David, I had that same tick, tick, tick from my marine band VHF with
masthead antenna. At first I thought it was my knotmeter's log but the
tick rate got way too fast for our boat speed. I went hunting for the
sound and it was arcing at the chassis mount UHF connector, I took my
chances, unplugged the antenna, put a jumper across the PL-259 and stuck
the coax down by the propshaft to offer a safe path for any lightning.
Nothing happened, no damage to the radio, no lightning was evident at
all then or for the rest of the day. Later in port (Catalina Harbor on
the west side of the isthmus on Santa Catalina Island) I gingerly
checked things out and returned the antenna to the radio which still
worked fine.
If two of us had this happen then it is likely not especially rare
although you are the only other person to volunteer this experience to
my knowledge.
Patrick NJ5G
On 4/20/2015 6:30 AM, David Robbins wrote:
I had to replace the front end protection diodes in a cb once. I started
hearing this tick-tick-tick sound from the radio, the receiver went dead, then
there was a lightning flash a mile or two away. then it started ticking again
until the next flash. I pulled the antenna line off the radio and it was
arcing across inside the pl-259. this was out on a high dry plane out west, I
don't think the storm ever got rain to the ground but it sure made an
impressive lightning show.
Apr 19, 2015 10:15:54 PM, patrick_g@windstream.net wrote:
Bill, in so doing you would be just as wrong as Hans. Re the CB
comment. To my knowledge we never replaced a CB for lighting causes.
Patrick NJ5G
On 4/19/2015 7:33 PM, Bill Aycock wrote:
Hans is right, if a little too gentle. I would have called the tale
"manufactured" on "Invented" rather than "Anecdotal".
Bill--W4BSG
-----Original Message----- From: Hans Hammarquist via TowerTalk
Sent: Sunday, April 19, 2015 2:44 PM
To: towertalk@contesting.com
Subject: [TowerTalk] Fwd: Near Field Lightning Damage
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
To: towertalk
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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