Mamba wrote:
I am installing a cellphone antenna at a country cabin. The cabin has a
steep "A" frame roof (metal) with dormers that stick out about 10' below the
peak. In addition, the cabin has metal siding all around the base, to a
height of about 12'.

I will install a vertical pole at the end of one of the dormers, with a 30"
Yagi cell phone antenna mounted on it. The pole will be attached to the
side of the dormer, with clamps screwed into the side of the facia and trim
boards, and will rise about 3' over the roofing of the dormer (also metal).
The antenna height will still be 7 or 8 feet below the peak of the roof.
Coax will run from the antenna to a signal booster inside the cabin.

While looking at the antenna installation instructions, I noted that
grounding is recommended for all installations. Trying to determine the
best way to do this, or if it is necessary at all. The cabin is in a canyon
in WA state. Lightning is a rarity, it's in a canyon about 200' below
adjacent ridge, and the metal roof of the cabin is a lot higher than the
antenna.... I anticipate using a wooden pole for the mounting of the
antenna, if that has bearing as well.

Q's on this project:

1. Is wooden pole optimal? Would metal or fiberglass be better? I only
need to elevate the antenna about 3' off the dormer. I was avoiding metal
because I thought it would generate further grounding issues. The protected
location makes wind a non-factor for pole material choice - i.e. doesn't
need to withstand high winds.

2. If I do run a ground wire, it would have to run down the side of the
cabin to (I presume) a big metal rod in the ground. The wire itself would
have to be attached to the side of the cabin, which is also metal. Would
this be just increasing a risk of electrifying the place if a strike was to
occur? Or would the wire need to be held away (via insulating material?)
from the metal siding?

Advice appreciated.



At the very least you will want to have a grounding block connected to a
proper earth ground as close to the building entry point as possible.
Depending on what sort of coax you are using a block such as used for
satellite antenna or cable TV may be suitable (and cheap). Otherwise you
may have to hunt for a suitable block but you _really_ do need one. If
you do have any sort of an insurance claim that might be even vaguely
related to the antenna installation you can be sure that the insurance
company's investigator will be looking for one.

http://www.sadoun.com/Sat/Installation/Grounding.htm

--
John McGaw
[Knoxville, TN, USA]
http://johnmcgaw.com