[ct-user] network update (direct induction)

Pete Soper Pete.Soper@Sun.COM
Thu, 16 Aug 2001 17:15:05 -0400

"Zoli Pitman HA1AG" <ha1ag@compuserve.com> said:
> I can only second this! Last Friday at 10PM local when heard a big
> thunderstorm approaching I disconnected all the radios, PCs and went to bed
> to take a short sleep before the WAE CW started. 15 minutes later a
> lightning hit the transformer station downhill (the mains connection is 300m
> cable directly to the station). This way Only the light tubes, the alarm
> system and my alarm clock was lost (plus the first 7 hours of the
> contest...).

Just to clarify what Mike N2MG wrote, a close strike can directly induce 
current into unshielded cables (and shielded cables where grouding is poor)
even when everything "external" is disconnected. This gives Rick's coax ethernet
implementation a definite edge over regular twisted pair, all other things 
being equal.

Last summer I lost a computer, multiple ethernet and sound cards, rig interface
logic chip, etc, etc even though my station was fully disconnected like Zoli's.
The new station I'm building will have zero unshielded cables, in addition to a
killer ground reference and full disconnect capability. If you live in an area 
with frequent lightning this doesn't sound like lunatic fanaticism :-)

And for a year I've been doing as Mike suggests, disconnecting *everything*.
The side effect is that I do almost zero non-contest operating these days,
but I just can't stand the damage that is a simple fact of life in this part
of the world.

Pete Soper AD4L