We had a rather bad storm the other day, lightning striking everywhere.
As I left work, it hadn't started in that area yet, but I could see it
off in the distance. I phoned my son to ask if he could disconnect the
long wire antenna from my Yaesu FRG-100, but he said that the area very
near my house already had a couple of bad lightning strikes. I told him
to stay away from the radio.

When I got home, most of the storm had abated, though as I traveled home
I could see massive lightning strikes occurring in areas around me. The
storm was accompanied by tremendous downpours, and flash flooding
warnings were issued.

The National Weather Service (NWS) screwed up on this one, they didn't
even issue the warning until after the storm had wreaked its havoc. Nice
work guys, Helen Keller could have done a better job.

I get home, assess the trees in the yard, everything looks normal.
Problem is that there is no power to the neighborhood, a condition that
remains unchanged for the next 1 ½ hours. No problem, I can use my
handhelds and portable shortwave radios.

My wife arrives home, and as she is walking through the yard, she talks
to the neighbor. The neighbor explains that the "wire antenna" in the
yard was struck by lightning. I go out into the yard to examine the
antenna and find it lying on the ground. I'm convinced that very high
winds somehow pulled the antenna down. I picked it up and examined it,
and lo and behold, some of the insulation is melted off. As I just
installed an arrestor of sorts (it's an old one that I bought on EBay, it
appears unused, a ceramic block with 3 terminals, 2 outer ones for the
antenna wire, and a center one for the grounding wire) about 3 weeks ago,
having had the antenna for a couple of years without it.

The melted insulation extended to the arrestor, and the wire after the
arrestor was normal in appearance. I examined the Yaesu, it appeared
normal, but there was no power in the house yet, so I couldn't tell if
operated ok. Being impatient by nature, I got the correct power cord,
took the radio to the car, opened the car hood, and connected directly to
the battery. The radio powered up, but didn't receive. It looked like it
wanted to receive, when tuning through the frequencies every once in
awhile I could hear a local station pounding through, overloading the
radio, but even with a makeshift antenna I could not receive anything
willfully on shortwave or broadcast AM.

I gave it up as toast, and I called AES in Cleveland, explaining that it
was lightning damaged. They said that I could sent it back, but that they
would in turn send it to Yaesu for a proper assessment. He explained that
Yaesu would try this and that, and probably end up saying that it was
irreparable.

Eventually the power came back on, so I took the radio and began to
experiment with it yet again. When I tried it at the car, I used both
antenna inputs, but I had forgotten to throw the switch on the back to
use the low input impedance connector, so I tried the radio again after
throwing the switch, placing the antenna wire in the Low Z connector,
turned the radio on, and viola, the radio worked. But why doesn't the
High Z terminal work. Since the radio had been exposed to such a large
transient, I decided to disassemble it to make sure that nothing else is
wrong. When I began to remove the screws to open the case, I noticed that
the side was discolored. I didn't remember seeing that before. Oh well, I
continued with my screw removal. When I removed the top of the radio, I
noticed a small point below the discolored area on the inner unpainted
chassis that was about the size of a capital O. With the top off, I could
not really see anything wrong with the radio, but was curious why the
High Z terminals didn't work. I consulted a schematic, and the only
difference between the inputs were the switch and a choke or inductor. I
could see the inductor, it appeared normal.

I decided to remove the circuit board and had to pull about 10 wire
connectors of various sizes from the board. This is a struggle, as there
wasn't always an easy way to start to pull the connector from its socket
by using a screw driver to twist and pop the connector out of its locked
position. I persevered and finally removed all the wires without damage.
I removed the screws securing the board, the antenna connectors, and the
power connector. Viola, I removed the board.

Surprise, a large blacked area was found just under the High Z antenna
terminal connection to the circuit board. Mostly soot, but some minor
damage to the chassis metal was observed as well. I examined the bottom
of the board and found that a ¼ trace that carries the High Z antenna
signal to the inductor was neatly vaporized. The board was in excellent
condition. The area that the trace occupied was unblemished, just the
trace itself was gone. I cleaned the inside of the radio and the circuit
board, soldered a wire to replace the trace, and reassembled the radio.
Viola, the High Z terminal worked.

The voltage path and its destruction seems to be as follows. The
lightning strike was largely shunted to ground by the arrestor, but a
surge continued on into the radio. Entering the radio, it jumped to the
chassis just under the connector, the surge exited the radio on the side
near the front panel close to the headphone jack. It jumped to my metal
cased DVD player that was so close to the radio that it just about
touched it, ruining that, somehow killed the clock radio that sat atop
the DVD player, altered the TV nearby, which still works by no longer
works by remote control. The surge entered the power system, and on
another floor of the house, killed my cable modem, my wireless router,
tripped the circuit breaker that fed the modem and router, blew 2 light
bulbs in the house, and tripped 2 GFI receptacles.

Questions:

1. The router and cable modem were on a different circuit from the power
for the radio and DVD player. The Radio, the DVD player, and the clock
radio were plugged into a spike suppressor strip. My house itself has
whole house spike suppression at the power meter. I took the spike
suppression strip apart to examine for damage, none was visible. If the
surge entered the power system, making it to the lighting panel, why
wasn't it shunted to ground by the power strip and the whole house
suppression which was only about 3 feet from the panel?

2. Could it have been electromagnetic forces that destroyed the cable
modem and router?

3. My equipment was not grounded or bonded. Surprisingly, the items that
were destroyed near my Yaesu were items that had internal power supplies,
so that a direct connection to the neutral was available. The items that
were powered by transformers, including the Yaesu itself, were
unaffected. I have a Uniden metal case scanner atop my Yaesu that was
plugged in, and off with a mechanical switch (part of the volume
control), this radio was unaffected. I also have a speaker system for my
DVD and TV in the bedroom, this was also off by a mechanical switch and
is transformer fed, this was also unaffected. Though the Cable Modem and
Router, as described above, were always on, so is a great deal of other
equipment in the house, including my main TV, DVD Player, AV Receiver,
and so on. Why the preference for some equipment and not the other?

4. Lastly, how can I have an outdoor antenna and survive a strike without
damaging equipment? I know that I should disconnect the wire when before
a storm, which I always do, but this day was not supposed to have storms,
and I couldn't get to the radio in time. Was the wire more likely to be
struck since it had been grounded? Unfortunately, the strike came down my
tree in the backyard, obliterating a limb at the top, (a very tall tree),
and traveling down the outside, casting off bark as it traveled. The line
in the bark comes right to the end of my wire antenna and no lower. Could
a "leader" have been initiated by the antenna grounding system that
actually led to the strike? The antenna itself was several feet from the
tree, tied to the tree trunk with a rubber tube. If the wire had
previously been removed from the radio and simply tossed onto the floor,
what may have happened with the surge?

Thanks for your comments, and be safe when lightning becomes an issue.

Dr. Artaud

You might as well give up trying to figure out lightning's
unpredictable ability to damage things. I had a direct hit on my
longwire years ago and the antenna was indirectly grounded to the ham
transceiver chassis. It still took out the output RF amp but did not
damage the receiver at all. The antenna was totally vaporized and what
was left of the ceramic insulators had the most beautiful copper
plating around the holes! The same strike opened up a buried AC cable
that controlled the yard lighting. That never did work correctly again
and I was too lazy to dig it up for repair. I'm glad your FRG was not
damaged any more than it was. I worked in high voltage physics years
ago and it was facinating.

Frank
Tucson

Dr Artaud wrote about his recent lightning strike, sorry for your damage
there Dr. I too, took a lightning strike a couple of years ago.
Thankfully, because I took some precautions, my radio gear didn't get
any damage but I can't say the same for the televisions, the cable
modems, phones, etc.

Questions:

1. The router and cable modem were on a different circuit from the power
for the radio and DVD player. The Radio, the DVD player, and the clock
radio were plugged into a spike suppressor strip. My house itself has
whole house spike suppression at the power meter. I took the spike
suppression strip apart to examine for damage, none was visible. If the
surge entered the power system, making it to the lighting panel, why
wasn't it shunted to ground by the power strip and the whole house
suppression which was only about 3 feet from the panel?

It may not have entered that way. Nearby strikes can induce a current
into the power lines running through the house. At a distant point from
the lighting panel the induced voltage could have started. As it courses
its way through the house wiring looking for a ground point it will work
through your appliances, etc. until it finds ground. Meanwhile, it may
never make it back to the panel.

2. Could it have been electromagnetic forces that destroyed the cable
modem and router?

Absolutely. Every cable wire, every phone wire, printer cable, etc acts
just like an antenna...picks up a voltage and carries it to the device.
That nearby strike packs plenty of power to place a huge voltage on a
wire. Most of these devices are low voltage and sucuumb to transients
easily.

3. My equipment was not grounded or bonded. Surprisingly, the items that
were destroyed near my Yaesu were items that had internal power supplies,
so that a direct connection to the neutral was available. The items that
were powered by transformers, including the Yaesu itself, were
unaffected. I have a Uniden metal case scanner atop my Yaesu that was
plugged in, and off with a mechanical switch (part of the volume
control), this radio was unaffected. I also have a speaker system for my
DVD and TV in the bedroom, this was also off by a mechanical switch and
is transformer fed, this was also unaffected. Though the Cable Modem and
Router, as described above, were always on, so is a great deal of other
equipment in the house, including my main TV, DVD Player, AV Receiver,
and so on. Why the preference for some equipment and not the other?

Precisely what I had happen at my strike. The televisions were
unplugged, but I neglected to unplug the cable tv channel boxes and when
the strike entered via the cable it was all that was necessary to
destroy 2 TV's, and 3 cable tv boxes, as well as the cable modem boxes.
Oddly, the computers survived although one modem on a laptop could no
longer be used. I plugged in a modem card and was able to work around
that damage. Sometimes there's no rhyme or reason as to why some pieces
of equipment survive while others don't.

4. Lastly, how can I have an outdoor antenna and survive a strike without
damaging equipment? I know that I should disconnect the wire when before
a storm, which I always do, but this day was not supposed to have storms,
and I couldn't get to the radio in time. Was the wire more likely to be
struck since it had been grounded? Unfortunately, the strike came down my
tree in the backyard, obliterating a limb at the top, (a very tall tree),
and traveling down the outside, casting off bark as it traveled. The line
in the bark comes right to the end of my wire antenna and no lower. Could
a "leader" have been initiated by the antenna grounding system that
actually led to the strike? The antenna itself was several feet from the
tree, tied to the tree trunk with a rubber tube. If the wire had
previously been removed from the radio and simply tossed onto the floor,
what may have happened with the surge?

You need a SINGLE POINT GROUND SYSTEM, I'm not shouting there..just for
emphasis. One and only one common ground system to which all equipment,
and the entrance panel ground share. This way, if a voltage makes it
onto your system, all points rise and fall at the same potential. It is
a potential difference between points that allows current to flow. If
all points rise and fall the same...no current flow, no damage
supposedly. After my strike (which was strong enough to blow ceramic
tiles to dust, and blow a 2 inch deep by 2 inch wide by 6 foot canyon in
my concrete housepad under those tiles!) I contacted PolyPhaser and
several other lightning companies, was invited to a 3 day lightning
damage symposium by Florida Power to learn more and see the various
company displays. I learned a lot. The results of which I have put up on
a web site showing what I did to install more safeguards to my system.
It is at http://www.knology.net/~res0958z/

I'm a bit to excess on this subject, once you've been hit you realize
the vulnerabilities. And with a 65 foot tower out back, a mere 15 feet
from the house, a bit more sensitive to the possibilities. Good luck
with upgrading your system.

Bill
KC9CS


Thanks for your comments, and be safe when lightning becomes an issue.

Dr. Artaud

On Sat, 02 Jul 2005 09:08:36 -0500, "Dr. Artaud"
wrote:



The National Weather Service (NWS) screwed up on this one, they didn't
even issue the warning until after the storm had wreaked its havoc. Nice
work guys, Helen Keller could have done a better job.


http://www.davisnet.com/productpics/big/7400dsk.jpg

Surge suppressors that use the AC wall outlet for ground are essentially
useless against nearby lightning strikes since the distance and relatively
small diameter wire conductor (16/18ga) to the main power panel earth ground
rod looks like infinite resistance to a large current surge. Relatively
smaller spikes on the AC line caused by appliance motors etc... can be
shunted, but not a huge current induced by a nearby lightning strike.

There is much good technical information at Polyphasor's web site which will
keep you busy with your research for some time.

"Dr. Artaud" wrote in message
. 97.142...
We had a rather bad storm the other day, lightning striking everywhere.
As I left work, it hadn't started in that area yet, but I could see it
off in the distance. I phoned my son to ask if he could disconnect the
long wire antenna from my Yaesu FRG-100, but he said that the area very
near my house already had a couple of bad lightning strikes. I told him
to stay away from the radio.

When I got home, most of the storm had abated, though as I traveled home
I could see massive lightning strikes occurring in areas around me. The
storm was accompanied by tremendous downpours, and flash flooding
warnings were issued.

The National Weather Service (NWS) screwed up on this one, they didn't
even issue the warning until after the storm had wreaked its havoc. Nice
work guys, Helen Keller could have done a better job.

I get home, assess the trees in the yard, everything looks normal.
Problem is that there is no power to the neighborhood, a condition that
remains unchanged for the next 1 ½ hours. No problem, I can use my
handhelds and portable shortwave radios.

My wife arrives home, and as she is walking through the yard, she talks
to the neighbor. The neighbor explains that the "wire antenna" in the
yard was struck by lightning. I go out into the yard to examine the
antenna and find it lying on the ground. I'm convinced that very high
winds somehow pulled the antenna down. I picked it up and examined it,
and lo and behold, some of the insulation is melted off. As I just
installed an arrestor of sorts (it's an old one that I bought on EBay, it
appears unused, a ceramic block with 3 terminals, 2 outer ones for the
antenna wire, and a center one for the grounding wire) about 3 weeks ago,
having had the antenna for a couple of years without it.

The melted insulation extended to the arrestor, and the wire after the
arrestor was normal in appearance. I examined the Yaesu, it appeared
normal, but there was no power in the house yet, so I couldn't tell if
operated ok. Being impatient by nature, I got the correct power cord,
took the radio to the car, opened the car hood, and connected directly to
the battery. The radio powered up, but didn't receive. It looked like it
wanted to receive, when tuning through the frequencies every once in
awhile I could hear a local station pounding through, overloading the
radio, but even with a makeshift antenna I could not receive anything
willfully on shortwave or broadcast AM.

I gave it up as toast, and I called AES in Cleveland, explaining that it
was lightning damaged. They said that I could sent it back, but that they
would in turn send it to Yaesu for a proper assessment. He explained that
Yaesu would try this and that, and probably end up saying that it was
irreparable.

Eventually the power came back on, so I took the radio and began to
experiment with it yet again. When I tried it at the car, I used both
antenna inputs, but I had forgotten to throw the switch on the back to
use the low input impedance connector, so I tried the radio again after
throwing the switch, placing the antenna wire in the Low Z connector,
turned the radio on, and viola, the radio worked. But why doesn't the
High Z terminal work. Since the radio had been exposed to such a large
transient, I decided to disassemble it to make sure that nothing else is
wrong. When I began to remove the screws to open the case, I noticed that
the side was discolored. I didn't remember seeing that before. Oh well, I
continued with my screw removal. When I removed the top of the radio, I
noticed a small point below the discolored area on the inner unpainted
chassis that was about the size of a capital O. With the top off, I could
not really see anything wrong with the radio, but was curious why the
High Z terminals didn't work. I consulted a schematic, and the only
difference between the inputs were the switch and a choke or inductor. I
could see the inductor, it appeared normal.

I decided to remove the circuit board and had to pull about 10 wire
connectors of various sizes from the board. This is a struggle, as there
wasn't always an easy way to start to pull the connector from its socket
by using a screw driver to twist and pop the connector out of its locked
position. I persevered and finally removed all the wires without damage.
I removed the screws securing the board, the antenna connectors, and the
power connector. Viola, I removed the board.

Surprise, a large blacked area was found just under the High Z antenna
terminal connection to the circuit board. Mostly soot, but some minor
damage to the chassis metal was observed as well. I examined the bottom
of the board and found that a ¼ trace that carries the High Z antenna
signal to the inductor was neatly vaporized. The board was in excellent
condition. The area that the trace occupied was unblemished, just the
trace itself was gone. I cleaned the inside of the radio and the circuit
board, soldered a wire to replace the trace, and reassembled the radio.
Viola, the High Z terminal worked.

The voltage path and its destruction seems to be as follows. The
lightning strike was largely shunted to ground by the arrestor, but a
surge continued on into the radio. Entering the radio, it jumped to the
chassis just under the connector, the surge exited the radio on the side
near the front panel close to the headphone jack. It jumped to my metal
cased DVD player that was so close to the radio that it just about
touched it, ruining that, somehow killed the clock radio that sat atop
the DVD player, altered the TV nearby, which still works by no longer
works by remote control. The surge entered the power system, and on
another floor of the house, killed my cable modem, my wireless router,
tripped the circuit breaker that fed the modem and router, blew 2 light
bulbs in the house, and tripped 2 GFI receptacles.

Questions:

1. The router and cable modem were on a different circuit from the power
for the radio and DVD player. The Radio, the DVD player, and the clock
radio were plugged into a spike suppressor strip. My house itself has
whole house spike suppression at the power meter. I took the spike
suppression strip apart to examine for damage, none was visible. If the
surge entered the power system, making it to the lighting panel, why
wasn't it shunted to ground by the power strip and the whole house
suppression which was only about 3 feet from the panel?

2. Could it have been electromagnetic forces that destroyed the cable
modem and router?

3. My equipment was not grounded or bonded. Surprisingly, the items that
were destroyed near my Yaesu were items that had internal power supplies,
so that a direct connection to the neutral was available. The items that
were powered by transformers, including the Yaesu itself, were
unaffected. I have a Uniden metal case scanner atop my Yaesu that was
plugged in, and off with a mechanical switch (part of the volume
control), this radio was unaffected. I also have a speaker system for my
DVD and TV in the bedroom, this was also off by a mechanical switch and
is transformer fed, this was also unaffected. Though the Cable Modem and
Router, as described above, were always on, so is a great deal of other
equipment in the house, including my main TV, DVD Player, AV Receiver,
and so on. Why the preference for some equipment and not the other?

4. Lastly, how can I have an outdoor antenna and survive a strike without
damaging equipment? I know that I should disconnect the wire when before
a storm, which I always do, but this day was not supposed to have storms,
and I couldn't get to the radio in time. Was the wire more likely to be
struck since it had been grounded? Unfortunately, the strike came down my
tree in the backyard, obliterating a limb at the top, (a very tall tree),
and traveling down the outside, casting off bark as it traveled. The line
in the bark comes right to the end of my wire antenna and no lower. Could
a "leader" have been initiated by the antenna grounding system that
actually led to the strike? The antenna itself was several feet from the
tree, tied to the tree trunk with a rubber tube. If the wire had
previously been removed from the radio and simply tossed onto the floor,
what may have happened with the surge?

Thanks for your comments, and be safe when lightning becomes an issue.

Dr. Artaud

smoke wrote:
Surge suppressors that use the AC wall outlet for ground are essentially
useless against nearby lightning strikes since the distance and relatively
small diameter wire conductor (16/18ga) to the main power panel earth ground
rod looks like infinite resistance to a large current surge. Relatively
smaller spikes on the AC line caused by appliance motors etc... can be
shunted, but not a huge current induced by a nearby lightning strike.

There is much good technical information at Polyphasor's web site which will
keep you busy with your research for some time.


"Polyphasor"

You might want to spell their name correctly when recommending them.

It is: http://www.polyphaser.com/kommerce_products.aspx

Good products, we use them exclusively where I work, and their products
work superbly. We get a lot of lightning strikes in the Gulf of Mexico
area. They have saved us and the taxpayers many hundred's of thousands
of dollars.

Les Locklear
Monitoring since ' 57
Located on the Gulf of Mexico
http://www.hammarlund.info/homepage.html

smoke wrote:

Surge suppressors that use the AC wall outlet for ground are
essentially
useless against nearby lightning strikes since the distance and
relatively
small diameter wire conductor (16/18ga) to the main power panel earth
ground
rod looks like infinite resistance to a large current surge.
Relatively
smaller spikes on the AC line caused by appliance motors etc... can be
shunted, but not a huge current induced by a nearby lightning strike.

There is much good technical information at Polyphasor's web site which
will
keep you busy with your research for some time.
----------------------

They can and do offer protection to the devices pluged into that
outlet, if said device doens't have any other connection. By clamping
the differential volatage they can really help. Not a cure all, but one
more tool.

Terry

A station my father and I shared came to an end by lightning strike,
when I was no longer interested enough to repair it, just from a nearby
strike, using a tri-bander beam with no particular ground path, just from
general reception of fields, and it was enough to blow out a collins 75a4
and a kw linear final at the end of about 100' of coax, almost all of it
indoors through conduits. That is to say, the antenna was not hit, but
just the rf load was enough to damage things.

I had outgrown ham radio, or whatever happens when you're 17, and moved
on to other things; and my father was more of a swl than a ham at
heart. He just bought another receiver and used its whip antenna.

Well it was interesting at age 12 for a few years anyway. Lightning may
be nature's way of telling you it's time for another hobby.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

Hello Dr Artaud,

You are very lucky. The damage could have been far worse. Your house
could have burned down!

As you have found out, the National Weather Service, while far better
than in the past, is not as reliable as we should like.

I personally have my shortwave antenna mounted in my attic so I am
somewhat protected from a lightning strike to the antenna itself, but I
ALWAYS make it a point to UNPLUG from the AC every piece of electronic
equipment I own when I am not actually using it.

It would be wise for you to do the same and, in your case, to
disconnect your antenna(s). I know it's a pain, especially with
computer routers, cable TV connections, etc., but, as you've found out,
surge protectors do not afford 100% protection. I have whole-house
surge protection as well as individual surge protectors - sometimes
more than one - protecting my electronic components, but there is no
substitute for unplugging.

Many years ago my parents lost three televisions to a nearby (50 feet)
lightning bolt; none of those TV's were operating at the time, just
plugged in.

Since then I have been almost "religious" in my care of my equipment,
not so much for the equipment itself, but for the possibility of a fire
as a result of a lightning strike entering my house and damaging
electronic components.

I must mention that there is absolutely no protection against a "bolt
from the blue." (In other words, a lightning bolt while you are
actually using your radio, computer, etc., when there was absolutely no
warning.) You just have to have luck in that case.

I NEVER use any electronic equipment when there is any weather threat
whatsoever (determined by looking out the window - not depending in the
NWS). Generally a thunderstorm lasts no more than a half-hour or so.
During the storm I don't even use battery-powered radios; their
circuits (especially the front end) can be damaged by a nearby
lightning strike.

But I hope you'll consider my "mantra:" UNPLUG, UNPLUG, UNPLUG!

Best,

Joe

- You'll drive yourself batty trying to figure out why lightning does
what it does.

- Might there have been *two* strikes? The one that hit your antenna &
damaged the Hi-Z input, and *another* one that hit the power lines &
damaged the other equipment?

- Even if there was only one, that strike on the antenna would have
induced some pretty high voltages on the AC line, which could have
caused the damage to the other gear.

- Around here you can pretty much assume there will be at least one
thunderstorm within 100 miles of Nashville on any given summer day.
From about early April through about late September, I leave my
antennas disconnected when not in use.
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com