[TowerTalk] Rohn towers

[Patrick Greenlee]

Thanks to everyone who offered information and opinions regarding 
various aspects of mast material sizing, economics, procurement, sources 
and whatever else I might be forgetting to list just now.

My K7NV prop-pitch motor rotator conversion is in hand.  Kurt set it up 
for a 2 inch mast and supplied me with specs for my guidance.

A 2.0" Dia x .250" wall 1026 DOM mast (yield = 85 Ksi) has a safety 
factor of 2.57 for a DB42 antenna (38.9 SqFt Effective Area) mounted 2 
feet above the tower top when the tower top is 94 feet above ground.
This is per ANSI/TIA-222-G, Exposure Zone C, on flat terrain in 
Pottawatomie County, OK which is a 90 Mph wind speed zone.

My passing interest in 0.375 material was to gain strength without 
increasing OD (where increasing OD would be better economics if I didn't 
have a rotator set up for 2 inch)  I don't really need more strength if 
I don't extend the mast much.  The 0.375 material would allow a little 
more extension with the same safety margin but isn't a real issue, just 
me dreaming of gilding the lily. Due diligence would be to use Kurts 
numbers and stop flailing around.

Thanks again for everyone's input.

Patrick   NJ5G