[TowerTalk] Yagi lightning protection

[Ian White G/GM3SEK]

Tom Rauch wrote:
>
>What I would do is install rugged very close spaced spark
>gaps across the contacts, perhaps by placing the gaps across
>the leads entering and leaving the box outside the box.
>
>If the antenna leads are at a low RF voltage point, and it
>appears that they are, I'd put an intentional rugged gap
>from the elements to the boom.

In this particular case, it seems that the relay contacts were already 
closed, and then were welded together by current flowing through them. 
Dave said:
 >> I suspect lightning hit one side of the element and the other side of 
the element arced to the boom which is grounded.  The relay contacts 
were in the middle.<<

To cover all possibilities, it seems like you'd need three spark gaps 
around the outside of the relay box: one from each side, going to the 
boom, and a third one from side to side.

Thin brass strip is a great idea - it certainly makes very sharp points.


-- 
73 from Ian G/GM3SEK