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Damaged by a lightning ?
Hi,
Was your house/shack stroken by Thor's hammer, I mean a lightning recently ? I am interested in your experience... If your installaiton was damaged by a strike event, I would like to now if : - you used a central ground point bonded to an external grounding system, as well as the home ground. - you left some gears switched on during the strike event - you left the TX switched on and the coaxial plugged without protection - you installed or not lightning controllers in your electric distribution panel - you had installed another protection - you swicthed off and unplugged all devices - you think that the energy came back via the grounding network (probably dut to a difference of potential in a device) Tell me only in a few words what was the most probable cause of the accident. At last, if you master the subject, do you really think that a grounding system, as best it could be as the advice provided by PolyPhaser for example, will never protect you against a direct strike on your antenna or on the house lightning conductor Why ? All this will help me to conclude the article dealing with this matter : http://www.astrosurf.com/lombry/qsl-...protection.htm Thanks in advance NB. Answer preferably through these forums to please everybody. Thierry ON4SKY |
I believe lightning struck my chimney and took out the lawn sprinkler
control system and a couple of appliances. After a while I found the reason. The clamp on the ground rod for the house ground wire had disintegrated and I think the disintigration was caused by galvanic action. I just replaced with awhat I thought was a better one and the new one didn't corrode. 73 hank wd5jfr "Thierry" To answer me in private use http://www.astrosurf.com/lombry/post.htm wrote in message ... Hi, Was your house/shack stroken by Thor's hammer, I mean a lightning recently ? I am interested in your experience... If your installaiton was damaged by a strike event, I would like to now if : - you used a central ground point bonded to an external grounding system, as well as the home ground. - you left some gears switched on during the strike event - you left the TX switched on and the coaxial plugged without protection - you installed or not lightning controllers in your electric distribution panel - you had installed another protection - you swicthed off and unplugged all devices - you think that the energy came back via the grounding network (probably dut to a difference of potential in a device) Tell me only in a few words what was the most probable cause of the accident. At last, if you master the subject, do you really think that a grounding system, as best it could be as the advice provided by PolyPhaser for example, will never protect you against a direct strike on your antenna or on the house lightning conductor Why ? All this will help me to conclude the article dealing with this matter : http://www.astrosurf.com/lombry/qsl-...protection.htm Thanks in advance NB. Answer preferably through these forums to please everybody. Thierry ON4SKY |
"Let us spray"?
"Henry Kolesnik" wrote in message ... I believe lightning struck my chimney and took out the lawn sprinkler control system and a couple of appliances. |
Safe Breaker wrote:
On Sun, 25 Jan 2004 15:49:25 -0000, "Airy R. Bean" wrote: "Let us spray"? Face it, if wit was sh*t you'd be constipated. I think you're being a bit harsh on Airy -- David |
"Henry Kolesnik" wrote in message ... I believe lightning struck my chimney and took out the lawn sprinkler control system and a couple of appliances. After a while I found the reason. The clamp on the ground rod for the house ground wire had disintegrated and I think the disintigration was caused by galvanic action. I just replaced with awhat I thought was a better one and the new one didn't corrode. Indeed, without care the binding between two metals is always "at risk". Polyphaser and other grounding kit manufacturers provide products to prevent this kind of corrosion, including coating for anchor guys (like Anchor Guard). Thierry 73 hank wd5jfr "Thierry" To answer me in private use http://www.astrosurf.com/lombry/post.htm wrote in message ... Hi, Was your house/shack stroken by Thor's hammer, I mean a lightning recently ? I am interested in your experience... If your installaiton was damaged by a strike event, I would like to now if : - you used a central ground point bonded to an external grounding system, as well as the home ground. - you left some gears switched on during the strike event - you left the TX switched on and the coaxial plugged without protection - you installed or not lightning controllers in your electric distribution panel - you had installed another protection - you swicthed off and unplugged all devices - you think that the energy came back via the grounding network (probably dut to a difference of potential in a device) Tell me only in a few words what was the most probable cause of the accident. At last, if you master the subject, do you really think that a grounding system, as best it could be as the advice provided by PolyPhaser for example, will never protect you against a direct strike on your antenna or on the house lightning conductor Why ? All this will help me to conclude the article dealing with this matter : http://www.astrosurf.com/lombry/qsl-...protection.htm Thanks in advance NB. Answer preferably through these forums to please everybody. Thierry ON4SKY |
The CBer reveals herself every time that she opens her mouth....
"Safe Breaker" wrote in message ... Face it, if wit was sh*t you'd be constipated. |
Station grounded to central ground (10 foot ground rod in Georgia Clay tied
to 60 radials each 60 feet long 1" below the surface put in before the house was built.) Power unplugged all antennas grounded via the antenna switch. 1/2 of G5RV up 40 feet, antenna vaporized with only bits and pieces found, the other half undamaged. Came in via powerlines and antenna. All electronic devices in the house destroyed All antennas on 80 foot tower were untouched. main stroke followed the powerlines in the attic. The overpressure blew vinyl siding off the house. In the hamshack the voltage exited the coax from a coiled section burning the rug. TS-830 and 440 destroyed in spite of being unplugged. 6 foot color TV, electronic air cleaner, VCR etc all destroyed. The only electronic survivor was a bedside GE $10 radio alarm clock. This is a rural setting on 29 acres. Closest house 1/2 mile away. All utilities underground from the road to the house. Closest overhead utilities are 1600 feet away. "Thierry" To answer me in private use http://www.astrosurf.com/lombry/post.htm wrote in message ... Hi, Was your house/shack stroken by Thor's hammer, I mean a lightning recently ? I am interested in your experience... |
"Thierry" To answer me in private use http://www.astrosurf.com/lombry/post.htm wrote in message ...
Hi, Was your house/shack stroken by Thor's hammer, I mean a lightning recently ? My mast has been struck twice in the last 4 years. I am interested in your experience... If your installaiton was damaged by a strike event, I would like to now if : - you used a central ground point bonded to an external grounding system, as well as the home ground. My mast is the central ground point. It's tied into to water pipe, which is about 2 ft away, and also tied into my "ground window" outside the shack. All the ground here is tied together, and at the same potential. The water pipe is iron, not pvc. - you left some gears switched on during the strike event Gears???? No compute... - you left the TX switched on and the coaxial plugged without protection Yes. So was my computer and monitor. Neither flinched at all. - you installed or not lightning controllers in your electric distribution panel No. - you had installed another protection No. - you swicthed off and unplugged all devices Yes. But to my radios only. IE: rig and amp unplugged from the wall. Phone line to the computer unplugged. All the other stuff in the house/room was left on and plugged in. My computer was on, as was the TV in the room, which is on cable. - you think that the energy came back via the grounding network (probably dut to a difference of potential in a device) Most all of the strike energy went straight to ground via the mast I'm fairly sure. I had no damage to anything anywhere. The only thing is did was blow a hole in my electrical tape "water cap" on the top of the mast. Also made the slightest arc spot on the end of the mast. You would have to look hard to see it. Tell me only in a few words what was the most probable cause of the accident. Accident? What accident? The lightning strike did exactly what I was intending/hoping it would do. At last, if you master the subject, do you really think that a grounding system, as best it could be as the advice provided by PolyPhaser for example, will never protect you against a direct strike on your antenna or on the house lightning conductor Why ? You can protect from a direct strike. The level of protection will depend on the clamping voltage of the gas tube, or whatever you use. The higher power gas tubes clamp at a higher voltage. If you want max protection use a low power protector. But I'm too paranoid to operate during lightning. I see no point anyway, being the static would be a mess... I totally unhook and ground all antennas. Also, my mast is much most likely to attract a strike rather than my antennas themselves. They just float along for the ride. My coaxes all run all the way down to the ground. The mast acts as a lightning rod in my case. I was sitting 15 feet away from my mast when it struck mine. In reality, it's kind of a non event..It's so quick , it's over before you realize what happened. The strike itself is pretty quiet if you have a low resistance connection like a well grounded mast. About like throwing a lightbulb on the ground and breaking it. Only the sonic boom overhead is loud. You also hear a click in your auditory nerves when you are that close. Lightning has also hit tall trees in our yard in that time period. The tree in the front yard was nailed a few months ago. MK |
Mark Keith . ..
^ - you left some gears switched on during the strike event ^ ^ Gears???? No compute... "Gear", not "gears". "Gear" is both singular and plural without the apostrophe but that sense doesn't translate well. He means "equipment". Frank |
Thierry wrote:
"I am interested in your experience." My electric utility company`s service standards book says: "National Electrical Code (N.E.C.) requires grounding to a "metallic underground water piping system" if available. Acceptable alternatives include a driven ground rod which is preferred by your company regardless of the type of grounding used. N.E.C. requires that the "interior metallic cold water piping system" be bonded to it." My home installation has metallic water piping inside and outside the house. A heavy cable connects cold water pipimg to the electrical service entrance and to an external ground rod. Telephone and TV cables are bonded to the electrical service ground. This is done to lessen the possibility of a potential difference between the various services. Nevertheless, I had a combination clock radio telephone which was burnt by a lightning strike. Enough potential difference was generated between the phone wiring and powerline wiring inside the house to fry the clock radio telephone which was at the opposite end of the house from the service entrance where services share a common ground point. It is a wood frame house. There was no protection at the clock radio telephone. Had low-pass filters with voltage-limiting on electrical and telephone outlets been installed and had they shared a common ground connection at the apparatus, it is likely no damage would have occurred. I`ve used MOV`s for power line surge protection with success against common-mode and differential-mode surges. Carbons and gas tubes are suitable for phone lines. I worked many years in broadcast stations, medium wave and short wave. Never saw a dime`s worth of lightning damage in the well protected stations in which I worked. I worked more decades with land/mobile and microwave radios and found ways to protect these too, mostly by using the same techniques already perfected in broadcasting. No. We did not use 120 radials for our VHF, UHF, and microwave towers, but we did use a separate ground rod en each tower leg. This was lightning protection. We also used closed circuit antennas grounded at the tops of the towers. Coax rejects common-mode lightning energy. We used zero protection across coax and never had a burnt transistor receiver front-end. Best regards, Richard Harrison, KB5WZi |
"Richard Harrison" wrote Coax rejects common-mode lightning energy. We used zero protection across coax and never had a burnt transistor receiver front-end. Richard, could you please explain the term "common mode lightning"? I've seen you reference that many times and meant to ask what that is. Apparently an uncommon mode burned through 300' of RG8 (literally melting the end connected at the radio) and disintegrated the internal coax post inside a Drake R8B. I sent the radio to Drake, and they explained that the lightning protection inside the radio was literally exploded, but it did it's job and the radio was easily and inexpensively repaired. The coax in question was disconnected about 150' from the house, but lightning apparently jumped from the tower feed across a foot of air space and back into the PVC pipe channel housing several coax, which led to the house. The Drake was the luckiest of the second-story ungrounded shack gear. The protecton on this particular installation was multiple radial-grounds from the base of the tower. It was a very nasty strike or set of strikes, as several outbuildings on the property all suffered equipment damage. _Maybe_ this was a case of ground current from the strike jumping into the coax, but in any case several coax carried very high charges into the home. Jack |
Jack Painter wrote:
"---explain the term "Common mode lightning"." A folded monopole or another antenna with a 1/4-wave short-circuited stub across its drivepoint is a low impedance except at resonance. At other frequencies containing most of the lightning energy, the exposed antenna is a short to the grounded tower. At the resonant frequency, the same voltage with the same polarity is imposed on both the center conductor and the inside of the coax shield. Inside the coax, currents in one conductor induce opposing and near equal currents in each other, cancelling. It worked for me in hundreds of locations over decades of time including countless lightning strikes to what was often the most exposed and salient structure for miles around. Best regards, Richard Harrison, KB5WZI |
Thanks Richard, I remember your explanation about a dipole being no
attractor of anything except it's resonant freq. But I guess the the currents in the coax weren't "near enough equal" in this one case. Kind of defines lightning as it's own anomoly when it wants to be, huh. Jack Richard Harrison wrote Inside the coax, currents in one conductor induce opposing and near equal currents in each other, cancelling. |
On Mon, 26 Jan 2004 14:14:21 -0500, "Jack Painter"
wrote: But I guess the the currents in the coax weren't "near enough equal" in this one case. This is the definition of Common Mode. Kind of defines lightning as it's own anomoly when it wants to be, huh. It means you lacked the Common Mode protection. Your earlier posting of: The coax in question was disconnected about 150' from the house, but lightning apparently jumped from the tower feed across a foot of air space and back into the PVC pipe channel housing several coax, which led to the house. The Drake was the luckiest of the second-story ungrounded shack gear. screams this big time. There was nothing anomalous about that lightning strike, it did what it was enabled to do. 73's Richard Clark, KB7QHC |
"Richard Clark" wrote
It means you lacked the Common Mode protection. Your earlier posting of: The coax in question was disconnected about 150' from the house, but lightning apparently jumped from the tower feed across a foot of air space and back into the PVC pipe channel housing several coax, which led to the house. The Drake was the luckiest of the second-story ungrounded shack gear. screams this big time. There was nothing anomalous about that lightning strike, it did what it was enabled to do. Richard, do you mean that if the coax had been left connected to the dipole it would have afforded common-mode protection? I think I understand what you're saying but would appreciate you tying that principle together. Thanks. Jack |
On Mon, 26 Jan 2004 16:02:38 -0500, "Jack Painter"
wrote: Richard, do you mean that if the coax had been left connected to the dipole it would have afforded common-mode protection? I think I understand what you're saying but would appreciate you tying that principle together. Thanks. Jack Hi Jack, Ask yourself "Where is ground in this picture?" THAT is the Common of the Common Mode. I see it discussed nowhere in your description. There is the inference of it being back in the house (code requires it) where lightning eventually found it, the hard way. As you describe it: The coax in question was disconnected about 150' from the house, disconnected where, how? Up the tower? At the bottom of the tower? Is the tower grounded? Does the tower ground meet code in being tied to the house ground? Is the coax grounded? Where? Does it supply ground? Where? The Drake was the luckiest of the second-story ungrounded shack gear. No ground? There are two problems with this statement. 1.) It is unlikely due to code; 2.) It means you accept Common Mode problems. It being unlikely does not mean you are protected (experience proves this), it means you went with the flow - of several KV. 73's Richard Clark, KB7QHC |
Jack Painter wrote:
"But I guess the currents in the coax weren`t "near enough equal" in this case." Yes, and I can`t guarantee common-mode or equal currents. If the folded unipole gets zapped, equal or non-equal currents may flow in both conductors. Induced currents are likely to be differential-mode. But if they are differential-mode currents, something else likely happens. The line flashes over. I seem to be very lucky to never have damage with so many opportunities for damage. We never lost a transistor radio front end with countless strikes as evidenced by the pitted antennas. We know the coax arcs in broadcast stations. Most stations have automatic circuits to kill the transmitter when the coax arcs. In medium wave broadcast stations there is almost always a Faraday screen to keep down the harmonic radiation. It gets countless zaps as evidenced by pock marks and metal splattered about its shield box.Even so, the coax gets arcs. When you are on the air, transmitter energy keeps the arc alive once a transient has struck the arc. Most transmitters are equipped with a momentary kill relay whose d-c coil circuit is completed by the coax arc. As soon as the transmitter is killed, the relay is de-energized and the transmitter returns to the air. In the 2-way radio world, the transmitter is going to drop out in a moment when the mike button is released, or the station was in the receive mode when the lightning hit and there is no energy to sustain the arc. The arc prevents conveyance of the energy to the radio. I never saw a broadcast transmitter with evidence of lightning inside the transmitter and we have a good ides that these stations get struck almost every time a dark cloud passes by. Best regards, Richard Harrison, KB5WZI |
Richard, my earlier posts described the grounding my friend, here is quick
summary: 1.Well grounded 100' tower, hundreds of feet of many radials, rods, etc. Survived many strikes. 2. Feedline from tower's dipole was disconnected about 20' from tower where it enters a buried pvc conduit that travels 150' to house, then up to second story shack. Where nothing is grounded, except by virtue of house AC wiring - a bad I know (not mine either). 3. Ground current from the tower strike most likely entered the coax feedlines at the disconnect point as they entered the pvc conduit then traveled on into house. 4. House current also took huge jolts, zorching all kinds of connected equipment, phones, tv's etc. 5. Outbuilding with radio equipment connected took huge hit, ball lightning inside room fried test cords connected to nothing, hanging on test bench, where the leads touched tile floor, huge blow-out of tile. AC power blew wall warts across room, computers next to each other had .22 rifle bullet sized hole between them. Equipment in this bldg was grounded, and some that was was damaged, others not touched. In short, a massive, multiple strike-path hit that may not be protectable from - but I realize there was a lot missing from a good ground picture here also. Jack "Richard Clark" wrote Ask yourself "Where is ground in this picture?" THAT is the Common of the Common Mode. I see it discussed nowhere in your description. There is the inference of it being back in the house (code requires it) where lightning eventually found it, the hard way. As you describe it: The coax in question was disconnected about 150' from the house, disconnected where, how? Up the tower? At the bottom of the tower? Is the tower grounded? Does the tower ground meet code in being tied to the house ground? Is the coax grounded? Where? Does it supply ground? Where? The Drake was the luckiest of the second-story ungrounded shack gear. No ground? There are two problems with this statement. 1.) It is unlikely due to code; 2.) It means you accept Common Mode problems. It being unlikely does not mean you are protected (experience proves this), it means you went with the flow - of several KV. 73's Richard Clark, KB7QHC |
On Mon, 26 Jan 2004 21:07:24 -0500, "Jack Painter"
wrote: Richard, my earlier posts described the grounding my friend, here is quick summary: 1.Well grounded 100' tower, hundreds of feet of many radials, rods, etc. Survived many strikes. 2. Feedline from tower's dipole was disconnected about 20' from tower where it enters a buried pvc conduit that travels 150' to house, then up to second story shack. Where nothing is grounded, except by virtue of house AC wiring - a bad I know (not mine either). 3. Ground current from the tower strike most likely entered the coax feedlines at the disconnect point as they entered the pvc conduit then traveled on into house. 4. House current also took huge jolts, zorching all kinds of connected equipment, phones, tv's etc. 5. Outbuilding with radio equipment connected took huge hit, ball lightning inside room fried test cords connected to nothing, hanging on test bench, where the leads touched tile floor, huge blow-out of tile. AC power blew wall warts across room, computers next to each other had .22 rifle bullet sized hole between them. Equipment in this bldg was grounded, and some that was was damaged, others not touched. In short, a massive, multiple strike-path hit that may not be protectable from - but I realize there was a lot missing from a good ground picture here also. Jack Hi Jack, You know, it sounds like the lightning hit your house/out-building and went toward the tower. 73's Richard Clark, KB7QHC |
Many thanks to all you you.
I will probably contact you personally very soon. 73's Thierry ON4SKY "Thierry" To answer me in private use http://www.astrosurf.com/lombry/post.htm wrote in message ... Hi, Was your house/shack stroken by Thor's hammer, I mean a lightning recently ? I am interested in your experience... If your installaiton was damaged by a strike event, I would like to now if : - you used a central ground point bonded to an external grounding system, as well as the home ground. - you left some gears switched on during the strike event - you left the TX switched on and the coaxial plugged without protection - you installed or not lightning controllers in your electric distribution panel - you had installed another protection - you swicthed off and unplugged all devices - you think that the energy came back via the grounding network (probably dut to a difference of potential in a device) Tell me only in a few words what was the most probable cause of the accident. At last, if you master the subject, do you really think that a grounding system, as best it could be as the advice provided by PolyPhaser for example, will never protect you against a direct strike on your antenna or on the house lightning conductor Why ? All this will help me to conclude the article dealing with this matter : http://www.astrosurf.com/lombry/qsl-...protection.htm Thanks in advance NB. Answer preferably through these forums to please everybody. Thierry ON4SKY |
Richard Clark wrote in message . ..
On Mon, 26 Jan 2004 21:07:24 -0500, "Jack Painter" wrote: Richard, my earlier posts described the grounding my friend, here is quick summary: 1.Well grounded 100' tower, hundreds of feet of many radials, rods, etc. Survived many strikes. 2. Feedline from tower's dipole was disconnected about 20' from tower where it enters a buried pvc conduit that travels 150' to house, then up to second story shack. Where nothing is grounded, except by virtue of house AC wiring - a bad I know (not mine either). 3. Ground current from the tower strike most likely entered the coax feedlines at the disconnect point as they entered the pvc conduit then traveled on into house. 4. House current also took huge jolts, zorching all kinds of connected equipment, phones, tv's etc. 5. Outbuilding with radio equipment connected took huge hit, ball lightning inside room fried test cords connected to nothing, hanging on test bench, where the leads touched tile floor, huge blow-out of tile. AC power blew wall warts across room, computers next to each other had .22 rifle bullet sized hole between them. Equipment in this bldg was grounded, and some that was was damaged, others not touched. In short, a massive, multiple strike-path hit that may not be protectable from - but I realize there was a lot missing from a good ground picture here also. Jack Hi Jack, You know, it sounds like the lightning hit your house/out-building and went toward the tower. 73's Richard Clark, KB7QHC Sounds like it. I'm fairly sure it didn't hit the tower. Or if it did, it also hit the houses at the same time. You don't get dime size holes in the house, unless the strike is traveling in the house. I don't think it's too likely ground currents traveled up the unconnected coax to the house. It would have gone on to ground at the tower, being it's well grounded. I think the upstairs part of the house was struck, and the coax from the drake, along with power wiring was the return to ground. Note all the damage in the house. Jack, you are one lucky $#^ *#^*@....:) It could have burned the house down. The coax to ground level from the upstairs drake may have routed a good bit of the strike out to ground. Not enough to save damage though..MK |
On Sun, 25 Jan 2004 15:03:59 +0100, "Thierry" To answer me in private
use http://www.astrosurf.com/lombry/post.htm wrote: Hi, Was your house/shack stroken by Thor's hammer, I mean a lightning recently ? I am interested in your experience... The " system" gets hit about 3 times a year on average. http://www.rogerhalstead.com/ham_files/tower.htm If your installaiton was damaged by a strike event, I would like to now if : Rarely does the system suffer damage. - you used a central ground point bonded to an external grounding system, as well as the home ground. The system uses a network, or grid of ground rods. 31 in the antenna and radio system, plus 5 for the house electrical system. It's all bonded together. - you left some gears switched on during the strike event Gears as in aircrafts ... Queens English Vs US English = Gear and aircraft:-)) Over here neither uses an s which is confusing to some. - you left the TX switched on and the coaxial plugged without protection Rarely is the gear disconnected and I don't remember the last time I disconnected a coax due to storms. - you installed or not lightning controllers in your electric distribution I do not have any in the distribution panel. I do have PolyPhasers for each coax mounted on a common bulkhead which is tied to the ground system using bare #2 copper cable. panel - you had installed another protection - you swicthed off and unplugged all devices Never bother. - you think that the energy came back via the grounding network (probably dut to a difference of potential in a device) I lost one computer due to a pulse coming in on the telephone line. Nothing spectacular. Tell me only in a few words what was the most probable cause of the accident. The one telephone cable was hot to ground with enough voltage to fry the solid state components. At last, if you master the subject, do you really think that a grounding system, as best it could be as the advice provided by PolyPhaser for example, will never protect you against a direct strike on your antenna or on the house lightning conductor I have 31 ground rods in the radio station ground system tied (cad welded) to over 600 feet of bare copper cable within 2 inches of the surface. All antennas are grounded either due to design, or a balun. The devices appear to work as advertised. Why ? I've lost one PolyPhaser with no damage to the rig that was hooked to it. (Kenwood TM-V7A) I had one lightening strike destroy a repeater antenna, blow out a section of 5/8ths inch Heliax about 30 feet down from the antenna, as well as blow off every bit of water proofing and all the silver plating from every coax connector at the top of the tower. The only damage was the input transistor in a two meter rig which was not the rig connected to the antenna that was hit. That rig was not protected by a PolyPhaser. Lightening and the results of a strike are unpredictable, but with the repeated strikes here, experience has shown me that apparently the PolyPhasers do their job in a well designed system. Last Summer I had a barrel connector (N type) short out in the coax from one of the 75 meter slopers to the tower mounted antenna selector. I'm assuming it was probably a near by strike, but I have no way of knowing for sure. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com All this will help me to conclude the article dealing with this matter : http://www.astrosurf.com/lombry/qsl-...protection.htm Thanks in advance NB. Answer preferably through these forums to please everybody. Thierry ON4SKY |
Roger Halstead wrote:
The " system" gets hit about 3 times a year on average. http://www.rogerhalstead.com/ham_files/tower.htm Interesting site. However the links to your larger pictures are all broken. They refer to files on your local PC eg: file:///C:/Documents%20and%20Settings/Administrator.ROGER2.000/My%20Documents/My%20Webs/ham_files/tower8.htm -- 73 Laurie - G6ISY |
On Wed, 28 Jan 2004 19:48:06 -0000, "Laurie"
wrote: Roger Halstead wrote: The " system" gets hit about 3 times a year on average. http://www.rogerhalstead.com/ham_files/tower.htm Interesting site. However the links to your larger pictures are all broken. They refer to files on your local PC eg: file:///C:/Documents%20and%20Settings/Administrator.ROGER2.000/My%20Documents/My%20Webs/ham_files/tower8.htm Thanks for telling me. I uploaded some frames for the local EAA Chapter and apparently "Front Page" in its infuriating propensity to change everything to it's way of thinking "did it to me" again. FP is great to work with "at times", but it uses sloppy and bloated code you don't need. And... If you forget it'll upload files other than what you planned. Down load 'em and then re upload them and you will find them reconfigured. sigh Back to fixing links. (I wonder what else may have been broken) I have nearly 60 megs on those pages. Again, thanks, Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com |
On Wed, 28 Jan 2004 19:48:06 -0000, "Laurie"
wrote: Roger Halstead wrote: The " system" gets hit about 3 times a year on average. http://www.rogerhalstead.com/ham_files/tower.htm Interesting site. However the links to your larger pictures are all broken. They refer to files on your local PC eg: file:///C:/Documents%20and%20Settings/Administrator.ROGER2.000/My%20Documents/My%20Webs/ham_files/tower8.htm sigh It wasn't as bad as I feared, but not as good as I hoped.:-)) Having a backup, I turned off the FP extensions on the server, up-loaded the tower.htm file using ftp and then went through it image by image. One directory missing, 4 files missing (htms) and one bad link. and one image. I have no idea as to where it put that image which is supposed to be in a sub directory one level down from ham_files which is one level down from the root. All-in-all, about 20 minutes to fix including the wait for FP to reconfigure. That utility can be great for some things and a royal pain for others. At least the frames still work. OTOH when I get the interactive *stuff* going I won't be able to turn them off. Again, thanks for letting me know about the broken links. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com |
Roger Halstead wrote:
sigh It wasn't as bad as I feared, but not as good as I hoped.:-)) [snip] All-in-all, about 20 minutes to fix including the wait for FP to reconfigure. That utility can be great for some things and a royal pain for others. I've got the same FP 't-shirt' :-) Again, thanks for letting me know about the broken links. You're welcome, all seems fine now. You have a much better head for heights than I have. -- 73 Laurie - G6ISY |
Thanks to all responding. A 20m antenna on top of the tower was demolished,
pieces landing 100' away. That one single feedline was connected and operating a wx-alert system in the shop. The house suffered zero structural damage, the roofline and 2 antennas on it was definitely not the source of any of the strikes. The outbuildings also suffered no structural damage or even marks. The coax(s) most definitely carried the lightning, now whether they got it from the ground current, tower, tower ground radials, that's anybody's guess. Coming into the shop, that was likely from the 20 meter feedline, but the explosion inside the shop right next to my friend was just "energy", the same kind that blew up floor tile from a patch cord hanging on a hook by itself. The computers destroyed were from energy in the AC wiring and cable modem network. From all I have read here, this hit was (luckily) one of rare intensity and diversity. Two strikes to the tower later in the summer of last year had only minor impact on anything. Jack "Mark Keith" wrote On Mon, 26 Jan 2004 21:07:24 -0500, "Jack Painter" wrote: Richard, my earlier posts described the grounding my friend, here is quick summary: 1.Well grounded 100' tower, hundreds of feet of many radials, rods, etc. Survived many strikes. 2. Feedline from tower's dipole was disconnected about 20' from tower where it enters a buried pvc conduit that travels 150' to house, then up to second story shack. Where nothing is grounded, except by virtue of house AC wiring - a bad I know (not mine either). 3. Ground current from the tower strike most likely entered the coax feedlines at the disconnect point as they entered the pvc conduit then traveled on into house. 4. House current also took huge jolts, zorching all kinds of connected equipment, phones, tv's etc. 5. Outbuilding with radio equipment connected took huge hit, ball lightning inside room fried test cords connected to nothing, hanging on test bench, where the leads touched tile floor, huge blow-out of tile. AC power blew wall warts across room, computers next to each other had .22 rifle bullet sized hole between them. Equipment in this bldg was grounded, and some that was was damaged, others not touched. In short, a massive, multiple strike-path hit that may not be protectable from - but I realize there was a lot missing from a good ground picture here also. Jack Hi Jack, You know, it sounds like the lightning hit your house/out-building and went toward the tower. 73's Richard Clark, KB7QHC Sounds like it. I'm fairly sure it didn't hit the tower. Or if it did, it also hit the houses at the same time. You don't get dime size holes in the house, unless the strike is traveling in the house. I don't think it's too likely ground currents traveled up the unconnected coax to the house. It would have gone on to ground at the tower, being it's well grounded. I think the upstairs part of the house was struck, and the coax from the drake, along with power wiring was the return to ground. Note all the damage in the house. Jack, you are one lucky $#^ *#^*@....:) It could have burned the house down. The coax to ground level from the upstairs drake may have routed a good bit of the strike out to ground. Not enough to save damage though..MK |
"Roger Halstead"
Rarely does the system suffer damage. ...one computer... ...one PolyPhaser... ...a repeater antenna... ...a section of 5/8ths inch Heliax... ...every bit of water proofing... ...all the silver plating... ...a two meter rig... ...a barrel connector (N type)... Geesus H. ! I guess so long as you think that you're happy, then you're happy. ;-) Carry on then. |
Working as a broadcast engineer at a MW (1390 kHz) station quite a few
decades ago, I have placed myself in the transmitter room so as to be able to look at the towers as a Summer storm passed. That transmitter did not have an automatic restore circuit. Well, I served as same. When I saw the lighting strike the towers, I would reset the breaker. The tubes (813s as I remember) would take that kind of abuse. My reflexes were good enough in those days that the listeners hardly knew anything happened. That is another trade that has disappeared. Richard knows! Have him tell about the cooked beasties across the current shunts. 73 Mac N8TT -- J. Mc Laughlin - Michigan USA "Richard Harrison" wrote in message news:25140-40159FDA- snip I seem to be very lucky to never have damage with so many opportunities for damage. We never lost a transistor radio front end with countless strikes as evidenced by the pitted antennas. We know the coax arcs in broadcast stations. Most stations have automatic circuits to kill the transmitter when the coax arcs. In medium wave broadcast stations there is almost always a Faraday screen to keep down the harmonic radiation. It gets countless zaps as evidenced by pock marks and metal splattered about its shield box.Even so, the coax gets arcs. When you are on the air, transmitter energy keeps the arc alive once a transient has struck the arc. Most transmitters are equipped with a momentary kill relay whose d-c coil circuit is completed by the coax arc. As soon as the transmitter is killed, the relay is de-energized and the transmitter returns to the air. In the 2-way radio world, the transmitter is going to drop out in a moment when the mike button is released, or the station was in the receive mode when the lightning hit and there is no energy to sustain the arc. The arc prevents conveyance of the energy to the radio. I never saw a broadcast transmitter with evidence of lightning inside the transmitter and we have a good ides that these stations get struck almost every time a dark cloud passes by. Best regards, Richard Harrison, KB5WZI |
"Jack Painter" wrote in message news:LRySb.3240$gl2.2307@lakeread05...
Thanks to all responding. A 20m antenna on top of the tower was demolished, pieces landing 100' away. That one single feedline was connected and operating a wx-alert system in the shop. Big omission... I now think the tower was hit, and piped the energy to the wx-alert system which then routed it to the rest of the house via the power wiring. Was that coax routed down to and snubbed to ground at the base of the tower? From the damage, it almost sounds like it was elevated in the air from the tower to the shop. The house suffered zero structural damage, the roofline and 2 antennas on it was definitely not the source of any of the strikes. The outbuildings also suffered no structural damage or even marks. The coax(s) most definitely carried the lightning, now whether they got it from the ground current, tower, tower ground radials, that's anybody's guess. Coming into the shop, that was likely from the 20 meter feedline, but the explosion inside the shop right next to my friend was just "energy", the same kind that blew up floor tile from a patch cord hanging on a hook by itself. The computers destroyed were from energy in the AC wiring and cable modem network. I bet the wx-alert box was the point where it got into the ac wiring. I just can't see lightning energy traveling towards the house on a coax that is on the ground. Once the lightning is at ground, normally it should stay there. It's where it wants to go. I don't see it ignoring the ground and radials at the tower, and preferring to go towards the house on the coax, if the coax wasn't even connected close to the tower. "I assume it was unhooked, and just laying on the ground." From all I have read here, this hit was (luckily) one of rare intensity and diversity. Two strikes to the tower later in the summer of last year had only minor impact on anything. I wouldn't leave any more unprotected feedlines hooked up during storms. I think all would have been ok, if not for that. Or at least assuming there was no strike on the power lines a short distance from your house when this happened. MK |
Mark:
"Mark Keith" wrote in Thanks to all responding. A 20m antenna on top of the tower was demolished, pieces landing 100' away. That one single feedline was connected and operating a wx-alert system in the shop. Big omission... I now think the tower was hit, and piped the energy to the wx-alert system which then routed it to the rest of the house via the power wiring. Was that coax routed down to and snubbed to ground at the base of the tower? From the damage, it almost sounds like it was elevated in the air from the tower to the shop. That feedline went underground at base of tower with all the rest. At the main feedline disconnect point (20' from tower and about 50' from shop), it went toward shop with two other feedlines, only the 20m was connected and running SkyWarn. Skywarn tranceiver was powered by pair of 12vdc batteries, which had a smart-charger (float) charge connected via AC power. All of that equipment was destroyed including things near to it and not connected. I bet the wx-alert box was the point where it got into the ac wiring. I just can't see lightning energy traveling towards the house on a coax that is on the ground. Once the lightning is at ground, normally it should stay there. It's where it wants to go. I don't see it ignoring the ground and radials at the tower, and preferring to go towards the house on the coax, if the coax wasn't even connected close to the tower. "I assume it was unhooked, and just laying on the ground." All other feedlines to shop and house were laying diconnected at the two PVC risers coning up out of ground about 20' from base of tower, 50' from shop. I wouldn't leave any more unprotected feedlines hooked up during storms. I think all would have been ok, if not for that. Or at least assuming there was no strike on the power lines a short distance from your house when this happened. MK Cable tv was knocked out for nearby homes as well, one or more utiilty poles may have been hit at the same time. On the 20m, It only takes one occurrence of bad judgement. Jack |
"J. Harvey" wrote in message m... "Roger Halstead" Rarely does the system suffer damage. ...one computer... ...one PolyPhaser... ...a repeater antenna... ...a section of 5/8ths inch Heliax... ...every bit of water proofing... ...all the silver plating... ...a two meter rig... ...a barrel connector (N type)... Geesus H. ! I saw the result of a lightening strike at Barkway on Royston Heath. The lightening came down our waveguide without any damage but inside teh equipemy huit it vapourised teh big circuit breaker on teh wall and left a hole wher it had been and chared melted wires some distance above and below wher the box had been mounted. I guess so long as you think that you're happy, then you're happy. ;-) cogito ergo sum Only some 3,000 years earlier. Gary7SLL |
On Sat, 31 Jan 2004 22:29:19 +0000 (UTC), "Gary Peach"
wrote: "J. Harvey" wrote in message om... "Roger Halstead" Rarely does the system suffer damage. ...one computer... ...one PolyPhaser... ...a repeater antenna... ...a section of 5/8ths inch Heliax... ...every bit of water proofing... ...all the silver plating... ...a two meter rig... ...a barrel connector (N type)... Geesus H. ! I saw the result of a lightening strike at Barkway on Royston Heath. The lightening came down our waveguide without any damage but inside teh equipemy huit it vapourised teh big circuit breaker on teh wall and left a hole wher it had been and chared melted wires some distance above and below wher the box had been mounted. Can't think of a better place for "lightening" to strike than Barkway. I kate it you where in eht RAF hewn all this happened? -- Jock. |
"Jock" wrote in message ... On Sat, 31 Jan 2004 22:29:19 +0000 (UTC), "Gary Peach" wrote: "J. Harvey" wrote in message om... "Roger Halstead" Rarely does the system suffer damage. ...one computer... ...one PolyPhaser... ...a repeater antenna... ...a section of 5/8ths inch Heliax... ...every bit of water proofing... ...all the silver plating... ...a two meter rig... ...a barrel connector (N type)... Geesus H. ! I saw the result of a lightening strike at Barkway on Royston Heath. The lightening came down our waveguide without any damage but inside teh equipemy huit it vapourised teh big circuit breaker on teh wall and left a hole wher it had been and chared melted wires some distance above and below wher the box had been mounted. Can't think of a better place for "lightening" to strike than Barkway. I kate it you where in eht RAF hewn all this happened? No, Engineer (Microwave) with PYE Telecommunications We had teh first non GPO television microwave link between Birmingham and London. We were trying to break teh GPO monopoly on supplying and also regulating radio communications. It must have worked because the GPO /BT is no longer the only supplieer. CML building Birmingham, Meriden, Cold Ashby, Barkway, Hill Crest (Highgate, just down teh road from the BBC station at Swains Lane) We were contracted to ATV. Teh Link was used to show the adverts going out in Birmingham to the sponsors in London. Thanks for taking the **** out of my creeping disability, It keeps a sens of proportion for me, console yourself that it won't last much longer and I won't be able to type at all. Gary7SLL |
"Roger Halstead" wrote
Computers run 24 X 7 (bout 32,000 hours run time a year) and are hard wired together with Cat 5 cable. No problems since going to UPSs with line conditioning. Last Fall, this one had over 57 transfers to the UPS over 3 months including 3 brown outs, one black out (quite a few hours), and the rest was line noise. I too had at least that many momentary high line-noise and brownout shifts to APC since Hurricane Isabel last September. But my computer runs in real time, so it could only get 8,736 hrs in a year if I left it on all the time :-) Jack |
On Sun, 1 Feb 2004 20:37:24 -0500, "Jack Painter"
wrote: "Roger Halstead" wrote Computers run 24 X 7 (bout 32,000 hours run time a year) and are hard wired together with Cat 5 cable. No problems since going to UPSs with line conditioning. Last Fall, this one had over 57 transfers to the UPS over 3 months including 3 brown outs, one black out (quite a few hours), and the rest was line noise. I too had at least that many momentary high line-noise and brownout shifts to APC since Hurricane Isabel last September. But my computer runs in real time, so it could only get 8,736 hrs in a year if I left it on all the time Note that was computer(s) as in plural. I have 4 :-)) Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com :-) Jack |
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