Hi Bob,
Do you use the regular Hy-Gain Boom-to-Mast Clamp for your Hy-Gain antennas?
73, Rich, N6KT
From: "Bob Shohet, KQ2M" <kq2m@kq2m.com>
To: towertalk@contesting.com; David Aslin G3WGN <david@aslinvc.com>
Sent: Wednesday, June 21, 2017 8:36 AM
Subject: Re: [TowerTalk] HyGain 155CA dampening rope
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
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|