HF, VHF, UHF, and Grounding

[Lauri-CoyoteFrostbite]

Damage from static electricity is hooey. That damage even made irrelevant by using an NE-2 neon glow lamp. It can change ten of thousands of volts into maybe 60 by simply conducting a milliamp of current.
..................westom1


I don't want to be insulting here, Westom.... but that is a lot of **** !

The majority of damage is done by static charges; whether they come from innocent little static electric charges when an engineer/tech/ham forgets to wear their discharge bracelets while working on a PC board etc., or the static pulse that cooks arrives via a 2 mile long lightning bolt that induces a massive secondary spike.


NE-2's and whatever suppression they offered went out with vacuum tubes--- sometime last century.... let's update the thinking here, (Solid State)----- and get real !

Lauri

 

[zz0468]

Damage from static electricity is hooey. That damage even made irrelevant by using an NE-2 neon glow lamp. It can change ten of thousands of volts into maybe 60 by simply conducting a milliamp of current.

In computer chips, where a conductor can be only a few hundred molecules wide, the static voltage that will cause damage is amazingly low. And a discharge can eat away half the width of a conductor and now the chip is ready for a later failure when it's most inconvenient. A milliamp of current would vaporize a conductor that small.

Damage from static is NOT hooey. You seem to have a lot to learn.

 

[westom1]

The majority of damage is done by static charges; whether they come from innocent little static electric charges when an engineer/tech/ham forgets to wear their discharge bracelets while working on a PC board etc., or the static pulse that cooks arrives via a 2 mile long lightning bolt that induces a massive secondary spike.

Damage from static charges comes from fables that also promote ESE devices. If static charges cause damage, then we are reading electrical numbers. None were posted for one obvious reason.

All electronics include massive protection from static charges. Even a Dick Tracy wrist radio implemented NE-2 neon glow lamps. That less than 1 milliamps created by a painful static electric discharge was made irrelevant by something that trivial - an NE-2. We would static discharge to that transceiver's whip antenna. Even that did not damage those much less robust 1960 transistors.

Static charges are also eliminated with wrist strap that includes a 1 megohm resistor. The fewer that know electric concepts know that is a least conductive item. And still it completely discharges static. Why. Numbers were already provided. And not challenged.

Those static discharges are completely different from lightning. Lightning is typically 20,000 amps. Effective protection from that and other similar transients (created by linemen errors, stray cars, tree rodent, wind, utility switching) is eliminated by something rated at least 50,000 amps. This superior solution is also a least expensive one. And found in every facility that cannot have damage - today and over 100 years ago. It also does what a 1 milliamp NE-2 neon glow light once did.

Posting empty denials says nothing. If static charges create damage, then we are reading reasons why; chock full of numbers from introductory (a 1st year course) electrical science. Not one number even defines a static charge. The fear (threat) is from hearsay. Is not based in well proven science - just like ESE devices that also magically claim to discharge air.

Claims by ESE manufacturers were rejected by the NFPA - authors of the National Electrical Code. So ESE manufacturers tried to sue the non-profit NFPA to force a bankruptcy. The ploy failed. Resulting studies noted a number one problem. Not one professional study was ever conducted to demonstrate that static discharge myth. Plenty of IEEE papers have repeatedly exposed that static discharge myth.

If I recall, the Bryan Panel Report was a classic example. Dr Mousa wrote many IEEE papers demonstrating the myth. Drs Uman and Rakov, two famous lightning researchers (I believe from U of FL) wrote a damning paper condemning the static discharge myth. But somehow we should believe static discharge is a threat only because subjective claims exist without any supporting facts and not even one number to say so.

So many other professionals also averted future damage or learned from their mistakes. Such as one in a nuclear hardened maritime communication station. Somehow we should ignore that engineer at WXIA, a solution implemented on the entire Orange County FL 911 system, a Nebraska radio station case study, Polyphaser's legendary application notes, the IEEE (papers and standards), GE and Westinghouse reasearch atop the Empire State Building, plenty of research on the Peissenberg tower in Germany, Sun Microsystems "Planning guide for Sun Server room", Motorola's R-56, Mil Standard 419, Qwest's standards for all telco switching stations, Dr Ufer's solution that made direct lighting strikes irrelevant, or both articles on protecting Ham stations in 2002 issues of QST Magazine

Even Lightning Safety Institute's "Principles of Grounding of Lightning Protection Systems per NFPA 780" says same::

1. Overview
Lightning wants to get to ground. It will follow the path(s) of least impedance to do so ...

2. Fundamental Principles
A. Low impedance paths to ground are preferred...
B. High impedance paths must be avoided...[\quote]

And then it describes what to install to have that protection:

3. Grounding

Earth grounds (not floating grounds) only recommended.

But somehow you just know static is the threat - without even one reason that says why and without any perspective (numbers). Protection of radio equipment (and everything else in the building) is about where energy from transients (including a 20,000 amp direct lightning strike) harmlessly dissipates. Those hundreds of thousands of joules must dissipate harmlessly outside in earth. Otherwise damage happens. Paragraph after paragraph that says why and with numbers. Because this stuff was routinely done successfully for so many decades.

Protection from discharging static in air (ie ESE devices) remains a classic scam.

 

[westom1]

In computer chips, where a conductor can be only a few hundred molecules wide, the static voltage that will cause damage is amazingly low.

Read numbers from datasheets. For example this interface chip will withstand up to 15,000 volts without damage. It says so even at the top of page one: https://datasheets.maximintegrated.com/en/ds/MAX1487E-MAX491E.pdf

All semiconductors are at great risk when not part of a system. When integrated, then interface semiconductors routinely withstand 2000 or 15,000 volts without damage. Ethernet always routinely withstood 2000 volts. Individual parts are sensitive to static discharges. Even when still working, the part could have suffered "overstress". But once part of a system, those parts are tough. Many soundbytes that promote fear of static discharges forget to mention those details. And never provide perspective - numbers. Concepts such as "overstress" never mentioned when fear is promoting myths.

We are not discussing protection of individual parts. We are discussing protection of systems, appliances, and everything inside a building. Even a least robust GFCI or dimmer switch remains undamaged IF a 'whole house' solution exists. Then a rare transient, that might threaten that or a dishwasher, clocks, central air, refrigerator, or smoke detectors, etc does not damage anything. Protection is always about how that current connects to earth - destructively or harmlessly. Even an Erico Tech Note demonstrated how protection is routinely done by professionals.

Best protection at electronics is already inside. Concern is for a rare transient that can overwhelm that existing robust internal protection. So many professional sources, instead, recommend the proven solution - that centers on what does the protection: single point earth ground. Where do hundreds of thousands of joules harmlessly dissipate? That answer says why facilities suffer direct lightning strikes without damage even to protectors - or interface semiconductors.

 

[westom1]

BTW, another example from research. Many believe lightning rods must be pointed. Research clearly demonstrated different. Blunt rods provide superior protection over pointed rods. Just another IEEE paper that would only be known to people who know this stuff.

 

[Lauri-CoyoteFrostbite]

.

Westom, I am going to remain professionally detach'd from further discussion -and respectfully disagree with you.
I'll leave it to the others that have followed this topic to be the judges ..........

________________Now, I'm off to joust with other windmills

Cheers !

Lauri

____________________________________

(.........for what its worth, I am a member of that IEEE you reference. Its common knowlege to use smooth, spheroid shapes on 'air terminals' etc., no secrets there )
.

 

[zz0468]

Read numbers from datasheets. For example this interface chip will withstand up to 15,000 volts without damage. It says so even at the top of page one: https://datasheets.maximintegrated.com/en/ds/MAX1487E-MAX491E.pdf

Impressive, but that specification does not apply to every device out there.

The rest of your post cites specific examples, but doesn't come close to representing the wide variety of systems and components out in the real world.

As a generalized statement that downplays the hazards of static discharge, your posts are wrong on more levels than I can keep track of.

Please stop.

 

[westom1]

Impressive, but that specification does not apply to every device out there.

No. Some are more robust than others. But all devices already contain robust protection. Some are more robust than others. With each decade, systems get even more robust. Just another reason why replies (or denials) should be citing specification numbers - as I have demonstrated even with an NE-2.

Back when the IBM PC came out, 120 volt electronics had to withstand up to 600 volts without damage. Today, computers are more robust. For example, one Seasonic supply now claims internal protection up to 1800 volts. Trends I have cited with numbers apply to all electronics. Data lines, that once were only good for maybe a hundred volts back then, are now required to withstand thousands without damage. Back then almost nothing claimeds 15,000 volts. Today, 2000 and 15,000 are routine.

Informed consumers properly earth a 'whole house' solution so that even direct lightning strikes do not overwhelm that robust internal protection.

We know what is necessary to protect all appliances. Same thing that protected all telco COs, mobile phone stations, munitions dumps, emergency response centers, and broadcast stations even 100 years ago. And not by protecting from static electricity. Even that was made irrelevant in the IBM PC and Apple II days.

Please stop posting denials supported only by speculation or hearsay. That is simply irresponsible. If anything is wrong, please post reasons why with numbers. Lauri--Coyote could not challenge any of it. Never even posted one fact to support what is actually an ESE scam. Even floating grounds caused more damage in that Nebraska radio station. Only posted were denials. - very unprofessional. A professional says why with numbers.

If you know otherwise, then do what is required. Please do not post what is currently only an emotional denial. Either you know why and post numbers that say so. So far, every denial was only justified by a fable.

Why was Polyphaser an industry benchmark? When properly earthed even many generations ago, then direct lightning strikes caused no damage. Polyphaser application notes were routinely cited in professional discussions - with reasons why and numbers - as professional do.

 

[zz0468]

No. Some are more robust than others. But all devices already contain robust protection. Some are more robust than others. With each decade, systems get even more robust. Just another reason why replies (or denials) should be citing specification numbers - as I have demonstrated even with an NE-2.

No. There are tens of thousands of IC types in current production. No one should have to cite every specific to support an assertion that static discharge remains a critical concern. You're free to disagree.

You said "Damage from static electricity is hooey."

I disagree. Enough said.

 

[K8KPO]

I had no idea that the subject of grounding and lightning was such a contentious issue. In fact, just a day ago I had started a thread in a ham group on facebook about people with an antenna on a roof and what their experiences were like, and one let's say "elderly statesman elmer" told me that if I was worried about lightning I should switch to model trains instead.

With that kind of mentoring from the older members of the ham community is it any wonder that so many people talk about feeling unwanted when they even show any interest in radio?

 

[westom1]

I disagree. Enough said.

You again read a soundbyte so as to even ignore the concept. Did you read the part about how a semiconductor is easily damaged when not part of a system? That same semiconductor can withstand 15,000 volts when part of a system. Please read what was posted - not a soundbyte that was intentionally setup as a strawman.

An unprofessional poster has intentionally confused static electricity with lightning. Static electricity is eliminated even by a less than 1 milliamp NE-2 neon glow lamp. NE-2 is an old technology. Even that old and less robust technology makes static electricity irrelevant. A professional would have acknowledged well proven science.

Another thing, that was also called static electricity (to create confusion), is maybe 20,000,000 milliamps. Major differences exist between static electricity (less than 1 millamp) and static electricity averted by the proven 50,000 amp solution. An unprofessional (subjective) recommendation ignores numbers.

Please learn to read paragraphs. Please stop posting if you are going to intentionally quote out of context. And please stop confusing ESD with lightning.

Demonstrated is why electronics already have superior protection from ESD. And for completely different reasons, electronics already contain robust protection from another electric current mistakenly described as static electricity. Professional organizations describe her ESE devices as ineffective. Unproven. Promoted only by junk science. No numbers identifies unprofessional recommendations - also called a sales gimmick.

 

[westom1]

I had no idea that the subject of grounding and lightning was such a contentious issue.

It is not contentious. By eliminating every post that does not say why with perspective (numbers), then what remains is widespread agreement. Unfortunately many even confuse a static electric discharge from a finger with lightning from a cloud. Major differences exist.

The old timer is correct in perspective. If an antenna is installed as required by code, then lightning is not a serous concern (for most). Of greater concern is lighting incoming from wires spread out miles in all directions - AC electric. Since those are far more likely to cause damage. Those cause a direct lightning strike to household appliances. That potential transient is maybe once every seven years. That more likely and that rare. It (not the antenna is properly installed) deserves more attention / concern.

Codes that require effective protection for an antenna (which means never using a floating ground) also are not required for AC mains. Where should your attention focus?

 

[prcguy]

I think the old guy recommending electric trains was a way of telling you a can of worms is being opened. I prefer to tell new hams that you are not going to lightning proof your stuff so disconnect your antennas and unplug equipment when in doubt, otherwise enjoy the hobby.

I had no idea that the subject of grounding and lightning was such a contentious issue. In fact, just a day ago I had started a thread in a ham group on facebook about people with an antenna on a roof and what their experiences were like, and one let's say "elderly statesman elmer" told me that if I was worried about lightning I should switch to model trains instead.

With that kind of mentoring from the older members of the ham community is it any wonder that so many people talk about feeling unwanted when they even show any interest in radio?

 

[westom1]

I think the old guy recommending electric trains was a way of telling you a can of worms is being opened..

Damage from lightning is directly traceable to human mistakes. Polyphaser's app notes were legendary among hams for explaining why that damage is routinely averted. Most all damage is averted by simply implementing and upgrading NEC requirements (ie hardwire has no sharp bends that would otherwise increase impedance).

Mobile phone towers are routinely struck without damage. Electronics atop the Empire State Building - 23 times annually without damage. Atop the WTC was 40 times annually.

Or learn from an engineer who states reality clearly:

Well I assert, from personal and broadcast experience spanning 30 years, that you can design a system that will handle *direct lightning strikes* on a routine basis. It takes some planning and careful layout, but it's not hard, nor is it overly expensive. At WXIA-TV, my other job, we take direct lightning strikes nearly every time there's a thunderstorm. Our downtime from such strikes is almost non-existant. The last time we went down from a strike, it was due to a strike on the power company's lines knocking *them* out, ...
Since my disasterous strike, I've been campaigning vigorously to educate amateurs that you *can* avoid damage from direct strikes. The belief that there's no protection from direct strike damage is *myth*. ...
The keys to effective lightning protection are surprisingly simple, and surprisingly less than obvious. Of course you *must* have a single point ground system that eliminates all ground loops. And you must present a low *impedance* path for the energy to go. That's most generally a low *inductance* path rather than just a low ohm DC path.

Is that 100% protection? Of course not. Generally it only does 99.5% to 99.9% of the protection. And then the IEEE puts that number into perspective.

Still, a 99.5% protection level will reduce the incidence of direct strokes from one stroke per 30 years ... to one stroke per 6000 years ... Protection at 99.5% is the practical choice.

Why do some claim protection cannot happen? They buy ineffective, high profit, devices (plug-in protectors, ESE devices, etc) by listening to recommendations without numbers. Suffer damage. Then somehow know effective protection is impossible. Even though it routinely exists in facilities that cannot have damage and that implement simple rules for earthing.

But again, that is protection on an incoming path that is often struck much less often. At greater risk is a path more often struck and that typically has no effective protection. AC mains.

All this stated previously. Since it contradicts popular myths, then some ignore well proven science. Damage so routinely averted as to be traceable to a human mistake. First step that is had for many - to learn that damage is easily averted. And that disconnecting is much less reliable.

If NEC required installation is ignored, then one should switch to model trains where all protection is already implemented and cannot be compromised. Even lesser NEC requirements are so easily implemented.

 

[W5lz]

For the average person;
1. There is no fool-proof protection from lightning. If it wants to, it's gonna.
2. The word grounding means different things to different people. Very basically, it's a worthwhile thing to do.
3. Lightening is not always 'fatal', but who the #3** wants to take a chance?
4. In this state, if you haven't been the victim of a lightning strike (or a near one) you are lucky. Wait a while.
5. Don't obsess about lightening. Take -reasonable- precautions and then forget about it.

Mentoring. If I can help someone I usually will. I don't "spoon feed" people. I figure if they want to know then they will research it and/or ask. Seems reasonable to me.

 

[westom1]

2. The word grounding means different things to different people. Very basically, it's a worthwhile thing to do.

There is no ground. There is digital ground, floating ground, ground plane on an antenna, virtual ground, safety ground in a receptacle, ground in floors that is relevant to static electricity, analog ground, chassis ground, and earth ground. Only relevant is earth ground. And not just any earth ground. Single point earth ground.

An AC utility demonstrates this with good, bad, and ugly (preferred, wrong, and right) solutions at:
Tech Tips - Duke Energy
then select Tech Tip 8.

Erico demonstrates same in a Technical Note entitled "The Need for Coordinated Protection" at:
https://www.erico.com/catalog/literature/TNCR002.pdf

Or course, Polyphaser's application notes, Motorola R-56, and Mil Standard 419 all were quite explicit. For effective protection, that requires most all attention.

 

[prcguy]

Again, citing commercial cell phone and broadcast towers that were designed and installed by professionals for lighting protection is vastly different than a ham in a typical house. I probably have a good 40yrs experience and am a retired broadcast engineer. Not that it means anything but it does play against your broadcast engineers statement.

Cell phone and commercial broadcast towers are not hammy push up masts or a flimsy Rohn 25s, they are big with 2" to 6" thick support legs or 12" and larger diameter well casing masts and will handle huge currents from a direct lightning strike. They have multiple ground rods and a buried ground ring bonded to the electrical system that feeds the equipment.

How many hamsters are going to trench around their house to bury a ground ring and cadweld a lot, and I mean a lot of 10ft ground rods to industry standard methods of no bends in the ground conductors, etc. The re-route all antenna cables to the side of the house where the electrical panel and central ground now live? I've never met one. I would like to do that at my house here in So Cal or better yet the one near Dallas that lightning dances around all the time, but I can't justify the expense or labor. I ground to NEC, I use PolyPhasers on most feedlines and Ethernet feeding my equipment and disconnect all antennas when storms are approaching.

Damage from lightning is directly traceable to human mistakes. Polyphaser's app notes were legendary among hams for explaining why that damage is routinely averted. Most all damage is averted by simply implementing and upgrading NEC requirements (ie hardwire has no sharp bends that would otherwise increase impedance).

Mobile phone towers are routinely struck without damage. Electronics atop the Empire State Building - 23 times annually without damage. Atop the WTC was 40 times annually.

Or learn from an engineer who states reality clearly:


Is that 100% protection? Of course not. Generally it only does 99.5% to 99.9% of the protection. And then the IEEE puts that number into perspective.

Why do some claim protection cannot happen? They buy ineffective, high profit, devices (plug-in protectors, ESE devices, etc) by listening to recommendations without numbers. Suffer damage. Then somehow know effective protection is impossible. Even though it routinely exists in facilities that cannot have damage and that implement simple rules for earthing.

But again, that is protection on an incoming path that is often struck much less often. At greater risk is a path more often struck and that typically has no effective protection. AC mains.

All this stated previously. Since it contradicts popular myths, then some ignore well proven science. Damage so routinely averted as to be traceable to a human mistake. First step that is had for many - to learn that damage is easily averted. And that disconnecting is much less reliable.

If NEC required installation is ignored, then one should switch to model trains where all protection is already implemented and cannot be compromised. Even lesser NEC requirements are so easily implemented.

 

[AK9R]

Folks, I think you all have beaten the dead horse quite sufficiently. And, it doesn't look like anyone is going to change the other's mind.

If you have something new to add to the conversation, please contribute. If you are just going to say the same thing over again, further repetitions are unnecessary.

 

[K8KPO]

I ground to NEC, I use PolyPhasers on most feedlines and Ethernet feeding my equipment and disconnect all antennas when storms are approaching.

Not that it matters, but this is the kind of succinct comment I like.

Carry on.

 

[westom1]

Not that it matters, but this is the kind of succinct comment I like.

He forgot to mention what Polyphaser requires. Those Polyphaser devices only do something useful when connected low impedance (ie less than 10 feet) to earth ground. And then the Polyphaser application notes describe what is necessary to make that earth ground effective.

What was not mentioned was a most succinct comment. "A protector is only as effective as its connection to and quality of earth ground."