Lightning

[K3UD]

Well, after almost 40 years it finally happend to me.

I was in my daughter's room talking to her about the lightning bugs she had caught that night. It was somewhat stormy with occassional flashes of lightning and the booms of thunder.

We were ready for the final tuck into bed when all of a sudden there was a tremendous flash and immediate boom. It sounded as though an artillary shell had struck the house. She started to scream "it hit the house...it hit the house" and I also thought so.

When it happened, the power never blinked. Went outside to see if anything was burning and what damage there might be. Nothing burning, no visible damage, getting dark, will look in the morning.

I really did not give the shack an immediate thought because everything was disconnected from the antennas as usual when storms are in the area, before we go to bed, or if we are away from the house. However, the Astron 35M supply was plugged in and power cables were connected to 2 HF radios. The station ground was also connected. My 2 meter FM transceiver was completly disconnected from anything and sitting on the top shelf of the wooden station console.

After my daughter finally got to sleep I went into the shack to check for possible damage. Flipped on the Astron, it came up with the usual thunk and attempted to power up the Yaesu FT-100. Nothing... looked at the meters on the supply.. no voltage.

Disconnected the supply, burned component smells now evident, Hooked up standby supply, connected to the Icom 737A.
Had voltage, 737 does not power up.

Took 737 out of the console, noticed bits of plastic and wire behind the radios. Found that the fuse holders and fuses disintegrated into little pieces. Yaesu had same damage.

Evidence of scorching on the 737 at ground connection, also the noticed scortching on the wall. Bad smell coming out of both transceivers, both history. Back side of antenna tuner blackend at the ground point. Check the ground bus, #10 wire melted and seperated in several areas.

Well at least I have my 2 meter transceiver since it was not connected to anything at all. Wrong! apparantly something had arced to it or maybe the EMP from the lightning did it in.

Inspected tower this morning figuring I would see evidence of the strike revealed nothing. every leg of the tower is grounded to an 8 Ft ground rod at each leg, there are 4 more 8 Ft rods tied together with the tower as well as a radial system tied to them, plus the station ground. No signs of damage to anything outside.

Got up this morning and turned on the TV in the bedroom 60 feet from the shack and on the other side of the house. Picture has the rainbow effect that happens when you put a magnet too close the the set. Same thing on the sewing room across the hall. No effect on the closest TV to the shack.

While I first thought that the tower took a direct hit, I am not now not so sure. I think that the strike was close to the far side of the house which would explain the effect on the TV sets and somehow tried to find its way to ground following the heating and colling ducts under the house. It found my ground system and tried to get out.

Other than my rotor which still works an old Radio Shack 2 meter handi, I am off the air for a while. Homeowners insurance good for replacement cost with $500 deductable. Bad, but better than not having a house for a while.

73
George
K3UD

[KB9YCO]

Sorry to hear that George, there have been some nasty storms this spring, some of the nastiest I've seen in a long time. In northeastern Illinois we've had everything this year as well; intense rain and thunderstorms with hail, tornadoes, flooding, heavy winds, you name it and we've had it this year too. I haven't heard of any major damage like you report here but I do know that many amateurs have had some serious repairs to do lately. Hope you get back on the air and glad there wasn't a fire or damage to your house, good luck & 73.

[K3UD]

Thanks for the thoughts Brett.

This is one of those things that you think may happen to someone else but not to you. Time to re-evaluate my grounding options when I replace everything.

73
George
K3UD

[WA5KRP]

BUMMER. #My buddy KD5OZM was zapped via ground in 2002. #Lightning struck a tree in his front yard, jumped to the water service buried below the tree's roots, and traveled into his home. #There it jumped into his electrical system and wiped out his appliances. #Black sooty marks were left around all wall switches and outlets. #It also went from the cold water pipe below his kitchen sink to a vent pipe (stink pipe), arcing over to his vertical HF antenna 20 feet away, exploding a balun and entering his shack. #Still don't know what did in his station - the surge from the electrical service or from his antenna. #

Bottom line: #lightning can get you from the ground.

Hope you're back on the air prontito.


WA5KRP
Texas

[n3mvf]

George,

Several years ago, I had a lightning hit near the house but not the house. Also, I didn't have any radio's plugged in and didn't have a tower at the time. #However, just about everything else plugged in didn't work after the strike. #TV, telephones, microwave etc had to repaired or replaced. #The strike was a tree across the street in the neighbors back yard. At that house, the utilities were underground as well.

To this day, I'm still amazed.

73 and good luck getting back on the air,
Greg

[KF4ZHL]

Sorry to hear this. That's a lot of equipment down the drain. High voltage is a strange and dangerous creature. You can read stories of arcs coming out of the walls to strike people. Electrical equipment that wasn't hooked to anything getting fried from induced currents. I was in a tent that got hit by lightning once while in the military. The light set bulbs exploded and the gas generator fried. Direct line comm equipment attached to us was destroyed. Everyone in the tent wearing anything metal (rings, dog tags, etc.) had a first degree burn for it in the exact shape of the worn item.

[ky5u]

Sorry George. Keep us posted on your attempts to get back on the air. Know many amateurs who disconnect their ground system, antennas, and power connections in a storm.

Ayway, sorry and hope you're back up soon.

[K9STH]

Sounds more like the AC line to the house was hit (pretty common experience!).

The only strike that I have had in over 32 years at this house is when the "pole pig" (power company transformer) at the back corner of my lot was hit (my towers have never taken a strike). The strike was carried into my house on the neutral to the breaker box (which is about 3 feet from my shack). It then divided with part going to the grounding system of my shack and the other part proceeded down the "3rd wire" of my house wiring.

The only damage that it did to the house proper was that the charge travelled along the 3rd wire to the refrigerator compressor. It then "jumped" to the copper tubing that ran the water to the ice maker and burned a "pin hole" in the tubing. This I didn't discover until the next day when I noticed a puddle of water under the refrigerator.

In the breaker box the "main" disconnect breaker for the house was blown completely to pieces! As for damage in the shack: Fortunately, I don't use many solid-state radios. The damage was confined to a number of AC plugs, blown fuses, a couple of "wall worts" blown to bits, a couple of off-on switches welded in place (nothing was "on" at the time - this happened in the middle of the night) and my 24 hour clock was permanently "altered"!

Due to the extreme efforts that I use in my ground system, there was no damage at all to it.

Frankly, I do not disconnect any antenna feedlines when storms come. However, I do have enough dissipation that prevents the "feelers" from starting on my main tower and short tower and thus I don't take strikes. Of course, nothing can prevent a strike under the "right" conditions. But, you can most certainly reduce those chances by a great amount.

Glen, K9STH

Jerry, very sorry to hear that those wayward electrons rampaged through your gear as well as the other stuff about the house! Been there, had that done to me, and empathize with you indeed, my friend!
================
FOR THOSE WHO CARE TO CHECK OUT THINGS.

The PolyPhaser Corporation has an EXCELLENT book called 'The Case For Grounding' (or words to that effect)

It may cost a few bucks.. but trust me.. It's like the ARRL HANDBOOK for grounding and protection information. WORTH THE COST! PolyPhaser has a website and the info is on there.
=====================

As for the zorched hardware...

It's that 'OH NO!.' "sinking pit of the stomach feeling" you get when you power up the gear and don't see anything and then you begin the process of isolation with that mounting sense of dread at what you'll find.

As one previous poster noted.. induced voltages from a ground-conducted lightning hit can produce some VERY weird effects and cause those wayward electrons to go places you would NEVER think they'd go.

I get involved, at work, with a couple of high voltage (80-180,000 volts AC/DC) test chambers where they do corona testing, breakdown voltage testing, and dielectric tests.

It wasn't till then that I TRULY learned about the multitude of ways those electrons can wander and places you don't want them to go.

Even with the protections they have in place to direct those electrons.. they STILL have 'unexplained' arcs and sparks via paths that you'd never think of. They have a low light level camera they use to document tests and they video tape these tests. When there is an arc or a corona, they play the tape back to analyze where it happened and why.

I have seen tape of an arc where the 85,000 DC voltage went from the electrode ball, to the cinder block wall (6 feet away), went DOWN the cinderblock wall by following the cement joints. It went to about 1 foot from the floor and jumped horizontally about 6 inches to a 90 degree angle bend painted cabinet edge. It flowed along about 3 feet of edge and at the corner bend, jumped over about 6 inches or so to the base of the safety cage which was made of painted, rounded edged, chain link mesh, and then up the mesh for about 6 inches then it jumped another 6 or 8 inches to the ground lead for the DC voltage return.

A total travel distance of about 18 linear feet. Scorch marks were found where the voltage jumped from/to each point as well as bubbled paint where the temperature of the metal cabinet edge was raised. We also found burn marks along the mesh where the voltage jumped from link to link.

The non-contact damage was a shielded meter in the test cabinet area where the induced voltages in the test cabinet assembly caused the meter movement to peg and shorted some of the meter turns and bent the meter needle.

All in all, VERY educational.

Jerry, my condolences, my friend and thankful I am no one was injured.

73
K3FT

[W5HTW]

Been there, done that, also. Though not with as much damage to the radios. One hit cost me three telephones (electronic kind, with amplified handsets for hard of hearing) a TV, a VCR, the garage door opener, mercury vapor yard lights (2 of them.) Another hit cost me no equipment at all, but opened the neutral to the house. The result was when I went outdoors to see what damage might have been done, and started back in, the metal doorknob bit me, only a tingle. I got out the meter and found there was 120 VAC on the doorknob. Yikes! With a dab more rain the resistance would have been lower and I would have been fried. Following morning i repaired the neutral break in the outside box.

Another hit took out a TV, a telephone, and a stereo FM receiver. The TV was junk, but the receiver just had the input coil blown, so it was repairable. Again, the phone was junk.

Static got my Icom 706, right after I bought it, but when I talked to Icom they agreed to fix it under warranty! So I shipped it away and got it back in a few weeks, good as new and only for shipping costs. That, though, was not a lightning hit.

Have lost probably five modems to hits on the phone line. New Mexico is the second hottest lightning area in the nation, behind Florida, so I have learned a lot. Each night, even on calm clear nights, I disconnect antennas and unplug the phone line to the computer. Too many calm, clear nights I have been awakened by a single flash and a crash of thunder.

Hope your insurance fixes you up and quickly. Good luck to you. Some insurance companies balk when they learn there are lightning-attracting devices such as towers and wires strung up in the sky!

My 'station ground' is a direct ground, using one-inch steel braid to two 8 foot copper rods, but my soil is desert, sandy, and not a good ground at all. I also linked a piece of that steel braid to the metal frame of my mobile home, and that is linked to neutral in the power line. It's the best I can do, due to soil and weather conditions. Oh, and I use mostly boat anchors, which can tolerate a lot more pulse input than the solid state 706.

Gosh, our dry thunderstorm season is just about to begin! Guess I need to get myself prepared again.

73
Ed

[W8MW]

George, sorry to hear about that ugly experience. #Is your station ground bonded to the house electrical ground? #Just curious about that.

73, Mike

[KC5SAS]

A couple of years ago I had a strike hit nearby and fried a TV, a VCR which was plugged to a separate TV in a completely different room. I also lost 2 Radio Shack desk top scanners and my computer in my shack.
Since we've had several posts from those of us who have lost equiptment to lightening strikes I have a question for the Group:

Has anyone here who has lost equiptment had it insured through the ARRL at the time and if so were you able to get enough money from the insurance to adequately rebuild your station?

Steve

[WA5KRP]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (AG4YO @ June 16 2004)</td></tr><tr><td id="QUOTE">Know many amateurs who disconnect their ground system, antennas, and power connections in a storm.[/QUOTE]<span id='postcolor'>
That's EXACTLY what I do........the whole process takes all of three minutes. #I want my equipment to have the same status as my household furniture or a shovel in the garage. #There's an awful lot of amateurs out there like George who have had lightning strike from the ground. #Sounds rediculous, but how can you argue with real life experiences?



WA5KRP
Disconnected, Texas

[K3STX]

George, Sorry to hear it. Here in Potomac we had them too, they were nasty. I have never even talked to me Insurnace Company about Ham radio, I am afraid if I bring it up they might say that my antenna is a lightning rod and deny my coverage. Maybe I should actually have a talk with them, now that I have some real money invested in this.

paul

[KC8QMU]

Sorry to hear about that, George. Just remember, radio equipment can eventually be replaced, some other things can't.

But still, it's a bummer. http://www.qrz.com/iB_html/non-cgi/emoticons/sad.gif

[K9STH]

STX:

Until recently, when the State of Texas decided that antennas and towers were covered under your normal homeowners policy, I had a separate &quot;rider&quot; for my antennas that provided 100 percent loss coverage (at current replacement cost, not &quot;pro-rated&quot;, etc.). It cost about $30 per year for each $1000 worth of coverage.

I collected 3 times from wind and/or hail damage over 30 years. Never have had a lightning strike on the tower so haven't had to claim that! The insurance company did pay on the lightning strike that came in through the AC power lines.

Glen, K9STH

[w5alt]

George, you have my condolences and I hope you get things repaired and back on the air soon.

About 7 or 8 years ago I apparently took a hit that came in through the phone line in the office where I had my ham shack at the time. The first I noticed was the cordless phone and fax machine were dead, then I noticed the modem on my computer didn't work, either.

But the PC was hooked to a TNC, powered from an Astron supply, and interfaced to the mic input on my IC-735. The TNC was dead, the Astron supply was dead. The audio input and VOX on the IC-735 was dead. When I finally got around to opening the 735, a couple of plastic cased transistors in the audio and VOX section had exploded. Fortunately the rest of the rig was fine and it was fairly easy to fix.

The only antenna hooked up at the time was an indoor whip. I guess I'm glad that I wasn't in the office at the time it happened!

As far as insurance, my homeowners insurance covers my radio and computer gear. I don't remember how much extra it costs, but it isn't very much. When I was buglarized, the insurance paid for a 2m rig and power supply that was stolen along with some computer equipment. Of course I needed the computers for my business, so the $$ came out of my pocket first. Clients don't really want to hear excuses about how you had problems finishing their projects on schedule and budget!

73,

[W9JI]

Dont forget when claiming insurance you should remember to replace the 737 that is not made any longer you need to quote a similar HF rig for replacement value. I think, and others should agree? the closest replacement for the 737 would be the Icom IC-7800 (http://www.texastowers.com/ic7800.htm) . Which when you consider that you are paying a $500.00 deductable your getting a fairly good deal http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

But sadly enough that only replaces one of your HF rigs http://www.qrz.com/iB_html/non-cgi/emoticons/sad.gif

Since you lost the FT100 and that model is not currently in production ,,,I think it is being replaced by the

Yaesu FTDX-9000 (http://www.yaesu.com/indexVS.cfm?cmd=DisplayProducts&ProdCatID=102&encProdID=LGAPdoibciM%3D&DivisionID=65&isArchived=0)

I would assume your 2 meter was a dual bander? then its current replacement is Icom IC-910H (http://www.icomamerica.com/amateur/satellite/default.asp)

I hope these links have helped you with your replacements http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

[WA5KRP]

http://www.computerpannen.com/cwm/contrib/blackeye/lol.gif #I want that muther to be my LAWYER!!!!



WA5KRP http://mindscraps.com/s/contrib/geno/rofl.gif
Bushwack, Texas

[XV2PS]

Sorry for you George. At least, this will make the people aware. We (at least me) often rely on the lucky draw not to think of the potential problem. http://www.qrz.com/iB_html/non-cgi/emoticons/confused.gif

[k4uug]

sorry to read of your loss I hope you had the ARRL insurance.I had some gear stolen a few years back and it paid to replace everything.In fact they got me a discount on the replacement. http://www.qrz.com/iB_html/non-cgi/emoticons/sad.gif

[k9kjm]

Sorry to hear of your damage to equipment. I agree with
K9STH. Most damage usually comes thru the AC power lines. (Which should also have an arrestor installed in the breaker box) And all grounds bonded together..... #
There was a series of three articles in QST a while back that gave really good info. Also read the tech notes #at the Poylyphaser website:
http://www.polyphaser.com/ppc_pen_home.asp
It takes a lot more than just a few ground rods connected with thin wire to make up a good ground system. But it does not have to cost an arm and a leg.
Used heavy gauge copper wire and strap make as good a ground conductor as brand new. You can do real silver solder with MAPP gas in a small hand held torch that is almost as good as a professional Cadweld joint. etc.
Homemade enhanced grounds can be made with copper tube drilled and filled with rock salt, etc.

[WA5KRP]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (k9kjm @ June 17 2004,00:34)</td></tr><tr><td id="QUOTE">You can do real silver solder with MAPP gas in a small hand held torch that is almost as good as a professional Cadweld joint. etc.[/QUOTE]<span id='postcolor'>
I've always wondered if MAPP gas has any advantage over a propane torch. I've never used MAPP. Any thoughts?


WA5KRP
Texas

[w5klb]

I have had a simular exeriance and it wasn't pretty for me either.

I had erected a ground plain on a push-up pole around 40 ft high and had guyed it down next to my home. I had around 50 feet of coax coiled up and just laying on the gound not attached to any radio equipment. Of course I grounded my antenna with a 8 ft piece of grounding rod. A storm blew up and lightning struck a tree a block and half away from home. This tree was about 10 feet or so away from a power line. It got the circuit breaker going to the dryer, my telephone, TV and the VCR. But the stangest thing was that it got the coil in the the ground plane. I am thankful that it wasn't hooked up to any radios.

I suspect that the surge of the lightning strike of the near by tree traveled down the wires. But no one else in my neighborhood had any problems-just my home.

It gets expensive to replace all the damaged home electronics, but I did it. A couple of weeks later I was talking with someone from the local electric company and they said that they would have replaced all damaged electronic and electric componets from that storm. NOW they tell me, after the fact. #http://www.qrz.com/iB_html/non-cgi/emoticons/confused.gif

K3UD,

I know how you must feel. I, too, have the &quot;Been there, done that&quot; t-shirt.

I hope you can get EVERYTHING replaced and be back on the air real soon. I know what a pain this can be.

[K8ERV]

I had an odd thing lately (no snide remarks). Usually storms approach. I had a no-warning very close-by strike. REALLY LOUD!! Don't know where it hit, no visible damage. But no warning.

I have a very big GE mov suppressor in my breaker box, and about 6 smaller movs sprinkled around the house. The bolt did not cause any damage. Lucky, I guess.

TOM K8ERV

ERV brings up a GREAT thing to consider.


Have a SUITABLY SIZED MOV (or similiar suppressor) installed at the MAIN BREAKER BOX where the commercial mains lines enter the house. Also consider doing the same for Telco lines.

It may costa few bux.. but as ERV noted.. and pros like PolyPhaser will recommend.

SOURCE protection is the FIRST and BEST way to keep those angry electrons from getting INTO your home inthe first place.

Again.

Suppressor at the MAIN power line box ..
Suppressor on the Telco/cable TV lines..
Suppressor on any other lines that enter the house.

GOOD GROUNDS!

73
K3FT

[K8ERV]

I just may have been the first person to put a MOV across a phone line, WAY BACK.

TOM K8ERV

[W0UZR]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Well at least I have my 2 meter transceiver since it was not connected to anything at all. Wrong! apparantly something had arced to it or maybe the EMP from the lightning did it in.
[/QUOTE]<span id='postcolor'>It's a good thing you wern't in the shack! You could have been fried.

Or better yet, It's a good thing that your daughter wasn't in the tub, or your wife.

Electricity seek the easiest path to ground, but with something on the shelf not hooked up to anything, then that shoots that rule.

[KC8KZY]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (wa5krp @ June 17 2004,02:19)</td></tr><tr><td id="QUOTE"></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (k9kjm @ June 17 2004,00:34)</td></tr><tr><td id="QUOTE">You can do real silver solder with MAPP gas in a small hand held torch that is almost as good as a professional Cadweld joint. etc.[/QUOTE]<span id='postcolor'>
I've always wondered if MAPP gas has any advantage over a propane torch. #I've never used MAPP. #Any thoughts?


WA5KRP
Texas[/QUOTE]<span id='postcolor'>
Mapp gas has a higher BTU content than Propane, and burns hotter. You can braze with the right torch, but only lighter gauge metals and copper piping. This, of course, depends on what style torch you use. Hope this helps answer your question.

Tom

[N1XHF]

Again sorry for the strike, at least everyone was safe!

[ky5u]

I have been a believer in PolyPhaser. The guy who founded the company did his initial tests years ago in Houston. He put them on a tall tower there with a history for strikes. After a storm, he'd climb the tower, replace the polyphaser and take it back to the lab.

After many strikes and climbs, the design was perfected. You can't beat real world testing!

[ae4fa]

You have my sympathies, George. So far I've only lost one cheap microwave to lightening. Can't imagine how you must have felt as it sunk in . . .

As I understand things, you've got one of two choicesL

1. Build an elaborate and complete ground system.

2. Unplug everything every time.

For now, I'm going with option #2. My rigs are completely free of external connections between operating sessions. It's a bit of a pain, but I'll be moving before too much longer. The house we're in is just a tempoorary situation while I build my wife's new house . . .

Anyway, best of luck, George, in getting everything replaced with minimal hassle.

[K3UD]

http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif2--></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (W8MW @ June 16 2004,14http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif2)</td></tr><tr><td id="QUOTE">George, sorry to hear about that ugly experience. #Is your station ground bonded to the house electrical ground? #Just curious about that.

73, Mike[/QUOTE]<span id='postcolor'>
No, they are not tied together and not tied to the phone ground.

I am now certain that the strike was at the far side of the house as my neighbor on that side also has the rainbow effect on her TVs. How it got to my station ground is anyone's guess as there is no evidence of it on the outside of the house where the adjacent to the shack and where the tower is. The ductwork theory still works for me as it is the only thing other than house wireing that runs the length of the house.

73
George
K3UD

[AG3Y]

We had a lightning strike so strong up at Ch 31 once that we could not get the &quot;rainbow effect&quot; out of our video monitors with a standard degausing coil. The magnetic influence was also in the steel racks and frames of the monitors!

We actually had to get a big bulk tape eraser ( one of those 2 inch RCA tape units ) to get the remnants of the gaus out of the picture.

I would hope that your situation doesn't call for such drastic means. You might end up demagnatizing all the static convergence magnets on the yoke, and that could be a real problem ( no YOKE ! http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif sorry, couldn't help myself )

Keep a good humor and all will be fixed eventually.

73 from Jim AG3Y

[K3UD]

Thanks to everyone who posted and shared their experiences.
I also appreciate the good thoughts and suggestions that have been passed on.

As someone mentioned, I am glad I was not in the shack and holding the D-104 which was connected to the Icom. As others mentioned, it could have been a lot worse. My wife was out shopping and my daughter was in bed and I was in a chair in her room. Thank God that no one was in the shower, outside where it hit or even doing dishes.

I think it was Steve, WB2WIK who once mentioned in another thread that the radios are really only boxes and could replaced.

Hopefully I will have this settled soon and start purchasing some radios. I will also find out what &quot;replacement cost&quot; really means in the lexicon of insurance speak. I have made notes of the grounding enhancements suggested and will certainly consider the polyphaser approach.

I hope that this post has generated some thoughts by those who have read it on the dangers of what can happen. Many of you have had the same experience but most have not.

This certainly does not just happen to the &quot;other guy&quot;.

73
George
K3UD

[N8CPA]

George, so sorry to hear you got zapped. Among amateurs, such an event is the sum of all fears. That is one sick feeling.

A few years ago, storm watches were going up just as I was about to go out to dinner with some of the folks from the Field Day gang--FD ended the day before. We planned to go storm spotting as soon as dinner was over. I hesitated long enough before leaving the house to disconnect rigs and my only computer from all power and antenna lines. The only thing left connected was the phone line to the computer's internal modem.

We were driving home from watching clouds where lightning was so intense that we had to wear sunglasses at 10http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif0 o'clock at night in order to see the storm structure. We followed the storm toward my home. When I was about a mile from the house, I saw a big, long, broad, purple streak reach from a cloud with an apparent aim for my neighborhood. The associated thunder clap exploded, deafening even as far as I was from the house at the time of the strike.

We arrived at the house with my ears still ringing. Thankfully,
the garge door opened when I pushed the remote. But as soon as we got into the house, the stench of fried components assaulted our noses. I checked each transceiver--all were okay. But when I turned on the computer, neither a pip, nor squeak.

A friend and I dismantled the computer and found a blown fuse in the power supply. All other circuits and components appeared undamaged. We soldered in new fuse, and it exploded as soon as power was applied. Since the computer was a proprietary model, I had to return it for professional service--unable to find a compatible PS--uncertain if that would even do any good. 10 days later I found out when I picked up the repaired computer from the servcie center.

Every system, except the power supply, was intact. According to the shop, every similar computer connected to a phone line at the time of the storm experienced the same fate in my neighborhood--power supplies lost, but nothing else.

I wish someone could explain to me, how a lightning strike, EMP, or related secondary surge can enter a computer via the phone line and destroy a power supply without destroying the modem through which it entered, or other nearby systems, or telephones. There must be a technical explanation, but I still haven't found a satisfactory one. To this day, I only connect outdoor antennas when I intend to transmit.

I use surge protectors for all power lines related to computer and transceivers. My ground system is a copper pipe on the floor, which I bonded to the household water pipe, but only after I verified the absence of PVC couplings. Each XCVR and tuner is individually grounded to a ground bus on my radio desk. #10 wire connects the bus to copper pipe on the floor. An additonal short run of #10 solid conductor connects the cold water pipe. All wall outlets are grounded. If I test for continuity from any radio cabinet to any other cabinet, I get tone. And there's still room for improvement. The system is the best I can make it for the time being and far short of ideal. So when the clouds start growing, I add prayer as a backup system. So far, thank God, no more incidents.

Good luck with your insurance settlements and gear replacements.

I had a dead tree fall on the power line at the house I'm renting during a storm. On the owner side of the meter. Broke the wire, had a big zap through the neutral (white) wire. Zapped about everything. Good ground on everything too. Came in through the neutral wire. You don't need lightning to get zapped.
N7SYY

[W0UZR]

I just thought of something.
The power lines have fuses on them, right? How is it that it didn't blow?

[K9STH]

UZR:

Think about it! A fuse blows as the result of too much current flowing into a load. It does not blow as the result of too much voltage. The condition of the load determines how much current is carried. Until lightning strikes, the load does not present too much of a load so that the fuse blows. If the lightning strike does enough damage then the load will increase so that the fuse blows. However, the fuse does not blow until after the load has increased. Since the load does not increase until after the lightning strikes the fuse doesn't usually protect the load from lightning. Kind of a &quot;catch 22&quot;.

Now, what are called &quot;reclosers&quot; (actually a sort of circuit breaker) often do open up when a lightning strike occurs and sometimes help. However, reclosers are usually only used on fairly large loads (like entire neighborhoods) so they don't always open. Fuses are often used on short runs like for the load on a single alley, etc.

Remember, that anything which is used by the electric company has to be able to withstand power surges several times the &quot;average&quot; current draw (air conditioning units starting, etc.). Thus, they are not that likely to blow when a lightning strike occurs. Otherwise, you would lose power much more often just do to momentary load increases due to &quot;normal&quot; happenings on the electrical grid.

Now, I do not disconnect anything! Remember, at remote two-way radio and microwave radio sites that there is no one there in most cases to disconnect the equipment from the antenna, power, etc. I employ the same things that I have recommended for installation at remote sites.

The pole pig behind my house has been hit by lightning. My neighbor across the street has lost three trees and a chimney to lightning. However, I have never been struck! Yes, there is always the chance that my towers may be hit (nothing is 100 percent foolproof against lightning). But, based on my experience I feel as safe as possible with my present situation. Frankly, it wouldn't do an iota of good to disconnect anything!

Unfortunately, there is little that can be done for a vertical (unless it just happens to be &quot;shielded&quot; like my HyTower is by something that has the ability to dissipate the charge). That is why amateurs using verticals are &quot;hit&quot; by lightning much more often that those with towers and horizontally polarized antennas. It is very easy to explain this by simple physics.

Glen, K9STH

[K9STH]

UZR:

The current from a strike actually varies during the strike. However, that is not what I was referring to.

First of all, if the strike happens between the fuse (or recloser) and the load, then there is no protection at all from the fuse (or recloser). The closer the strike to the eventual load (read your house!) then the more of an effect that it is going to have.

Now, if the fuse (or recloser) is between the load and the lightning strike, then it usually doesn't do any good to protect the load (again read your house) from the strike because the fuse (or recloser) is not going to open fast enough! Now, if the load increases (due to damage from the strike - i.e. shorted transformer, damage within your house, etc.) then the current that is supplied by the electric utility is going to increase and may &quot;blow&quot; the fuse (or recloser).

It is from the electric utility company that the additional current is going to come from after the initial strike and NOT from the lightning itself.

Of course since lightning doesn't seem to like to &quot;follow the rules&quot; at some point during an actual strike it may &quot;blow&quot; the fuse (or recloser). But, don't count on it! The surge due to increased load is much more likely to cause the fuse (or recloser) to open. However, again, this is due to the current supplied by the utility and not due to the current from the lightning strike.

That is what I was trying to say about the &quot;catch 22&quot;. The load requirements are not enough to blow the fuse (or recloser) until after the load is damaged by the lightning. Then, the current from the utility company may cause the fuse (or recloser) to blow. But, the fuse (or recloser) is not going to blow and protect the load from the lightning. Thus, until the load is damaged by the lightning the fuse (or recloser) won't blow. Then, the fuse (or recloser) will blow but not until the lightning has already done the damage!

If the strike is such that the fuse (or recloser) is between the load and the lightning strike, occasionally the fuse (or recloser) will open and protect the load. Sometimes this will happen such that the load is damaged and the fuse (or recloser) is opened. But, more often, the fuse (or recloser) will not open (due to the relatively short duration of the strike as compared to the time element that is necessary for the device to open) and the damage occurs even though the circuit was &quot;supposedly&quot; protected by the fuse (or recloser).

Really, the purpose of the fuse (or recloser) is to protect mainly from shorted transformers or direct shorts of the distribution line to ground (like a tower falling onto it). Even a tree will not present sufficient load (in most cases) for the fuse (or recloser) to open since a tree does have a &quot;fair&quot; amount of resistance. A tree falling is much more likely to actually break the line which presents a dangerous situation because the &quot;downed&quot; line usually will still have voltage on it.

Glen, K9STH

[W0UZR]

I deleted my post after rereading yours again a couple of times, and kinda found that out. And I figure I was reading something in your post that wasn't there. Cause it sounded like that you said the lightning strike gets stronger of a current towards the end of the strike than at the start of it, and I couldn't make sense out of that.

I read your post again, and things started to take a different shape. So,,what you're saying is that the lightning comes along, and fries things, and causes a short circuit, and then maybe take out the fuse on the pole. And that would make more sense since there is more amperage in the power in the line to begin with than there is in a LIGHTNING STRIKE! It takes some people a long time to get it, (like me), but we get there.

Maybe I can go to the head of the class even.....daaa

UZR,

Lightning is composed of a 'leader' which helps to provide a path for the arc to find a ground. Without getting into the physics or engineering of 'how' lightning does what it does.. suffice it to say the 'leader' has far less voltage than the rest of the stroke. Yes, a lightning stroke has more than just one component to it.


The reason the fuse doesn't 'blow' when lightning hits - to amplify what K9STH posted -

A fuse (even the 'fast blow' types we use) ALL depend on the fusible link - the part the melts open when a surge hits - reaching some temperature and melting which opens the circuit. If a breaker, it requires reaching some value which makes the lever trip.

Back to fuses, since that's the thing we're discussing.

It takes a finite amount of time for the temperature in the fusible link to reach the point where it will become hot enough to reach the melting point and then open. (this is the 'rise time' from normal to overload status in the fuse) MOST normal 'surges' in our gear is within the rise time that the fuse is designed for and it will open before damage is done.

There is a time delay between the time the link reaches the melting point and the time that it melts and produces an air gap sufficient to keep any further current from flowing.

If you add up these time delays (and the major fuse manufacturers ALL have this data available for the asking) you will find it is 'slow' in reacting to the increase in current brought about by the voltage increase which occurs during a lightning strike.

The 'rise time' from normal to peak voltage from the strike is (usually) much faster than the time required ot 'open' the fuse. Therefore, a dangerous voltage level can be present and damage your gear LONG before the fuse even realizes 'Tis TIME TO PROTECT AND SERVE!'

I don't have the exact 'rise time' figures range for lightning strikes, but it is well under the rise time that a fusible link is designed to handle.

That is why they make 'gas filled' protectors for use as lightning arrestors as well as other things such as those designed for ElectroMagnetic Pulse (EMP) protection.

BTW.. Lightning is a form of EMP, just FYI, &lt;grin&gt;

These EMP devices ARE designed to accomodate the fast 'rise time' necessary to clamp the input to prevent damaging surges reaching the gear.

Polyphaser has EXCELLENT literature on this andgives MUCH informatoin which is quite valuable!

73
K3FT

[WA5KRP]

K3UD,


Your big event gave us a thread with a lot of great posts. What's the latest from your insurance company - are they going to come through for you?

73


WA5KRP
Texas

[W0UZR]

Yah, Great posts! We're hearing from the best in the business now. If these boys don't know, not many people are going to know.

And they raise points that I haven't thought of. Chuck made it a lot more understandable by saying that the lightning strike is of such of a short duration, that it doesn't have time to blow a fuse. And,,

Glen brought up the fact that lightning doesn't have much amperage to begin with, which is another strike (haha) for being able to blow a fuse on the power line. So lightning strikes becomes a lot more understandable here.

Now the fact that if it can fry a radio that is on a shelf away from everything makes me think of the &quot;Balls of Lightning&quot; that I referred to coming out of the outlet thing. So that's what could have happened.

Another thing that hasn't been mentioned is that lightning isn't DC current, isn't AC current, which has some stability. It is static electricity. It is the same thing as getting a shock from a light switch in the winter, but on a lot larger scale. I forgot, but I thought I saw a weather channel program that said that lightning is 13,000,000 volts, or is it 130,000,000 volts? anyway, it is an astronomical number like that. After all,,,

How far is it from that cloud to the ground here? A quit a ways. So to get static electricity to arc that distance takes a lot of static electricity. And that makes it all the more reason that it doesn't &quot;Follow the rules.&quot;

[K9STH]

Lightning actually usually has a lot of current as well as voltage! However, it is usually of very short duration.

Of course lightning is of the &quot;female&quot; gender. That is, it has a &quot;mind of its own&quot;! It can do just about anything that it takes a mind to do.

Glen, K9STH

[ke4mej]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (K9STH @ June 21 2004,14:41)</td></tr><tr><td id="QUOTE">Of course lightning is of the &quot;female&quot; gender. #That is, it has a &quot;mind of its own&quot;! #It can do just about anything that it takes a mind to do.[/QUOTE]<span id='postcolor'>
That may be the most &quot;enlightening&quot; statement i've ever seen on this subject (even though some might say it's not exactly politically correct.) #We can study and research until we think we know it all, but lightning and other natural phenomenon will often do things that we just don't think are possible. #We learn as much as we can, prepare as best we can, but sometimes we just have to sit back and watch the show!

73
Chuck