Outdoor antennas during storm

[tonsoffun]

Hi everyone,
I am really scratching my head at the glass jar idea....... Alot of these posts I see on here always talk about the things you can do to protect from lightning etc.
How about some real serious protection for your coax system!

I purchased 4 of the these Coaxial Impulse Suppressors/Arrestors and will never have to worry about forgetting to disconnect my coax in a storm.
http://www.iceradioproducts.com/impulse1.html#1
Can you imagine if lightning will strike when your holding that coax trying to disconnect it..... not good at all.

People, invest some money in trying to protect your system.
Enough of me babbling on, just trying to open peoples eyes on a very serious topic.
Take care

 

[N8RUS]

Ground Rise Potential

A direct strike to the ground may introduce so much energy to the area of the strike the ground cannot handle it all...hence the strike continues to seek another ground which may be the electrical system of a nearby building. 30 yrs + in the fire service I have seen this very rarely but it can happen. In one case we had fire damage in the building around receptecles in walls that contain a common circut with no other damage. Yes, lightning will travel across the ground to another point.

 

[hoser147]

I guess if they would have figured it out , they would have captured it along time ago, and gave us a break on our electric bill.:roll: With the season coming upon us, Just be safe whether your messing with your antenna, tower or anything that is electrical in nature. Every Spring this seems to pop up in a thread and its a good thing.............Hoser

 

[Chevyman22360]

Hi everyone,
I am really scratching my head at the glass jar idea....... Alot of these posts I see on here always talk about the things you can do to protect from lightning etc.
How about some real serious protection for your coax system!

I purchased 4 of the these Coaxial Impulse Suppressors/Arrestors and will never have to worry about forgetting to disconnect my coax in a storm.
http://www.iceradioproducts.com/impulse1.html#1
Can you imagine if lightning will strike when your holding that coax trying to disconnect it..... not good at all.

People, invest some money in trying to protect your system.
Enough of me babbling on, just trying to open peoples eyes on a very serious topic.
Take care

Do those arrestors protect against a direct lightning strike? These are what I have in my lines right now http://www.memphisamateur.com/index.asp?PageAction=VIEWPROD&ProdID=404 How do the two compare?

 

[OceanaRadio]

http://n9mxq.ham-radio-op.net/oldpage/strike/ is all I have to say... Pictures are worth a thousand replies.. And for those who actually go look at the page.. I'm still using the same glass jar that took the hit...

Very light coax such as you apparently use might not carry enough energy to exceed the dielectric value of a heavy glass jar. But the rapid heating could disintegrate glass and it looks like you were lucky there. Of course such a risky protection scheme should nonetheless have the single antenna coax in the jar before the splitter. Sorry you lost a stereo, vcr and tv to figure that out.

RG8U coax breaks down completely at about 5500v and thinner coax at lower values.

The fallacy that nothing can protect you in a direct strike assumes the entire lightning attachment is somehow delivered directly to the radio. If the radio was on the roof or the top of the antenna tower, it could indeed become fertilizer for a wide area. But realizing the limitations of coax, and accounting for a good antenna mast grounding system, proper coaxial shield grounding, bonding to make the entire system as equi-potential as possible, and a good surge arrestor before the radio, lightning can indeed strike many times with no ill effects to the system. However the AC wiring must also be surge-protected, preferrably at the AC meter or entrance panel, and again at the equipment connections. There is far more damage imparted to electronics from lightning surges through the power lines cable and telco, including buried lines, than from quite rare direct attachments to a modest-height antenna system.

73,
Jack

 

[n9mxq]

Very light coax such as you apparently use might not carry enough energy to exceed the dielectric value of a heavy glass jar. But the rapid heating could disintegrate glass and it looks like you were lucky there. Of course such a risky protection scheme should nonetheless have the single antenna coax in the jar before the splitter. Sorry you lost a stereo, vcr and tv to figure that out.

RG8U coax breaks down completely at about 5500v and thinner coax at lower values.

The fallacy that nothing can protect you in a direct strike assumes the entire lightning attachment is somehow delivered directly to the radio. If the radio was on the roof or the top of the antenna tower, it could indeed become fertilizer for a wide area. But realizing the limitations of coax, and accounting for a good antenna mast grounding system, proper coaxial shield grounding, bonding to make the entire system as equi-potential as possible, and a good surge arrestor before the radio, lightning can indeed strike many times with no ill effects to the system. However the AC wiring must also be surge-protected, preferrably at the AC meter or entrance panel, and again at the equipment connections. There is far more damage imparted to electronics from lightning surges through the power lines cable and telco, including buried lines, than from quite rare direct attachments to a modest-height antenna system.

73,
Jack

And exactly WHAT coax was in the jar? Hmmmmm? Yes I know a glass jar isn't the best for lightning protection. And no matter what all the experts say, if you get a direct hit, you're screwed.. No matter what widgets you have in your coax.

This was NOT a direct strike. I NEVER said it was. I just posted to illustrate the glass jar in action. Yes it saved me arc damage inside the room (which I was unable to adequately ground due to restrictions). Had this been a direct strike, the coaxes and antennas probably would have vaporized.

This is the last time I'll visit this thread, I unsubscribed days ago, but out of morbid curiosity came back.

So lets repeat the mantra kiddies GROUNDING GROUNDING GROUNDING...

All the "experts" can tear me up now for being a heretic and still using my glass jar.. But it's better than leaving the coax ends hanging where they could arc and start things on fire..

Yeesh, ya share some pictures.. and this is what you get..

 

[commstar]

N9mxq,
I am with you brother! Put me in the undecided wing of your heretic compound.

Jeezus you guys (you experts) you should open your minds a bit. Because it seems unconventional does not mean the guy wears a tinfoil hat. There are so many things in this world that work but cannot be explained such as water witching, low-dose aspirin/heart attacks, and beaten women who stay with their abusive husbands.

All hoser did was suggest putting the ends of his coax into a empty glass jar.In theory,this seems to me to function as a insulator thereby disrupting the ground path. Seems simple enough to me and qualifies good linear thought for me.I would also like to point out hosers defense that he is a retired firefighter (thanks for your service btw) and think about it is he going to use something that is inherently dangerous or stupid in his own home?

You guys talk about electrical charges and lightning like they are dynamite on their own.
Not true. From what I have been told the visually spectacular explosive nature comes largely from the water content in some of the items struck. Essentially, it is the water molecules cooking off and moving thru the items in a big hurry. I get my information from a close family member who is now a retired high-voltage utility worker (and lightning safety trainer for his former employer) - and has been struck by lightning twice.

One strike blew off the three smaller fingers on his right hand. The other made him chase loose multi-orgasmic younger women and drink clear alcohol (he says) but no physical impairment. I'll take his word based on experience and research subsequent to these these events caused him to complete.

He also says that anything one does to interrupt the ground path will tend to make you less attractive target for a strike.

I am not suggesting the jar works, that it is the only or best answer but it seems like it might be worth additional research and could be used in a pinch without any real downside.

Thanks for a most thought provoking post hoser!

 

[hoser147]

You are Welcome Sir, and thanks for the comments. By no means is the glass jar a substitute for proper grounding and surge protection or arrestors. Call it what you want, but I will continue to use it as an extra measure to my own satisfaction as many people do. There are several other posts on the issue also. If you have a direct hit, the possibilities of damage are endless. All you can do is try to make sure your setup, whether its one scanner or 100, is protected. Beyond that if it happens its going to happen, you can take measures to minimize the damage in your shack, and I hope everyone has. Good Scannin Hoser

 

[OceanaRadio]

He also says that anything one does to interrupt the ground path will tend to make you less attractive target for a strike.

Sad. Even Ben Franklin admitted his own mistake in original concept of what are today known as "Franklin Rods", in that they do absolutely nothing to attract or prevent a lightning attachment. They only provide a safe path to earth if lightning does attach to them. There has never, in any kind of research, ever been any suggestion that interrupting a ground path makes an object less attractive to lightning.

I am not suggesting the jar works, that it is the only or best answer but it seems like it might be worth additional research and could be used in a pinch without any real downside..

Additional research on the glass jar? Well, LPSI, NASA and others have tested rocket-triggered lightning for over twenty years and the mason-jar protection-scheme has somehow escaped them. They do blow a lot of stuff up, and the ohmic-heating of lightning is only one of the seveal forces involved in its destructive power.

For definition purposes, a direct attachment of lightning means contact to an object by any part of the stepped-leader connection and its return-stroke. Side-flashes or branches thereof are considered indirect attachments. A direct attachment can range from low-energy 1-10Ka to 200Ka or higher connections. Indirect attachments from branch-leaders or side-flashes vary from less than 1Ka to over 10Ka. A "nearby strike" can also cause damage when ground potential rise from saturated levels of energy in and around the earth and grounding systems allows fast connections to the structure through its grounding systems of AC wiring and/or antenna grounding connections. Proper bonding not grounding, is what maintains equipotential to minimize the damage from saturation of a grounding system when one part of the system has lessor or greater potential than other parts, hence allowing inductive current flow between them.

I wouldn't expect folks who post here trying to help others act in a safe manner about lightning protection to agree that the mason jar is a good plan. I never said it couldn't help if nothing else was available, it is simply not a good choice given many better alternatives.

Rgds,

Jack

 

[kb2vxa]

Hi lightning bugs,

Somehow that "Leyden jar" myth persists despite all common sense so let's have a bit of fun with it without getting all technical about it.

"I am really scratching my head at the glass jar idea."

If you scratch it'll never heal.

"A lot of these posts I see on here always talk about the things you can do to protect from lightning etc."

Most are pretty funny, at least until somebody learns the hard way.

"How about some real serious protection for your coax system!"

Yeah, it's about TIME they got serious!

"I purchased 4 of the these Coaxial Impulse Suppressors/Arrestors and will never have to worry about forgetting to disconnect my coax in a storm."

I'd worry if I were you, if your coax is a path to ground watch it go up in smoke. Diversion is the best protection (the principle of the lightning rod), give it another and better path to follow and most certainly DO NOT put the equipment in ANY path it may find on it's own. Such an extreme high voltage discharge is capricious and just may decide to ignore everything else and find ground through the radio and house wiring... OOPS!

I trust NOTHING! While proper grounding and suppression techniques are useful and offer some protection there are NO guarantees when you incur the wrath of the gods. The best you can do is learn from a professional and laugh at some of the silly stuff here like capturing lightning in a jar. Oh there's some pretty good info here but you have to dig through a mountain of poop to find that pearl that someone cast before swine, that bit he ate but passed through unabsorbed.

OK, go ahead and say I took another poke at the non technical people if you like but the truth remains if all you have to offer are folklore and your best guess it's not good enough.

Tackling the jar myth and the "I'm armor plated" notions head on, TRUST NOTHING! No armor can shield you from the fire of the gods so do the best you can and pray you don't take a serious hit. Here's a pearl for you, the jar is superfluous so disconnect the coax and just lay it on the floor. That way if it arcs to something at least your equipment won't be in its fiery path. Now will you jar heads finally get real? If such a discharge is powerful enough to arc through six to eight miles of insulating material (air) do you REALLY think a millimeter or so of glass can stop it? I've seen with my own eyes as little as 30,000 volts puncture glass and when I finally managed to get up off the floor I was a believer.

On the thirty first floor
A gold plated door
Won't keep out
The Lord's burning rain.
(Sin City, a little Country music from The Flying Burrito Brothers ne Byrds.)

 

[popnokick]

Every commercial tower has glass jars...Right?

Of course. Every commercial, professional tower installation I've seen has glass jars. A lot of people are dispatched when storms approach. They race to the tower sites to disconnect the multiple coax cables and place them in the glass jars. NOT!!

I'll look for refs, but someplace in the document of a a scientific study of lightning I recall reading that an important preventative step for lightning strikes is to continually bleed off to a proper ground the static charge that constantly accumulates on outdoor antennas. Seems that in the moments prior to a lightning strike, the static charge spikes up to a huge number for a few moments, then BOOM comes the strike. A proper lightning grounding/protection system (as has been described in this thread and elsewhere) does exactly that: continually bleeds off static buildup to ground. The charge never has a chance to "accumulate" on the antenna system prior to the strike. If you disconnect the coax and insulate it from the grounding system, you may be defeating the path that the static "leader" charge can take to ground. As has been noted, it WILL find another way to ground.

This is why they tell you that if you are outdoors as a storm approaches and you suddenly feel your hair stand up or the sensation of static electricity, drop to the ground. You are probably about to be struck.

Of course, properly installed lightning protection is going to be external to the point of entrance to the building, and the path to ground should still be present. But it doesn't seem that touching the connector(s) to the radio from the coax and unbalancing the system... even if grounded... as a storm approaches would be a good idea.

 

[kb2vxa]

"I recall reading that an important preventative step for lightning strikes is to continually bleed off to a proper ground the static charge that constantly accumulates on outdoor antennas."

Pop, you're treading on shaky ground here, half right, half wrong. Stati-Cat and other dissipater manufacturers talk a good talk but under scrutiny of RF engineers replacing damaged equipment they can't walk the walk. There's heated debate in the industry so don't expect me to carry it over here, lets just say as I have said many times before there is but one guarantee in life and that's death. On the other hand it seems when they taught about lightning charge-discharge in high school science many of you were asleep and I'm not a teacher so just go back and catch up on your own.

As for bleeding off charge, it won't prevent a hit but it will protect you from becoming a path to ground for a heavy static buildup. That's why ham operators in desert areas employ discharge systems on ungrounded antenna elements, wind blown dust can charge an antenna to lethal potential. You have probably seen the sparks fly from helicopter blades in night vision shots, sending that through your body to ground will surely kill you. Ask any CG or Navy aerial SAR personnel about the Jesus stick and how it's used.

Pop, I never said anything about interrupting a path to ground by unscrewing coax and putting it in a bottle or otherwise so please don't mislead them just as they're starting to learn something. For the confused, go back and re read what I wrote in it's entirety, please don't dissect it.

Oh, if you feel your hair stand up you have about a millisecond to live it happens that fast. What you see in those TV science shows is extreme slow motion, at normal speed it's over in the span of a blink. I tell you what, you are welcome to put me to the test during the very next lightning storm. If you're that foolish the gene pool is better off without you peeing in it. (;->)