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[TowerTalk] Lightning Strike - Post-strike analysis

Subject: [TowerTalk] Lightning Strike - Post-strike analysis
From: WD0M <>
Date: Tue, 18 Sep 2007 15:36:35 -0600
List-post: <>
It was a heck of a way to get your heart going from about 60 beats per 
minute to full throttle in about 1 microsecond.  About 2:00 AM a couple 
of days ago, we were treated to an incredibly loud blast, just outside 
our home.  I'm not certain if the lightning bolt hit the tower, or hit  
just really close by.....there was no delay between the flash and the 
blast.  Here are the results of what seemed to have happened.

Early the next morning, I fired up the ham gear (Icom 756 Pro, Alpha 
87a, SteppIR 4L with the 40/30M add-on), and everything worked!  That's 
great news!  I was concerned about all the gear, naturally, and 
especially curious about the SteppIR - but it came through without 
incident, stepper motors and the controller as well.

I had to restart my computer, since it had gone off line and powered 
down.  Turns out that it wouldn't work...sorta.  After playing around 
with it for some time, I realized the 7 internal USB ports on the Dell 
9100 had all been fried.  I have an old V1.0 USB 3-port PCI card that I 
installed, and I was able to connect the keyboard to it and check it 
out.  Every time I now start the computer, it proudly tells me it can't 
find the keyboard....then it goes right ahead and starts up and all is 
well....except the 7 fried USB ports.  I also have a data backup 
external USB hard drive that runs every night, and all the data was 
there.  Good - no data loss.

The next thing I noticed is that my less than 10 month old multifunction 
printer/scanner/FAX was dead.  That led me to check the telephone on my 
desk - it too was dead.....and that gave me the idea that the lightning 
had found it's way into the shack through the phone line.  Our telephone 
service company says there is a surge arrestor in the junction box 
outside the home, which is right outside my shack, just a foot or two 
away from the gear.

The phone company is coming over to check their surge arrestor, and 
replace it at my request.  I'm also purchasing an uninterruptible power 
supply (UPS) with network, phone and DSL surge suppression 
features....and hope that will take care of the ancillary equipment, 
should old Thor decide to take another event we oh so 
devoutly hope doesn't recur.

I spent lots of time, effort and money to install a lightning protection 
system, and it had worked - for the ham gear.  What I forgot was the 
telephone/DSL line that needed protection.  I removed the DSL filter 
from the phone line and found that on the filter, the line leading to 
the telephone had been turned into toast.  That explained why the phone 
and the multifunction printer/scanner/FAX were no longer working - the 
path from the telephone line went right to the printer.

Why the fried USB ports?  I can only assume that the telephone line's 
passing within inches of the USB cables induced a voltage in them that 
caused the sensitive parts of the USB chips in the Dell terminally to 
release their smoke in a fit of protest toward my failure to protect them.

The bottom line is that if there's a way inside, lightning will find 
it.  Don't forget the phone/DSL line, or for those with cable TV, that 
line as well.  My web site <> 
has a description of my attempts to prevent any "extra" electricity from 
finding its way into the shack, for those interested (or, see the link 
below the signature below). 

Due adulation and high praise is to be given to the ARRL, ICE, and 
Polyphaser, whose advice I followed, and ICE, whose protectors I 
use.....but don't forget the phone line, as I did....and have the phone 
company verify that their suppressor is in place and functional.

Some reference material:

Thor's Hammer <>

Polyphaser - Protecting an Amateur Radio Station 

ARRL Lightning Protection - Part 1 

ARRL Lightning Protection - Part 2 

ARRL Lightning Protection - Part 3 

ARRL Lab Notes - Lightning - Part 1 

ARRL Lab Notes - Lightning - Part 2 

Stay safe out there....



Joe Hannigan - WDØM
Pagosa Springs, CO


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