[TowerTalk] HyGain 155CA dampening rope

[Grant Saviers]

I used the HyGain supplied polypro rope in 2x TH7DX which survived 
several New England hurricanes.  It's pretty difficult to estimate what 
wind conditions will excite a vibration and the mutual mechanical 
coupling of elements is very complicated.   A vertical of 3" irrigation 
pipe which I guyed at 50% and 100% was a perfect mechanical resonator 
(my bad) and failed at the 50% point from fatigue.  So if your antenna 
is "singing" it is only time until fatigue wins.  There is no lower 
limit of stress in aluminum which eliminates fatigue.  In steel there is.

SteppIR uses a clever end cap scheme for the elements.  The caps are 
notched to let water out and a small piece of open cell foam is inside 
to keep the bugs out.  It is a PITA to find hornets in the boom while on 
the tower.  My A4S had solid caps on the boom and I was quite surprised 
by the boom weight and slosh from it being filled with water when trying 
to put it on the tram - not good!

Grant KZ1W

On 6/21/2017 7:22 AM, David Aslin G3WGN wrote:
> 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 at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>