[TowerTalk] Grounding guidelines

[Tom Rauch]

> However, it still remains unclear to me what to ground and whether a
> lightning arrestor on the top of the tower is mandatory.

Ground the tower, insulate the guy lines and ground the guy lines 
at the anchors, ground all the feedlines leaving the tower and 
NEVER have them travel above ground to the house entrance.

As for the "static dissipator" on the tower top, it does nothing if you 
have big yagi's up there anyway. All these static dissipators do is 
create a small cloud of ionized air.

That might help reduce the voltage gradient near the top on a calm 
day, but it won't do anything if you have big yagi up there.    
 
> or must not lightning arrestors be put on the top of towers? Other
> docs suggest burying plenty of copper rods connected by copper straps
> set radially to the tower base in order to ground the tower itself. Is
> this necessary ?

Buried radials are the best bet. You need large surface area to 
spread the current out.

If you can borrow a copy of The National Association of 
Broadcasters  Handbook (The NAB Handbook) it has an entire 
chapter on lightning protection. I follow most of their suggestions, 
and without disconnecting anything I have had an occasional 
lightning hit with no damage. (I have a 95 meter tower, as well as 
several shorter antennas spread over a large area.)

That text is more reliable than rumors, hear-say, or the words of 
well-intentioned people who happen to sell equipment.
73, Tom W8JI
W8JI@contesting.com 

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