I have the first edition of the ARRL book. What is significant about the second edition that is different from the earlier edition? Russ, N3CO
Sent from Yahoo Mail on Android On Fri, Jul 28, 2023 at 7:14 PM, Jim Brown<j...@audiosystemsgroup.com> wrote: On 7/28/2023 1:31 PM, Al Lorona wrote: > Please don't laugh at me; I'm a transplant from a region of the country with > essentially no lightning to a region where you have to worry about it quite a > bit. The answer is, as KK9A said, to follow proper grounding and bonding to the letter. N0AX's ARRL Book on the topic, to which I contributed, is excellent. You want the Second Edition, published about a year ago. The book also references the slide deck for my tutorial talks. Don't let "audio" in the link fool you -- it's all about grounding and bonding in the shack for lightning protection and to minimize RFI. http://k9yc.com/GroundingAndAudio.pdf On 7/28/2023 3:04 PM, Keith Trinity WE6R wrote: > Please, PLEASE disconnect your COMPUTER from your radio(s) if lightning > is in the area! > > Almost ALWAYS lightning damaged gear that comes in for repair, was hit > _thru the comm port!_ > (lightning hits Cable/DSL lines). This is the result of failure to follow proper grounding and bonding, and the failure of equipment mfrs to properly bond cable shields to the chassis at the point of entry. That failure to common to all ham mfrs, including Elecraft. This construction error was first addressed in 1994 by a ham working in pro audio, Neil Muncy, ex-W3WJE (SK), and he called it "The Pin One Problem," because Pin 1 of the XLR connectors used to carry balanced audio is the shield contact. I addressed it beginning on page 5 of this RFI tutorial, which started out life in 2007. k9yc.com/RFI-Ham.pdf A major contributor to that lightning damage are the MOV-based surge protectors provide power to interconnected equipment. The MOVs short to the green wire; the IR drop in the green wire from that current spike raises the reference potential for equipment plugged into it, and the difference between that and the chassis of interconnected equipment that's grounded somewhere else fries the interconnected circuitry. We started seeing this in pro audio systems in the early '90s, with no antennas involved. The solution was elimination of those MOV protectors, replacing them with series-mode units that stored surge in a monster inductor, then discharged it slowly as a trickle after the strike had passed. A colleague blew out the Ethernet ports of computers in his small design office from exactly this mechanism. Again, no antennas were involved. 73, Jim K9YC ______________________________________________________________ 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 eru...@yahoo.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
