[Towertalk] Grounding mast to tower

[K7LXC@aol.com]

In a message dated 4/1/02 7:14:41 PM Pacific Standard Time, goudpj@mac.com 
writes:

> How does one go about guaranteeing a good RF ground between a 
>  rotating mast and the tower proper?  I'm assuming that a thrust 
>  bearing isn't adequate, even a Rohn TB-3, but I'm sure I could be 
>  quite wrong.

    The mast is metal, the TB and its holding bolts are metal, it's attached 
to the metal tower - seems like that's enough for me. 

>  
>  Additionally, a lightning hit to an attenna or the mast would just 
>  arc across or flash ionize the air and form the conductive path to 
>  the tower in that manner, does this jibe with others' experience in 
>  these matters?
>  
    Boy, you lost me on that one. If the antenna or tower is hit, then your 
tower ground should be useful. In addition it'd be helpful to have the cables 
from the tower protected before they go into your building. Then they'd 
probably be okay. 

    I don't know what a flash ionization is. Everything except the insulated 
elements are connected to the tower and to the tower ground so they should be 
okay. You get arcing when you have potential differences between conductors - 
that's why everything in the ground system is tied together so they all rise 
and fall at the same rate. Then you don't have any arcing. 

Cheers,
Steve    K7LXC
TOWER TECH