Hi If indeed a proper ground system *could* be depended on to “bleed off” and prevent discharge things would be *much* simpler. Indeed I’ve been on towers and decided to exit that location as the bleed process became audible. It very much does happen. It simply is not a 100% sort of thing.
Bob > On Jun 19, 2018, at 12:01 PM, Scott McGrath <scmcgr...@gmail.com> wrote: > > Probably the easiest and most economical grounding system is the halo ground > with antenna grounds bonded to the halo and the house ground bonded to the > halo as well. > > The halo conductor sizing is governed by local codes, But really what you > are doing ensuring that the entire structure and earth around it is at the > same potential so a nearby strike does not cause ground currents to flow. > > A direct strike is probably going to fry anything it hits because of the > gigajoules of energy concentrated within the discharge > > But a proper ground system also ‘bleeds off’ the potential difference thereby > preventing discharge > > Content by Scott > Typos by Siri > > On Jun 19, 2018, at 11:19 AM, Bob kb8tq <kb...@n1k.org> wrote: > > Hi > > 18” down in a swamp likely is plenty for conductivity. 18” down in a sandy > desert (or on an ice sheet) may be way > short in terms of conductivity :) The real answer to any of this is “that > depends”. (Yes, the ice sheet grounding > problem is from a real case that shows up in some class notes from way back > ….). > > Some locations get multiple hits on a weekly basis in the summer. Other > locations get a close strike once every > few decades. What makes economic sense for one probably does not make sense > for the other…. A “full up” > protection setup can easily run into hundreds of thousands of dollars. I’d > much rather spend that kind of money > on a Maser … or two …. or three :) …. this is TimeNuts after all …. > > Bob > > > >> On Jun 19, 2018, at 10:56 AM, Scott McGrath <scmcgr...@gmail.com> wrote: >> >> The 18” inch requirement is partially for damage resistance and partially to >> ensure adequate soil moisture for conductivity. >> >> Content by Scott >> Typos by Siri >> >> On Jun 19, 2018, at 10:50 AM, jimlux <jim...@earthlink.net> wrote: >> >> On 6/18/18 6:39 PM, Glenn Little WB4UIV wrote: >> >>> To do the grounding correctly, all connections exterior to the building are >>> to be welded. >>> The cable to ground rod welds are to be 18 inches below grade. >>> The exterior cable is to be number 2 copper or larger. >>> To bond numerous ground systems together, a number 2 copper cable is to be >>> buried at 18 inches and welded to each ground system. >>> If using eight foot ground rods, a ground rod is to be driven every 16 feet >>> along the connecting cable and the cable welded to the rod. >> >> >> It helps to know *why* some requirements exist - I suspect the 18" burial >> requirement is to avoid accidentally digging it up or damaging it. I can't >> think of an electrical reason for it. >> >> >>> A lot of work, but, cheaper, in the long run, than continuing to >>> repair/replace equipment. >> >> It depends >> >> Unless you're doing geodetic or precision timing work with a 2 or 3 band >> GPS, replacement GPS antennas are cheap. >> I'd worry about the receiver and related equipment, but the antenna itself >> might be sacrificial. >> >> As always, there's a risk/budget tradeoff >> >> >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> https://lists.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> https://lists.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > https://lists.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > https://lists.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to https://lists.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.