[TowerTalk] AB-577 questions

[Pete Smith N4ZR]

I have a 3-element 6-meter yagi that I would like to put above the C-3E 
on my B-577.  I think probably the smart way to do this would be to 
mount it on a 5-6 foot mast that is the right size to drop down inside 
the stub mast at the top of my AB-577 and secure it with a through 
bolt.  Does anyone happen to know the inside diameter of the stub?  I'm 
sorry but I didn't measure this before putting it up; for that matter I 
don't remember if the stub is even open at the top.

-- 
73, Pete N4ZR