In short, yes. The rope just lays in the elements. From what I'm told
the rope size should be about 1/4 to 1/2 the element ID, and type of
rope doesn't matter (use whatever is cheap).
I recall reading about this trick for taming element vibration due to
vortex shedding effect in gentle breeze / light wind many years ago. I
thought it was in an ARRL Antenna Book but I have not recently been able
to find the old reference. I asked around about this over the summer
because my 6m antenna was having a problem. In a light steady breeze the
element tips were vibrating at about a 200 Hz rate, and those tips were
moving up and down over at least a two inch span! I could hear it
humming 100 feet away from the 100 foot tower and could feel it strongly
at the base of the tower. Three methods of limiting the problem were
mentioned:
1. Rope laying in the element as I am doing. Some commercial antennas,
including my HyGain TH11DX use this method in the element tip sections.
2. Weight the tips of the elements. Some have used this method by using
short pieces of EHS guy wire inside the element tips.
3. Spiral wrap the element with some kind of cord that is about 1/10 the
element diameter. This *may* be the most effective method (?) but I
don't favor it because it will inhibit ice and snow shedding. I am also
unsure about making the spiral wrap stay put unless it is glued in place.
I am hoping the first method works!
I considered combining methods 1 and 2 but there is/was no available
information on what might happen in that case.
73,
Paul
On 9/28/22 10:33, mikflathead@aol.com wrote:
Does the rope just lay in the elements? Mike
-----Original Message-----
From: Paul N1BUG FN55mf <paul@n1bug.com>
To: NEWSVHF@mailman.qth.net <newsvhf@mailman.qth.net>;
vhfcontesting@contesting.com <vhfcontesting@contesting.com>
Sent: Wed, Sep 28, 2022 5:21 am
Subject: Re: [VHFcontesting] [NEWSVHF] 222 Sprint
Conditions were extremely variable! I got 13 QSOs in 9 grids, all
SSB/CW. Not too bad considering where I'm located but it sure gets slow
after the first hour.
At the start everyone was weak! I had to resort to CW to work N1JEZ and
K1TEO! Then I got N2SLN in FN22 on SSB with a good signal, somewhat
surprising considering that WSW direction has always been hard from here.
Around 0100 someone found the propagation switch and moved it to the ON
position. I heard K1PXE calling on SSB. Pete was 55 which may be the
strongest I've ever heard him but he quickly faded. We switched to CW,
easily completing the QSO. Pete was peaking close to S5 again at the
end. A moment later K1TEO was up to S9+. What a change from an hour earlier!
Best distance was N2JMH at 470 miles on SSB with a great signal. I
copied a few good solid CW transmissions from W1XR at 560 miles but Jim
couldn't hear me.
Some "easy" ones were missed because I never heard them calling in this
direction. That's normal.
There was a bunch of us waiting for K1DY like cats by a mouse hole! I
didn't hang around long after working Bill as I hadn't had any other
QSOs in over an hour and I needed more sleep. I hope he had fun working
the gang.
I managed to get the clump of dirt and vegetation debris out of the 6
meter driven element and rope run through three elements yesterday. I
came in to take a break and fell asleep, so still have four elements to
do. I am able to pull the 1/4" rope through where there is only a 3/16"
gap on either side of the U bolts holding the element to the boom by
running a stiff wire through the element, tapering the end of the rope
and taping it to the wire. It took some trial and error to figure out
how to tape it so it stays on but will still squeeze through. This is
one application where the ultra-cheap ultra-thin vinyl tape actually
works better than the good stuff! The ropes are wedged in pretty tight
at the center of the elements and shouldn't move. That's good because I
am thinking about not capping the ends of the elements. They have never
been capped before. I know water gets in around the U bolt and if it
can't run out the end I could have elements filling with water.
73,
Paul N1BUG
FN55mf
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