Re: [Elecraft] A dumb question about lightning
I especially agree with your last sentence. However I like to describe it as: "Every device is at the same potential". Nothing will be damaged even if everything is at 20,000 volts- as you say, no current will flow. -John NI0K -Original Message- From: elecraft-boun...@mailman.qth.net On Behalf Of Bill Frantz Sent: Friday, August 4, 2023 3:32 PM To: Elecraft List Subject: Re: [Elecraft] A dumb question about lightning While you are trying to make sense of the best practices lightning protection documents: N0AX’s ARRL book “Grounding and Bonding for the Radio Amateur” Motorola’s STANDARDS AND GUIDELINES FOR COMMUNICATION SITES https://www.blm.gov/sites/blm.gov/files/Lands_ROW_Motorola_R56_2005_manual.pdf K9YC’s Power, Grounding, Bonding, and Audio for Ham Radio. http://k9yc.com/GroundingAndAudio.pdf There are a few items of AC electrical behavior to keep in mind: Lightning is produced by a giant spark-gap transmitter. It is a VERY broad RF signal centered at about 1 MHz. There’s no such thing as a wire at RF, they are all transmission lines. Everything has both inductance and capacitance. These inductances will affect the way grounding lines work. Conductors at RF exhibit what is called the surface effect, where the current is limited to the surface of the conductor. This is why 50cm (2 inch) wide copper leads, with their large surface area, are recommended. (Note that the surface effect is also important for AC power distribution systems at 50 or 60 Hz.) Proper bonding in the station can make all the equipment “float” at the same voltage above the local soil. If no current flows through the equipment, it will not be damaged. 73 Bill AE6JV __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to jasimm...@pinewooddata.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] A dumb question about lightning
While you are trying to make sense of the best practices lightning protection documents: N0AX’s ARRL book “Grounding and Bonding for the Radio Amateur” Motorola’s STANDARDS AND GUIDELINES FOR COMMUNICATION SITES https://www.blm.gov/sites/blm.gov/files/Lands_ROW_Motorola_R56_2005_manual.pdf K9YC’s Power, Grounding, Bonding, and Audio for Ham Radio. http://k9yc.com/GroundingAndAudio.pdf There are a few items of AC electrical behavior to keep in mind: Lightning is produced by a giant spark-gap transmitter. It is a VERY broad RF signal centered at about 1 MHz. There’s no such thing as a wire at RF, they are all transmission lines. Everything has both inductance and capacitance. These inductances will affect the way grounding lines work. Conductors at RF exhibit what is called the surface effect, where the current is limited to the surface of the conductor. This is why 50cm (2 inch) wide copper leads, with their large surface area, are recommended. (Note that the surface effect is also important for AC power distribution systems at 50 or 60 Hz.) Proper bonding in the station can make all the equipment “float” at the same voltage above the local soil. If no current flows through the equipment, it will not be damaged. 73 Bill AE6JV __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] A dumb question about lightning
Not sure you got an answer to your question ... two rules of thumb: 1. Follow the NEC, it's incorporated in building codes, essentially the law, and failure to do so could possibly invalidate your insurance claim should you need to file for damages. 2. Read and use the techniques and procedures in the ARRL Grounding and Bonding book, don't make up your own. I think the book is about $30. It is well worth the price. 3. Avoid advice from internet lists ... see #1 and #2 above. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County jerry wrote on 7/31/2023 2:14 PM: Interesting. Suppose the service entrance is at one end of the house, and the ham shack at the other end? I don't think it's physically possible to provide a low inductance path that's 60 feet long, is it? Would a solution be to DC-isolate the station from the grounded antenna? Say with a wideband toroid 1:1 transformer? Then ground the station through the 3rd pin of the AC outlet? Here in the San Francisco Bay Area, lighting is rare. It used to be entirely unheard of - we just don't get the kind of convective weather that produces it. We're more about coastal stratus. But with climate change, that might be changing. There was quite a display once last year. - Jerry, KF6VB On 2023-07-31 13:20, Fred Jensen wrote: Be very careful of advice regarding lightning protection. There are some very good sources, starting with the NEC and including material from ARRL. Some is somewhat non-intuitive. For example, the NEC requires that any additional "earth electrodes" [aka ground rods] be bonded to the service entrance earth electrode with a low inductance path. There's been quite an array of advice circulating here recently, much of it wrong, some dangerous. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County Geoffrey Feldman wrote on 7/28/2023 5:02 PM: First thing and foremost - switches are mostly not relevant to protection. Energy that can travel 1000' through the sky is likely to continue across most switches. So, the utmost of safety is what you indicated you did - disconnect. By disconnect, I mean either disconnect outside the building, leaving the feed on the ground or leave the feed connected to a copper plate that is in turn connected to an 8' deep ground stake. On the inside of the house, disconnect the lines from that plate and leave them on the floor. Another such stake near the feed point of the antenna is also a great idea. If it's possible to lower the antenna when not in use, that's a great idea. This should be the default when not in use. You have the belief that no grounding system is perfectly effective (for all imaginable strikes) - maybe, but a good grounding system is far better than foolishness. A grounding system, or an antenna is not a "lightning magnet". If it doesn't strike it won't. If it does it will and the grounding system assures the energy will be less likely to cause harm. Some places and circumstances are more or less likely but everywhere is possible. If that possibility happens, a good grounding system is why it is likely to be survived. A key thing to understand is that when Lightning strikes in nature, all the energy travels along the surface of the ground. It can do this for many feet and be lethal doing it. Anything that stands along the radius from the point of the strike (one part closer and the other further) is in danger. Four legged animals, having more distant contact points, more dangerous. The purpose of a ground stake (8' straight down) is to channel the electricity deep, rather than along the surface. Don't use emotional theories. Read the lightning mitigation and grounding books offered by the ARRL. Use UL approved conductors and stakes. Do not use your homes electrical service ground stake. Keep that separate. All the above is a "cliffs notes" and so is anything else posted here. Read the books. Ask senior members of a local club, to review your plan. W1GCF Geoff -- This email has been checked for viruses by AVG antivirus software. www.avg.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] A dumb question about lightning
Hi, Everybody, I greatly apologize for escalating the list traffic with my question on lightning. I merely wanted to get your thoughts on disconnecting equipment in addition to grounding and bonding. And the overwhelming consensus-- in both public and private responses-- is that yes, in fact, most people physically disconnect, rather than relying 100% on grounding and bonding to protect their equipment. So I'm going to continue to do so, accepting this practice as necessary in the state where I now live. Keep on reading the books, installing proper grounding, follow the law, and follow good practice. And good luck avoiding a direct hit! Regards, Al W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] A dumb question about lightning
Hello Bob, thank you very much. I appreciate your information. I do plan to
connect everything together, although I will only be able to go around half of
the house. There’s nothing going on in the front of the house, including
antenna, or electricity.
Gerry Leary Wb6ivf
On Jul 31, 2023, at 7:49 PM, Bob McGraw wrote:
Fred is absolutely correct on this point. The NEC {National Electrical Code}
clearly states that all driven grounds MUST be bonded to the AC mains service
entrance ground. There is NO exception to this procedure. An exception does
exist when the structure is XX number of feet distant from the AC mains
service. (I forget the distance number).
In general, your station ground must be bonded to the AC mains ground.
Otherwise, your equipment is in the current path between two or more different
ground points. Even with antennas disconnected or grounded, and the station
turned off, the path of least resistance between the two grounds is through
your equipment. That will definitely let the smoke out of the box. Not good.
Please deal with science and facts. DO NOT rely on "old ham lore" that is most
likely incorrect and gets more and more incorrect with the telling or writing.
73
Bob, K4TAX
Message: 20
Date: Mon, 31 Jul 2023 13:20:06 -0700
From: Fred Jensen
To: Geoffrey Feldman
Cc:elecraft@mailman.qth.net
Subject: Re: [Elecraft] A dumb question about lightning
Message-ID:<87985aa1-b606-cec8-f07c-5edbadbdc...@gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Be very careful of advice regarding lightning protection.? There are
some very good sources, starting with the NEC and including material
from ARRL.? Some is somewhat non-intuitive.? For example, the NEC
requires that any additional "earth electrodes" [aka ground rods] be
bonded to the service entrance earth electrode with a low inductance
path. There's been quite an array of advice circulating here recently,
much of it wrong, some dangerous.
73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County
__
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Re: [Elecraft] A dumb question about lightning
Fred is absolutely correct on this point. The NEC {National Electrical
Code} clearly states that all driven grounds MUST be bonded to the AC
mains service entrance ground. There is NO exception to this
procedure. An exception does exist when the structure is XX number of
feet distant from the AC mains service. (I forget the distance number).
In general, your station ground must be bonded to the AC mains ground.
Otherwise, your equipment is in the current path between two or more
different ground points. Even with antennas disconnected or grounded,
and the station turned off, the path of least resistance between the two
grounds is through your equipment. That will definitely let the smoke
out of the box. Not good.
Please deal with science and facts. DO NOT rely on "old ham lore" that
is most likely incorrect and gets more and more incorrect with the
telling or writing.
73
Bob, K4TAX
Message: 20
Date: Mon, 31 Jul 2023 13:20:06 -0700
From: Fred Jensen
To: Geoffrey Feldman
Cc:elecraft@mailman.qth.net
Subject: Re: [Elecraft] A dumb question about lightning
Message-ID:<87985aa1-b606-cec8-f07c-5edbadbdc...@gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Be very careful of advice regarding lightning protection.? There are
some very good sources, starting with the NEC and including material
from ARRL.? Some is somewhat non-intuitive.? For example, the NEC
requires that any additional "earth electrodes" [aka ground rods] be
bonded to the service entrance earth electrode with a low inductance
path. There's been quite an array of advice circulating here recently,
much of it wrong, some dangerous.
73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County
__
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Re: [Elecraft] A dumb question about lightning
Jim's slides give great examples and the msg or either keeping all connections at the same potential or completely isolated is all very good advice. Having dealt with this my entire life in industry though, there is one more thing to add. Lightning strikes are always matters of probability. If you get a DIRECT strike, no bonding etc. is sure to save you with the energy released in such a hit. We are talking possibly hundreds (even thousands) of amps of current and very high voltages. On TWO occasions I have witnessed those Square-D Whole House line protectors blow clear out of the breaker box in a direct strike into a smoldering pile on the floor. My take-away from that is the only marginally safe place for my expensive radios was as disconnected and in the shipping boxed in the (faraday) closet in the basement during a storm (just like an airplane). Dr. William J. Schmidt email: b...@wjschmidt.com -Original Message- From: elecraft-boun...@mailman.qth.net On Behalf Of Jim Brown Sent: Monday, July 31, 2023 5:25 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] A dumb question about lightning On 7/31/2023 2:14 PM, jerry wrote: > Interesting. Suppose the service entrance is at one end of the house, > and the ham shack at the other end? I don't think it's physically > possible to provide a low inductance path that's 60 feet long, is it? I've posted a link to my tutorial, which covers this, but which folks who need to know what's in it haven't bothered to read. Fred is absolutely correct, BY LAW, all grounds in a premises MUST be bonded together. In his ARRL book on the topic, to which I contributed, Ward Silver, N0AX, recommends a perimeter ground ring, connecting multiple driven rods. A full perimeter ring wasn't practical for the building that houses my shack, so I did a half perimeter ring from the sub-panel for the building to the shack on the other side of the building. Jerry is entirely correct -- indeed, the rule of thumb for bonding between a tower and the building(s) where there's no mains power at the tower is to NOT bond if the tower is more than 100 ft from grounds for the building (and some references suggest 60 ft). The whole point of bonding all the grounds is so that in the event of a strike, the entire premises rises as closely as practical to the same potential, minimizing the potential difference between grounded equipment and surfaces. Re-posting the link. http://k9yc.com/GroundingAndAudio.pdf And it's NOT mainly about audio. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to b...@wjschmidt.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] A dumb question about lightning
On 7/31/2023 2:14 PM, jerry wrote: Interesting. Suppose the service entrance is at one end of the house, and the ham shack at the other end? I don't think it's physically possible to provide a low inductance path that's 60 feet long, is it? I've posted a link to my tutorial, which covers this, but which folks who need to know what's in it haven't bothered to read. Fred is absolutely correct, BY LAW, all grounds in a premises MUST be bonded together. In his ARRL book on the topic, to which I contributed, Ward Silver, N0AX, recommends a perimeter ground ring, connecting multiple driven rods. A full perimeter ring wasn't practical for the building that houses my shack, so I did a half perimeter ring from the sub-panel for the building to the shack on the other side of the building. Jerry is entirely correct -- indeed, the rule of thumb for bonding between a tower and the building(s) where there's no mains power at the tower is to NOT bond if the tower is more than 100 ft from grounds for the building (and some references suggest 60 ft). The whole point of bonding all the grounds is so that in the event of a strike, the entire premises rises as closely as practical to the same potential, minimizing the potential difference between grounded equipment and surfaces. Re-posting the link. http://k9yc.com/GroundingAndAudio.pdf And it's NOT mainly about audio. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] A dumb question about lightning
These kinds of questions are exactly why there is an entire ARRL book on the subject. Short version, you need a system that provides both a safety ground for the AC power wiring and an RF ground for lightning protection. In 2020, both the CZU Lightning Complex and SCU Lightning Complex fires were large destructive fires started by lightning. My weather station counts lightning strikes near Palo Alto. It recorded 27 in Jan, 17 in Feb, and 16 in March. That would be one thunderstorm in Texas, but it is still enough to damage a radio. wunder K6WRU Walter Underwood CM87wj http://observer.wunderwood.org/ (my blog) > On Jul 31, 2023, at 2:14 PM, jerry wrote: > > Interesting. Suppose the service entrance is at one end of the house, > and the ham shack at the other end? I don't think it's physically > possible to provide a low inductance path that's 60 feet long, is it? > > Would a solution be to DC-isolate the station from the grounded antenna? > Say with a wideband toroid 1:1 transformer? Then ground the station through > the > 3rd pin of the AC outlet? > > Here in the San Francisco Bay Area, lighting is rare. It used to be > entirely > unheard of - we just don't get the kind of convective weather that produces > it. We're more about coastal stratus. But with climate change, that might be > changing. There was quite a display once last year. > >- Jerry, KF6VB > > > On 2023-07-31 13:20, Fred Jensen wrote: >> Be very careful of advice regarding lightning protection. There are >> some very good sources, starting with the NEC and including material >> from ARRL. Some is somewhat non-intuitive. For example, the NEC >> requires that any additional "earth electrodes" [aka ground rods] be >> bonded to the service entrance earth electrode with a low inductance >> path. There's been quite an array of advice circulating here recently, >> much of it wrong, some dangerous. >> 73, >> Fred ["Skip"] K6DGW >> Sparks NV DM09dn >> Washoe County >> Geoffrey Feldman wrote on 7/28/2023 5:02 PM: >>> First thing and foremost - switches are mostly not relevant to protection. >>> Energy that can travel 1000' through the sky is likely to continue across >>> most switches. So, the utmost of safety is what you indicated you did - >>> disconnect. By disconnect, I mean either disconnect outside the building, >>> leaving the feed on the ground or leave the feed connected to a copper plate >>> that is in turn connected to an 8' deep ground stake. On the inside of the >>> house, disconnect the lines from that plate and leave them on the floor. >>> Another such stake near the feed point of the antenna is also a great idea. >>> If it's possible to lower the antenna when not in use, that's a great idea. >>> This should be the default when not in use. >>> You have the belief that no grounding system is perfectly effective (for >>> all >>> imaginable strikes) - maybe, but a good grounding system is far better than >>> foolishness. A grounding system, or an antenna is not a "lightning >>> magnet". If it doesn't strike it won't. If it does it will and the grounding >>> system assures the energy will be less likely to cause harm. Some places and >>> circumstances are more or less likely but everywhere is possible. If that >>> possibility happens, a good grounding system is why it is likely to be >>> survived. >>> A key thing to understand is that when Lightning strikes in nature, all the >>> energy travels along the surface of the ground. It can do this for many >>> feet and be lethal doing it. Anything that stands along the radius from the >>> point of the strike (one part closer and the other further) is in danger. >>> Four legged animals, having more distant contact points, more dangerous. >>> The purpose of a ground stake (8' straight down) is to channel the >>> electricity deep, rather than along the surface. >>> Don't use emotional theories. Read the lightning mitigation and grounding >>> books offered by the ARRL. Use UL approved conductors and stakes. Do not >>> use your homes electrical service ground stake. Keep that separate. >>> All the above is a "cliffs notes" and so is anything else posted here. Read >>> the books. Ask senior members of a local club, to review your plan. >>> W1GCF Geoff > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to wun...@wunderwood.org __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.n
Re: [Elecraft] A dumb question about lightning
Interesting. Suppose the service entrance is at one end of the house, and the ham shack at the other end? I don't think it's physically possible to provide a low inductance path that's 60 feet long, is it? Would a solution be to DC-isolate the station from the grounded antenna? Say with a wideband toroid 1:1 transformer? Then ground the station through the 3rd pin of the AC outlet? Here in the San Francisco Bay Area, lighting is rare. It used to be entirely unheard of - we just don't get the kind of convective weather that produces it. We're more about coastal stratus. But with climate change, that might be changing. There was quite a display once last year. - Jerry, KF6VB On 2023-07-31 13:20, Fred Jensen wrote: Be very careful of advice regarding lightning protection. There are some very good sources, starting with the NEC and including material from ARRL. Some is somewhat non-intuitive. For example, the NEC requires that any additional "earth electrodes" [aka ground rods] be bonded to the service entrance earth electrode with a low inductance path. There's been quite an array of advice circulating here recently, much of it wrong, some dangerous. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County Geoffrey Feldman wrote on 7/28/2023 5:02 PM: First thing and foremost - switches are mostly not relevant to protection. Energy that can travel 1000' through the sky is likely to continue across most switches. So, the utmost of safety is what you indicated you did - disconnect. By disconnect, I mean either disconnect outside the building, leaving the feed on the ground or leave the feed connected to a copper plate that is in turn connected to an 8' deep ground stake. On the inside of the house, disconnect the lines from that plate and leave them on the floor. Another such stake near the feed point of the antenna is also a great idea. If it's possible to lower the antenna when not in use, that's a great idea. This should be the default when not in use. You have the belief that no grounding system is perfectly effective (for all imaginable strikes) - maybe, but a good grounding system is far better than foolishness. A grounding system, or an antenna is not a "lightning magnet". If it doesn't strike it won't. If it does it will and the grounding system assures the energy will be less likely to cause harm. Some places and circumstances are more or less likely but everywhere is possible. If that possibility happens, a good grounding system is why it is likely to be survived. A key thing to understand is that when Lightning strikes in nature, all the energy travels along the surface of the ground. It can do this for many feet and be lethal doing it. Anything that stands along the radius from the point of the strike (one part closer and the other further) is in danger. Four legged animals, having more distant contact points, more dangerous. The purpose of a ground stake (8' straight down) is to channel the electricity deep, rather than along the surface. Don't use emotional theories. Read the lightning mitigation and grounding books offered by the ARRL. Use UL approved conductors and stakes. Do not use your homes electrical service ground stake. Keep that separate. All the above is a "cliffs notes" and so is anything else posted here. Read the books. Ask senior members of a local club, to review your plan. W1GCF Geoff __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] A dumb question about lightning
Hello Fred, I am getting ready to put up a hex beam. I’m going to put it on a 31 foot self supporting aluminum mast from US towers. The mast sits on a base, and the base will sit on a concrete pad. that is 4 ft.² and 6 feet deep. Would you offer me a little advice on grounding, for lightning protection. My plan, is to push an 8 foot rod into the ground close to the concrete block that the base of the tower will be mounted on. I may use lightning arrester’s there, and also add a ground rod that is Sunk into the ground near the house where the coax will go through the wall. Do you think this will work well or do you or could you offer me other suggestions if this one doesn’t sound good? Thank you very very much. Gerry Leary Wb6ivf On Jul 31, 2023, at 2:20 PM, Fred Jensen wrote: Be very careful of advice regarding lightning protection. There are some very good sources, starting with the NEC and including material from ARRL. Some is somewhat non-intuitive. For example, the NEC requires that any additional "earth electrodes" [aka ground rods] be bonded to the service entrance earth electrode with a low inductance path. There's been quite an array of advice circulating here recently, much of it wrong, some dangerous. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County Geoffrey Feldman wrote on 7/28/2023 5:02 PM: > > First thing and foremost - switches are mostly not relevant to protection. > Energy that can travel 1000' through the sky is likely to continue across > most switches. So, the utmost of safety is what you indicated you did - > disconnect. By disconnect, I mean either disconnect outside the building, > leaving the feed on the ground or leave the feed connected to a copper plate > that is in turn connected to an 8' deep ground stake. On the inside of the > house, disconnect the lines from that plate and leave them on the floor. > Another such stake near the feed point of the antenna is also a great idea. > If it's possible to lower the antenna when not in use, that's a great idea. > This should be the default when not in use. > > > You have the belief that no grounding system is perfectly effective (for all > imaginable strikes) - maybe, but a good grounding system is far better than > foolishness. A grounding system, or an antenna is not a "lightning > magnet". If it doesn't strike it won't. If it does it will and the grounding > system assures the energy will be less likely to cause harm. Some places and > circumstances are more or less likely but everywhere is possible. If that > possibility happens, a good grounding system is why it is likely to be > survived. > > > A key thing to understand is that when Lightning strikes in nature, all the > energy travels along the surface of the ground. It can do this for many > feet and be lethal doing it. Anything that stands along the radius from the > point of the strike (one part closer and the other further) is in danger. > Four legged animals, having more distant contact points, more dangerous. > The purpose of a ground stake (8' straight down) is to channel the > electricity deep, rather than along the surface. > > > Don't use emotional theories. Read the lightning mitigation and grounding > books offered by the ARRL. Use UL approved conductors and stakes. Do not > use your homes electrical service ground stake. Keep that separate. > > > All the above is a "cliffs notes" and so is anything else posted here. Read > the books. Ask senior members of a local club, to review your plan. > > > W1GCF Geoff > -- This email has been checked for viruses by AVG antivirus software. www.avg.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to gerrylear...@icloud.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] A dumb question about lightning
Be very careful of advice regarding lightning protection. There are some very good sources, starting with the NEC and including material from ARRL. Some is somewhat non-intuitive. For example, the NEC requires that any additional "earth electrodes" [aka ground rods] be bonded to the service entrance earth electrode with a low inductance path. There's been quite an array of advice circulating here recently, much of it wrong, some dangerous. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County Geoffrey Feldman wrote on 7/28/2023 5:02 PM: First thing and foremost - switches are mostly not relevant to protection. Energy that can travel 1000' through the sky is likely to continue across most switches. So, the utmost of safety is what you indicated you did - disconnect. By disconnect, I mean either disconnect outside the building, leaving the feed on the ground or leave the feed connected to a copper plate that is in turn connected to an 8' deep ground stake. On the inside of the house, disconnect the lines from that plate and leave them on the floor. Another such stake near the feed point of the antenna is also a great idea. If it's possible to lower the antenna when not in use, that's a great idea. This should be the default when not in use. You have the belief that no grounding system is perfectly effective (for all imaginable strikes) - maybe, but a good grounding system is far better than foolishness. A grounding system, or an antenna is not a "lightning magnet". If it doesn't strike it won't. If it does it will and the grounding system assures the energy will be less likely to cause harm. Some places and circumstances are more or less likely but everywhere is possible. If that possibility happens, a good grounding system is why it is likely to be survived. A key thing to understand is that when Lightning strikes in nature, all the energy travels along the surface of the ground. It can do this for many feet and be lethal doing it. Anything that stands along the radius from the point of the strike (one part closer and the other further) is in danger. Four legged animals, having more distant contact points, more dangerous. The purpose of a ground stake (8' straight down) is to channel the electricity deep, rather than along the surface. Don't use emotional theories. Read the lightning mitigation and grounding books offered by the ARRL. Use UL approved conductors and stakes. Do not use your homes electrical service ground stake. Keep that separate. All the above is a "cliffs notes" and so is anything else posted here. Read the books. Ask senior members of a local club, to review your plan. W1GCF Geoff -- This email has been checked for viruses by AVG antivirus software. www.avg.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] A dumb question about lightning
Geoff, I certainly understand your "do it right" approach...the impossible: 8 ft ground rods -- I have bedrock at 36-42". When I put the tower up, I tried. I rented a heavy SDS hammer drill and, despite hours of trying, never got deeper than 5 ft. And what good is a single, shallow rod in rock? "Lower the antenna to the ground when a storm approaches." I'm not going out at 2 a.m. to fool with antennas. With frequent storms,I might as well leave the antennas on the ground except when operating. Not worth the time and effort to pull them back up for an hour of operating. Too much of a mess and tangle to leave them on the ground, I'm talking 60,and 80 and 40m antennas, support lines, coax, etc. Tangles. I don't operate that much, and it would not be worth all the hassle. Technically I know you are right. From a practical standpoint, it's probably time to turn in my license and sell the equipment. (My Novice license was issued 60 years ago.) Solutions have to be practical. Quitting the hobby is the only practical solution I see. 73, Ken WA8JXM On Mon, Jul 31, 2023 at 10:57 AM Geoffrey Feldman wrote: > > > First thing and foremost - switches are mostly not relevant to protection. > Energy that can travel 1000' through the sky is likely to continue across > most switches. So, the utmost of safety is what you indicated you did - > disconnect. By disconnect, I mean either disconnect outside the building, > leaving the feed on the ground or leave the feed connected to a copper > plate > that is in turn connected to an 8' deep ground stake. On the inside of the > house, disconnect the lines from that plate and leave them on the floor. > Another such stake near the feed point of the antenna is also a great idea. > If it's possible to lower the antenna when not in use, that's a great idea. > This should be the default when not in use. > > > > You have the belief that no grounding system is perfectly effective (for > all > imaginable strikes) - maybe, but a good grounding system is far better than > foolishness. A grounding system, or an antenna is not a "lightning > magnet". If it doesn't strike it won't. If it does it will and the > grounding > system assures the energy will be less likely to cause harm. Some places > and > circumstances are more or less likely but everywhere is possible. If that > possibility happens, a good grounding system is why it is likely to be > survived. > > > > A key thing to understand is that when Lightning strikes in nature, all the > energy travels along the surface of the ground. It can do this for many > feet and be lethal doing it. Anything that stands along the radius from > the > point of the strike (one part closer and the other further) is in danger. > Four legged animals, having more distant contact points, more dangerous. > The purpose of a ground stake (8' straight down) is to channel the > electricity deep, rather than along the surface. > > > > Don't use emotional theories. Read the lightning mitigation and grounding > books offered by the ARRL. Use UL approved conductors and stakes. Do not > use your homes electrical service ground stake. Keep that separate. > > > > All the above is a "cliffs notes" and so is anything else posted here. Read > the books. Ask senior members of a local club, to review your plan. > > > > W1GCF Geoff > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to wa8...@gmail.com > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] A dumb question about lightning
First thing and foremost - switches are mostly not relevant to protection. Energy that can travel 1000' through the sky is likely to continue across most switches. So, the utmost of safety is what you indicated you did - disconnect. By disconnect, I mean either disconnect outside the building, leaving the feed on the ground or leave the feed connected to a copper plate that is in turn connected to an 8' deep ground stake. On the inside of the house, disconnect the lines from that plate and leave them on the floor. Another such stake near the feed point of the antenna is also a great idea. If it's possible to lower the antenna when not in use, that's a great idea. This should be the default when not in use. You have the belief that no grounding system is perfectly effective (for all imaginable strikes) - maybe, but a good grounding system is far better than foolishness. A grounding system, or an antenna is not a "lightning magnet". If it doesn't strike it won't. If it does it will and the grounding system assures the energy will be less likely to cause harm. Some places and circumstances are more or less likely but everywhere is possible. If that possibility happens, a good grounding system is why it is likely to be survived. A key thing to understand is that when Lightning strikes in nature, all the energy travels along the surface of the ground. It can do this for many feet and be lethal doing it. Anything that stands along the radius from the point of the strike (one part closer and the other further) is in danger. Four legged animals, having more distant contact points, more dangerous. The purpose of a ground stake (8' straight down) is to channel the electricity deep, rather than along the surface. Don't use emotional theories. Read the lightning mitigation and grounding books offered by the ARRL. Use UL approved conductors and stakes. Do not use your homes electrical service ground stake. Keep that separate. All the above is a "cliffs notes" and so is anything else posted here. Read the books. Ask senior members of a local club, to review your plan. W1GCF Geoff __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] A dumb question about lightning
No such thing as a dumb question about lightning. I spent 15 years in South Florida. I've seen some lightning! Welcome to KY. I'm in middle TN and do understand lightning. The ARRL publication by Ward Silver, Grounding and Bonding for the Amateur, is about the best compilation available and understandable. Three points I consider as mandatory: (A) All efforts for lightning protection should be implemented outside of the house. Never inside. (B) All driven station and tower ground rods must be bonded together and back to the AC Mains ground outside of the structure. (C) Each piece of equipment should be bonded to a common point such as the station power supply , using dedicated bonding jumpers. All efforts are toward mitigation of lightning damage. 73 Bob, K4TAX On 7/28/2023 4:14 PM, elecraft-requ...@mailman.qth.net wrote: Message: 19 From: Al Lorona To: Elecraft Reflector Subject: A dumb question about lightning Please don't laugh at me; I'm a transplant from a region of the country with essentially no lightning to a region where you have to worry about it quite a bit. We had a doozy of a storm last night, with lots of lightning overhead. I felt like a sitting duck, even though I had grounded both sides of the balanced feedline of the antenna, switched the antenna switch to the middle (grounded) position, and even disconnected the coax leading to the K3's rear-panel antenna port. Whenever lightning happens, I always wonder if it really is in fact better to ground everything. Because, doesn't that essentially make a lightning rod of the antenna? If I simply disconnected the antenna and left it floating, wouldn't it be less likely to attract a lightning bolt? I'm of the belief that it's better to try to avoid a direct hit than to attract one and trust your grounding system to do its thing. I'm of the belief that no grounding system is perfectly effective. Al? W6LX/4 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
