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Re: [TowerTalk] Fwd: Near Field Lightning Damage

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Fwd: Near Field Lightning Damage
From: Patrick Greenlee <patrick_g@windstream.net>
Date: Sun, 19 Apr 2015 21:28:54 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
No crew casualties were reported.

 Sorry for your lightning induced damage.

One of the most common ways to sustain injury from lightning is to be standing on your own two feet, squating or otherwise, when a bolt hits the ground nearby. Your feet act like the wipers of a potentiometer and a percentage of the voltage of the discharge is felt as a voltage difference from one foot to the other with current flowing from one foot to the other via your legs and lower abdomen. Not a good thing.)

Sounds like a joke but isn't. For protection from lightning damage as described above you stand on one leg or with one foot atop the other.

Patrick    NJ5G

On 4/19/2015 7:31 PM, Mickey Baker wrote:
​N2JFS>> ​"
I believe a EMP strong enough to take out a watch also will take out the
person carrying that watch.
​"

I sustained a serious injury in 2000 when lightning hit a tree about 10'
away from where I had squatted. My gastrocnemius sustained damage which
resulted in compartment syndrome, a trip to the emergency room and a 4
compartment fasciotomy. It was a big deal to me, but a common lightning
injury. No direct hit, but indirect serious injury.

​This is typical of injury caused by near field induced current by
lightning.

Be careful out there!

Mickey N4MB​





On Sun, Apr 19, 2015 at 3:44 PM, Hans Hammarquist via TowerTalk <
towertalk@contesting.com> wrote:

This sounds very anecdotal. Yes, a near strike lightning may take out CB
radios etc but that it took out digital watches make me suspicious. The are
usually metal encapsulated and very immune to external field. I believe a
EMP strong enough to take out a watch also will take out the person
carrying that watch.


Depending on the grid size, a Faraday cage is useful for the EM from a
lightning as the "M" will introduce back EMF in the cage which will
neutralize the "M".


I hope the "falme" will not be too long,


Hans - N2JFS



-----Original Message-----
From: Patrick Greenlee <patrick_g@windstream.net>
To: towertalk <towertalk@contesting.com>
Sent: Sat, Apr 18, 2015 10:18 pm
Subject: Re: [TowerTalk] Near Field Lightning Damage


Back in the 80's a tuna boat pulled into San Diego with every device on
board
containing a semi-conductor inoperative.  CB radio, Marine VHF,
SSB, SONAR,
RADAR, VHS tape player, SatNav LORAN, and on and on...  All
the crew members
wore digital watches which were all totally dead.

One near miss by a large
lightning stroke took out everything with solid
state semiconductor junctions.
The good news was they didn't have a
spotter chopper aloft at the time
dependent on the aircraft beacon band
transmitter on board to find the boat
(helipad is the roof of the pilot
house.)  We theorized it was the EMP that
ate everything as there was no
evidence that the bolt hit the boat.

Later
when asked what could be done to provide an immune backup comm
radio we told
them a mu metal box.  A Faraday cage wouldn't stop the
magnetic pulse.

Just
a thought in case there are any serious preppers in our midst.

Patrick
NJ5G
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