Hello Fred, I am getting ready to put up a hex beam. I’m going to put it on a 31 foot self supporting aluminum mast from US towers. The mast sits on a base, and the base will sit on a concrete pad. that is 4 ft.² and 6 feet deep. Would you offer me a little advice on grounding, for lightning protection. My plan, is to push an 8 foot rod into the ground close to the concrete block that the base of the tower will be mounted on. I may use lightning arrester’s there, and also add a ground rod that is Sunk into the ground near the house where the coax will go through the wall. Do you think this will work well or do you or could you offer me other suggestions if this one doesn’t sound good? Thank you very very much.
Gerry Leary Wb6ivf On Jul 31, 2023, at 2:20 PM, Fred Jensen <k6dg...@gmail.com> wrote: Be very careful of advice regarding lightning protection. There are some very good sources, starting with the NEC and including material from ARRL. Some is somewhat non-intuitive. For example, the NEC requires that any additional "earth electrodes" [aka ground rods] be bonded to the service entrance earth electrode with a low inductance path. There's been quite an array of advice circulating here recently, much of it wrong, some dangerous. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County Geoffrey Feldman wrote on 7/28/2023 5:02 PM: > > First thing and foremost - switches are mostly not relevant to protection. > Energy that can travel 1000' through the sky is likely to continue across > most switches. So, the utmost of safety is what you indicated you did - > disconnect. By disconnect, I mean either disconnect outside the building, > leaving the feed on the ground or leave the feed connected to a copper plate > that is in turn connected to an 8' deep ground stake. On the inside of the > house, disconnect the lines from that plate and leave them on the floor. > Another such stake near the feed point of the antenna is also a great idea. > If it's possible to lower the antenna when not in use, that's a great idea. > This should be the default when not in use. > > > You have the belief that no grounding system is perfectly effective (for all > imaginable strikes) - maybe, but a good grounding system is far better than > foolishness. A grounding system, or an antenna is not a "lightning > magnet". If it doesn't strike it won't. If it does it will and the grounding > system assures the energy will be less likely to cause harm. Some places and > circumstances are more or less likely but everywhere is possible. If that > possibility happens, a good grounding system is why it is likely to be > survived. > > > A key thing to understand is that when Lightning strikes in nature, all the > energy travels along the surface of the ground. It can do this for many > feet and be lethal doing it. Anything that stands along the radius from the > point of the strike (one part closer and the other further) is in danger. > Four legged animals, having more distant contact points, more dangerous. > The purpose of a ground stake (8' straight down) is to channel the > electricity deep, rather than along the surface. > > > Don't use emotional theories. Read the lightning mitigation and grounding > books offered by the ARRL. Use UL approved conductors and stakes. Do not > use your homes electrical service ground stake. Keep that separate. > > > All the above is a "cliffs notes" and so is anything else posted here. Read > the books. Ask senior members of a local club, to review your plan. > > > W1GCF Geoff > -- This email has been checked for viruses by AVG antivirus software. www.avg.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to gerrylear...@icloud.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
