[TenTec] Grounding manual for Hams

Sat May 17 16:24:40 EDT 2014

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 at 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 at 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 at 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
> |> _______________________________________________
> |> TenTec mailing list
> |> TenTec at contesting.com
> |> http://lists.contesting.com/mailman/listinfo/tentec
> |_______________________________________________
> |TenTec mailing list
> |TenTec at contesting.com
> |http://lists.contesting.com/mailman/listinfo/tentec
> 
> --
> Sent from my Android device with K-9 Mail. Please excuse my brevity.
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
> 
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec