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] Lightening static
It isn't limited to vertical antennas at all. I once got zapped with a thick 2 inch long bright blue arc from an 80m Inverted-V that didn't have any static bleedoff. I used to just short the shack end of the coax for that purpose, but one time I had forgotten to do that until I remembered just as a storm was approaching in the distance. As I reached down to put on the sorted PL259 (I had one hand on the concrete floor) the zap nailed me on the other hand. The biceps of both arms were sore for three days. Anything that can generate a difference of potential is a potential risk. It's informative to look up how much voltage is required to create a 2" arc in dry air. I can't find a source, but it would probably also interesting to see what kind of current is necessary to make the arc almost 2 mm thick. 73, Dave AB7E On 7/31/2023 2:54 PM, Gmail wrote: Static buildup is a problem mostly with vertical antennas. __ 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] Lightening static
Static buildup is a problem mostly with vertical antennas. Wind blowing across the antenna creates static. Measure the end of the coax cable to see if there is DC connection to ground. Some of the lightening devices have static drain inductors. I think AC/DC does. Polyphasers do not. Coil “Q” coil on a butternut ant asks as a static drain choke. The black box matching units on Cushcraft verticals have a static drain choke. If there is not a DC path to ground, use a 1 megohm resistor or static drain choke. Do not disconnect cables inside the house. I have seen lightning jump 5 feet from a cable on the floor to a wall ac outlet. Do not bring lightning into the house, where it goes is unpredictable. ARRL, I think the “ doctor is in” did a story about coax switches and lightening. The switch contacts are to close together. Lightening will weld the contacts. Ray Sent from my iPad __ 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:
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] Lightning
My antenna is a broad-banded, low-Q, folded-fan vertical, low profile at just 33 ft. tall on a city lot. It covers 160m thru 6m with just a few components in its "tuner box" at feedpoint on the ground. Of course everything is directly connected to Mother Earth ground, DC wise and RF wise, which Hiram Percey referred to as 'plumber's delight.' It has 36 slightly buried radials and 38 ground rods in the back yard. Trees around here are much taller. Utility grounds are tied in. I sleep fairly well during storms. 73, Roy K6XK __ 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
[Elecraft] K3 For Sale (loaded)
For Sale Original owner / non-smoking environment K3 s/n 1193 was just replaced with K4D # 1285 Includes: * KPA3 - 100w internal amp * KIO3 (Remote I/O rev C) Serial CAT communications, digital I/O control, audio I/O for use with sound cards, dual speaker and headphone jacks, Aux connector * KXV3 RF I/O, RX antenna, XVTR connections, IF out * KAT3 ATU, AUX antenna input * KRX3 Sub Receiver (able to fully use Diversity RX) * KSYN3A (K3S) upgraded synthesizers in both main and sub * Roofing Filters * Main: 2.7khz, 400hz, 250hz * Sub: 2.7khz, 400hz * The following modifications / enhancements have also been installed * Front panel Microphone Circuit Modification * KI03 rev C upgrade (see above) K3IOBUFFKT * 12VDC OUT current mod KPA3 12V Sense Mod * K3 VFO Tuning Noise Reduction * IF Output Buffer Gain Modification * DSP upgrade * Audio Output Chip Protection Mod K3 AF Output Mod Kit * AF Stage Upgrade Line Out and Speaker Amp * CW Keying rise time mod CWRTMDKT * KRX3 Subout connector not installed / not needed but info and parts supplied * KPA3 Power Connector Replacement - Gold Pin mod * All K3 and Option manuals as well as modification documentation * (4) Spare set of knobs for AF gain / RF gain * Spare B VFO tuning knob * Spare SO-239 with attached plug (plugs into KAT3) * Spare KI03 Main Rev C with (1) KI03 Remote Module rev B and (1) KI03 Remote Module rev XD (all working, just removed due to upgrade. OTHER: * Small top cover scratche by middle rear screw about ¼ long. * Slight crack in VFO B knob repaired by Elecraft when in California for Gold Pin mod. (does not impact operation) * NOTE: A spare knob will be supplied (also slight crack and also repaired by Elecraft) * Latest revision firmware installed (MCU = 5.67, FPF = 1.26, DSP1 = 2.88, DSP2 = 2.88) * Pictures available on request Asking $2500.00 - - Includes insured UPS ground shipping to CONUS destinations. ($2400.00 if shipping not required) 73, Bruce N1LN __ 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] Lightning and grounding
Lightning is attracted to the highest point contact on earth from a cloud passing overhead. If your tower, or tree in the yard, the chimney on your roof, or the roof itself can be the closest to the heavily charged cloud passing just overhead. When the leader from earth, tree, building or tower is attracted to the opposite charge in the cloud and contact is made through the ionized air, the charged cloud will complete the contact and then the intense lightning bolt discharges to earth or structure with millions of volts of energy. With that in mind, the best way to handle that charge is to spread out that discharge of all the energy. I have ground rods placed around my tower at 10 foot intervals, all the ground rods are connected with #6 stranded copper wire buried about a foot deep. The coax cable has the shield grounded at the copper rod at the base of the tower. I also have the coax shield grounded at the ground rod just outside the shack before it enters the house. There are a total of 8 ground rods around my house starting at the utility power line input including the ground rod at the coax entrance. They are all interconnected by buried # 6 stranded copper wire. I also have an antenna (Alpha) 4 pole switch to ground the coax inside the house. A final measure is to disconnect the equipment from utility power at the station as well. We do not receive as many storms as Southern states do here in MA, but it only takes ONE, and we had a bad one back in 2005. It was a ground strike somewhere on our hill and it knocked out computers, TVs garage door openers, telephones, and other electronics all across the hill to as many as 20 houses. The flash of lightning was blinding as I just happened to be looking towards the windows facing the hill behind our house where a high tension tower and lines cross the hill about 300 feet behind the house. I remember checking for damage throughout our house and I witnessed blue corona from lower level outlets , very unnerving to say the least. So I take grounding VERY seriously and followed the ARRL latest book on Bonding and Grounding. Spread out the discharge of millions of volts of energy. Dick / W1REJ __ 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
Re: [Elecraft] K4 and Yamaha CM-500 Mic?
Pete, I'm using a CM500 that is a year or so old. It replaced one that finally fell apart and I was tired of gluing it back together. When I replaced the headset, I did not need to make any adjustments! I went from a K3 to a K4 with the Yamaha headset plugged into the rear connectors. My Mic gain on the K4 is set at 12. TX rear mic configuration is Bias ON Preamp OFF. 73 George AI4VZ On Mon, Jul 31, 2023 at 9:32 AM Pete Smith N4ZR wrote: > My CM-500 is about 4 years old, and shedding ear-pads, but it works fine > with my K3. > > 73, Pete N4ZR > > On 7/31/2023 6:52 AM, Alan Bloom wrote: > > I had never used my CM-500 on a K3 so I can't do that comparison. But > > on the K4 I had to turn on the internal mic preamp and set the mic > > gain all the way to maximum. That seemed to give about the correct > > level - I could talk at normal loudness to get 5 on the ALC. > > > > I also use the CM-500 on my laptop to record a radio show. I had to > > turn up the gain close to max on the computer as well. I think > > late-production CM-500s just tend to have low microphone sensitivity. > > > > Alan > > > > > > On 7/31/2023 1:40 AM, Oscar Staudt wrote: > >> When I got my K4D a month ago, I unplugged my Yamaha CM-500 mic and > >> headphones from my K3, and plugged them into the back of my K4. I set > >> the > >> mic input to rear, and mic bias on. I expected the mic to perform > >> like it had in the K3. > >> > >> > >> I attempted to get 3-5 bars of ALC by turning up the mic gain > >> control. Even > >> with the gain up to 80, I’d have to speak *very* loudly to just get a > >> flicker on the ALC meter. > >> > >> > >> I then went back into the mic configuration and turned on the preamp > >> (14dB). > >> After that I could get some ALC bars with the mic gain around 65 or > >> more. But > >> I still had to talk much louder than I had to with the same mic on > >> the K3. > >> (note: mic level on the K3 was set around 7). > >> > >> > >> Question: Is it reasonable to expect that I’d have to have the mic > >> gain at > >> such a high level - and still have to talk louder than my normal (K3) > >> level? > >> > >> > >> BTW, I can hook up the MH-4, switch to front mic, and all works > >> smooth with > >> mic gain around 12. > >> __ > >> 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 a...@elecraft.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 pete.n...@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 gdanne...@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] K4 and Yamaha CM-500 Mic?
My CM-500 is about 4 years old, and shedding ear-pads, but it works fine with my K3. 73, Pete N4ZR On 7/31/2023 6:52 AM, Alan Bloom wrote: I had never used my CM-500 on a K3 so I can't do that comparison. But on the K4 I had to turn on the internal mic preamp and set the mic gain all the way to maximum. That seemed to give about the correct level - I could talk at normal loudness to get 5 on the ALC. I also use the CM-500 on my laptop to record a radio show. I had to turn up the gain close to max on the computer as well. I think late-production CM-500s just tend to have low microphone sensitivity. Alan On 7/31/2023 1:40 AM, Oscar Staudt wrote: When I got my K4D a month ago, I unplugged my Yamaha CM-500 mic and headphones from my K3, and plugged them into the back of my K4. I set the mic input to rear, and mic bias on. I expected the mic to perform like it had in the K3. I attempted to get 3-5 bars of ALC by turning up the mic gain control. Even with the gain up to 80, I’d have to speak *very* loudly to just get a flicker on the ALC meter. I then went back into the mic configuration and turned on the preamp (14dB). After that I could get some ALC bars with the mic gain around 65 or more. But I still had to talk much louder than I had to with the same mic on the K3. (note: mic level on the K3 was set around 7). Question: Is it reasonable to expect that I’d have to have the mic gain at such a high level - and still have to talk louder than my normal (K3) level? BTW, I can hook up the MH-4, switch to front mic, and all works smooth with mic gain around 12. __ 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 a...@elecraft.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 pete.n...@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] K4 and Yamaha CM-500 Mic?
I had never used my CM-500 on a K3 so I can't do that comparison. But on the K4 I had to turn on the internal mic preamp and set the mic gain all the way to maximum. That seemed to give about the correct level - I could talk at normal loudness to get 5 on the ALC. I also use the CM-500 on my laptop to record a radio show. I had to turn up the gain close to max on the computer as well. I think late-production CM-500s just tend to have low microphone sensitivity. Alan On 7/31/2023 1:40 AM, Oscar Staudt wrote: When I got my K4D a month ago, I unplugged my Yamaha CM-500 mic and headphones from my K3, and plugged them into the back of my K4. I set the mic input to rear, and mic bias on. I expected the mic to perform like it had in the K3. I attempted to get 3-5 bars of ALC by turning up the mic gain control. Even with the gain up to 80, I’d have to speak *very* loudly to just get a flicker on the ALC meter. I then went back into the mic configuration and turned on the preamp (14dB). After that I could get some ALC bars with the mic gain around 65 or more. But I still had to talk much louder than I had to with the same mic on the K3. (note: mic level on the K3 was set around 7). Question: Is it reasonable to expect that I’d have to have the mic gain at such a high level - and still have to talk louder than my normal (K3) level? BTW, I can hook up the MH-4, switch to front mic, and all works smooth with mic gain around 12. __ 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 a...@elecraft.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
