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Hi all,
I live on the cal. Redwood coast and in the redwood forest .i have 100+ foot trees right in my back yard, overhanging my house. How much do I need to worry about lightening striking my fm antenna, which is on a 10 ft mast?
"When the demon is at your door, in the mornin' it won't be there no more"
Steely Dan
Follow Ups:
From being a electrician for a few years and having actually dealt with lightning strikes I can add this.
If lightning does hit that, it will simply fry, or more like explode that antenna and never make it down that antenna wire.
Secondly lightning wants the best path to ground. that electrical mast next too the antenna will do the trick. Add a lightning rod to that and ground the piss out of that! It will save you a lot of trouble in the end anyway.
We have a lot of close lightening strikes. I have everything (including very large FM antenna) I can think of grounded with 6 rods at various locations. Lots of rocks here, was pounding one rod in, it made a complete U turn and ended up coming up behind me. If I was a cartoon character it would have caught my belt and ratcheted me up at each pound.
The strikes that have caused damage have all appeared to have done so through the AC. Power supplies etc., were damaged, not the front end of FM tuners, etc. I have lightening discharge devices on the AC, but things have still gotten damaged. When possible now I unplug the devices that are the most difficult to repair/replace at the first sound of thunder.
Since my antenna is about 60 ft. From my other earth ground, I just pounded a 1000 ft...no, just 8 ft copper rod into the ground. Now resting with a beer and ice pack on my back. Thank god it has been raining non stop here forever, at least the first couple feet were wet earth!
"When the demon is at your door, in the mornin' it won't be there no more"
Steely Dan
Later Gator,
Dave
I know...shopping for a reasonably priced run of 10 ga wire.
"When the demon is at your door, in the mornin' it won't be there no more"
Steely Dan
on a forested rise overlooking the Willamette Valley, with 110-foot Douglas firs, a couple of just-as-tall coast redwoods, a host of Ponderosas, and a giant oak within spitting distance of the rotored Winegard. The antenna installer grounded the setup, calling that "routine."
As a side note, you live in beautiful country.
Jim
http://jimtranr.com
The short answer is Yes, and is mandatory by the National Electrical Code (NEC), Article 810. The highest piece of metal sticking upwards on top of a structure is essentially an Air Terminal of a lightning protection system. Trees and where you live don't enter into the requirements at all, and the NEC is adopted by all 50 states.
The antenna mast is required to be grounded.
The (assumed) coaxial cable antenna lead-in is also required to have a listed antenna discharge unit (aka: lightning arrestor) or - more commonly - a coaxial cable shield grounding block.
How this is all accomplished and sizes and types of wire used is beyond this note. Essentially everything including telephone service and cable TV coaxial cable is required to be interconnected and grounded at a single point; typically at or near the incoming electrical service.
The referenced linky below is an OK general outline. You can ignore the parts dealing with ham radio transmitting antennas. Note that it is based on the 2011 NEC, which is the basis of the 2013 CA Electrical Code, which is the current governing document for (assuming) Mendocino County. AFAIK.
The user instructions for any receiver or tuner I've seen always have antenna grounding instructions included.
Later Gator,
Dave
Believe me, I do!
I spend $600 a year to have limbs trimmed, and had a forester examine the trees recently, which came out well.
"When the demon is at your door, in the mornin' it won't be there no more"
Steely Dan
Well, we don't get lightning much where I live just south of SF. I remember one day with a lot of lightning fifteen years ago. Wow, that was fun, though we don't usually get really close hits where I am, which is underneath trees, but also on the side of a hill with more tree on top.
I think you should ground it. I'm waiting to get around to grounding mine SOMEDAY. I usually disconnect it from my tuner during a storm figuring I'm more disposable than my tuner ;-)
Is that a power line right over your antenna? I think you should have a grounding block installed. I also do use a Monster power strip with antenna an arrester for the TV and I wonder whether that is sufficient even for the tuner? That would be a halfway measure IMO.
No, that is an optical illusion, antenna is on the back of the house. Thanks for your input.
"When the demon is at your door, in the mornin' it won't be there no more"
Steely Dan
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