Mark - Since the tower itself and the mast are effectively grounded, an
additional rod on top is not really needed. However, if you really like
overkill, you could attach a pointed bronze lightning rod to the top of
the mast, and along with your coax in the rotator loop clamp a piece of
the bronze braided grounding cable from the rotating mast to the tower
leg. This will do two things (in theory): The point will allegedly
help to drain off static buildup near the tower, and the grounding strap
will overcome the little resistance resistance caused by the thrust
bearing and may even protect the rotator. Mind you, this is all theory
from my point of view...I've never done any of the above. I'm not into
gross overkill (although some of my friends might disagree!).
73
Dave Colter WA1ZCN
Lowell, Mark wrote:
>
> Greetings from Gloucester, VA.
>
> I am new to tower talk and have not yet seen this thread as I digest the
> immense archives. I can't imagine a better place to learn about erecting
> towers!
>
> I am planning my first tower, 110' of R25G, Phillystrand guys, with a
> modest 2el multiband HF quad on top (20-10), 2m/440 quads nested inside,
> and some small sidemounted verticals lower down. I will also use a sidearm
> to support the center of a 160m dipole for the lower bands.
>
> I am very concerned about drawing lightning strikes, as this tower will be
> at least 25' above the surrounding trees. It would seem that a lightning
> rod on the very top of the mast, with a correspondingly good ground system
> below, would provide the best protection from the inevitable strikes.
> (thanks to this reflector, I now know how to build a good grounding system
> !)
>
> I plan to run a heavy, flexible strap from the bottom of the mast to one
> of the tower legs (or all three?) to conduct the majority of the strike
> current.
>
> Can I use a copper plated ground rod, upside-down, with the point at the
> top for a suitable lightning rod? Will this also have decent dissipative
> effects to prevent minor strikes?
>
> Thank you all for your comments!
>
> --...MARK_N1LO...--
>
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