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

[jerry]

On 2022-08-24 12:27, Dr. William J. Schmidt wrote:

> I worked with a guy at Honeywell who was trained in atmospheric
> discharges in his graduate work at MIT.

*** And I once worked for a little company that made
railroad equipment.  Our devices sat by the railroad tracks and 
monitored passing trains.  Life and property were at stake.  And 
apparently, steel railroad tracks in the middle of nowhere get a LOT of 
lightning strikes.   Our equipment
was designed to survive all near strikes, and to break in an 
easily-fixed manner in case of a direct strike.

   This was many many years ago, but I remember that each digital I/O 
input was a comparator.  And the part that went to the outside world had 
a special surge supressor zener, a series high wattage resistor, and 
.... I forget what else.

   In general, that gadget was the highest quality thing I ever worked on 
- both in hardware and in software - and everything I've worked on since 
has been crap in comparison.

                - Jerry, KF6VB