Welcome to the "Lost Words Club." I'm 80 and have been loosing words for the past many years. Frustrating, but relaxing the brain usually produces the word. Sometimes as much as hours later to maybe days. I've startled my wife more than once by uttering a word several days later and she wants to know what the heck am I talking about. Fun and games of being old.
Dave, excellent explanation. I've got the required pieces in my DX Eng cart, now just waiting for clearance from neighbors and HOA to "install" a temporary mast.
Very good video Dave, since I'm on top of a mountain with lightning coming down to the ground, I have purchased these flat for trailer plugs for the lighting and have them connected between my rotor control and the cable after the installation of these mentioned lightning arrestors. This way there's absolutely no connection between an expensive green heron rotor box and the cable going outside.
Dave, omce again, a great video. Concise and informative. Thanks. The screws that come with the AD arrestor is a 1.5" set screw. You can go to Menards or any hardware store and get a 3/4" set screw of appropriate size to secure the arrestor. No need to cut the bolt to length. I used an entry panel from Kp7F metalworks and had to find a 3/8" stainless steel screw from Bolt Depot. If they don't have it, it's not made.
Very cool! When I was undergrad in EE, University of Colorado Boulder, 1970's I designed, (Very important to know how much water you have in Colorado) a circuit to measure water well depth ........worked well for several weeks until lightning struck and destroyed it. Duh.. lightening arrestors are important on more than your antenna.........
Good presentation, but I believe you leave a false sense of security that I want to address: Take this from someone who has been struck by lightning: "Lightning Arrestors" are useless against direct hits. They can bleed off static charges and possibly clamp induced charges from nearby strikes, but they are physically incapable of taming the raw power of a lightning bolt. Two reasons: 1) These piddly devices are no match for the thousands of amperes present in a direct lightning strike. They will be obliterated with little suppression of lightning; 2) Even if these "arrestors" could completely direct a lightning bolt to earth ground, the resistance AND REACTANCE in the ground path still raises the "arrestor" location thousands of volts above the local earth ground even if mounted directly to a ground rod. That charge (thousands of volts and its attending current capacity) is free to enter the shack unimpeded as it seeks a lower impedance path to earth. (I mention impedance: remember the ground cable from an "arrestor" to earth ground has both resistance and inductance; thus it has a reactive component. The waveform of a lightning strike is almost a perfect impulse--an extremely fast-rising current pulse that sees the conductor inductance as a significant impedance. Remember, X=L*di/dt. For an example, go to a commercial broadcast installation; every grounding conductor is a flat copper strip which minimizes both resistance and inductive reactance.) Many people ground their antennae during storms; however, simple "grounding" is not an answer either. In my last lighting strike (I've had 3 in my 50-year life in ham radio), the bolt hit one end of a dipole. The feed line was tied directly to a ground rod outside the shack. This bolt vaporized the #12 copper dipole and both #14 conductors the feed line, and it blew the top 6-inches of dirt away from the ground rod. But it did not stop there: The extreme current entering the ground rod was opposed by the impedance of the rod and the resistance of the earth itself. This raised this potential at this point far above earth potential. Some of that potential went up the ground cable into the shack and destroyed almost everything (hf radio, antenna tuners, audio filter and all three computers). All the telephones, televisions and the security system also bought the farm. My third strike was an expensive reminder of a lesson I learned from my second lightning strike. The one and only one sure method to keep lightning out of the shack is to disconnect feed lines and control cables outside the shack and move them as far from the shack/home as possible. On that second strike, the ladder line to the dipole was disconnected and laying on the ground out in the middle of the yard well away from the house/shack. That strike drilled out an arm-deep hole in the ground and blew all the copper out of the ladder line, but there was no other damage. I no longer make the mistake of leaving the feed lines connected during bad weather (or if I'm not at home). I believe it is important for your viewers to understand that the commercial "arrestors" may provide some benefits, but they are no substitute for complete isolation of antennae (read that "lightning rods") and control cables from the shack during thunderstorms. (BTW, in my previous life as an electrical engineer, I've seen several lightning hits on 12kv systems in and around my place of employment. When you see a 12kv-rated lightning "arrestor" destroyed by lightning or see a 15-kv-class insulator flashed over and shattered by lightning, you might understand why I consider the amateur "arrestors" as piddly devices. I'm accustomed to following building codes which require grounding grids under building connected to every metal building column with a 4/0 conductor via CADWELD.) DE KG5AR
I could not agree more - the name 'lightning arrestor' is not realistic, although these devices are still a good practice for handling static charge build up.
Very true - surge arrestor not a lighting strike protector. I was walking through the local mall car park a while back and lightning struck one of the car park lighting poles about 20 steps from me… scorched earth might be a good description. I’m afraid any of our radio kit would have been a charred ruin, arrestor or no.
WELL SAID! With no disrespect to Dave, there is a cottage industry within ham radio that exaggerates the effectiveness of these little devices. They might bleed off some static charge, thereby preventing damage in one case, but to call them lightning arrestors is almost criminal deceit. The rotor cable unit Dave shows contains eight metal oxide varistors. My electric cooktop also contains those for surge protection on the 240V line. I happened to be standing in front of it one day as a storm approached. The cooktop was turned off. A distant lightning strike induced a surge on the line. Under the glass, the thing started arcing like a welder, for perhaps 8-10 seconds. Out came the smoke. I disassembled the unit. The MOVs were burned away, the circuit board burned, power supply was toast. I’ll reiterate that this was not a direct strike, just a high-energy spike on the line. We routinely unplug all electronics and appliances, and trip breakers for the major appliances. I hadn’t even made it that far that day. This was our third lightning damage event. The first two also occurred via power and telephone lines. Maybe the coaxial and control cable devices offer some protection against routine charge accumulation, but don’t bet your life or property on them if a storm is anywhere in the area. Listen to what KG5AR says about current, resistance, inductance, and reactance. A “big wire” or a gas discharge tube isn’t what we intuitively think under these conditions.
Hi Bill, Just wanted to take a minute to thank you for the time and trouble you took to document your experience with and perspective on lightning "arresters." I have copied and saved your comment after reading it several times to let it all sink in. I guess "Static Arresters" wouldn't sell as well. I now realize that I haven't come across any reports of these arresters actually saving anyone's equipment from direct or nearby strikes. A question, if you don't mind: Did your homeowner's insurance cover your devastating loss? Or did you have specific coverage on your equipment? I am a recently retired new ham putting together my first station and can't imagine re-buying everything. Have not heard anything about ham insurance, but seems like a good idea if it even exists. I live in an area with infrequent lightning, but it might make as much or more sense to get insurance, disconnect when not in use/away/during storms than buying a bunch of pseudo-lightning arresters. 73, John - KK7JBZ
Ferrites and coax loops help too. Nautel supplies them to fit up to 3 inch hardline! MOV's, supressor inductors and gas tubes are available as low cost parts to build your own. The latter are what you use for openwire lines. AC power protectors are even move important, unless you have an antenna taller than the power lines. Then you have to get serious with rods on top of the tower, quarterwave shorting stubs and such.
I just monitor the weather and any sign of a storm i unplug and detach all coax and cables from the radio. no amount of lightning protection will do anything if you get a nearby or direct strike, yes protection can help reduce the damage but once a strike hits it's time to get your wallet out and replace everything.
Need to attach a connector to the arrestor I have since it doesn't have the long protrusion that goes through the copper bar which I do have. What crimping tool works with solid #6 ground wire? And what connectors would I use? Thanks for any suggestions.
Question: The lightning arrestor is the last thing before the coax enters the shack. If I have a single piece 200 foot run from the shack to the antenna, at the antenna is OK for the arrestor?
Thank you Dave, for a very informative explanation. Can you mount the lightning arrestors high on a superiorly grounded tower and use the tower as a ground? I ask because my shack is on the 2nd floor, so my coax would need to go from the antenna, to the base of the tower, then back up to the shack again. Thank you.
Unfortunately no - you will have to go down first and then up again with your coax. I have a similar setup and lightning arrestors need to be as close to the actual ground rod as possible if you want them to perform optimally. You always want to keep the impedance/distance from the arrestor to ground as small as possible. In the situation you describe, the mast would act as a large resistor. Even a few ohms is too much with the amount of energy from lightning. Hope this helps.
I forget where I read it (not a wives’ tale, but a professional source), but that source recommended an arrestor at the top of the tower, another at the base where the coax makes its turn, and a third at the building entry. This had to do with both impedance to the high frequency AC component of a lightning strike and its tendency to take a straight course, whether that means staying in the conductor or not. As we all say, nothing will stop a direct strike, but these schemes are intended to reduce potentials induced in antenna system cables by nearby strikes...or not so nearby.
The blue disks look like thyristors or similar surge protectors, used in plain AC power strips as well. They can fail open or shut, but more importantly they wear out after enough surges. So you know they eventually will fail. Probably should be replaced after one lightning strike, even if they are intact. No?
Coaxial surge protectors are built to divert voltage transients that occur on the center conductor, not the shield. You would presumably have the shield grounded anyway-and that includes the PL-259 shell.
I question the wisdom of building any lightning suppression device inside a plastic enclosure. These lightning suppressors use one more more Varistor (s). If a large surge current is applied to this device it may lead to an instantaneous short resulting in violent explosion. This is why we normally see amateur lightning suppression devices built in metal enclosures.
I agree with you. Mini lightning arrestors use a spark device to shunt the lightning to ground. I’ve used alpha delta for ages. Right now I’m using Morgan arrestors. They are all held in a large steel box which is carefully grounded.73 from Dave
Welcome to the "Lost Words Club." I'm 80 and have been loosing words for the past many years. Frustrating, but relaxing the brain usually produces the word. Sometimes as much as hours later to maybe days. I've startled my wife more than once by uttering a word several days later and she wants to know what the heck am I talking about. Fun and games of being old.
Dave, excellent explanation. I've got the required pieces in my DX Eng cart, now just waiting for clearance from neighbors and HOA to "install" a temporary mast.
Very good video Dave, since I'm on top of a mountain with lightning coming down to the ground, I have purchased these flat for trailer plugs for the lighting and have them connected between my rotor control and the cable after the installation of these mentioned lightning arrestors. This way there's absolutely no connection between an expensive green heron rotor box and the cable going outside.
Dave, omce again, a great video. Concise and informative. Thanks.
The screws that come with the AD arrestor is a 1.5" set screw. You can go to Menards or any hardware store and get a 3/4" set screw of appropriate size to secure the arrestor. No need to cut the bolt to length. I used an entry panel from Kp7F metalworks and had to find a 3/8" stainless steel screw from Bolt Depot. If they don't have it, it's not made.
Very cool! When I was undergrad in EE, University of Colorado Boulder, 1970's I designed, (Very important to know how much water you have in Colorado) a circuit to measure water well depth ........worked well for several weeks until lightning struck and destroyed it. Duh.. lightening arrestors are important on more than your antenna.........
You keep knocking it put of the park. Another outstanding video that answers plenty of questions. You are doing what the ARRL should be doing.
Good presentation, but I believe you leave a false sense of security that I want to address:
Take this from someone who has been struck by lightning: "Lightning Arrestors" are useless against direct hits. They can bleed off static charges and possibly clamp induced charges from nearby strikes, but they are physically incapable of taming the raw power of a lightning bolt. Two reasons: 1) These piddly devices are no match for the thousands of amperes present in a direct lightning strike. They will be obliterated with little suppression of lightning; 2) Even if these "arrestors" could completely direct a lightning bolt to earth ground, the resistance AND REACTANCE in the ground path still raises the "arrestor" location thousands of volts above the local earth ground even if mounted directly to a ground rod. That charge (thousands of volts and its attending current capacity) is free to enter the shack unimpeded as it seeks a lower impedance path to earth.
(I mention impedance: remember the ground cable from an "arrestor" to earth ground has both resistance and inductance; thus it has a reactive component. The waveform of a lightning strike is almost a perfect impulse--an extremely fast-rising current pulse that sees the conductor inductance as a significant impedance. Remember, X=L*di/dt. For an example, go to a commercial broadcast installation; every grounding conductor is a flat copper strip which minimizes both resistance and inductive reactance.)
Many people ground their antennae during storms; however, simple "grounding" is not an answer either. In my last lighting strike (I've had 3 in my 50-year life in ham radio), the bolt hit one end of a dipole. The feed line was tied directly to a ground rod outside the shack. This bolt vaporized the #12 copper dipole and both #14 conductors the feed line, and it blew the top 6-inches of dirt away from the ground rod. But it did not stop there: The extreme current entering the ground rod was opposed by the impedance of the rod and the resistance of the earth itself. This raised this potential at this point far above earth potential. Some of that potential went up the ground cable into the shack and destroyed almost everything (hf radio, antenna tuners, audio filter and all three computers). All the telephones, televisions and the security system also bought the farm.
My third strike was an expensive reminder of a lesson I learned from my second lightning strike. The one and only one sure method to keep lightning out of the shack is to disconnect feed lines and control cables outside the shack and move them as far from the shack/home as possible. On that second strike, the ladder line to the dipole was disconnected and laying on the ground out in the middle of the yard well away from the house/shack. That strike drilled out an arm-deep hole in the ground and blew all the copper out of the ladder line, but there was no other damage.
I no longer make the mistake of leaving the feed lines connected during bad weather (or if I'm not at home). I believe it is important for your viewers to understand that the commercial "arrestors" may provide some benefits, but they are no substitute for complete isolation of antennae (read that "lightning rods") and control cables from the shack during thunderstorms.
(BTW, in my previous life as an electrical engineer, I've seen several lightning hits on 12kv systems in and around my place of employment. When you see a 12kv-rated lightning "arrestor" destroyed by lightning or see a 15-kv-class insulator flashed over and shattered by lightning, you might understand why I consider the amateur "arrestors" as piddly devices. I'm accustomed to following building codes which require grounding grids under building connected to every metal building column with a 4/0 conductor via CADWELD.)
DE KG5AR
I could not agree more - the name 'lightning arrestor' is not realistic, although these devices are still a good practice for handling static charge build up.
Very true - surge arrestor not a lighting strike protector. I was walking through the local mall car park a while back and lightning struck one of the car park lighting poles about 20 steps from me… scorched earth might be a good description. I’m afraid any of our radio kit would have been a charred ruin, arrestor or no.
WELL SAID! With no disrespect to Dave, there is a cottage industry within ham radio that exaggerates the effectiveness of these little devices. They might bleed off some static charge, thereby preventing damage in one case, but to call them lightning arrestors is almost criminal deceit.
The rotor cable unit Dave shows contains eight metal oxide varistors. My electric cooktop also contains those for surge protection on the 240V line. I happened to be standing in front of it one day as a storm approached. The cooktop was turned off. A distant lightning strike induced a surge on the line. Under the glass, the thing started arcing like a welder, for perhaps 8-10 seconds. Out came the smoke. I disassembled the unit. The MOVs were burned away, the circuit board burned, power supply was toast.
I’ll reiterate that this was not a direct strike, just a high-energy spike on the line. We routinely unplug all electronics and appliances, and trip breakers for the major appliances. I hadn’t even made it that far that day.
This was our third lightning damage event. The first two also occurred via power and telephone lines.
Maybe the coaxial and control cable devices offer some protection against routine charge accumulation, but don’t bet your life or property on them if a storm is anywhere in the area. Listen to what KG5AR says about current, resistance, inductance, and reactance. A “big wire” or a gas discharge tube isn’t what we intuitively think under these conditions.
And aren't lightning strikes something on the order of 2.2 *MV?*
Hi Bill,
Just wanted to take a minute to thank you for the time and trouble you took to document your experience with and perspective on lightning "arresters."
I have copied and saved your comment after reading it several times to let it all sink in.
I guess "Static Arresters" wouldn't sell as well. I now realize that I haven't come across any reports of these arresters actually saving anyone's equipment from direct or nearby strikes.
A question, if you don't mind: Did your homeowner's insurance cover your devastating loss? Or did you have specific coverage on your equipment? I am a recently retired new ham putting together my first station and can't imagine re-buying everything. Have not heard anything about ham insurance, but seems like a good idea if it even exists. I live in an area with infrequent lightning, but it might make as much or more sense to get insurance, disconnect when not in use/away/during storms than buying a bunch of pseudo-lightning arresters.
73,
John - KK7JBZ
Ferrites and coax loops help too. Nautel supplies them to fit up to 3 inch hardline! MOV's, supressor inductors and gas tubes are available as low cost parts to build your own. The latter are what you use for openwire lines. AC power protectors are even move important, unless you have an antenna taller than the power lines. Then you have to get serious with rods on top of the tower, quarterwave shorting stubs and such.
I just monitor the weather and any sign of a storm i unplug and detach all coax and cables from the radio. no amount of lightning protection will do anything if you get a nearby or direct strike, yes protection can help reduce the damage but once a strike hits it's time to get your wallet out and replace everything.
Put your radio in a grounded Faraday cage to protect it from a direct lightning strike.
I hope you're doing okay.
Need to attach a connector to the arrestor I have since it doesn't have the long protrusion that goes through the copper bar which I do have. What crimping tool works with solid #6 ground wire? And what connectors would I use? Thanks for any suggestions.
As always thank you, Dave!
I'll be applying some correct fixes to a 9:1 long wire that I learned about here. You rock!
73 de N2NLQ
Question: The lightning arrestor is the last thing before the coax enters the shack. If I have a single piece 200 foot run from the shack to the antenna, at the antenna is OK for the arrestor?
Control cables can also be used for antenna couplers.
Thank you Dave, for a very informative explanation. Can you mount the lightning arrestors high on a superiorly grounded tower and use the tower as a ground? I ask because my shack is on the 2nd floor, so my coax would need to go from the antenna, to the base of the tower, then back up to the shack again. Thank you.
Unfortunately no - you will have to go down first and then up again with your coax. I have a similar setup and lightning arrestors need to be as close to the actual ground rod as possible if you want them to perform optimally. You always want to keep the impedance/distance from the arrestor to ground as small as possible. In the situation you describe, the mast would act as a large resistor. Even a few ohms is too much with the amount of energy from lightning. Hope this helps.
I forget where I read it (not a wives’ tale, but a professional source), but that source recommended an arrestor at the top of the tower, another at the base where the coax makes its turn, and a third at the building entry. This had to do with both impedance to the high frequency AC component of a lightning strike and its tendency to take a straight course, whether that means staying in the conductor or not.
As we all say, nothing will stop a direct strike, but these schemes are intended to reduce potentials induced in antenna system cables by nearby strikes...or not so nearby.
Thanks!
Thanks!
Dave would it be wise to use your house steel beem as a ground
How is the lightning taken into custody? Would be interested in a more detailed explanation.
There is no 'arresting' in case of a direct strike. See Bill Brown's explanation below.
@@erpece _Whooosh_
The blue disks look like thyristors or similar surge protectors, used in plain AC power strips as well. They can fail open or shut, but more importantly they wear out after enough surges. So you know they eventually will fail. Probably should be replaced after one lightning strike, even if they are intact. No?
More likely MOV's - Metal Oxide Varistors
@@jptucsonaz8503 Certainly could. Both have the same failure issues, IIRC.
Good deal
Wouldn't a hose Clamp and wire tighten around the pl 259 connected to a ground rod work
Coaxial surge protectors are built to divert voltage transients that occur on the center conductor, not the shield. You would presumably have the shield grounded anyway-and that includes the PL-259 shell.
Thanks Dave. May your radio waves propagate far far away and your lightening go straight to ground. 🙄 73s.
👍🏻👏🏻👏🏻👏🏻👏🏻👏🏻👏🏻👏🏻👏🏻👏🏻
Remember boys and girls - Polyphasers are not waterproof.
What is the difference between polyphasers and arresters? I see two types in the picture. If serves the same purpose, which one is better?
What “ rings “are you talking about? Washers?
He is talking about putting a crimped ring terminal on each of the wires before attaching them to the surge protector.
@@DanielHallmark ok thanks
I question the wisdom of building any lightning suppression device inside a plastic enclosure. These lightning suppressors use one more more Varistor (s). If a large surge current is applied to this device it may lead to an instantaneous short resulting in violent explosion. This is why we normally see amateur lightning suppression devices built in metal enclosures.
I agree with you. Mini lightning arrestors use a spark device to shunt the lightning to ground. I’ve used alpha delta for ages. Right now I’m using Morgan arrestors. They are all held in a large steel box which is carefully grounded.73 from Dave