Masts and stacking considerations

[Stan Griffiths]

>Adam  AA7FT said:
>
>> When I used to use 3" mast, I reduced it to 2" from below the  thrust
>> bearing (mondo!) to the
>> rotator.  This can be done by looking at pipe tables for id and od's.  No
>> bending strength
>> is needed below the thrust bearing, so the 2" is OK.
>
>I only know what I've been told by Dick, K5IU. The force on the mast 
>above the bearing is transferred to the mast below the bearing. So in
>your case the 2" pipe may bend when a strong enough force is applied
>to the 3" mast.
>
>
>-- 
>
>73
>Kris AA5UO
>mraz@aud.alcatel.com

It makes a huge difference WHERE the change from 3 inch to 2 inch mast
material takes place.  If you stay with 3 inch mast for a couple of feet
below the bearing and then taper to 2 inch, that is FAR better than going to
2 inch immediately below the bearing.

Stan  w7ni@teleport.com