[TowerTalk] Source for 20' Mast

[TexasRF@aol.com]

It seems that nothing is a simple as it first appears; masts  included.
 
The structural steel commonly used for industrial applications is usually  
made of an alloy with a 40,000 psi yield strength. While this may be enough for  
modest antenna loads, it is inadequate for large antennas and/or stacked  
antennas. One of the computer programs will allow quick analysis of mast  
stresses. This material is not galvanized and the buyer has to arrange for that  if 
needed. High carbon steel material typically has a yield strength of 80,000  to 
85,000 psi; more than twice the strength of the commonly available mild steel 
 using in construction/industrial applications.
 
6061-T6 aluminum is attractive from a cost and weight standpoint. Typical  
yield strength of this material is 38,000 to 42,000 psi. The same big/stacked  
antenna concerns apply to aluminum.
 
Chrome-moly is a wonderful material but it too has some issues: it is  
usually shipped without heat treatment to allow easy fabrication. Heat treating  is 
often done after the fabrication is complete. You can buy heat treated  
material but you have to ask for it and pay for the heat treatment charges.  
Typically the steel company does not do the heat treating; another company does  
that. Also, there is the issue of galvanizing; the steel company is not into  
doing that either.
 
After checking into all the issues you can begin to understand why a good,  
strong, galvanized mast is so expensive; there is a bunch of work and shipping  
to prepare the product properly! 
 
73,
Gerald Williamson/Texas Towers
(we sell galvanized carbon steel and aluminum masts, tel 800 272 3467,  
_www.texastowers.com_ (http://www.texastowers.com) )
 
In a message dated 9/10/2005 3:38:18 P.M. Central Standard Time,  
kd4e at verizon.net writes:

Do you  live near anyone who builds racing cars?

They use chrome-moly which is  stronger than the
galvanize mast but also costly to ship.  They  might
sell you from their excess or let you buy into an
order they are  planning to place.

The other place you might look is a metal  recycling
shop.  We have one near here that often has lengths
of  6061 (I think that is the number) thick wall  aluminum
pipe.

doc

> My question is: What other options  can I explore for masts of similar  
> length & strength (I am  3 miles from the Atlantic Coast)? Are there  
> other suppliers  closer to Rhode Island?
>
> Thanks for any advice.  73,  Brian, K1NW
>    

_______________________________________________

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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