[Elecraft] <elecraft at mailman.qth.net> Subject: Re: [K3] KIO3 failure mode

[Dr. William J. Schmidt]

Lightning seems to me the topic on all of the groups currently... so we must be in storm season!

I worked with a guy at Honeywell who was trained in atmospheric discharges in his graduate work at MIT.  I guess Honeywell was looking into survival of military equipment at the time.  He knew I was a ham and told me I was an idiot if I thought I could stop a 30K Amp lightning discharge. He told me the only thing that really works is disconnecting the electronics (which we all already know).  He also beat into me that damage does not necessarily occur from lightning itself, but rather different potentials in all of your entrance paths.  So its key to make sure that the phone, cable, power, antennas, rotor cables, etc are all tied together so that no matter what, they maintain the same potential during a lightning strike (not necessarily to GROUND).  There are many ways to do this of course, but there are two very good references to follow that basically talk about the same thing.  One was published by Ron Block and is only two pages (its out in the SteppIR groups files section).  The other is a complete book on commercial installations and lightning proofing published by PolyPhaser Corp called “Lightning Protection and Grounding Solutions for Communication Sites” , first edition by Ken Rand, copyright 1999.  That is copyright so I can't upload it.

Happy reading!