Ground is a Myth! | 2024 ARRL National Convention

 

Ground is a Myth! | 2024 ARRL National Convention

Click-Bait ...
Myth is IMO the wrong word to use. There is a large amount of misunderstanding about safety grounding and IMO even more about RF grounding.

We spent a lot of time and effort on RF and safety grounding/bonding on military ships and field communication sites. For the casual Ham Radio operator it might be a Myth but for professional communicators, it can be deadly important to have good grounding for RF and safety when you have high power systems in close proximity to people and equipment running 7/24 with lives depending on that communications.
https://en.wikipedia.org/wiki/Counterpoise_(ground_system)

This is a HF transmitter site I worked at. Each circle is a grounding system for each transmitting antenna or array of antennas. We used chemicals on the coral to decrease the RF electrical resistance to increase radiated power.
https://www.navy-radio.com/commsta/keywest.htm

The same type of grounding was used at the receiver site.
https://www.google.com/maps/@24.5721731,-81.6727634,276m/data=!3m1!1e3?entry=ttu

https://apps.dtic.mil/sti/tr/pdf/ADA239808.pdf

 

Gnd is not a myth. He just don't know how to use it.

 

I am not even gonna bother with the article for I'd see his mental ills and cringe.

 

There is indeed the "mythical plane" of zero resistance and uniform zero potential able to instantly absorb huge amounts of power while not deviating a millivolt from true "ZERO potential". Actual ground is quite a bit different. That is seldom available. So most of us are restricted to the real world, at least currently. This leaves us with a less than perfect plane that suffers from both some bothersome internal impedance and some unfortunate areas of other than zero voltage. So that "Perfect Ground" is only available in the area that I am not allowed to mention on this forum.

 

There is indeed the "mythical plane" of zero resistance and uniform zero potential able to instantly absorb huge amounts of power while not deviating a millivolt from true "ZERO potential". Actual ground is quite a bit different. That is seldom available. So most of us are restricted to the real world, at least currently. This leaves us with a less than perfect plane that suffers from both some bothersome internal impedance and some unfortunate areas of other than zero voltage. So that "Perfect Ground" is only available in the area that I am not allowed to mention on this forum.

We never expected perfection or zero as that would be unrealistic and it's something nobody expects as a practical result or designs for. For plain electrical grounding we wanted equal potential at all points tied (bonded) to ground so the ground potential rise from X energy source into earth ground and the resulting current/energy path to earth to be a low impedance shunt. Grounding systems were designed so unwanted energy would take the least harmful path instead of into our devices and equipment.

 

There is indeed the "mythical plane" of zero resistance and uniform zero potential able to instantly absorb huge amounts of power while not deviating a millivolt from true "ZERO potential". Actual ground is quite a bit different. That is seldom available. So most of us are restricted to the real world, at least currently. This leaves us with a less than perfect plane that suffers from both some bothersome internal impedance and some unfortunate areas of other than zero voltage. So that "Perfect Ground" is only available in the area that I am not allowed to mention on this forum.

Do you think this is an empirical limitation or could it be solved with the proper encoding? I wonder if enough header information sent with the payload could offset the effects of a non-ideal ground.

This is a bit off topic but I speculate this is how our bodies are able to cope with huge changes in temperature and being subjected to an electric or magnetic field. Somehow our brain is able to modulate all these signals and keep us alive! The neuroscience I've looked at suggests this is because of elaborate encoding.

 

I think the core of the problem is the relativistic nature of physical laws. I‘m not talking about Einsteinian Relativity, I’m referring to the fact that things are always relative to other things. Electrical potential doesn’t have an absolute existence, it is relative to the high and low potential points you measure between.

This is not at all clear to most people. Even if they ”know“ it, they fail to take it into account in their reasoning. The problem is compounded due to the nature of human reasoning and language. We have a very strong tendency to “confuse the map with the territory”.

Words create reality for most people, who (sensibly) don’t spend much time on philosophy or semantics. If two things share a name almost all people assume they are analogs in every way they can imagine. Very often something analogous lead to the naming but as with all analogies there are hard limits to the validity.

So, “ground” can be very confusing. I think even more so than “earth” which being so incommensurable with things in a circuit is somewhat protected from ”textual reasoning”. While “earth“ can mean the planet or dirt, we generally don’t say something like “this is a big pile of ground in the driveway”. This more abstract nature of “ground”, being the lowest state of things (floor in UK talk) makes it seem so philosophically malleable.

Add to this the general method of instruction when it comes to aspects of electromagnetics that are, ultimately, completely unlike anything we experience and things get worse. Analogies are used (as always) in teaching, and that’s necessary unless you can manage to use nothing but math.

But those analogies have the hard limits mentioned above which people cross right over never noticing the virtual magic smoke that is choking the knowledgable folks in the room. I think, so far as I can see, this can be filed under the category of “the human condition“ and unless there is a radical social shift, this is with us for the foreseeable future.

 

I think the core of the problem is the relativistic nature of physical laws. I‘m not talking about Einsteinian Relativity, I’m referring to the fact that things are always relative to other things. Electrical potential doesn’t have an absolute existence, it is relative to the high and low potential points you measure between.

This is not at all clear to most people. Even if they ”know“ it, they fail to take it into account in their reasoning. The problem is compounded due to the nature of human reasoning and language. We have a very strong tendency to “confuse the map with the territory”.

Words create reality for most people, who (sensibly) don’t spend much time on philosophy or semantics. If two things share a name almost all people assume they are analogs in every way they can imagine. Very often something analogous lead to the naming but as with all analogies there are hard limits to the validity.

So, “ground” can be very confusing. I think even more so than “earth” which being so incommensurable with things in a circuit is somewhat protected from ”textual reasoning”. While “earth“ can mean the planet or dirt, we generally don’t say something like “this is a big pile of ground in the driveway”. This more abstract nature of “ground”, being the lowest state of things (floor in UK talk) makes it seem so philosophically malleable.

Add to this the general method of instruction when it comes to aspects of electromagnetics that are, ultimately, completely unlike anything we experience and things get worse. Analogies are used (as always) in teaching, and that’s necessary unless you can manage to use nothing but math.

But those analogies have the hard limits mentioned above which people cross right over never noticing the virtual magic smoke that is choking the knowledgable folks in the room. I think, so far as I can see, this can be filed under the category of “the human condition“ and unless there is a radical social shift, this is with us for the foreseeable future.

My THANKS to "Y" for the well worded explanation!

 

I think the core of the problem is the relativistic nature of physical laws. I‘m not talking about Einsteinian Relativity, I’m referring to the fact that things are always relative to other things. Electrical potential doesn’t have an absolute existence, it is relative to the high and low potential points you measure between.

This is not at all clear to most people. Even if they ”know“ it, they fail to take it into account in their reasoning. The problem is compounded due to the nature of human reasoning and language. We have a very strong tendency to “confuse the map with the territory”.

Words create reality for most people, who (sensibly) don’t spend much time on philosophy or semantics. If two things share a name almost all people assume they are analogs in every way they can imagine. Very often something analogous lead to the naming but as with all analogies there are hard limits to the validity.

So, “ground” can be very confusing. I think even more so than “earth” which being so incommensurable with things in a circuit is somewhat protected from ”textual reasoning”. While “earth“ can mean the planet or dirt, we generally don’t say something like “this is a big pile of ground in the driveway”. This more abstract nature of “ground”, being the lowest state of things (floor in UK talk) makes it seem so philosophically malleable.

Add to this the general method of instruction when it comes to aspects of electromagnetics that are, ultimately, completely unlike anything we experience and things get worse. Analogies are used (as always) in teaching, and that’s necessary unless you can manage to use nothing but math.

But those analogies have the hard limits mentioned above which people cross right over never noticing the virtual magic smoke that is choking the knowledgable folks in the room. I think, so far as I can see, this can be filed under the category of “the human condition“ and unless there is a radical social shift, this is with us for the foreseeable future.

+1


The Potentials are all relative.

 

Do you think this is an empirical limitation or could it be solved with the proper encoding? I wonder if enough header information sent with the payload could offset the effects of a non-ideal ground

I have read this about six times now and I still have no idea of what it could possibly mean.

 

I have read this about six times now and I still have no idea of what it could possibly mean.

I'm speculating on different forms of information transmission and storage. I suppose the most primitive yet monumental example is digital encoding. Just by changing our paradigm a bit, we got rid of many problems inherit with analog circuits but the discreet components are fundamentally the same.

I wonder if the same could be done with the how we view a "0V" potential. Fibre optics intrigues me because it continues to show more information can be transmitted over the same medium in the same amount of time. In other words, the lossless encoding and compression is getting better and maybe it will get the point where noise doesn't matter.

 

In the electrical circuit sense, the word I have always used to indicate a 'grounded' conductor is 'Earth'.
And this refers to planet Earth.
See attached, ,especially page 2 !

 

In the electrical circuit sense, the word I have always used to indicate a 'grounded' conductor is 'Earth'.
And this refers to planet Earth.
See attached, ,especially page 2 !

There are times when you need to make your own 'Earth'.



The 'ground' plates are not for electrical safety, they provide a very low impedance path to the building 'Earth' ufer grounding system for high energy beam transients.
https://www.ecmag.com/magazine/arti...ground-defining-and-understanding-ufer-ground
The entire machine 'floats' (it's bolted with earthquake restraints) on the ground plane so ground potential rise is uniform between equipment subsystems, reducing the likelihood of damage from alternative interconnect conductor and utility safety ground paths.

 

Is anyone here actually disagreeing with her about anything? She is certainly no lightweight.

To quote myself.

Click-Bait ...
Myth is IMO the wrong word to use. There is a large amount of misunderstanding about safety grounding and IMO even more about RF grounding.

Don't start out calling something a 'Myth' when you well know it's not a 'Myth' and then spend a large amount of time and effort explaining why it's not a Myth.

 

She's really explaining how the idea is vague to many and is often oversimplified, so the use of the term "myth" is in that vein, that the belief about it held by many is mythical, not accurate, "black magic". I agree its not a great title but she does give an interesting talk. A better title might be "Everything you know about ground is wrong!" or something.

"Everything complete newbies know about ground is wrong!" might have been a little better. I just don't know anyone with experience in their field (from electricians to RF engineers) with that many misconceptions about the general grounding practices of their field and would not expect very skilled industrial electricians to be RF grounding experts. Most of the confusion IMO is about labeling and symbols, not about what 'grounds' are and how they function at each level of practical application.

 

I used the word "Mythical" to describe that perfect concept that is actually not available. The Mythical version is a zero resistance plane that is able to accept infinite charge at any rate while the voltage remains at true zero volts across the entire plane.

Except in that place that I am not allowed to name, which the reason was never explained to me.

 

I used the word "Mythical" to describe that perfect concept that is actually not available. The Mythical version is a zero resistance plane that is able to accept infinite charge at any rate while the voltage remains at true zero volts across the entire plane.

Except in that place that I am not allowed to name, which the reason was never explained to me.

That's the thing, we only need good, not perfect. The Mythical version is like the old physics joke.
...

A physicist, an engineer, and a psychologist are called in as consultants to a dairy farm whose production has been below par. Each is given time to inspect the details of the operation before making a report.

The first to be called is the engineer, who states: “The size of the stalls for the cattle should be decreased. Efficiency could be improved if the cows were more closely packed, with a net allotment of 275 cubic feet per cow. Also, the diameter of the milking tubes should be increased by 4 percent to allow for a greater average flow rate during the milking periods”.

The next to report is the psychologist, who proposes: “The inside of the barn should be painted green. This is a more mellow colour than brown and should help induce greater milk flow. Also, more trees should be planted in the fields to add diversity to the scenery for the cattle during grazing, to reduce boredom”.

Finally, the physicist is called upon. He asks for a blackboard and then draws a circle. He begins: “Assume the cow is a sphere....”.

 

Ham radio is important for communication when internet and cellular are down.
When tornados and other disasters occur. A ham operator instinctively positions themselves to avoid dead spots.
A counterpoise is better than no ground for handheld line of sight. Aircraft use virtual ground like many of our circuits.
With low band radio achieving low SWR without ground is possible but is not always the most ideal, noisy potentially hazardous.
A full spectrum ELF, VLF ect, radio comm center will pick up faint distress signals and must be reliable all the time.
They do not rely on volunteers and repeaters on ham bands. They use dedicated ground, cannot rove and reposition.
One statement for radio license is that "proper grounding is essential for safety and efficiency" Old school.
A balanced view is that many times it does not matter however safety always comes first.

 

Ham radio is important for communication when internet and cellular are down.
When tornados and other disasters occur. A ham operator instinctively positions themselves to avoid dead spots.
A counterpoise is better than no ground for handheld line of sight. Aircraft use virtual ground like many of our circuits.
With low band radio achieving low SWR without ground is possible but is not always the most ideal, noisy potentially hazardous.
A full spectrum ELF, VLF ect, radio comm center will pick up faint distress signals and must be reliable all the time.
They do not rely on volunteers and repeaters on ham bands. They use dedicated ground, cannot rove and reposition.
One statement for radio license is that "proper grounding is essential for safety and efficiency" Old school.
A balanced view is that many times it does not matter however safety always comes first.

OK, Sparky. Evidently you have never been in a position of stepping into harms way to protect others. Some of us have been.
Safety DOES NOT always come first. Certainly it is important, but not always first importance.