[TowerTalk] High VSWR

[Jim Thomson]

Date: Thu, 29 Aug 2019 15:18:59 -0400
From: "john at kk9a.com" <john at kk9a.com>
To: Doug Ronald <doug at dougronald.com>
Cc: Mal Speer <malco at carolina.rr.com>, towertalk at contesting.com
Subject: Re: [TowerTalk] High VSWR

<That is a bad and sad accident but again lucky no one was injured by a
<falling object or a cable snapping back. Wow, that is a tough environment.
<Take a breather and I am sure you'll move forward again.  The tower and
<rotator should be able to handle anything that you will likely put up plus
<it looks like it is an RF quiet location.

<73,
<John

##  This  could  have  all  been  alleviated by  the  use of a single  $3.00  nicropress  crimp. 
The  cable  will  break  before the  crimp  lets go.  I would use  TWO  nicropress  crimps
for  this  application. 

##  with  14,300  lb  tension  on  the  lift  cable,   the  .5 inch cable is  too  small.  Typ you  
use the cable  with no more than  20%  of  its  ratings.   .75 inch  would be operating at 24%...
and  the bare min  size  for this  application.  .75 inch  winch  cable  is  readily  available. 

##  Looks  like a single U  bolt  used on  each  ele  half.....  hard  to  tell  by  the  pix.   For the
long  eles, it  needs  a min of  2  per  half...  and  preferably  3-4  per  side. 

##  with  more  boom on the  shorter ele  side.....vs  the   longer  ele  side, the required  rotor
torque  will  be  sky high.   They  have  mounted the  boom  at its   CG.   They  should have 
mounted at  center of  boom,  and  added  a counterweight  at  light  end  of  boom. 

Jim  VE7RF