[Towertalk] Quad question for mechnical enginners

[K7LXC@aol.com]

In a message dated 6/4/02 9:32:18 PM Pacific Daylight Time, VSal@teltone.com 
writes:

> The question is :
>  If I use thrust bearing on the 2 inch aluminum conduit mast ( two coupled 
10
>  foot sections) - what should be the SAFE height of the mast above the top 
of
>  the tower?
>  I am guessing that the mast could act as a spring and the section inside 
the
>  tower should be as long as feasible. I just do not want to bend the section
>  above the bearing if it is made too long. 
>  
>  My rotator is garden variety Ham rotator - no brake. I am not too concerned
>  if the rotator cannot handle the start/ stop . My main concern is not to
>  bend the mast above the bearing.
>  
    Good thinking. Snohomish County is a 75 MPH windspeed zone (they're all 
listed at  <A HREF="http://www.championradio.com">www.championradio.com</A> 
under Tech Notes). 

    What's the square footage of your proposed antenna? With this info, I can 
make a more educated guess. 

    Is your proposed aluminum conduit suitable? Probably not. Conduit is not 
rated for strength; at the minimum you would need real aluminum (i.e. 
6061-T6) but even it might not be strong enough. 

Cheers,
Steve    K7LXC
TOWER TECH -
Professional tower services for commercial and amateur