. I have never lost an
element or element tip and I believe that is from the combination of using
the dampening rope held on by the element endcap plus the fact that I DOUBLE
hoseclamp every telescoped element section. (I replaced all the Hygain
element clamps with Stainless Steel hoseclamps). I then generously taped
over every hoseclamp with Scott's 33 electrical tape. What I did is a lot
of extra time and energy and expense and it has been worth every penny since
I have never had a single failure in 18 years since I put up my first tower
and 105CA.
My qth and all antennas have survived two tornados (F0 and F1), the 110 mph
gusts of Hurricane Sandy and 85 mph gusts of Hurricane Irene and countless
violent Thunderstorms, Nor'easters and icestorms. I am 100% certain that
would not have been possible without the use of the dampening ropes/endcaps,
replacing and DOUBLE hoseclamping (with stainless steel hoseclamps) each
telescoped element piece and taping over the hoseclamps.
My thinking was that the cost of an extra $50 and two hours work per antenna
on the ground for these items is nothing compared to the time, energy and
hassle of losing a piece of or an entire element before or during a contest
or when the wx precludes taking them down to fix them.
73
Bob KQ2M
From: David Aslin G3WGN
Sent: Wednesday, June 21, 2017 10:22 AM
To: towertalk@contesting.com
Subject: [TowerTalk] HyGain 155CA dampening rope
Mindful of Steve's 'Prime Directive' which suggests I absolutely should use
the dampening rope in my recently acquired used 155CA, what is the
experience of the TowerTalkian brains trust of the need for the rope in a
155BA/CA at a relatively exposed site?
73, David G3WGN M6O
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