[Elecraft] [OT] A dumb question about lightning

[Jim Brown]

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