But don't expect it to provide a clue as to how to build a ground system for
proper lightning protection...it is concerned most about electrical safety
grounding...important but not the all inclusive answer.
Cecil
Sent from my iPad
> On May 17, 2014, at 3:24 PM, P C A <xtraham58@hotmail.com> wrote:
>
> 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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