Ground is a Myth! | 2024 ARRL National Convention 

As I was attending warranty training, we all noticed the heat sink (fin) at chassis ground next to the popular test point (pin) that was at 130v above earth ground. It kept us awake as the class progressed. That was a practical demonstration that "ground" is a relative term.

This is a super-good presentation, and hopefully will be assimilated by all of the attendees at the convention. I lived through almost all of the problems and content of this video. As an EMC/EMI and Lightning engineer, it was obvious that there are "many grounds" within any larger system, particularly where larger powers are transmitted. Ground loops, Ground bounce, Electrical or Radiative leakage, Adjacent coupling (even through iron pipes), all occur. Formulas for these are available in any college textbook. Locally, there are no universal grounds, including lightning. Just look at the sites where people died, when entrenched or climbing into gullies in the mountains, where the strokes/strikes just go down the creek bed, near or through them. If you want a good ground near a beach, find a place where a bolt hit the sand, and dig around it. You will find a glassified wormlike area going many feet deep, and these are often filled with molten lead or solder, and sold as objects of art. That lightning strike (probably the only one of several) has managed to find its "own" ground. Hits on vehicles often go through all of the tires, and flatten one or all. RF burns can occur along any conductor where a resonant structure/length occurs. This often happens along long coils (like a Tesla coil), where the local lateral or angular resonances amplify the stray radiated fields. Seen these things many times, and there are videos on the Inet which show these various EM effects.

Excellent Excellent Excellent presentation ! Absolutely enjoyed her presentation ! Thank You !!!

Wow! Finally someone who actually understands. So many people don’t understand.

Kristen, I enjoyed your presentation. I answer lots of questions about grounding for "Ask Dave." This has not changed any information in my head, but has sure changed my perspective. Thanks for taking this back to basics. 73 de KE0OG

Kristen thanks for a great presentation overall. Many of us have multiple antennas on multiple poles with a separate ground rod for each. I keep harping about the importance of bonding ALL GROUND RODS TOGETHER OUTDOORS, AND TO THE UTILITY GROUND AS CLOSE TO THE SERVICE ENTRANCE AS POSSIBLE. If LIGHTNING strikes an average 30KA bolt multiplied by a NEC specified ground resistance of 5 ohms or better yields 150 KV ground bounce for the struck antenna/pole. The other ground rods on other antennas/poles will show much less voltage, depending upon the distance from the one Struck. This can bring 150KV into your shack on one feed line. Not good. If you bond ALL grounds including together with heavy copper cable, all your feedlines and your entire home will bounce to as much as 150KV but the Differential Voltage between all feed coax and connected equipment should be only a very few KV,.and unlikely to set your shack or home on fire. David ac9cx Power electronics engineer for 5 decades, now retired.

I would say, maybe not a myth but rather it's a question of an ideal ground vs a "real" ground. Like an ideal voltage source, ideal resistor, ideal short circuit, etc. vs their real counterparts. Theory vs practical.

This explains why some things worked for me at a certain QH and not work at others. I learned by trial and error working out of apartments as well as homes. This pretty well sums up what grounds are all about. Great presentation Kristen.

I almost blew this off because of the title, but I'm glad I watched it. It was very informative and Ms. MacIntyre was a good speaker. Well done!

Great presentation, thank you for sharing.

2:00 - Wow! This is one of the few times since school that I heard a talk using the term ‘podium’ correctly! You stand on a podium to give a lecture behind a lecturn.

EXCELLENT presentation Kristen !!

Very nice presentation. Almost like a relief in a way because the subject of ground is not an easy thing to understand and sometimes even contradictory. Thank you for explaining that the theory of ground has many facets to it and it can be many different things to many different people and many different situations.

Great presentation, thanks for sharing the experience

@21:35 - this PS does not seem to have a 3 prong AC, so the chassis is probably floating and would be dangerous if the "hot" breaks off inside the chassis. Taking that ground screw - connect it to other equipment chassis'. This is not safety - it may be noise reduction. One could (not code compliant) take that ground screw to the outlet ground, and then it would be electrically "safer" but not code or CSA/UL compliant. One could replace the AC with a 3 wire AC and connect the AC ground to the chassis on the INSIDE of the PS (with strain relief). This would be CSA/UL compliant (but not certified). The DC coming out is most likely floating wrt to the chassis ground.

Incredible presentation. I learned a ton from this. Thank you!

If there is a potential gradient across the ground, there is a cause. It happens over KM+ but it should be negligible over a few meters. Chassis are connected to an earth conductor because humans are likely connected to earth already, so it minimizes potential differences experienced by humans. In the case of fully isolated circuits, like a transformer where one side is mains powered and the other side isn't, there will be no potential difference between conductors on one side to the other. Sadly, if there is a fault, for example a short across the transformer, and a human is touching the "isolated" side, there will suddenly be a large potential across the human. This is why we earth every exposed metal we practically can. Antennae are obvious exceptions.

A great review of grounds except for leaving out the connection to the service entrance. Kristen should add this to the presentation. The ARRL handbook and NEC handbook shows this. David ac9cx describes the details below. My system is close to what he suggests except the connections are inside the garage below the service entrance panel where they stay dry. I found a foot of 2 in by 1/4 in copper buss bar at the scrapyard and connect my antenna cable lightning arrestors, ground rods, well casing, and SE panel to it by 4 ga wires less than 12 in long. Other wires go to the copper baseboard loop and water pipes. It is the short, large connection to the service entrance panel that is most important to protect your equipment from the ground bounce when 30K amps flows along your antenna cables from a lightning strike. Philip KD1JK

Thank you for this very nicely presented refresher! For understanding things, a historical perspective can be very helpful. I‘d like to recommend KathyLovesPhysics videos (and book); lightning is covered, too.

Greetings from Sweden! You got yourselves a thumps up and a new subscriber 🎉

An earth ground rod is needed for household electrical circuits to enable the Earth Leakage breaker to trip if you touch an active (live) main wire while for example, you are standing in a puddle of water. As most neutral cables are earthed in the meter box, the current would flow to earth/ ground via your feet to complete a circuit back to the ground rod and hence the neutral at the meter box. This would then cause an inbalance between the active and neutral cables at the Earth Leakage breaker and trip the power, hence quickly preventing you getting a shock. So, in this type of household circuit a ground rod which provides an earth connection is very important to have. A ground fault interrupter doesn't need an earth connection, as the neutral is linked in the meter box to ground, but it does use the ground/ earth to detect a leakage current to earth and trip.

Many operators confuse themselves with the word "equipment" about everything connected to power supplies, tuners, meters, external speakers, etc. If you're "grounding" ANY of that stuff we mistakenly call "Ham Radio *equipment*", you are actually violating NEC (National Electric Code), to the same thing you ground appliances such as a clothes dryer to. I get such a kick out of these per-snicketty stuck-up Advance Extra Class operators that think that their license, class particularly is like to a Ph.D in Electrical Engineering and all other fields of study, 🤣🤣🤣!" I too work from an apartment on the 2nd floor with an antenna (HF) mounted on the aluminum balcony railing and this application has worked for many years! I remember an Advanced Extra class op trying to tell me that I should ground my station to the center screw that holds the face plate of the wall outlet to the receptacle - what a LID! But that's what some of these class clowns in Ham Radio like to do, is give a newbie bad advice that could actually cause great damage, injury, and death, and then have the audacity to say, "Well, he's gotta learn!" And grounding even the antenna has very little, if anything to do with the VSWR, as many a Ham have lied to me about that as well. VSWR has to do with resonance and impedance matching. Otherwise, a great presentation on the "Ground Myth". KD8EFQ/73

Thank you for this great presentation which complete the book grounding and bounding. Please can we get the PDF of this presentation too, to keep as reference on the subject? Thank a lot

I'm a physician of internal medicine. And taught biochemistry to medical students We have same problem in medicine: many, many words are misused; definitions are wrong or change depending on author; and no one bothers to understand what is actually happening. People simply settle on contrasting and inconsistent definitions... It's a clusterf@ck. And apparently the bureaucrats want it that way. It keeps the smart curious types confused and largely intellectually impotent

In AC generated current, at the higher voltages, the ground can be used to complete the circuit. But that is not the same as the ground that you have in you home. In your home the earth ground is used mainly to discharge static electrical charges from the devices hooked up to the system or static charges created by lightening electromagnetic discharges transferred into the structure of the building. The fact that the ground doubles as a safety in case the "hot" side of the circuit somehow comes in contact with the metal case of the device being powered does not change that fact. AC current will follow the easiest path back to the transformer, which is the "neutral" side of the circuit and is why the ground and "neutral" wires are bonded in the main distribution panel. Perhaps static charges are why you have grounds on radio circuits. I can easily see how higher powered radios would create static charges that need to be safely discharged into the earth.

Excellent talk!

As an electrician I am required to provide a grounding conductor in the power systems that I install. Most times this is required by the NEC and adopted by some authority that has jurisdiction over me to select or reject my installations. An entire (250) article in the NEC is dedicated to grounding and bonding. I assumed that some people smarter than me developed this theory and process. The term ground maybe is not the perfect word. Pick anonther one.

Makes me wish I had been there, very good presentation. 10/10 KD8TAE ARRL Life Member

that person has definitely proven that you can use a different word for something and then explain it in a way that shows it was the same thing as everybody meant when they used the regular word for it.

Interesting presentation. My shack is upstairs and my only earth/ground is the domestic supply ground. I have kept all leads both DC and AC as short as possible and fitted ferrite clamp on beads on the inputs to all equipment. Thank fully I don't have any hot ⚡🔥 ⚡spots. 73's

Extraordinary presentation. I’m “book learned” and this dose of practical reality is MOST welcome ! Where is the material to truly learn non-intuitive radio - continuation/prequel/sequel to this presentation please ? @davecasler notwithstanding, see y’all in a similar vein.

The US GFI (Ground Fault Interrupter) is often called an RCD (Residual Current Device) here in UK which gives a slightly easier route to seeing that that some current (residual) managed to get away from the expected wiring loop. Ground is a big topic ! It may not be a myth, but the ideal ground is always inaccessible!

Very great way to look and think about what really is or isn't grounding.

In Gestalt Psychology ground is the context out of which the figure emerges. It's a matter of perception.

So refreshing to hear a woman give a technical talk about radio … RfF … grd .., etc. outstanding. Wish more women would be doing this .👍🥃🇦🇺

"Ground is a Myth!" And yet I stand on ground every day. Perhaps I am myth!

It was mentioned that connecting ground connector on equipment chassis to outside rods can "invite" lightning to inside. Won't coax shield itself invite lightning anyway? (lightning antenna -> coax shield -> radio -> electrical ground -> electrical rods outside house/at transformer station - as a path)

The next thing you know, they'll be rolling out a clickbait title like "the earth's not just flat, it's a cube."

Neutral for homes is how we get 120v from 240v. The center tap is halfway between the full 240 coil, so running a circut through half the coil gives you 120v. Power is going back to its source. Generated power travels through ground back to the generator. "Reference" is relative.

I think I am in love. There is a reason I run all the ground radials, they work.

She's pretty good & I'm glad she is pointing this out. So many grounding Myths out there. Nice Work ⚡🙏⚡

Ground is when humans are not being neurotic. it's a reference. It can also be an invisible attractor to even out any difference as becomes apparent depending on the situation. Static, lightning the list goes on. I would avoid ground spread radials and stick with balanced antenna evenly matched and spaced up in the air from earth and other objects. Or. If using radials try to use a solid metal sheet such as a big tin roof, but many radials are almost as good. Ideally you would want to be able to change antenna height above earth for different situations. I guess we could say that ground is halfway between the PD but not always depending on the reason / situation.

Ground is a good place to grow carrots and potatoes. 😂

This is an overused word and not understood by most. There area two terms to use instead. One is RETURN for DC and AC circuits. For RF it is the counterpoise or other half of the antenna.

3:40 lol ;) great presentation!

Thank you very, very much for sharing such important information 73 de CS7BDO

Excellent presentation! RF ground cannot be understood without some theory (Maxwell Equations).

A myth? Maybe not but definitely not as finite as it’s made out to be. As I understand it ground is essentially a capacitor that is far too large to be charged meaningfully by the supply voltage. The great benefit of grounding is filtering noise fed back into the line side because RF tends to do funny things to electronics not built for it. Electricity doesn’t just take the shortest path, it takes all paths proportional to their resistance/impedance. The shorter the path to ground, the lower the impedance for that path and a higher current results. The paths that run back through the utilities are higher impedance by comparison to a local ground and so pass a lower current.

Excellent Teaching Observations of the distinction between an arbitary Zero Absolute by definition of circumstances and trivial zeros floating in flat-space ground-state No-thing-defined.

CRANEs are 500ft shorebirds composed of steel truss whose main diet is frogs and small fish. Cranes are commonly found in wetlands and large construction sites. (Wrong, no such cranes exist. The word "crane" has several conflicting meanings. If we combine them, then we create a nonsense-crane, a non-existent crane.) GROUND is a power-company earth-connection used as circuit-common voltage-reference connected to a metal chassis and required for longwire antennas? Wrong. Ground doesn't exist. It's a myth. Construction equipment isn't powered by small frogs, and to cut through the confusion, simply stop using the word "crane." Just use some other, more accurate labels. The same goes for "Ground." Stop using that word. If you mean "circuit-common," then say that, and don't say "ground." Also, say "outdoor earthing-stake," and "chassis connection" and counterpoise-element, and negative supply terminal.

THANKS, THIS WAS A VERY AWESOME REPORT ON GROUND. GOD BLESS YOU. 73 KE7LGD SOUTHWEST UTAH.

since this was recorded, the questions were nearly impossible to hear.Suggest the presenter repeat the question for the recording.

This is the best presentation on this I have ever seen - thank you for this - it is a valuable contribution to the Hobby

So, are all the ARRL license manuals (which show the proper station set up with a copper pipe as a common grounding point which is then connected to a ground rod and bonded with the home's service ground rod) going to be updated to reflect this?

I believe a word missing here is, " Earth ", or, " Earthing " ! I have a feeling that this lecture may serve to confuse especially a newcomer ! Just because you have an opinion, doesn't mean it is correct ! Many times, you are combatting the devices planted before you show up with radio equipment ! Old electrical house wiring, as an example ! To try and sway someone from not using grounds, is reckless at best ! I could go on, but then I would sound like the speaker ! Odd that no one in the audience has taken exception to things she is saying ? Perhaps the material wasn't on their computers, as they were memorizing the answers ? Oops....! 😳 I think Tesla would be in disagreement ! 🤔.....?

This is exactly how mages used to talk back in the day. But they were in to fire. Everyone else was like what dude!? Is it on fire or not? Same thing really. It's still "magic"

Wow, This gal is good. I could tune-in to her anytime.

Now that I know "ground is a myth", I guess I no longer need to waste my time on lightning safety grounding or RF grounds either! Thanks ARRL, you've saved me so much money at my QTH!!

This was fantastic and super useful to me as a new ham. Thank you Kristen!

Thanks

What about digital ground

Greatly enjoyed the talk - very useful and clear take on the topic. Thanks. Cheers ...

It’s a marketing ploy by Big Copper to sell you more wire. When I was a kid we didn’t have any of this grounding nonsense.

Space Station and moon ships kind of show this?

Ground is no myth. Because when you're dead. That's where you're going to return to.

Hi Kirsten, Respectfully, I strongly disagree with the title of this presentation. I honestly believe it to be dangerous. It is 0200 local and hopefully I can make my disagreement with you clear to others. There is a ground. You must ground. Ground is not a myth. Ground is a requirement in all jurisdictions. Many use the National Electric Code. We in California have a more restrictive State electrical code. Outlets must be grounded. A driven rod outside of the station location in many, if not most situations is a violation and just plain dangerous. ALL current must flow back to the ground at the main panel. There are some exceptions. As a former Deputy Building Inspector, I want all current to flow back to the panel's ground and not a driven rod somewhere in the event of a fault. Why the ARRL is teaching with the title that Ground is a Myth is in my view irresponsible and dangerous. Respectfully, Jim Heath W6LG RU-vid Elmer and licensed for more than 60 years and an ARRL Life Member with many ARRL awards. Please excuse typos as I am taking strong chemotherapy at this time.

All i know is that there is something there if i only look at the lightning behavior, between cloud to cloud , cloud to earth , cloud to cloud to earth and in the believe that all these are so called static electricity or energy, tell me !

So is the ARRL insignia a myth?

JUST A NOTE ABOUT 6 YEARS AGO I LOST AROUND $2500 WORTH OF REGS TV's BECAUSE LIGHTING CAME UP THROUGH MY GROUND RODS. #@%##$@!!!

Well. ground seems pretty clear to me, but I have a hard time following you.

"Ground" is an observable, repeatable phenomenon that we have been using for decades.

All due respect, you did a very dangerous job of confusing new operators! Grounding is an important safety feature of any electrical system with operating voltages over 28 volts. You being confused doesn't excuse dispensing wrong information.

The ground has a negative charge . air has the opposite which is positive charge