[TowerTalk] Re: (Tower Talk) Antenna element vibration damping - How

[Jim White K4OJ]

...with riveted elements I have never had a tip fall out!  My HyGain and 
Cushcraft beams have all been modified to riveted element construction, 
which also do NOT snag on the guy wires on the way up!

It is cheap and easy...

Cordless drill with 1/8" hs bit... drill... insert pop rivet... squeeze 
rivet tool... voila... done...

K4OJ



Bill wrote:
> I have noticed that most everyone uses rope in the elements to dampen
> element vibration, but it is not a cureall. I have used this idea as well,
> but have had mixed results. Both my 5 element Hygains (15 and 10) had
> serious element vibration, even with the rope. The tips of the elements
> would vibrate off within a few months. Never had the problem with my old
> TH6DXX.
> 
> This isn't just a Hygain problem though, my 6 element KLM 10 meter
> monobander had the same problem. My 6 element 15 was just fine. I have had
> two Force 12 antennas and have not had a problem even without the rope
> trick.
> 
> I can still remember the broken element ends on the 5 element Hygain with
> the rope hanging out.
> 
> Bill, W5VX
> 
> -----Original Message-----
> From: towertalk-bounces at contesting.com
> [mailto:towertalk-bounces at contesting.com]On Behalf Of David Robbins
> K1TTT
> Sent: Friday, August 08, 2003 1:49 PM
> To: va3pl at cuic.ca; towertalk at contesting.com
> Subject: RE: [TowerTalk] Antenna element vibration damping - How
> 
> 
> Contrary to what others have said... get the heaviest, thickest rope you
> can slide into the element and still have room for it to flop around.  I
> like a tight nylon braid or old hemp/sisal because its heavy, I would
> guess you could also use a flexible wire rope also but have never seen
> it done.  The dampening action is achieved by the rope moving around
> inside the element to absorb the vibration energy.  A rope about 1/2 of
> the ID of the tubing is generally good.  One other thing interesting
> about it is that it is generally most important to have rope in the
> middle of each side of the element... that is, generally the vibration
> is worst about 1/2 way out from the center to the tip of the elements.
> So if you have a choice (like the element is made of 3 pieces on each
> side) put rope in the middle section and maybe the outer one, rope near
> the boom end does much less for vibration.
> 
> Depending on the element construction you can hold it in the element
> with either the end cap or the bolts that go through the element to
> either hold it to the boom or to hold sections of it together.
> 
> 
> David Robbins K1TTT
> e-mail: mailto:k1ttt at arrl.net
> web: http://www.k1ttt.net
> AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
> 
> 
> 
>>-----Original Message-----
>>From: towertalk-bounces at contesting.com [mailto:towertalk-
>>bounces at contesting.com] On Behalf Of VeeAthreePL
>>Sent: Friday, August 08, 2003 17:41
>>To: towertalk at contesting.com
>>Subject: [TowerTalk] Antenna element vibration damping - How
>>
>>I have had read somewhere on this reflector that in order to damp
> 
> element
> 
>>vibration in the wind you have to insert rope inside the elements.
>>I am just about to install my Mosley TA36 with 40M kit and would like
> 
> to
> 
>>install such a modification. How it is done exactly?
>>Thanks
>>73 de Andy - VA3PL
>>
>>_______________________________________________
>>
>>See: http://www.mscomputer.com  for "Self Supporting Towers",
> 
> "Wireless
> 
>>Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041
> 
> with
> 
>>any questions and ask for Sherman, W2FLA.
>>
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> 
> 
> 
> _______________________________________________
> 
> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
> Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
> questions and ask for Sherman, W2FLA.
> 
> _______________________________________________
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> 
> _______________________________________________
> 
> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
> 
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_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.

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