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[TowerTalk] Re:rope in elements

To: <>
Subject: [TowerTalk] Re:rope in elements
From: (
Date: Wed, 28 Mar 2001 10:01:11 EST
In a message dated 3/28/2001 00:56:25 Eastern Standard Time, writes:

> Someone is wrong here. Several people just did testify
>  on this reflector that Force12 antennas will vibrate and
>  drop element parts, I think I will beleive the stories
>  from real life experience.
>  Sure doesnt seem very safe to buy this Force12 stuff
>  73, Jim SM2EKM

Reality doesn't count, it is the software and computer simulations that are 
Very soon we won't have to live real lives, we can live in VR (virtual 
reality) lives. Everything will be calculate and displayed for us, and there 
will be "no problems" :-)

I am making prediction here that riveted junctions will eventually fall apart 
(matter of time and conditions, sure as the sunspots), work themselves lose, 
and tubing will wiggle (as long as there is minute difference between two 
mating diameters, not compression fitting).

Elements will vibrate in some situation. No way designers can predict and 
simulate all possible installation situations. Antenna is the part of 
mechanical structure (incl. tower, mast, guys, etc.) that is prone to 
vibration at certain configurations and can induce vibrations even into 
vibration "free" antenna. Eventually some will vibrate and fall apart! The 
remedy is so simple, cheap and fool proof (da rope)!

Now has anyone experienced frozen (cracked) water filled elements when using 
nylon ropes inside the elements with inside tubing diameter larger (abt 50%) 
than diameter of the rope? If you seal the elements with caps, the amount of 
condensation that would get accumulated (and equally expelled over the years) 
is minuscule to cause any significant water collection sufficient to fill the 
element and cause splitting due to ice. (Assemble antenna on a dry day, use 
shampagne corks :-)

I admire work of Force 12 team, but I think in this case they are off the 
mark (too much marketing going on)? If their elements and rivets fail, then 
the claims are obviously false. There are laws of physics that computers 
might not be grasping or considering yet. 

I rope and cork my elements, use hose and muffler clamps with sleeves, and I 
haven't sued myself yet for antennas falling appart :-) But what do I know, 
there are experts armed with computers who know better. 

Yuri, K3BU, VE3BMV, VE1BY, etc.

(BTW I am really mechanical engineer and have seen some fatigue failures of 
designs that had multiple safety factors and were not supposed to vibrate. 
Gimme anything that's not supposed to vibrate, and most likely I will make it 
shake :-)
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