[TowerTalk] Broken masts

[Jim Thomson]

Date: Thu, 6 May 2010 08:08:46 -0700
From: "Mike" <noddy1211 at sbcglobal.net>
Subject: Re: [TowerTalk] Broken  masts

http://www.tashtowers.com/pricelist.html

Scroll down the list and you will see weight, size and length.  TT will be
about the same price.

Mike, K6BR

##  This outfit has excellent prices on the  20'  x 3/8"  chromolly masts.  They are not only
way cheaper than US Tower corp  CM-20... they are also stronger,  120 ksi  vs  107 ksi. 

## I just bought a CM-20.. from  US Tower corp... since my local trucking outfit happened
to be driving right past their door.. and so I paid nothing for the shipping. 

## The CM-20, from UST.. is also  20' long x 3/8"  thick... but only 107 ksi.   The galvanizing
job on the UST  CM-20 is superb.   Both weigh 140 lbs.   The tashtowers version is 
120/107 = 12.1% stronger.... nothing to sneeze at... and WAY  cheaper than the UST  version. 

## Array solutions also sells  4130 masts.  His are only  2"  OD  x .25"  thick.. and are 105 ksi. 
The array solutions masts  are 96 lbs.. and are shipped inside cardboard tubes to protect em.

  http://thebont.com/spreadsheets/AnalysisOfAntennaMastStrength.htm

##  try all the various configs of mast material on the above mast spreadsheet ...1st...
Before you buy anything.  Also  consider any FUTURE wind loading requirements... like
the 40m yagi you decide to install.... 5 yrs down the road... and can't.... cuz the mast is 
not strong enough.  Ok, now you gotta  remove all the ant's.. remove the stock mast..
replace with stronger mast... re-install all the ants, plus new 40m ant at top of mast, etc
etc.  A lot less hassle to just install a stronger mast to start with. .. and cheaper.  With
changing WX patterns, a stronger mast may well be a smart move.  

later... Jim  VE7RF