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.
then you have golfers and lawn mowers... vehicles... things that generate their own currents but arent grounded their somewhat isolated... but building potential. so even in the middle of no where with taller and better grounded things, these get hit because it becomes an easier path for earth generated lightning in normal situations. these fields move... the greater differnces in energy snap... we see these as aurora in extreame cases. lightning without clouds or storms... until it happens...
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.
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
@@denverbraughler3948 I didn't think she gave any advice on how to ground electrical distribution systems, but anybody making decisions about how to wire their mains power from a few seconds of info in a youtube video is probably not going to be swayed into correct behavior by a comment on that video...
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.
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.
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.
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.
It’s unfortunate that the downstream completion of a circuit is labeled with names like “ground”, “neutral”, or “grounded conductor” when it’s really the drain, sewer, return, or post-utilization leg. It deserves a better label. “Frame” and “earth” sound like reasonable labels for non current-carrying references of electric potential with the understanding, of course, that they are local and limited by the resistance/impedance for the frequency under consideration.
In the "Split Phase and Neutral' slide [there are no slide numbers] European houses are not fed 240-0-240 in the way shown. Houses in USA are fed 120-0-120. Europeans are single 240 VAC. That's why there aren't transformers on poles for every three houses all over the place like there is in the USA. A much larger transformer is located locally and ground mounted (they are too massive to put on wooden poles). The phases are balanced at that point by assigning an equal load of houses so that one side of the transformer is not loaded more than the other. It also provides the ability for commercial users to pick up 3 phase at 415 VAC with little difficulty. The systems are quite different.
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!
Hi Phil… I take it from your comment you live in the UK and have knowledge on the subject of ‘ground’ I’ve just built my ‘shack’ but the radio equipment is not yet installed… I have a purpose build place in the back garden and my understanding is that ground should be taken back to the consumer unit as one point of ground. ( which I’ve done btw ) My ham friend is insisting that I drive a rod into the ground at the shack and everything should go to that. Can you point me in the direction of knowledge in the UK regarding ground or can you advise please. I’m willing to put an earth rod in ( bought one at B&Q ) I’m just not sure it’s necessary after watching SO much about USA ground advice / issues. I do agree with Jim W6LG but I’m open to advice from a UK source… there’s not a lot I’ve found so far from the UK perspective. Thanks very much.73.
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.
If by "earth leakiage breaker" you're referring to the so called "Ground Fault" Circuit Interrupter, she explained in the video why that actually has nothing to do with ground. The GFCI breaker doesn't care where the missing current went, only that it's missing.
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.
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.
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
It is a cluster fk. Bureaucrats don’t have an agenda beyond not looking like fools. Generally, when in doubt, increase grounding and bonding is the bureaucratic mantra simply because they don’t understand. The practical way to think about it is to keep things of value (perhaps a patient?) isolated from a substantial voltage difference. Perhaps a piece of equipment requires a patient to be energized to some degree, bird on a wire as it were. Inappropriate grounding can be as dangerous as a knife in a toaster.
@@VoltamatronSr A managerial aristocracy of corporate-government profiteers quietly determines what medicines are deemed good or bad. As a direct result, medicine in the USA is ranked 72nd in the world overall; and physician errors are the third cause of death in the USA. The extent to which propaganda shapes the decisions and affairs of people may surprise even the most well informed. Since the 1930s, the US Congress has delegated legislative, executive, and judicial powers to over 200 independent regulatory commissions. Those agencies enact over ninety percent of all US federal law. They are ruled by individuals who are unelected and largely unaccountable to the Courts and Congress and motivated solely by Calvinistic interests or monetary gain. Often these regulatory agencies become captives of the industry they regulate, as in the case of the US FDA (a captive subsidiary to the pharmaceutical industry) because it is in the economic self-interest of those who run the agency to obtain lucrative post-government- employment in the very industries they are charged to regulate. The result is widespread corruption, biased and perverse enforcement of the law, and anti-competitive regulation. Obama’s New Appointee to Head the FDA was a Big Pharma Mega-Lobbyist; as was Trumps and Bidens.
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.
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.
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
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
"I get such a kick out of these per-snicketty stuck-up Advance Extra Class operators" Sounds like "sour grapes" en.wikipedia.org/wiki/The_Fox_and_the_Grapes "People who speak disparagingly of things that they cannot attain"
@@Charlie-n7i "And, I wasn't trying to "attain anything" here" You didn't, so okay then! As it happens, I agree that "grounding" your radio while on the second floor of an apartment is worse than a pointless exercise, depending on what sort of radio it is. I also agree that *some* Extra Class amateur radio operators are more engineer qualified than others. I also had the First Class FCC radiotelephone license (back when it existed) and *that* was a tough examination. Even though I am "extra" I am still learning!
Aluminium railings and power supply chassis!? I did have an aluminium power supply chassis once. A Lambda power supply but that was the only one I had in alloy.
Thanks so much Kristen for the interesting presentation! She describes and explains the issues around grounding in our hobby very nicely and clearly. Martin OL5Y
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.
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
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.
22:24 "The best we can do is differentially stabilize at certain points". I propose we call those points "ground" because we need a simple name that suggests a purpose. We can then document the purpose of those points and how they are used in practice. The universe of grounds is so vast it defies calling them a myth. In use they are a reference point for something and in practical circuits that is generally self-identified in the diagram. In practical terms I would use the "ground" in my electrical panel to measure circuitry in my house. I would not, except for curiosity, use my ground to measure circuits in a neighboring house. That is not a practical circuit.
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
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.
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.
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.
@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.
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 UA-cam 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.
This argument is extremely flawed. Ground doesn't save you at an outlet from a shock. Ground is only for the protection of a lightning strike. Lighting absolutely wants to flow to earth. This is the only time that earth will or may keep you a little safer. I'm the days of no path to earth lightning use to come through telephones, TV's, ECT. This is what ground or a path to earth is providing. Don't believe me, grab a hot wire and a ground or a neutral and a ground if the neutral has unbalanced current flowing through it and you will get nailed! No safety to you at all in that regards.
Sorry about your chemotherapy. That stinks. However, your comment suggests you either didn’t want the video or didn’t understand it. I didn’t see or hear her say to ignore the NEC or not use safety grounds, she was just pointing out that “grounds” aren’t the infallible things we often think they are and they may have unintended consequences.
Grounding to the earth with rods is about lightning. Dry air rubs against the ground creating a voltage potential. The rods provide a path for lighting to go through rather than your equipment.
@@LTVoyager: He is correct. She did reference NEC when she clearly doesn’t understand the terminology or purpose. Her points are (1) that electrical ground isn’t a global minimum just as bottom or ground isn’t universal, and (2) that RF ground isn’t the same as DC ground or low frequency (50/60 Hz) ground. Absolute potential is still measured with respect to a local minimum. She stated clearly that she doesn’t understand these things, e.g., power supplies, GFCI.
@@denverbraughler3948 No, he is incorrect. Give one example of something she said that is dangerous. Potential isn’t measured compared to a local minimum. Potential is measured between any two points. No requirement for minima. She seemed to understand GFCI just fine. As I recall, she clearly stated that the GFCI measures any difference in current between the supply and return conductor. What else is there to understand about a GFCI? That is the fundamental principle.
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)
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!!
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?
NO and you are not really paying attention. What you refer to is lightning protection. That kind of ground (among the many mentioned by her) is a place to put the lightning energy other than your home. So the answer to your speculation is: WATCH IT AGAIN. Ground can also be a counterpoise, but so can radials on the ground or a dish or the other side of a dipole or whatever. AND if you look at the License manuals and so on, read for comprehension.
@@GeoffreyFeldmanMA W1GCF de AB2ZI... Gee. Thanks. In the spirit of Elmering you truly gave a well thought out and succinct explanation. I understand the difference between lightning and RF in the shack getting on the equipment chassis. IF there is no RF in the shack then yes, you wouldn't have any on the equipment. In the talk, reference, especially at the end, is made to RF burns and RF in the shack. The ARRL license manuals, which I use in my classes (ARRL Diagram 0076) shows what I stated. Each chassis is connected to a common ground bus directly (1/2" copper pipe is recommended) with a hose clamp. The end of the ground bus is then connected to a "Low-impedance Conductor As Short As Possible" to a ground rod with the proper clamp. The text of the book(s) then recommends that ground rod also be bonded with a single large copper wire to the main house service ground rod. I was asking for clarification on THAT point. I've emailed you the diagram so you can see what I was talking about...
Very good! I ditched radio shack ground rods a long time ago. I never want an isolated ground rod connected to anything that is connected to or plugged into an outlet connected to commercial power. Under certain conditions ( like lightning) a very large voltage gradient can exist from one ground rod to another that can destroy equipment. This is widely misunderstood!
Anyone who has never installed user level and commercial level LF/HF/VHF radio gear on a motor yacht, a sailing yacht, an oil tanker, an aircraft, or a passenger ship is no expert regarding grounds.
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.
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.
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 ! 🤔.....?
I encourage everyone to use appropriate grounds and to bond to the building’s grounding electrode system if located in or on a building or using electrical power which isn’t independently and separately derived at your location. Just because “ground” potential is relative doesn’t negate the necessity and functionality of proper bonding and earthing. It would be nice if current-carrying “grounds” had a separate meaningful name like “return” or “drain”. (“Neutral” is not a meaningful name.) “Earth” is a good name except it leaves her with the question of “where exactly is this patch of earth?”.
@@denverbraughler3948 I think the above video, is just one example of how people have surrendered to the idea, that it's O.K. to let someone else do your thinking for you ! And sadly surprisingly this was not a young per se, crowd, never questioned her opinions ! Just as a side note, I wonder if there are records available showing how many times lightning was diverted by way of Lightning Rods installed, that kept homes struck by lightning, from catching fire ?
The artificial ground is similar to the artificial xmas tree and look @ all the artificial ingredients in your food. Pretty soon we're all going to be artificial humanoidz. Even our automobiles are becoming artificial. Our news. Our family. Our organizations. Some say it's Fake this or that. And we have it now confirmed by artificial intelligence. Our signal reports are now even artificial. We are artificial in two more steps.
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"
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.
the confusion in antenna grounding comes from reflection (surface waves) and also from lightning protection with a load of urban myth thrown in. Moist ground does reflect better than dry as in it helps to form / balance the mirror image of the waveform in those type of antenna systems but it's better to get the correct distance above earth with both elements (for the task in hand).
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 !
Some neat content, but the smug, iconoclastic attitude really detracts from the presentation. It's kind of a strawman argument -- take the ideas people have about ground and slay them, but never really talk about why GND is everywhere and how it's really used in a proper way. People who fall for the rhetoric too much will now repeat the idea that "ground is a myth", and never take any engineering that uses the concept seriously. Ground is exactly what she says at the end -- a reference voltage that is what you say it is. It is a local abstraction that's useful for reasoning about return currents and spurious currents in unbalanced systems. For a "myth" it sure is a useful one; it wouldn't be in schematics and the NEC if it wasn't. So in that sense, it certaiinly exists, and what needs to be disabused is the false notions and misunderstandings of ground, not ground itself.
Kind of a misleading title. ARRL has published a Grounding and Bonding book and yet you dont even reference it. The NEC requires you bond your antennas (and therefore station ground) to your home's grounding electrode system and ultimately the utility grounded conductor. I think all this presentation will do is discourage hams from following these basic electrical safety requirements so they can operate safely.
Yes, the thing she said not to do for lightning is exactly what we're supposed to do according to the code. What are the odds that her idea is correct, and the NEC ended up in crazy land after so much empirical data over a long period of time?
I guess this PhD (Piled higher and Deeper) lady knows more than all the PE's and Civil Engineers of the world, right? 🤷♂️ You are very dangerous, Kristen. Either you don't understand real engineering, or you did a very poor job trying to make your case. Most of what you are saying is going over my head, and I'm sure it went over most of those in the audience.
'Ground' is a human abstraction that has a meaning dependent on the context in which it is used. Understanding the context and the objective of a particular 'ground' is important to implementing real systems in the physical world. This is something I've struggled to understand and I think videos like this are valuable to people trying to develop their intuition of the concept.
@@nullptr472Checkout the voyager pictures in correlation with spectral analysis. You can see that earth and moon are caught in the sun's magnetic orbital radio band, alternating thermal current, Schumann resonance every 18 minutes is the AC resonating. The reason why the moon does not rotate is because the moon is caught in Earth's DC toroidal reflectance.
Ground-Bounce in digital circuits has been observed for several decades. This is just like ground-bounce in the Earth, during ground-bounce-earthquakes. Same concept applies for both.
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.
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.
then you have golfers and lawn mowers... vehicles... things that generate their own currents but arent grounded their somewhat isolated... but building potential.
so even in the middle of no where with taller and better grounded things, these get hit because it becomes an easier path for earth generated lightning in normal situations.
these fields move... the greater differnces in energy snap... we see these as aurora in extreame cases. lightning without clouds or storms... until it happens...
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 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!
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
Don’t get your information about grounding 50/60 Hz electrical distribution system from anything that she said.
@@denverbraughler3948 I know nothing but may I ask why you say this? What is your understanding. This is a serious question.
@@denverbraughler3948 I didn't think she gave any advice on how to ground electrical distribution systems, but anybody making decisions about how to wire their mains power from a few seconds of info in a youtube video is probably not going to be swayed into correct behavior by a comment on that video...
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.
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.
Wow! Finally someone who actually understands. So many people don’t understand.
Yep. I'm laughing at the people who have made comments and clearly don't get it. They disagree.
Do you guys know there’s an electrical engineers version of cosmology?
And it’s making the standard model folks look foolish.
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.
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.
It’s unfortunate that the downstream completion of a circuit is labeled with names like “ground”, “neutral”, or “grounded conductor” when it’s really the drain, sewer, return, or post-utilization leg. It deserves a better label.
“Frame” and “earth” sound like reasonable labels for non current-carrying references of electric potential with the understanding, of course, that they are local and limited by the resistance/impedance for the frequency under consideration.
In the "Split Phase and Neutral' slide [there are no slide numbers] European houses are not fed 240-0-240 in the way shown. Houses in USA are fed 120-0-120. Europeans are single 240 VAC. That's why there aren't transformers on poles for every three houses all over the place like there is in the USA. A much larger transformer is located locally and ground mounted (they are too massive to put on wooden poles). The phases are balanced at that point by assigning an equal load of houses so that one side of the transformer is not loaded more than the other. It also provides the ability for commercial users to pick up 3 phase at 415 VAC with little difficulty. The systems are quite different.
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!
Hi Phil… I take it from your comment you live in the UK and have knowledge on the subject of ‘ground’ I’ve just built my ‘shack’ but the radio equipment is not yet installed… I have a purpose build place in the back garden and my understanding is that ground should be taken back to the consumer unit as one point of ground. ( which I’ve done btw ) My ham friend is insisting that I drive a rod into the ground at the shack and everything should go to that. Can you point me in the direction of knowledge in the UK regarding ground or can you advise please. I’m willing to put an earth rod in ( bought one at B&Q ) I’m just not sure it’s necessary after watching SO much about USA ground advice / issues. I do agree with Jim W6LG but I’m open to advice from a UK source… there’s not a lot I’ve found so far from the UK perspective. Thanks very much.73.
Excellent Excellent Excellent presentation ! Absolutely enjoyed her presentation ! Thank You !!!
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.
If by "earth leakiage breaker" you're referring to the so called "Ground Fault" Circuit Interrupter, she explained in the video why that actually has nothing to do with ground. The GFCI breaker doesn't care where the missing current went, only that it's missing.
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.
Lectern.
@@WhoFlungPoo2024 Thanks, TROLL: my dad _told_ me I’d never learn to spell! (Dad, have you come back from the DEAD?!)
He also said, “ It’s a d?#$ poor mind the can’t think of more than one way to spell a word!”
Sadly, she got other terminology like “ground fault” wrong. Not every word means what you think it should mean.
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.
In a closed electrical system all a "ground" is, is a return to source. Just like your neutral.
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
It is a cluster fk. Bureaucrats don’t have an agenda beyond not looking like fools. Generally, when in doubt, increase grounding and bonding is the bureaucratic mantra simply because they don’t understand.
The practical way to think about it is to keep things of value (perhaps a patient?) isolated from a substantial voltage difference. Perhaps a piece of equipment requires a patient to be energized to some degree, bird on a wire as it were. Inappropriate grounding can be as dangerous as a knife in a toaster.
@@VoltamatronSr A managerial aristocracy of corporate-government profiteers quietly determines what medicines are deemed good or bad. As a direct result, medicine in the USA is ranked 72nd in the world overall; and physician errors are the third cause of death in the USA. The extent to which propaganda shapes the decisions and affairs of people may surprise even the most well informed.
Since the 1930s, the US Congress has delegated legislative, executive, and judicial powers to over 200 independent regulatory commissions. Those agencies enact over ninety percent of all US federal law. They are ruled by individuals who are unelected and largely unaccountable to the Courts and Congress and motivated solely by Calvinistic interests or monetary gain. Often these regulatory agencies become captives of the industry they regulate, as in the case of the US FDA (a captive subsidiary to the pharmaceutical industry) because it is in the economic self-interest of those who run the agency to obtain lucrative post-government- employment in the very industries they are charged to regulate. The result is widespread corruption, biased and perverse enforcement of the law, and anti-competitive regulation. Obama’s New Appointee to Head the FDA was a Big Pharma Mega-Lobbyist; as was Trumps and Bidens.
WHO would come if they asked to get your gene therapy.
Great presentation, thanks for sharing the experience
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.
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.
Great presentation, thank you for sharing.
Incredible presentation. I learned a ton from this. Thank you!
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
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
"I get such a kick out of these per-snicketty stuck-up Advance Extra Class operators"
Sounds like "sour grapes"
en.wikipedia.org/wiki/The_Fox_and_the_Grapes
"People who speak disparagingly of things that they cannot attain"
@@thomasmaughan4798 "Sour grapes" = raisins. Good, healthy raisins.
And, I wasn't trying to "attain anything" here. Move along now.
@@Charlie-n7i "And, I wasn't trying to "attain anything" here"
You didn't, so okay then!
As it happens, I agree that "grounding" your radio while on the second floor of an apartment is worse than a pointless exercise, depending on what sort of radio it is.
I also agree that *some* Extra Class amateur radio operators are more engineer qualified than others. I also had the First Class FCC radiotelephone license (back when it existed) and *that* was a tough examination.
Even though I am "extra" I am still learning!
Aluminium railings and power supply chassis!? I did have an aluminium power supply chassis once. A Lambda power supply but that was the only one I had in alloy.
EXCELLENT presentation Kristen !!
Thanks so much Kristen for the interesting presentation! She describes and explains the issues around grounding in our hobby very nicely and clearly. Martin OL5Y
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.
Greetings from Sweden!
You got yourselves a thumps up and a new subscriber 🎉
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
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.
Myth can mean the same as Legend… would that work here?
22:24 "The best we can do is differentially stabilize at certain points". I propose we call those points "ground" because we need a simple name that suggests a purpose. We can then document the purpose of those points and how they are used in practice. The universe of grounds is so vast it defies calling them a myth. In use they are a reference point for something and in practical circuits that is generally self-identified in the diagram. In practical terms I would use the "ground" in my electrical panel to measure circuitry in my house. I would not, except for curiosity, use my ground to measure circuits in a neighboring house. That is not a practical circuit.
Outstanding! Thank you.
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
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.
Makes me wish I had been there, very good presentation. 10/10 KD8TAE ARRL Life Member
That's why it's on here. I can watch it over here 👍🏻🇬🇧
She's pretty good
& I'm glad she is pointing this out.
So many grounding Myths out there.
Nice Work ⚡🙏⚡
She started some of her own.
@@denverbraughler3948 I can agree that she oversimplified some points.
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.
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.
ua-cam.com/video/EcHEWH8Eh0Q/v-deo.htmlsi=fP5e4aRShRk3jWPD
Grounding
Very great way to look and think about what really is or isn't grounding.
Neighbor's house hit by lightning. Every appliance and all electronics without a ground prong on the plug survived. Everything else... toasted.
Excellent talk!
@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.
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 UA-cam 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.
This argument is extremely flawed. Ground doesn't save you at an outlet from a shock. Ground is only for the protection of a lightning strike. Lighting absolutely wants to flow to earth. This is the only time that earth will or may keep you a little safer. I'm the days of no path to earth lightning use to come through telephones, TV's, ECT. This is what ground or a path to earth is providing.
Don't believe me, grab a hot wire and a ground or a neutral and a ground if the neutral has unbalanced current flowing through it and you will get nailed! No safety to you at all in that regards.
Sorry about your chemotherapy. That stinks. However, your comment suggests you either didn’t want the video or didn’t understand it. I didn’t see or hear her say to ignore the NEC or not use safety grounds, she was just pointing out that “grounds” aren’t the infallible things we often think they are and they may have unintended consequences.
Grounding to the earth with rods is about lightning.
Dry air rubs against the ground creating a voltage potential.
The rods provide a path for lighting to go through rather than your equipment.
@@LTVoyager:
He is correct. She did reference NEC when she clearly doesn’t understand the terminology or purpose.
Her points are (1) that electrical ground isn’t a global minimum just as bottom or ground isn’t universal, and (2) that RF ground isn’t the same as DC ground or low frequency (50/60 Hz) ground.
Absolute potential is still measured with respect to a local minimum.
She stated clearly that she doesn’t understand these things, e.g., power supplies, GFCI.
@@denverbraughler3948 No, he is incorrect. Give one example of something she said that is dangerous.
Potential isn’t measured compared to a local minimum. Potential is measured between any two points. No requirement for minima.
She seemed to understand GFCI just fine. As I recall, she clearly stated that the GFCI measures any difference in current between the supply and return conductor. What else is there to understand about a GFCI? That is the fundamental principle.
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)
"Ground is a Myth!"
And yet I stand on ground every day. Perhaps I am myth!
LoL
The ham, the myth, the legend!
Just don't stop thinking! I think therefore I am... If I stop... POOOF... I'm not!
since this was recorded, the questions were nearly impossible to hear.Suggest the presenter repeat the question for the recording.
Good presentation, explanation of importance of grounding
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!!
I think maybe I can save money on future Handbook purchases too. 🤣
I think I am in love. There is a reason I run all the ground radials, they work.
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?
NO and you are not really paying attention. What you refer to is lightning protection. That kind of ground (among the many mentioned by her) is a place to put the lightning energy other than your home. So the answer to your speculation is: WATCH IT AGAIN. Ground can also be a counterpoise, but so can radials on the ground or a dish or the other side of a dipole or whatever. AND if you look at the License manuals and so on, read for comprehension.
@@GeoffreyFeldmanMA W1GCF de AB2ZI... Gee. Thanks. In the spirit of Elmering you truly gave a well thought out and succinct explanation.
I understand the difference between lightning and RF in the shack getting on the equipment chassis. IF there is no RF in the shack then yes, you wouldn't have any on the equipment.
In the talk, reference, especially at the end, is made to RF burns and RF in the shack. The ARRL license manuals, which I use in my classes (ARRL Diagram 0076) shows what I stated. Each chassis is connected to a common ground bus directly (1/2" copper pipe is recommended) with a hose clamp. The end of the ground bus is then connected to a "Low-impedance Conductor As Short As Possible" to a ground rod with the proper clamp. The text of the book(s) then recommends that ground rod also be bonded with a single large copper wire to the main house service ground rod.
I was asking for clarification on THAT point.
I've emailed you the diagram so you can see what I was talking about...
Very good! I ditched radio shack ground rods a long time ago. I never want an isolated ground rod connected to anything that is connected to or plugged into an outlet connected to commercial power. Under certain conditions ( like lightning) a very large voltage gradient can exist from one ground rod to another that can destroy equipment. This is widely misunderstood!
Reflect is the right word.
In Gestalt Psychology ground is the context out of which the figure emerges. It's a matter of perception.
Anyone who has never installed user level and commercial level LF/HF/VHF radio gear on a motor yacht, a sailing yacht, an oil tanker, an aircraft, or a passenger ship is no expert regarding grounds.
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.
Excellent presentation! RF ground cannot be understood without some theory (Maxwell Equations).
It gets complicated if you use ground planes in the GHz region. Lots of inductors and stray capacitors randomly thrown in for good measure.
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.
It's called a strawman argument.
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 !
🤔.....?
I encourage everyone to use appropriate grounds and to bond to the building’s grounding electrode system if located in or on a building or using electrical power which isn’t independently and separately derived at your location.
Just because “ground” potential is relative doesn’t negate the necessity and functionality of proper bonding and earthing.
It would be nice if current-carrying “grounds” had a separate meaningful name like “return” or “drain”. (“Neutral” is not a meaningful name.)
“Earth” is a good name except it leaves her with the question of “where exactly is this patch of earth?”.
@@denverbraughler3948
I think the above video, is just one example of how people have surrendered to the idea, that it's O.K. to let someone else do your thinking for you !
And sadly surprisingly this was not a young per se, crowd, never questioned her opinions !
Just as a side note, I wonder if there are records available showing how many times lightning was diverted by way of Lightning Rods installed, that kept homes struck by lightning, from catching fire ?
I have been saying do not bond your RF GROUND and ELECTRICAL GROUND for years!!!! HALLELUJAH!!!!! SOMEONE FINALLY UNDERSTANDS WHAT IM SAYING.
Wow, This gal is good. I could tune-in to her anytime.
Thank you very, very much for sharing such important information
73 de CS7BDO
The next thing you know, they'll be rolling out a clickbait title like "the earth's not just flat, it's a cube."
Wow!! I’d better tear up my Eng degree and tell my colleagues at the power company we don’t need no damn grounds.
THANKS, THIS WAS A VERY AWESOME REPORT ON GROUND. GOD BLESS YOU. 73 KE7LGD SOUTHWEST UTAH.
3:40 lol ;) great presentation!
This is the best presentation on this I have ever seen - thank you for this - it is a valuable contribution to the Hobby
Ground is a good place to grow carrots and potatoes. 😂
😂
@@ARRLHQ Also note that the fields where these products grow, happen to be GOOD grounds. Only thing better is flood plains.
Thanks
What about digital ground
Ground is no myth. Because when you're dead. That's where you're going to return to.
Instead of opining ridiculously watch the VIDEO on which you thoughtlessly comment and work to understand it.
Our poor space probes are jealous!
Geoffrey (below) obviously does not understand the Irish concept, that one side of the "ground" is better than the other side of the "ground".
The artificial ground is similar to the artificial xmas tree and look @ all the artificial ingredients in your food. Pretty soon we're all going to be artificial humanoidz. Even our automobiles are becoming artificial. Our news. Our family. Our organizations. Some say it's Fake this or that. And we have it now confirmed by artificial intelligence. Our signal reports are now even artificial. We are artificial in two more steps.
@jwdevine great comment. Made me chuckle!
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"
Greatly enjoyed the talk - very useful and clear take on the topic. Thanks. Cheers ...
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.
the confusion in antenna grounding comes from reflection (surface waves) and also from lightning protection with a load of urban myth thrown in. Moist ground does reflect better than dry as in it helps to form / balance the mirror image of the waveform in those type of antenna systems but it's better to get the correct distance above earth with both elements (for the task in hand).
I'm here to inform the new methods to use LILLY-WAVES
So refreshing to hear a woman give a technical talk about radio … RfF … grd .., etc. outstanding. Wish more women would be doing this .👍🥃🇦🇺
So is the ARRL insignia a myth?
JUST A NOTE ABOUT 6 YEARS AGO I LOST AROUND $2500 WORTH OF REGS TV's BECAUSE LIGHTING CAME UP THROUGH MY GROUND RODS. #@%##$@!!!
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 !
Space Station and moon ships kind of show this?
Some neat content, but the smug, iconoclastic attitude really detracts from the presentation. It's kind of a strawman argument -- take the ideas people have about ground and slay them, but never really talk about why GND is everywhere and how it's really used in a proper way. People who fall for the rhetoric too much will now repeat the idea that "ground is a myth", and never take any engineering that uses the concept seriously.
Ground is exactly what she says at the end -- a reference voltage that is what you say it is. It is a local abstraction that's useful for reasoning about return currents and spurious currents in unbalanced systems. For a "myth" it sure is a useful one; it wouldn't be in schematics and the NEC if it wasn't. So in that sense, it certaiinly exists, and what needs to be disabused is the false notions and misunderstandings of ground, not ground itself.
Mike Holt is having a stroke
there is a lot here...... study.... a few times and again later on..
Kind of a misleading title. ARRL has published a Grounding and Bonding book and yet you dont even reference it. The NEC requires you bond your antennas (and therefore station ground) to your home's grounding electrode system and ultimately the utility grounded conductor. I think all this presentation will do is discourage hams from following these basic electrical safety requirements so they can operate safely.
Yes, the thing she said not to do for lightning is exactly what we're supposed to do according to the code. What are the odds that her idea is correct, and the NEC ended up in crazy land after so much empirical data over a long period of time?
Should the arrl think of changing their symbol😂
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.
Well. ground seems pretty clear to me, but I have a hard time following you.
I guess this PhD (Piled higher and Deeper) lady knows more than all the PE's and Civil Engineers of the world, right? 🤷♂️ You are very dangerous, Kristen. Either you don't understand real engineering, or you did a very poor job trying to make your case. Most of what you are saying is going over my head, and I'm sure it went over most of those in the audience.
"Ground" is an observable, repeatable phenomenon that we have been using for decades.
'Ground' is a human abstraction that has a meaning dependent on the context in which it is used. Understanding the context and the objective of a particular 'ground' is important to implementing real systems in the physical world.
This is something I've struggled to understand and I think videos like this are valuable to people trying to develop their intuition of the concept.
@@nullptr472Checkout the voyager pictures in correlation with spectral analysis. You can see that earth and moon are caught in the sun's magnetic orbital radio band, alternating thermal current, Schumann resonance every 18 minutes is the AC resonating. The reason why the moon does not rotate is because the moon is caught in Earth's DC toroidal reflectance.
You didn't listen to the lecture on which you comment. How sad.
Ground-Bounce in digital circuits has been observed for several decades. This is just like ground-bounce in the Earth, during ground-bounce-earthquakes. Same concept applies for both.
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.
She never said not to use safety grounds or ignore the NEC. Why are you making stuff up?
With all due respect, it was clear from the get-go Kristen's "confusion" was a rhetorical device. The only genuine confusion was yours.
The ground has a negative charge . air has the opposite which is positive charge
Your great God of plus and minus will not help you here
It is all Relative.
Does that explain heaven and he🏒🏒
😅
Much ❤ Love
🌎🌏🌍☯️⚡️
World🌞Peace