I think everyone should start by reading the National Electrical CODE , NEC on
grounding, work from there. This is in part of the National Fire Prevention
Association NFPA.Andy
>
>
> Eric,
>
> You're the right man for the job of writing this manual. I like the
> lightening protection for a chapter, RF grounding for a second chapter, and
> a third on getting them both in sync.
>
> Being a sociologist by training I can appreciate the engineers reputation
> for being concise - so why not establish a drop box with the two chapters as
> a start. Open it up to everyone for reading, you take one chapter and
> another guy a second chapter - form a small team for each chapter with
> access to edit and away you go?
>
> I'll be happy to read the drafts as a non-engineer and comment accordingly.
>
> Kris KM2KM
>
> MERSCHROD
> 123 Warren Road
> Ithaca, NY 14850
> Skype: Merschrod
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of R. Eric
> Sluder - W9WLW via TenTec
> Sent: Saturday, May 17, 2014 10:36 AM
> To: Discussion of Ten-Tec Equipment; Robert
> Subject: Re: [TenTec] Eagle problem?
>
> Ya know gentlemen; I think that some of you should gather and contribute
> your vast knowledge of grounding and lightening protection to establish a
> standards document that Hams can use.
>
> Imagine a standard that all Hams could reference that has been vetted by
> those who's credentials and industry experience provide a truly usable and
> safe reference for all.
>
> A lot of what I read is accurate, but some of it is questionable in my mind
> based on my industry training and experience in telecommunications and now
> hospital building construction. I've used IEEE, BICSI, TIA, ANSI, NEC and
> other similar references and they all collide at some point in the way to
> provide ground (earth) and lightning protection. I share all that because
> this debate has me confused at different points, and I can't imagine how the
> humble Ham who's a Dentist, truck driver or whatever their profession is -
> try to follow along and gain a general understanding of grounding and
> lightening protection (two different disciplines with commonality).
>
> We all could benefit (and save our stations) by some of you really smart and
> well versed chaps gathering and hammering out a standard we could all live
> and operate by.
>
> Be well, operate safely during the storm season and save your loose change
> for a Patriot. Jim Whalton gave me the run down yesterday at the TT
> booth... it looks like fun.
>
> 73 - Eric
> W9WLW
>
> On May 16, 2014 7:47:03 PM EDT, Robert <rmcgraw@blomand.net> wrote:
> |I had 3 pieces of 1" braid in place to bond the rotating mast to the
> |sleeve at the top of my tower. A lightning strike burned all 3 into.
> |Balled ends on the strands confirmed this.
> |
> |73
> |Bob
> |
> |
> |Sent from my iPhone
> |
> |> On May 16, 2014, at 6:04 PM, Stuart Rohre <rohre@arlut.utexas.edu>
> |wrote:
> |>
> |> Jim, don't we all use Flukes now? :-) I do have several at home and
> |work. I was remembering a discussion of a rig fault where the pin
> |intended for grounding, had not been grounded at the radio connector
> |entry to chassis.
> |>
> |> Good point you make about low ranges needed for ohms measuring.
> |There are some good build it yourself low ohms measuring circuits out
> |there, to extend the range of an ordinary meter. The Graf (author)
> |series of circuit diagrams books includes at least one. The ham
> |magazines in last 40 years had one or more.
> |>
> |> In the midst of measuring things, most good troubleshooting includes
> |a thorough visual inspection to see how things are bonded and grounded,
> |and if the circuit board is providing the connection to chassis.
> |> Unfortunately, we had not done a pre service inspection of the
> |following radio incident:
> |>
> |> For high current faults, we have seen a Yaesu 5100 that had RF
> |connection to circuit board and its DC negative power line to same
> |circuit board at other end of chassis. A lightning event on the tower
> |induced shield current down the coax to the radio , across the circuit
> |board, vaporizing part of the ground copper, and then to the DC
> |negative line which returned to AC third pin and power supply chassis.
> |>
> |> The bonding was done by an experienced power plant engineer, but it
> |provided an extra return path through that circuit board trace, that
> |caused severe damage to the trace. Luckily, that radio has survived
> |that, with a bus bar now bonding DC negative to the coax connector
> |shell external to the chassis. (No longer relying on the radio circuit
> |board traces.) The radio worked even after losing part of the board
> |copper, but only if the coax was connected, which was grounded to the
> |tower and earth providing a return through the AC third pin. That
> |observation prompted us to open the radio, which then showed the
> |missing trace.
> |>
> |> As for braid failures, literature about high current faults has
> |stated that braid can blow apart in a near direct strike, as little
> |shards of wire. Indoors in someone's shack that could cause injury, or
> |put small shorts into places hard to find.
> |>
> |> Copper flashing could be used in place of braid. The use or either
> |was to provide low inductance through wide flat conductors used for
> |bonding equipment together.
> |>
> |> Stuart Rohre
> |> K5KVH
> |> _______________________________________________
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>
> --
> Sent from my Android device with K-9 Mail. Please excuse my brevity.
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