I totally agree that the radio should not ever be connected to it’s own separate ground rod! One quick example is if there is a lightning strike near the house or power panel ground rod, it can elevate the ground potential several thousand volts above the ground potential where the radio is grounded. If the radio was not grounded both the hot wire, neutral wire and the bare ground wire in the power feed to the radio would all stay at the same relative potential. However if the radio chassis was connected to its own ground rod it you would essentially have a conductor connecting both ground rods and a potential difference of several thousand volts might exist between each end. The radio chassis would be near the far end. Current would flow from one rod through the radio chassis to the other rod. The black and white wires, while being 120 volts between them could actually be a few thousand volts above the radio chassis. Who knows what might happen! It’s best to let all three wires ( black, white and bare) float up and down together. My radio station does not have its own ground rod. For one thing it’s too far from the main panel for me to connect the two ground rods and it’s not necessary. I am a retired EE with experience in power, lighting, interior communication, radio and electronics. Several years in each area.
Excellent comprehensive series Jim. As an electrical engineer that works heavily in the automation world I have witnessed my fair share of ground problems especially with ground loops. Your conclusions addressed my concerns with often recommended multiple groundling locations (service ground, station ground and antenna/remote tuner ground) that have left me with an extremely uneasy feeling. Thanks for taking the time to walk through this topic in detail.
I'm getting ready to cross this bridge very soon! Just bought the ARRL book, Grounding and Bonding. I'm going to replace a rotten galvanized pipe that is on my mains. Then install 2 x 8' ground rods. One for my AC panel mains and another under my shack window. Going to tye them together with 8ga bare solid copper to my MFJ window passthrough. One the other side of the passthrough, a ground buss bar. Going to install gas style coax lightning arrestors grounded to the rod under the window... I agree with you on not using the adapter with ground to receptacle plate screw...
Thanks for the video, sir. I am an engineer and a Ph.D. Heh... that and five bucks might get you a Starbucks. ;) I've also been working with audio for a long time and have had the crap shocked out of me by potential difference between the PA and my guitar amplifier (through the microphone). I have not yet decided whether having a double ground for the station equipment is a good idea. My initial thought is that the earth ground from the panel should be the right way to go. If I install a second ground, then there is the possibility that there will be a potential difference between the two. I haven't figured this out, quite yet. Bonding the station components together seems like a very good idea because it equalizes the potential of the cabinets. I have no desire to be shocked by potential difference between the various pieces of equipment. We don't have lightening here very often in Carson City. But when we do I'll disconnect the antenna(s) from the system. I'm hoping to be a new ham operator by the end of the month. I'll take my test(s) the middle of the month.
For me, grounding at the panel is my preference. For audio, I prefer to use an isolation transformer if the grounds need to be isolated, but still keep them grounded at the panel. The more grounds one has I think the better.
Copper wire has a resistance over distance. A #16 for a ground wire has a resistance for 10 feet would be about 0.04 ohms. At 15 amps, that would be around 0.6 volts. Though not much, if the current were to go up, the voltage drop from one end of the wire to the other also goes up. Most romex wire today has the ground connection a size smaller than the black and white. (So 12 awg black/white/red would bundled with a 14 awg ground.) A 15 amp circuit would have a #16 awg grounding wire. A 20 amp circuit would have a #14 awg grounding wire. The romex wires in my house are about 30 feet long, so if I were to have new romex cable for #14 awg, the ground wire resistance would be 0.12 ohms. Doesn't seem like much, but if there was ever a high current you could use ohm''s law to calculate the voltage. This is why they say in a RF station use #8 or #6 awg wire.
David Thompson Well, I have been zapped by all sorts of things but in my experience with both radio and audio is that "hard grounding" i.e. Direct to earth screws with the audio and/or RF, it also sometimes can do weird stuff to other equipment like making a PC not turn on as some safety thing in the PSU senses that. I have not figured out why this is as in theory it shouldn't make a difference at least to my basic understanding of the subject, but it does. So I basically use the ground in the socket even though I occasionally get zapped by something or other, and I think Jim had a good point about it potentially defeating the ground fault trip switch, which I hadn't even thought of before. I do know some guys who think the opposite of this but I care more about things working right than some theoretical debate point and eliminating the occasional zaps I get from stuff. Just my 2ct, 73's.
Funny, all those credentials and not yet a Ham ? That easily should have been given to you, as part of your degree ! IMHO ! Once licensed, you'll learn just how over qualified you really are ! Good luck finding anyone on the Ham bands, nowadays that can keep up ! Question begs ? Did you go from first test to Extra, in one setting ? Most frustrating thing for older Radio Amateurs, is the lack of practical experience, one would have experienced, coming up through the ranks, as you began as a Novice, and worked your way up ! Now, sadly, no longer a requirement ! Essentially you now have Extras that can't answer questions a Novice would know ! And that, is a no shitter !
I'm glad I watched this. I sympathize with your neighbor; when I first got into ham radio, I read several books about setting up a shack and was distinctly told by at least one reference that I should bond my equipment chassis grounds and run them immediately through a *short* earthing wire out the wall to an earthing rod. I did this and never had any problem. I'm not an expert, but I still think that is a good idea for equipment which does not have the chassis tied to the electrical ground. Two stories, neither of which are first hand, that may aid in understanding: In an electrical engineering class, the instructor was asked what, exactly, was the difference between earth and ground. His answer: "Around here, about 5 volts." An industrial building had a large amount of heavy-duty electrical equipment on the second floor. Unbeknownst to anyone, the second floor electrical system was not bonded to the electrical system on the first floor. Everything on each floor ran properly, so it was quite some time, and only after a serious injury, before it was discovered that the ground potential between the two floors was some 20,000 volts. Firsthand story about neutral vs. ground: A friend of mine had an older house with a countertop cooktop and a hood above, with the cooktop controls in the front face of the hood (a nice design that puts the controls at eye level). She complained that she sometimes felt a slight electric shock when she touched the cooktop and the hood simultaneously. I brought over my meter and found the potential difference between the cooktop and the hood was 73 volts. The unit worked, so the neutral was OK, but that's not the same thing as having a ground connection despite the neutral being connected to ground at the panel.
220v in US in your home is AC using two legs of 110v so it's a "balanced" system flopping back and forth 60 times a second ...wire running a heating element in a stove or water heater (code did not require for many years)a spare neutral (aka ground wire) due to this fact Im not sure your analysis of the stove is correct
@@steelboymi Could you expand on this a bit more? The electrical shock was undeniably there (I should have mentioned that the difference was present when the cooktop was turned off). It sounds like you're saying the potential difference between the two was normal. I would expect that the cooktop and the hood would share a common ground.
@@pseudorandomly I don't know enough about how they are wired...modem cooktops tend to have 220v elements to heat and microwaves are 110v so microwave is on one of two "legs" that are coming in from power company. I'd be tempted to move the breaker for microwave on slot up or down in the panel (whichever way had slack in the wire) but that me I have plenty of experience with residential panels...there is still live power to the box when main breaker is off so not a job for novice
Jim, you are one of the few people that has a good understanding of bonding, and grounding. You separated grounding from earthing but electrically they are the same. The issue that I think many people face is when they cannot establish electrical equipotential across everything, The cable, transceiver, tuner, amplifier, and the electrical system supplying the station equipment. First bonding needs to be established to a common point which is the inter intersystem bonding termination and you explained that as good as Mike Holt could have. Ground loops happen where there is a difference of potential not multiple paths to ground. If everything is as equipotential there is no electrical pressure to move electrons so noticeable current to flow. Never float your equipment, if ti comes with a grounded power supply ground it and provided everything is bonded you should not have any problems electrically. Also have also said the electrons to not want to go to ground they want to go back to the source and the source is the transformer which created the neutral and bonded the center tap to ground. Electrons will use the ground as a path back if no other patch exist, they want to get back home :) If you do not electrically ground station equipment that path could be you. RF wise you cannot just dump RF current into the earth, that is not where it wants to go. The electrons was to go back home and home for the returned DC voltage is the transmitter. A properly constructed station should have minimal return voltage provided you have a decent vswr. Once the DC electrons get back to the transmitter the transmitter does not really want them either so it passed them off either through you to ground which goes back to the transformer feeding the station with power or the generator. The other and safer path is using the system bonding connection(s) which would be the path of least resistance taking a majority if not all of the voltage back to the source, the generator or transformer. Long story short DO NOT LIFT GROUNDS bond everything together to solve issues safely.
Very carefully written and helpful. No matter how you and I might try to explain what goes on, many will just close their minds to learning when it comes to grounding, earthing, bonding. There are a few bullet points that can be used ham radio operators that would make things so much easier. I am working on that draft of bullet points. I am not sure how it will turn out. Perhaps a series of questions would be helpful. This last week I got 2 emails where the writers indicated that their stations were grounded and/or bonded with #6 wire. To test all of this, I did wrap the room with foil and strips of copper that are about 20awg and 3 to 4 inches wide. I have the frame of my desk tied to the copper and foil. I have 3/4 inch copper pipe in a T configuration under the desktop and connected to the frame. I have short lengths of 1.5 inch wire flat braid from the copper pipe to the equipment. That braid is kept wide over its entire length; even at the connection points. Each piece of equipment has its short piece of that braid. All of that ties to a 1 inch copper pipe in the attic that runs directly to the common ground about 20 feet away. I am still learning and trying to apply where I can. I did this extreme set up as a test. The test is, will it make any difference. Thanks again. 73, Jim W6LG
Thank you for another great video. I simply love the calm, non-judgemental way that you express your thoughts and mentor, or "Elmer", others. In answer to your question about GFCI (aka RCD in New Zealand), I believe that having a separate ground connection should NOT defeat the GFCI. As I understand it, a GFCI continually monitors the current through both the Line (aka "Live" or "Phase") wire and the Neutral wire as a circuit pair. The device is designed to open, or "trip", any time the current flowing through these wires are different from each other. Therefore, if a radio or other electrical device or cable developed a fault that allowed current to go direct to ground, or otherwise bypass the expected path back through the GFCI, then any persons or equipment in the faulty path should be protected. This would be why GFCI breakers in homes were first introduced for external, garage, and "wet" areas within the homes. For my station I have obtained an isolating power transformer which I am planning to install for my station. I've wanted to do this for a line while. It is partly for safety purposes, but also in hopes to help keep RF off the house wiring. Thanks again for your excellent videos. 73, Alan
Hi Alan, I misspoke or just had a brain short circuit about the GFCI. My only excuse is that the first ones sold here may have been different. In any case, you are correct. Let's talk about current flowing to the ground wire/terminal. Here we have 120vac (typically a little higher). If say more than 10ma flowed through the ground wire in the 3 conductor cord, would the current in the the neutral and hot still be in balance? If say 1amp were to go to ground, what might happen with the other 8 amps? Just thinking out loud Alan. Let me know what you think. Thanks & 73, Jim
@@ham-radio Kirchhoff’s Current Law tells me that if part of the current on the Line went to ground then the amount of current on the Neutral must decrease. So, in your example, if the Line (source wire) had 10 amps coming in then 10 amps ***should*** be going back out on the Neutral (return wire). If, say 1 amp somehow made it's way over the 3rd Ground wire, or any other return path, then that law says that the the Neutral wire should only have 9 amps going back. This would put the current out of balance by 1 amp, as seen by the GFCI. It is important to note that the current bypass leakage may be by a path other than Ground. For example, say we have a very large amp with NO Ground wire, pulling 50 amps, fed by a dedicated GFCI. Let's say that amp has an internal Neutral open fault. The amp would not turn on. Now, let's say we connect a coax cable from that amp to a radio being fed by a separate breaker or GFCI. If the coax, perhaps the shield, completes the lacking Neutral connection through the radio's Neutral wire then a possible overload condition could occur on the radio power circuit. In this example I guess one would have the choice of electrocution by completing the ground, or by fire from the resulting radio power cord overload. Back to the original GFCI example, the GFCI should trip as soon as it detects that there is an imbalance between the current in the Line and the Neutral. "As soon as" is relative, as most things are, since how fast it trips and at what level of imbalance it trips will be defined by the design and construction. I believe that in the U.S. the residential GFCIs are designed to trip beginning at 5mA and to do so in something under 1 second. Incidentally, I'm fairly familiar with U.S. power and general house wiring as I'm and ex-pat and spend most of my life in Texas. As grand as that is, I'm neither an electrician nor a Ph.D, but I've been shocked enough times to know what it feels like. Cheers, Alan
I'm not an electrician, but I've done a lot of wiring. For clarification, it should be noted that the two hot wires from the pole (pig) are 120 volts each, which combined give 240 volts. For our purposes, we only use one of the hots for 120 volts. I agree, for safety's sake the equipment needs to be grounded to the main service. The reason that subpanels require four wires (two hots, a neutral and a ground) is so that a short will go back to the main panel, tripping the breaker. A seperate earth rod defeats that purpose. I've read conflicting advice on ham radio earthing/grounding, some say the equipment needs its own earthing rod which is totally separate from the main service earthing rod, others say they should be tied together. I am new to ham radio, so it could well be that a separate earthing rod can reduce interference/noise in some situations. But a separate earth rod dedicated to the ham equipment is electrically dangerous and is a shock hazard.
You'll have a problem when the ground wire is connected to the second earthing rod without a bond to the the ground on the electrical panel. The earthing rod to earth has a high enough resistance that the breaker won't trip. That's one of the reason why the ground wire is bonded to the neutral wire in the main breaker box.
I agree with your comments, and this is the quickest way to start an argument at a ham club! This was our tech talk topic a few months ago at our local ham club, and we soon discovered that the recommendation of having a separate ground system for radio equipment was against our local building code, saying that everything must be connected together.
Just seeing this now, 3 years later... my understanding is that that "separate ground" isn't supposed to be separate. The ground rod outside the shack (if you place one) is supposed to be bonded to the ground rod for the electric supply for the house (at least so many feet apart and using a wire of such and such a gauge, etc.)
You can have two ground rods if you tie them together to equalize the voltage in the system, otherwise you have two separate circuits and run the risk of creating a voltage potential in one with a lightning strike. I recommend the ARRL book “Grounding and Bonding for the Radio Amateur“.
In the last image with the red X over the neutral, the GFCI is still going to trip regardless of the earth rod. GFCI outlets and breakers work by comparing the current on the hot wire versus the neutral wire. With the X on the neutral, the hot is going to have current flowing while the neutral is not. GFCI trips.
I agree, and there is one other item worth mentioning here and that is the "earth grounding" of the antenna tower. The tower should be grounded at the base and not back at the main panel. Having two "earth grounds" that are not bonded together and are separated by a distance (varies but lets say 30') can easily have a different potential between the two but, what are the chances you will be touching both at the same time? It is a difficult question and requires much thought due to the number of variables present in a given situation.
Thank you Jim, being a relatively new ham I have discovered that your videos are the best out there. We're actually fairly close neighbors me being just outside of Sacramento. Next up is my General test. Your videos are invaluable. Thanks again!
@@ham-radio Rocklin is a very nice area, There are good medical facilities nearby. I have to worry as well about that too. Sutter Roseville which isn't too far would be a good choice. I hope you're doing well.
Jim, I recently had a bad RFI situation on 160 meters when running my AL-811H linear amp. Everything I touched on the radio, mic, amp etc. resulted in RF burns. I started using a small neon bulb to touch the radio, mic, etc. to test for RF to avoid the RF burns. The bulb would light up so bright, that it was glowing with blue highlights. So I hard grounded the AL-811H amp to a nearby water pipe (under the kitchen sink). Amazingly, that fixed ALL of that RF problem, and I can't get my little neon bulb to light, and no more RF shocks no matter what power level I run. Thinking about what you said about it being a violation of the NEC to run multiple ground rods, I did an experiment. Instead of 'hard grounding' the amp to the water pipe with my piece of solid #14 wire, I put a .001 uf 7KV (coupling) capacitor in series with the ground wire, and viola, it also worked!. So you ,might want to mention that, - by putting a "capacitor" (of suitable voltage rating) in series with the ground wire to the secondary ground rod, you maintain the original AC & DC ground path while having a secondary ground rod for the needed RF path. This will satisfy the NEC. Also, you've made mention about running everything back to the service entry ground point (and service entry ground rod). Only problem is, that this is impracticable, and the long distances from the ham shack and the service panel is what is causing these situations in the first place. Ferrite beads and what not are all good things, but when you have serious RF (from 160 meters), the only remedy is a close by ground rod, or water pipe, and the way to stay in compliance with the NEC is to put a RF coupling capacitor with the ground wire to the ground rod (instead of hard-grounding the equipment to the ground rod).
Thanks. Someone how, this morning, I am not fully understanding the placement of the .001 cap. Can you send a private email to me with a drawing or perhaps a different way to describe what you did? Also, what is the SWR, feedline and antenna. You sure have a lot of RF in the room and I am wondering why that is happening. Thanks, Jim
Thanks for responding Jim... My feedline is Belden 9913 (foil shield). SWR leaving the shack is basically 1.1:1, and the antenna is a "loop", or modified inverted "ell". The principal is simple, and you said something in your video which set up the solution perfectly. You (correctly) said that 'we're dealing with DC paths, AC paths, and RF paths". Hard bonding ham equipment to local/nearby ground rods (or water pipes), bonds ALL of those paths (AC, DC & RF), when in fact we're only interested in shunting the RF path. And that's we're we get in trouble with the N.E.C. Much like the way it's done in RF (linear) amps, the "RF" component is shunted to the desired path (the output Pi network) via a coupling "plate" capacitor which passes the RF current, but blocks the DC (and AC) voltage. The solution is to simply put a capacitor (of suitable voltage rating) in "series" with the ground wire going to the local ground rod(s) or water pipe. I made a quick video demonstrating this situation, and can be seen here : ruclips.net/video/inZlg5B7FgQ/видео.html You (or anyone) can correspond via e-mail via my ARRL e-mail forwarding address which can be found on my QRZ page for call sign: N4MRN 73's for now Jim, Steve / N4MRN
Hello Jim. I remember living in a house with the old BX cable with the 2 wires wrapped up in paper and 2 prong outlets. The metal outer cover acted as the earth ground, I believe. The house I have now has modern wiring and gfi system. My shack equipment is not grounded to an earth rod. I have read up a little on this and have come to the conclusion that my rig is modern enough that the chassis is earth grounded through the lower prong on it`s 3 prong plug, and outlet. All of my electric power tools have the same 3 prong plugs. I believe it is known a double insulation. Thanks and I will be waiting for the next one.
Hello again Jim, Good explanation about grounds. An even more complex situation is an HF radio on a boat with optional connections to shore power. Boats have "water" connections as well as shore power ground which is alway a few volts different than the water. Anyway, one note about GFIs. They do not use the mains earth ground to detect a fault. GFIs will work exactly the same without an earth ground connection. I have tested this. GFIs measure the difference between the hot and return currents. If they are the same, all is well. If they are different, then some current is going somewhere else and it trips. The GFI cannot directly sense current to ground. If only knows that some of the current flowing out through the circuit isn't making it back.
Ya, I had that wrong. I had different type many years ago and for some reason that stuck with me even though things have changed. GFCI can be installed in an older home with 2 wire AC lines to each convenience outlet because they don't need that third wire. Thanks. 73, Jim
Thanks Jim ... I agree with you. My situation is exasperated by being off grid. I had a situation where dc ground had a voltage difference between ac ground. Ground is a reference voltage .. be careful what your reference is and make sure the whole system agrees on that reference.
Like you said, rf grounding is variable compared to AC/DC. I’ve always been told to run a ground rod 8’ along with a single radial under earth. BUT, here’s where I get confused, if your equipment is grounded via the 3rd prong, wouldn’t that make it bonded upon plug in? I also see most people saying to bond the rf with the ac ground. Well, wouldn’t that create a loop through the outlets and box ? It’s so confusing that I just give it to you guys to figure out. Lol. Look forward to each video.
I will point out that a GFI does not care where the current is lost. It measures the current difference between the hot lead and the return neutral lead, if it’s more than 5 milliamperes it opens the circuit. A neutral wire and a ground wire is bonded at the main panel. But the difference is the neutral is a current carrying conductor at all times. The ground is reserved to carry a large enough current to trip circuit breaker. It is a redundant path. If you could imagine a washing machine with no ground system. A hot lead breaks loose inside and falls against the frame of the machine. Now the frame is electrified. Anyone touching the frame of the machine and a cold water source could be shocked to death. Now that same system is grounded. The exterior frame is now connected to the ground. That wire falls inside and touches the machine frame and is grounded to the surface. It immediately creates a large current that trips the breaker and eradicates the electrical hazard. This was the system before GFI’s.
THANK YOU for covering the topic. As an FYI, my GCFI/GFI breakers do not have a ground connected to them, but they do have a neutral passing through it near the hot. How mine work is they sense a difference of current between the hot and neutral (black and white) wires and trip the breaker if the current in both does not match. Your breakers could be and are most likely different than mine. I don't like the idea, but they thing the reasoning behind it is that if the current is different from the black and white wired, then it must be traveling through the ground wire.
That’s what I have heard too. There’s a solenoid in the outlet such that as soon as there is a discrepancy between the hot and neutral the breaker will trip. The reasoning being that if is isn’t in the neutral, it’s not where it is supposed to be. Technology connections put out a great video on this.
Hi, Jim hope you're well, can I say first I was watching your videos long before I was a Ham and they helped me so much so thank you for producing these videos, Here in the UK from what I have read we run two different systems new houses run PME where we have a series of ground rods from the property to the substation. If I were to add another rod outside and ground my equipment to it, and if there was an issue with my electrics and any residual current was sent to ground my little old earth rod could pick that up and send it straight to my equipment and potentially me :) The other issue I have is my shack is on the 3rd floor of my house. So if I was to run an earth wire from the 3rd floor to the earth rod at ground level; I have just potentially just created an antenna if when any stray RF gets into it. So I created an artificial earth on the 3rd floor using random cut radials and a MFJ-931. allowing me to tune the random wires to the band im using This dealt with any stray RF, and reduced my noise floor. 73 regards David
Good video, Jim. I like your production style and easy manner. I've subscribed. I'm an SWL since 1970 and a new ham. I have to say, I've never seen ANY subject with so many conflicting opinions and guidance. Certainly, there must be ONE answer to the subjects you raise here. (No wonder you waited so long to bring this up!) I eagerly await the next video.
Really confusing topic as the ARRL book on Bonding and grounding says you should tie your equipment to a common ground and out to a ground rod. Great video as usual and a topic that is so relevant!! Thanks -73- W1KPS
My background is in process control in a pulp and paper mill. I typically worked with shielded balanced wire from field equipment to a DCS (distributed control system) and coaxial communication lines between DCS's. I also worked with high voltage single phase and three phase electrical systems. Shielding and grounding issues were a big part of my job. In my understanding, a typical USA residential breaker panel, has two hot legs (black wires or a red and black wire) and a neutral leg (white wire) measuring between either hot leg and the neutral leg there should be 120 volts AC. Measuring across the two black legs there should be 240 volts. That is because the transformer (pig) is dropping the higher line voltage (my residence the incoming voltage is 25KVAC) dropping to 240 volts. The transformer primary windings are at 25,000 volts AC, the secondary windings are generating 240VAC. The neutral is center tapped in exactly the center of those secondary windings supplying the 120 volts between the neutral and either hot leg. The voltage at the breaker will measure line voltage. The neutral will measure zero volts. But the current (amperage) on the hot wire and the neutral will be the same! The bare copper safety (ground) wire should not carry any voltage or current unless there is an electrical fault. The reason the safety ground (bare copper) wire from the grounding rod(s) is bonded at the neutral buss is to bring the neutral buss to earth ground at that specific location and to establish a zero voltage potential as referenced to earth ground. Earth ground is electrically active! I have personally measured between two earth grounding systems approximately a quarter mile apart and seen more than 50 volts combined AC and DC! The induced electrical current caused huge noise problems in my equipment! The same will happen to radio communication if grounding isn't taken seriously.
Excellent video, it all makes sense, except for one thing. We add ground rods at the tower and at the entry point of the shack for the lighting/static arrestor's on the coax and this will take the equipment chassis to ground. Is this different because of the braided shield in the coax. Wow, I'm confused.
Excellent point you make. I am working on that answer. Honestly, I have had little time to spare since we are selling the house and moving closer to our oldest son because of my health. I have drawn the graphics in Photoshop, gotten some graphics and help from the expert, Mike Holt and his company. Tomorrow is my 70th birthday and I will try to take some time to do the voice-over for the next video answering the question. The short answer is, in my view, my opinion as verified with experts, dangerous to have that second ground rod separate from the ground rod, Ufer, or water pipe at the main panel. You can have a fault that does not trip the breaker. Thanks for asking. Stay tuned! 73, Jim Heath W6LG
Hello. Thanks for the video. I enjoy watching your content. I will soon be designing my first shack and have been thinking about grounding/bonding. Would it be an issue if you were to tie the grounding rod to the house ground. Grounding rod attached copper plate to where the coax enters the house, that is then connected to the bonding strap (piece of copper pipe) located behind the components, finally, the pipe is connected to the house ground via the outlet grounding plug. The antenna ground, bonding strap and house ground are all connected.
Well Jim you sure open Pandora’s box with your take on grounding. When living in Florida in the 70’s we had Florida Power & Light give a talk at our Hamfest. After the hour long talk someone asked when, “when do stop with all this grounding”. His answer was, when you run out of money. 😳 At that time he suggested connecting your radios ground to your ground rod and have that rod connected to the ground rod that’s connected to your meter. Had my electric meter replaced in 2004, and they placed two rods to the meter 10 ft apart. ????? 73 Wd4dda
Jim, see Dave Casler's episode 8. He advocates a common ground. His reasoning is that the green ground in the house wiring is too far away from the outside pole ground. It seems that there are multiple opinions on this subject. I even see a real PhD responded in comments here and was also ambivalent regarding grounding. Great video and I really appreciate your sharing of knowledge.
Hi and thanks. I don't watch Dave's videos. I believe he presents good information. I just don't want to inadvertently copy his material or ideas. So, I purposely don't follow Dave. I did send a letter to him a last year but that did not go anywhere. There is another guy in CA who's videos are contain a lot of incorrect information. I have watched several of his and I am shocked by the lack of knowledge. Back to your question, in the other 2 videos I do try to follow the NEC and the CA electric code. I do recommend a single point ground of all equipment. I don't recommend a daisy chain. I do recommend a very low impedance conductor. Everything must go to the Intersystem Bonding Termination. My view is that using the "green" (it can be another color) wire is too great an impedance. Watch the two videos from May and see what you think. Mike Holt is the expert that I relied upon and his recognized in the US as the leading expert on the subject. Back to Dave, Dave is a good guy and provides good videos with lots of solid information. As I said, I just don't want to accidentally copy his material or ideas. I hope that at some time in the future Dave and I can communicate frequently. Thanks, Jim
Wow! I’ve been misled all these years. Everything I’ve been told is the way I have my station grounded. I have NO RFI issues at all. I have one 8ft ground rod drilled thru my garage floor to earth. I have a 3/4” copper water pipe running the length of my bench. All of my equipment is connected to that pipe and the pipe is connected via 1” thick copper braid. The connection from my equipment to the water pipe is via 3/4” copper braid. Should I connect the ground to the ground rod at my panel or start all over? Confused! Thanks for the video I think?
Thanks. Many have asked the same question. I plan on a "to the point" episode with my view of the NEC requires and what works for us. A short answer to your question, is the ground rod, in my view, should be connected to the main panel grounding buss bar. Any fault at the equipment must return to the main panel (sub panel is another issue to be discussed). The path of the current must flow to the panel so that the breaker can trip. As you know, current will flow through several paths depending on the resistance/impedance. If you had a short through your body and most of the current flowed to your low impedance ground connection, the breaker might not trip. RFI and the rest is another issue. Basically, you keep that RF out of the shack. All of the instruction books for transmitters that I have ever looked at have the same connection that you describe. You can have an antenna ground and cable ground for example. They too, in my view, must connect to the main pane. I hope that helps a little. It is very confusing. 73, Jim W6LG
I just acquired a full system for an older gentleman that he no longer wanted. When I was taking apart his system there was no ground wire attached to anything. I'm wondering how he pulled that off.
Jim! Glad to see you're doing well :) I've been subscribed to your channel for a couple years now. We've talked on the air briefly once. I hear you out there often. I was at a hamfest today and acquired a High Sierra screwdriver antenna based on looks (and price) alone. I had very little knowledge about them, other than that they look well made and online many were making comparisons to the Tarheel. Lo' and behold my internet searches have revealed that this is an antenna that you used to produce! What a wonderful discovery! I'm excited to get this antenna in operation. I hope it works as good as the internet says it does!
Jim, I am a Ph.D. and a retired university professor. I have worked with all sorts of laboratory electronics, radio transmitters, high voltage and high current sources. I watched electricians install wiring in new homes when I was only five years old. I replaced a light bulb socket on a lamp as a nine year old. Electricity, AC or DC, in the right place is great, but in the wrong place, deadly and destructive. The same with RF energy. We are blessed to have voltage sniffers that detect AC voltage on live electrical lines, voltmeters, etc. Better to use a meter than your body to find electricity or RF. Think before you move. Read a lot and ask good electricians, electronic technicians, RF engineers, etc. I am still learning!! N0QFT, Glen
This is it seems the most controversial subject in radio ! I’m not an EE but I started by grounding at the antenna - to keep the lightning out of my house, then I added a specialized and grounded Balun where the coax came in the house - to keep the RF out of the shack, the I added braided grounding straps to my antenna tuners - and I noticed that my noise floor came down a bit. I haven’t seen any ground loops yet but I cant help but think that the way to deal with that would be to bond all of the ground rods together so they came to equal potential. I’ll bet that older houses - perhaps with rotten ground rod for the mains - are the ones seeing the ground loop problems ?
I hope this series is eventually going to teach me how the heck to ground my ham antennas against lightning. I'm out in the middle of the desert and putting up even a dual-band stick would make it the tallest thing for _miles_. Worse, I have a multiband vertical that is *not* DC-grounded and I've no idea how to protect that should I erect it.
You just never know when you will take a strike. Read all the books, even took a class. Then one day we had a sever lighting storm rolled in. Tv's, surge protectors, all took a hit. The only sure way is to disconnect the power and RF. I had removed the RF lines from my radios but forgot to unplug the power supply. Went thru surge protector, then power supply, then one of my radios. Learned the hard way.
@@jeep146 Even unplugging won't stop everything. I learned that lesson the hard $7000 way back in 1993. I always unplugged antennas and power cords when not operating. Always! I crawled under the desk and unplugged the power strip that had everything on the bench plugged into it. One plug disconnected all AC power to the bench. Then while under there, I disconnected the incoming coax from a coax jumper that went up to the equipment on the bench. All fine and good, except I left the power plug and coax jumper laying about 18 inches away from the incoming coax connector. I took a direct strike on my tower. I was coming down the road on the way home and actually SAW the strike hit my tower. When I came in the shack, it was full of smoke and that smell you get when you know it's a major hit. What had happened was the lightning jumped the 18" gap between the antenna coax and the plug on the power strip cord. Everything was toast. There was a burned spot several inches wide and 18" long from where the destroyed coax connecter laid and where the destroyed power plug laid. The insurance adjuster crawled under the bench to take a picture because he said he had never seen anything like that and no one would believe him if he didn't have a picture. So, when you rely on disconnected cables, make SURE they are well away from anything that is close enough to arc to. I know from experience that 18" is not far enough. I've not had a strike since, but I disconnect my antennas outside the shack now. I have read, but not verified, that if you have an open ended coax going back outside and just laying on the ground, you can connect a disconnected antenna coax to it and the lightning strike will be further directed back outside the shack. I'm not sure enough of that to trust it. I'd rather just have it not come in the shack to begin with. One thing I've learned over the years that if lightning wants in, it's going to come in regardless of what you do. However, my new shack is an all-steel building with no windows and all metal doors. If it gets in here now, it's because the building came apart somewhere, in which case damaged radios is the least of my worries. I watched a tornado pass within less than a quarter mile of my place a week ago today, so it could happen.
If am running all my HAM related equipment off DC/battery (say two different batteries) do I still need to ‘ground’ any of the equipment? I noticed the avail grounding studs off my of my equipment…do I need them in this situation/setup is the question. Thanks in advance.
I have been zapped by appliances before that were improperly wired, or an outlet improperly wired. The reason having that third ground prong is important is this: A properly wired appliance will have that third wire go to cabinet/chassis ground. That's it's intended purpose. An A/C appliance such as a washer/dryer/fan/stove will very happily continue to work if the hot and neutral leads are reversed. I have had appliances that had the entire cabinet carrying a voltage of 120 volts A/C and worked fine. The unique property of A/C motors that they will run happily reverse polarity makes cabinet grounding essential. I had an electric dryer with a 3 prong outlet (now 4 prong are mandatory) that was improperly wired at the hookup point. Again, 120 volts into the cabinet and 120 volts to one heating coil and the neutral/ground to the other coil. The motor ran fine, but it didn't get very hot! Having a dedicated chassis ground wire is the ONLY way to assure that a hot power lead is not running to the chassis/cabinet because if it is, you will immediately have a short. If you don't have a GFI outlet you might even have some fireworks!
Yes, exactly. Some guys don't quite get the neutral versus ground wire and what that can mean. In short, it means trouble that could kill someone. Maybe you mentioned this, but one famous ham recommends cutting off that pin that you point out is very important. He says he is a Phd. I wonder. Thanks, Jim
I had a situation with an outlet where hot and neutral were reversed. So if you touched the metal chassis on one appliance and touched another on a normal outlet, you could get a shock. Neither of these appliances used a third pin.
Sorry about the typo and incomplete note.I proposed running an additional grounding wire from my new ground rod the fifty feet or so feet to the existing service ground to maintain continuity. There is the matter of an RF ground for antennas as well as equipment grounding for the transceiver, etc. while the service outlet presents a neutral wire that is also grounded at the service panel. It all seems like one leg of a circuit to me. No GFIS at my operating position either.
Understanding Entropy and its use of voltage to return matters to an even state is my key to understanding grounding. Charge carries energy. Flowing charge is current .Current is a means to even out potential differences. These differences are voltages. Entropy manifests itself through current in an unrelenting way to eliminate the voltage anyway it can. Entropy is inevitable and unavoidable. It will happen, current evens out the potential difference. The neutral wire parallels the hot wire. The circuit spot between neutral and hot is where the load goes. The load is a light bulb, a power supply, toaster, computer, televisions. A limit is placed by means of an overcurrent protector in our electrical panel box in serie with the hot wire creates a "controllable" power deliverable. The current which trips the breaker is well beyond that which our bodies can tolerate, particularly once our skin is compromised.We operate on less power than a 50 Watt bulb. The inline overcurrent protector is the means to prevent fire, it does not prevent an electric shock to a human being. That over protection is the means to stop the flow. Everywhere a load is between neutral and hot energy is dissipated and voltages are evened out. Entropy likes that.. We are harnessing the energy transfer between hot wire and neutral to do our bidding. Meanwhile entropy continues to lurk in the background seeking a way to even things out without any regard for intended use. Entropy has many agents, they include circuit boards, the shielding around the conductors, and the metal case around the equipment. All places where a short can occur. A wire connecting the equipment case to the ground provides current a path independent of the unfortunate equipment operator who touches an energised case , and provides a means to allow sufficient current to bleed out the energy and maybe trip the overcurrent protector before the power delivered starts a fire or finds a path through us. Not a fail safe by any means, but an additional level of protection. Now that path to ground is also now doing Mr Entropy's bidding, and will probably find some nefarious way to even out some other Voltage difference, and allow the flow of current in other places where one does not want it and that is the rub.....KD2RBF John
Had an interesting discussion with a friend who’s an electrician. His biggest concern was creation of a ground loop. My proofed idea was to drive an additional ground rod near my operating point and use it primarily as an antenna ground. Seems different to me even though I x tgat werd fretting lossy eartvnvolved
Just to clarify for some asking or wondering on comments below. Circuit breakers/fuses protect the wires and devices of an electrical system. GFCI (ground fault circuit interrupter) protect you. 50mA thru the body is considered lethal. GFCIs trip (open) at 7mA. Any current from the hot (Black or Red in a dwelling in the USA) conductor to ground in access of 7mA will trip the GFCI regardless of load on any other conductor on the circuit.
Thanks Sal. I know about the mistake I made in the video. Thanks for the clarification and help. Regards, Jim PS I got across 3KV DC and woke up across the room on the floor with burns. I was a teenager then. Tough lesson!
@@jeffkardosjr.3825 correct. it also differs in what part of the world you are. household GFCI's here trip at, or below 30 ma. medical devices require 5ma or less to trip. This coming from Ireland.
Hi Jim, what do you think about connection the ground lugs of all your "units" together but not to earth. Will it help to reduce noise and still be safer? Carl AB1ZI
I have a 5-gallon bucket of water in the corner of my shack. I run a wire from the ground tabs on the back of my gear to a piece of junk steel that I tossed into the bucket of water. Seems to work great.
You are a master. The more I learn the less I know. Can you help me understand why as on almost all of my gear there is a ground post. I have them all connected to common ground bar with tinned copper flat strap. From there about a 5 foot run to the 8foot rod with solid copper flat strap. The FT 950 is feed by 30A supply . They are on 15 amp non GFI circuit . Every thing else including the 600W solid state amp is on a 20A GFI for now. My question is two part. Do they need to be earth grounded and does that need to be bonded to the AC earth ground. What could happen either way. You presentation are very honest and over flowing with decades of real experience. Not theory. I admire and respect that. Waiting for my General ticket to be posted. Do you have any connections.😉
Thanks and yes I can. If you had 10 boxes on your operating desk/table and there was a ground wire run from box 10 to box 1 and then to a common point, box 10 would have a different voltage above ground from box 1. And, you could have a ground loop or hum. Each box needs to have a ground STRAP to a common point. A driven rod separate from the electrical panel, depending on some other factors, may be unsafe. And, it may be a violation of the NEC. I know the ARRL promotes that idea and I believe they are sadly mistaken. Additionally, there is no such thing as a RF ground. RF does not magically flow into the ground. If there is a fault, you want the current to flow back to the main panel or sub-panel. If some of the current flows into the ground during a fault, the breaker may not trip. I would make certain that your GFCI is indeed rated for 20 amps and has the appropriate wire size; probably should be #12AWG. 73, Jim
@@ham-radio Humm. Well they all are common point connected to a bus bar definitely not in series. So you are saying both AC earth ground and station earth should be bonded? Also your quick response reminds me of when people actually cared. Thanks so much.
Power Plant Electrician for 35+ years. Do what ever it takes to protect you and your equipment from voltage on the wrong path, but remember as a ham we also have to keep our noise level down to the lowest value... The best ground as in RF would be on a large steel ship in sea water. The ocean is the best counterpoise, but ships have the ground and neutral isolated for electrolysis reasons. You should get voltage from the nuetral to the ground on the whole ship. The radio grounds are wide copper strips that connect to the ships hull. More later, Thanks Jim. Corey Wade KG6TVJ or on my boat it might be a ship FCC Call letter system.
I have seen that. Some guys think that 6AWG as called out in the NEC is the answer. Flat and wide copper is good. As I am starting from zero, grounding will be step 1. Thanks Corey! 73, Jim
i have a seperate ground rod for the high tv mast on a metal roof up on the mountain here. the mast and metal roof are bonded together with 4 g solid bare wire i skrounged off a 40' pole and hammered a seperate ground rod from the two i have for the house elect system. im just grounding the mast, do you think i should ground the threaded ring on the feedpoint connector? because that will go back to the pannel via chassis ground. also i was thinking of grounding the (skin effect) static discharge of the 3 conductors of the fan dipole. what do you think?
Your (radio station) ground rod should also be connected to your electrical panel. My ground cable comes inside the house, connects to my station's single point ground and then continues to the ground on the electrical panel. If not connected you could have a potential difference between the grounds. Check out the ARRL book on grounding and bonding.
Please watch all of the Parts to this discussion. You may want to follow the ARRL. Or, you may want to do as shown and enforced by most jurisdictions using the National Electric Code. You can have a potential difference between ground rods if incorrectly installed and incorrectly bonded. Thanks Chuck. Regards, Jim
@Jim W6LG I'm sure you're busy as you prepare to leave Wolf Mountain. I apologize if I am intruding. I too am leaving California. The high taxes and gasoline and everything else and the political climate has caused me to just want the heck out. I'm looking at a 25-acre parcel in Alabama where they get regular thunderstorms. The home that is there already is somewhat awkward although solar-powered and their water heater is wood fed. Not quite my cup of tea. I'd like to have it pulled down and put a nice log cabin in there. I have read of people that have dug a trench all the way around their house at about 6 inches deep and they put I believe it was half inch or maybe even only quarter inch copper pipe all around the house and it dead-ends just below the service panel. The various antenna towers could be tied to this also but that's beyond my knowledge level. To the point, if this type of grounding were used and tied to the central ground point of the electrical system would this provide improved ground protection especially in thunderstorm alley?
Thanks for the video. I watched your video and now I don't know what to do. Should I use a Earth Ground Rod or not? And if not, then do I just plug all my equipment into my house outlets and be done with it? I've been a ham for over 30 years now and only operate on the 2m and 70cm bands with local repeaters. But do use HF during Field Day events. Now I'm looking to purchase a flagpole antenna, but this video is now discouraging me on if I should jump into the HF world with not grounding my equipment properly. I don't want to use my new gear; when I purchase it, and get electrocuted or destroy my new gear from improper grounding. What do I do or what should I do?
Thank you for the video and information. What about RF ground? Would that tie into the same electrical ground or is that supposed to be a separate ground? It appears to be connected to the electrical ground via the SO-239 connectors and case of the equipment but it kinda makes sense that you might have noise from that setup. Maybe that's where the "Bucket Load" of ferrite chokes comes into play. :-) This topic is confusing but fun! 73's
Holy hockey sticks. I’m a BSME with plenty of practical experience in DIY electrical work. You throw this sacred cow out on the tracks and say, “see you later”. I had an in depth experience working with the Franklin Research Institute on hardening Automotive wiring and airbag ignition systems. Good ground to the vehicle ground was one crucial element in removing spurious RF from wiring systems. There were many more. I don’t understand why you wouldn’t want to clear off any spurious RF noise from your transmission and receiver instruments. They are in metal cabinets but there are many high frequency sources out there hat will go right through the gaps and openings in the units. I don’t see the use of ferrite beads or similar devices at each critical component too protect points where spurious RF inputs would cause problems. Help me understand. It sounds like your friends problem was that the ground circuit was acting as an RF antenna and back feeding into his transmitter. Please excuse my electrical naivety but seeing those giant copper plates in some grounding systems would give me the feeling that some sort of wide band diode is required on elaborate ground systems.
I'm a elctrician, retired. I've never had access to a device that could measure the difference of potential between two parallel grounds. Say from a far bedroom outlet and an outlet next to the panel. Maybe NASA of MIT does. Just my 2 cents. So l just followed the drawings. 😊
Hi again Jim this is without doubt a complex subject, there is a video around where someone is encouraging the lifting of the safety ground from equipment and therefore relying on the interfacing cables to handle fault current. I know it is tempting (and it does work at fixing earthloops) but it is a dangerous practice. I probably would not lose any sleep over taking the safety ground off of a few of my rigs but definitely not from an amplifier with a 3200v B+. As an incidental piece of useless info the current transformer in many RCCBs is often only half wave rectified, so a sudden fault may cause a trip on the next half cycle of the supply. There is no guarantee at all that if I grab hold of the B+ that it will trip at all. RCCBs do have the merit that they will still operate even if our radios are "grounded" by multiple paths. FWIW how many pleasure boats get around groundloop issues when connected to shore power (it can aggravate electrolytic corrosion) is to use a back to back diode arrangement in the ground wire. This arrangement allows the "grounds" to float a volt or so apart. I think a similar arrangement might be useful in our hobby but we all know what will happen when significant RF currents flow through the diodes! Potentially (no pun intended) it could be useful at reducing groundloop issues but of course the diodes need to be up to the job.
Hello! I think that I follow most of what you are describing. Yes, it was Doctor X who has a video wherein he clips the ring that provides a path to ground. So his example is that the equipment is connected only to the neutral and the "hot". His recommendation is, well, dumb. Even more than dumb for a supposed PHD. I would sure like to see his thesis. Today and yesterday I have been chasing a problem that may be close to what you described. I found (the hard way) that when a (so far not found) wall wart is connected other devices connected to the large power supply have roughly 24 volts on the plus side. There are about 15 devices running on approximately 12vdc. It appears that one of them has a "hot" ground. It is 0330 local and i got up to disconnect all devices and slowly reconnect with a volt meter connected to the rails of a the large power supply. Enough about that! Just an FYI, I have 3 inch wide copper running around the room. As of yesterday, I have a large diameter copper pipe under the ham desk. That copper pipe is now connected to the 3 inch ground strap. Today I will run flat wide straps from that copper pipe to the transceivers, linears and miscellaneous stuff. Since I really don't think there is an RF since the impedance from a typical ham station to a common ground is way too high to do anything at HF. To test that, I have this room wrapped in foil and copper, tied to the desk frame & pipe, all connected to a wide copper strip to the common ground about 20 feet away. I will let you know if there appears to be any affect connected versus disconnected to the extensive ground. Thanks and I hope this makes sense. I am making lots of typos. 73, Jim
Jim W6LG hi, fwiw I have seen very similar to what you describe, a standard 13.8v power supply was the cause. A pass transistor had a speck of swarf bypassing the insulating kit causing the can (the collector with about +24v on it) to be connected to the chassis of the supply. Good luck with your fault finding, 73
Oh..good to know. That is what I am reading at the power supply. Now I am going to back under my desk with a voltmeter. I watched a little of the news on the satellite TV. 73, Jim
Yes and for 10 years I was across from them at Dayton. Enough said. Their videos don't get many views given the effort and years on RUclips. Mostly I don't watch others videos. I did watch a few recently and was shocked, gobsmacked. One guy with 100k subscribers is giving some really screwy advice and purports to be an RF engineer. 73, Jim
All cabinets must be bonded together and grounded to your home's green electrical ground wire. Right? Antenna must be earthed separately from equipment cabinets but together with coax shield (if it's a vertical). Right?
So Jim. I live in an older house about 70 miles from you in Pittsburg. I do not have GFCI breakers. I do however have a separate Ground (earthing) rods for just the Ham equipment. Your saying either bond both grounding systems together or just use the house AC grounding system? You didnt get into lengths of grounding or earthing wires. Can they become resonate and give you other problems? Is the shorter the better? Love your videos Jim, love to hear you on the air one day. Where can i find you on the air? Sal KI6UNF.
Hi Sal, I am still in the building phase after the move. So I am not on the air. I recommend that you follow the NEC. Mike Holt has a website with really good information. Low impedance path to ground is better. I would put the all together. My big station was on the second floor, with several amplifiers, towers and antennas. I had no ground on the station other than the wall outlets. I was there for 38 years. 73, Jim
howdy Jim, I've been out of radio for a very very long time. I blew the dust off my old mobile and hooked it up in the house. So I have ?'s. I mechanically connected the antenna pole to an earth ground, I used a MFJ-270 lightning surge protector and connected the ground wire from it to the earth ground the pole is connected to. I put another earth ground at the entry window and mechanically connected a wire from there to the earth ground of the antenna pole. At the window i used a so-239 3 in. long for entry and grounded that to the earth ground at the window. One of my questions is does this seem to be the right way? The other question is should I connect these 2 earth grounds to the 2 earth grounds I have for the AC entry at the electric meter?
QUESTION: If your antenna is grounded properly (8' copper clad iron rod), is your equipment then also not grounded to earth via the coax shield? QUESTION 2: Is it not best to use braided wire as grounding and bonding medium in order to prevent the buildup of RF and/or to prevent it to travel? At one point in my life I constructed my shack on the second floor of my house, which created all sorts of RF issues that had to be addressed. I would tend to agree with most of your reasoning. But ground is ground. And shield is ground in most situations. Is it not? No wonder this subject is avoided more often than not. 😉
My radio room was on the second floor above the garage. Other than the electrical ground, there was no RF ground. Many RF engineers believe that there is no such thing as an RF ground. I did work from there with high power and big antennas. I had 8 active elements on 20 meters with 10db gain. Your Q2, what do you mean by RF build up? Braid is not the best. Those little wires that make up the braid can be trouble. Your Q1, what is properly grounded? For example, how would a dipole be properly grounded? It is a balanced antenna. If you have lots of RF in the radio room, I wonder about the kinds of antennas that you have. Are you using an 'end fed'? Thanks for asking great questions. 73, Jim
@@ham-radio Well...that was many years ago when I was first licensed. I was running mostly on a home brew 10 meter ground plane. Which of course the ground plane was grounded to earth ground via solid copper wire to 8' copper clad rod along with ground radials in earth. Quite the setup. Worked the world on 25 watts via a Uniden President 2510. Loved that little rig. I actually did managed to eliminate the RF issue in the shack (a vacant bedroom) by grounding all of my equipment with baided copper grounding jumpers (made from old coax shielding) to a grounding block, which was then grounded to earth via heavy duty braided wire. I was advised that RF has less ability to build up on braided wire becasue the braiding causes RF to cross itself out. Though I have heard of people who actually make the shielding in their coax resonant. (true?) Mind you, that I lived in an old century home at that time which had the old knob and post through most of the house, and certainly no grounded outlets. In fact, some rooms only had one electrical outlet as I remember. Hardly to code by todays standards. I believe that much of my RF issue came from a home brew dipole, and two beams that I had up at the time. I eventually built an actual shack on the first floor with upgraded electrical and GFI. But that was three homes back in life. Thanks for your input Jim. Steve
If you have a situation where you're Ham equipment is Separately earthed , here we got earth leak detection or something like that in a normal installation where a breaker would trip if it detects current from the Earth connection killing power but, what if your ham equipment earth is taking all this current , maybe because it's closer to earth or has a larger cable connected to the earth rod and your main supply doesn't get enough current to trip ? so could this have the potential to keep your faulty equipment live ?
I have a separate ground to earth from station bus panel but I tied this to the ac panel ground rod. Each mast is also earth grounded and those are tied together to the common earth ac panel ground. Is this correct or over kill?
Grounding and bonding is indeed one of the most controversial topics in ham radio. I have read many articles and watched videos on the subject. None seem to agree with the others. Then I found the ARRL book "Grounding and Bonding for the Radio Amateur". ALL WHO ARE CONCERNED WITH GROUNDING SHOULD READ THIS BOOK. One thing the book and the National Electrical Code requires is that all ground rods should be bonded together with heavy copper wire or strap. Your final drawing does not show bonding of the two earth rods. My transceiver is not connected to the AC ground through the DC power supply, only to the station RF ground. My old tube boat anchor is of course grounded to the AC ground. Also the GFCI outlets should not be connected directly to the RF ground, only the AC ground. With the bonding of the AC ground rod with all RF ground rods, all equipment is at the same ground potential. Any accidental contact of AC to any chassis will trip a GFCI or circuit breaker. 73 K9AEE
Hi Jim Great video! I have a question. I have a relatively NEW Samsung refrigerator that produces almost s9 static across all amateur bands when the inverter inside of it runs.. Is this due to grounding or earthing within the building or is it just interference I can expect from an inverter? I have suffered for along time with this interference. I know it's the fridge because when I turn the power point off the noise completely disappears. Is it caused by a leaking socket or something, here power outlets are 240V AC at 50Hz. I would like to know your thoughts. Would be good to fix my only interference. Jordan VK2LPF
Hello Jim, Please name your videos with the actual topic identified at the beginning of the title. We know it is "Ham Radio Basics" and we know you "Jim W6LG". We expect the video will "Talk About" something. When I look at your video lists, I cannot tell what the topics are without opening them to see the whole title. It might be better to say "Grounding, Bonding, Earthing, Shielding and Protecting - Jim W6LG". That way, when the title gets truncated to ~32 characters, I can still know what it is about. "Grounding, Bonding, Earthing, Shielding and P" is better than "Ham Radio Basics--Jim W6LG Talks About Gro" BTW, great videos. I have just subscribed. : )
Great video - stimulating and thought provoking. Are you saying that all HAM Radio transceivers should have built in power supplies because they would be safer because they would be grounded through their electrical connection? Michael VA6XMB
If the neutral does float the green wire becomes the carrier to the panel to blow the breaker but this will also cook your radio if your bonding using the ac bond rather than a separate non connected to ac ground!
Thanks Rob. I will discuss the some of the reason for being QRX for a few weeks soon. Then I will do a series of videos on buying a home. 73, Jim ...thanks, always nice to hear from you Rob!
Well, I like your reasoning, but I think there is a flaw. 1. The ground doesn’t bypass GFI. If the neutral current doesn’t equal hot current then the GFI trips, disrupting the hot, shutting everything off. 2. Assuming a nonGFI outlet, if the radio is earthed properly, then wouldn’t the current flow through the earthing system rather than the person, following the path of least resistance. If not earthed, a person would be creating a primary path for current to flow to the earth -> electrocution, but in an earthed system a less resistive path already exists, and so the person is spared. I am an Electrical Engineering student, not a PhD or anything. I could easily be wrong, but that’s my understanding as of this point.
I think you are correct and I was wrong about the functioning of the newer GFCI outlets and breakers. As I read the NEC and others, they want the ground lines to all lead back to the main panel or sub-panel (if the sub is on another building). I am currently working on the next video when there is time and I feel up to it. It makes good sense to me to have all current flow through the panel and not straight to ground. Thanks, Jim
A 110 volt 3 wire system - you have 2 safety wires, the white & green, no way will I cut the ground prong off my cord connectors - antenna I do go to some trouble to grd. my antenna, & mast, for lightning protection - But I keep separate from my equipment ground. Just my 60 yrs in the electrical field. Different people all have different solutions for earthing/grounding.
I have only used one of those ground prong isolaters once and it was because the ground from my oscilloscope probe was shorted to the ground lug and was shorting out the negative side of my low voltage power supply. I do prefer to have when possible multiple grounds. But if needed to use an isolation transformer instead of the two prong adapter.
In my opinion there is no need for all the grounding at the station, the only necessity for grounding is at the antenna outside before it enters the house to protect against static and lightning. Most homes built within the last 30 years and maybe before should already have adequate protection from earth faults and to guarantee protection there should be RCD protection which all the ham equipment should be plugged into in the shack similar to what you would use for electric garden equipment, lawnmowers etc. In my opinion , apart from grounding the antenna there should be no need to ground anything in the shack separated from the house electrical protection circuitry because that’s what it’s there for in the first place. I’m not an electrical engineer so my views are purely personal if in doubt ask an electrical professional.
I'm beginning to think an RCD built into a socket would be a very good idea ? if there's any earth fault at all with the equipment it will cut the power.
Good topic. Now your diagram has issues. 1-If it's a GFCI breaker, the neutral goes terminal on the breaker, not the buss bar, there's a pig tail on the breaker to go the neutral bar. GFCI: Good point on the ground current GFCI have been known to trip in the presence of RF because of the FET. 2- those receps are wired incorrectly. The "hot" and the neutral need to be pig tailed like the ground is. By hooking one hot to one screw and "out" to the other screw that little tab between the two screws is carrying the current of the rest of the circuit. That's why you'll see recps go dead but the breaker doesn't trip, but recep has burned in half. I'll paraphrase the code in as that it says. A device must be able to be removed from circuit with out interrupting the circuit. The reason for the two screws is to be able to break that tab so to accommodate two circuits, ie one switched and one constant hot. But never from different legs to prevent the possibility of 240 vac being there. The "white" is considered a current carrying conductor and the buss bar is "bonded" to the panel via a bonding screw that ties the buss to the case. A broken neutral is looking for a path, the ground isn't or shouldn't be. Just saying. I'm was an electrical contractor of 22+ years and retired electrical supervisor for the state. 73 W9DLP
Hello Jim. I saw your title about grounding and thought I'd watch because it's always interesting to read what people think and what their ideas are about grounding. All grounds are not created equal as you talked about at the beginning of your video. ruclips.net/video/3vvvv5QVZoA/видео.html . Mike Holt explains grounding and bonding better than anyone I've watched.
Yes anything help when comes to reducing noise. I am thinking use a 4ft electric fence ground rod. The full size 8ft is little difficult. The other thing about lighting is usually your equipment isn't distroyed by a direct hit , direct hit is rare unless you live on a peak or have a really high tower. Power surges from powerline can result from a lighting somewhere down the line, that can cause some damage. Just disconnect everything when storm hits.
But Jim! Kristen McIntyre, K6WX, ARRL First Vice President, has just announced that ground is a myth! So we don't need to worry about any of this! No RF ground references, no tower/lightning safety grounds - we can so much money now! 🤣
GFI looks at the current going out the hot and the current coming back on the neutral. If there is a difference the GFI will trip! Don't matter if it comes back on ground wire or if it finds another way to ground! Any difference between what goes out the hot and coming back the neutral will trip it. It is only mileamps
In the US I don't know of a Ham radio that is not capable of working off a 12 volt battery(ies). If fact it's more of a problem running off AC as you need a power supply to convert to 12 v dc. I believe Jim leaves it out for simplicity.
My radio is grounded to a earth rod. Not to house earth or water pipes etc. When the ground wire is removed i get a increase in noise level by 3 s points . I have been told never connect to electrical mains earth.
@@samgrieg some houses are are pme so there is no earth here in the uk. I live in a old hose so all could be fine but its the way i was told to do it when i did my foundation course. As now the weather is getting better time to sort antenna earths etc.
Definitely not a good idea to use those three prong adapters without the ground tab. If you ever get a short of hot to equipment cabinet and you touch the cabinet while its shorted to the cabinet you get electrocuted. Whereas with the tab screwed to a grounded outlet box the device short should cause the circuit breaker to trip from over current in the short and that saves your life. Sometimes people with Phd's don't have any common sense!
I totally agree that the radio should not ever be connected to it’s own separate ground rod! One quick example is if there is a lightning strike near the house or power panel ground rod, it can elevate the ground potential several thousand volts above the ground potential where the radio is grounded. If the radio was not grounded both the hot wire, neutral wire and the bare ground wire in the power feed to the radio would all stay at the same relative potential. However if the radio chassis was connected to its own ground rod it you would essentially have a conductor connecting both ground rods and a potential difference of several thousand volts might exist between each end. The radio chassis would be near the far end. Current would flow from one rod through the radio chassis to the other rod. The black and white wires, while being 120 volts between them could actually be a few thousand volts above the radio chassis. Who knows what might happen! It’s best to let all three wires ( black, white and bare) float up and down together.
My radio station does not have its own ground rod. For one thing it’s too far from the main panel for me to connect the two ground rods and it’s not necessary. I am a retired EE with experience in power, lighting, interior communication, radio and electronics. Several years in each area.
Thank you for a clear, concise example of what can happen. If you want, privately send your callsign and email address to me. 73 Jim
Excellent comprehensive series Jim. As an electrical engineer that works heavily in the automation world I have witnessed my fair share of ground problems especially with ground loops. Your conclusions addressed my concerns with often recommended multiple groundling locations (service ground, station ground and antenna/remote tuner ground) that have left me with an extremely uneasy feeling. Thanks for taking the time to walk through this topic in detail.
I'm getting ready to cross this bridge very soon! Just bought the ARRL book, Grounding and Bonding. I'm going to replace a rotten galvanized pipe that is on my mains. Then install 2 x 8' ground rods. One for my AC panel mains and another under my shack window. Going to tye them together with 8ga bare solid copper to my MFJ window passthrough. One the other side of the passthrough, a ground buss bar. Going to install gas style coax lightning arrestors grounded to the rod under the window... I agree with you on not using the adapter with ground to receptacle plate screw...
Thanks for the video, sir. I am an engineer and a Ph.D. Heh... that and five bucks might get you a Starbucks. ;) I've also been working with audio for a long time and have had the crap shocked out of me by potential difference between the PA and my guitar amplifier (through the microphone).
I have not yet decided whether having a double ground for the station equipment is a good idea. My initial thought is that the earth ground from the panel should be the right way to go. If I install a second ground, then there is the possibility that there will be a potential difference between the two. I haven't figured this out, quite yet.
Bonding the station components together seems like a very good idea because it equalizes the potential of the cabinets. I have no desire to be shocked by potential difference between the various pieces of equipment.
We don't have lightening here very often in Carson City. But when we do I'll disconnect the antenna(s) from the system.
I'm hoping to be a new ham operator by the end of the month. I'll take my test(s) the middle of the month.
For me, grounding at the panel is my preference. For audio, I prefer to use an isolation transformer if the grounds need to be isolated, but still keep them grounded at the panel. The more grounds one has I think the better.
How can you have a potential difference between two points both connected to ground?
Copper wire has a resistance over distance. A #16 for a ground wire has a resistance for 10 feet would be about 0.04 ohms. At 15 amps, that would be around 0.6 volts. Though not much, if the current were to go up, the voltage drop from one end of the wire to the other also goes up.
Most romex wire today has the ground connection a size smaller than the black and white. (So 12 awg black/white/red would bundled with a 14 awg ground.) A 15 amp circuit would have a #16 awg grounding wire. A 20 amp circuit would have a #14 awg grounding wire.
The romex wires in my house are about 30 feet long, so if I were to have new romex cable for #14 awg, the ground wire resistance would be 0.12 ohms. Doesn't seem like much, but if there was ever a high current you could use ohm''s law to calculate the voltage. This is why they say in a RF station use #8 or #6 awg wire.
David Thompson Well, I have been zapped by all sorts of things but in my experience with both radio and audio is that "hard grounding" i.e. Direct to earth screws with the audio and/or RF, it also sometimes can do weird stuff to other equipment like making a PC not turn on as some safety thing in the PSU senses that. I have not figured out why this is as in theory it shouldn't make a difference at least to my basic understanding of the subject, but it does. So I basically use the ground in the socket even though I occasionally get zapped by something or other, and I think Jim had a good point about it potentially defeating the ground fault trip switch, which I hadn't even thought of before. I do know some guys who think the opposite of this but I care more about things working right than some theoretical debate point and eliminating the occasional zaps I get from stuff. Just my 2ct, 73's.
Funny, all those credentials and not yet a Ham ?
That easily should have been given to you, as part of your degree !
IMHO !
Once licensed, you'll learn just how over qualified you really are !
Good luck finding anyone on the Ham bands, nowadays that can keep up !
Question begs ?
Did you go from first test to Extra, in one setting ?
Most frustrating thing for older Radio Amateurs, is the lack of practical experience, one would have experienced, coming up through the ranks, as you began as a Novice, and worked your way up !
Now, sadly, no longer a requirement !
Essentially you now have Extras that can't answer questions a Novice would know !
And that, is a no shitter !
I'm glad I watched this. I sympathize with your neighbor; when I first got into ham radio, I read several books about setting up a shack and was distinctly told by at least one reference that I should bond my equipment chassis grounds and run them immediately through a *short* earthing wire out the wall to an earthing rod. I did this and never had any problem. I'm not an expert, but I still think that is a good idea for equipment which does not have the chassis tied to the electrical ground.
Two stories, neither of which are first hand, that may aid in understanding:
In an electrical engineering class, the instructor was asked what, exactly, was the difference between earth and ground. His answer: "Around here, about 5 volts."
An industrial building had a large amount of heavy-duty electrical equipment on the second floor. Unbeknownst to anyone, the second floor electrical system was not bonded to the electrical system on the first floor. Everything on each floor ran properly, so it was quite some time, and only after a serious injury, before it was discovered that the ground potential between the two floors was some 20,000 volts.
Firsthand story about neutral vs. ground: A friend of mine had an older house with a countertop cooktop and a hood above, with the cooktop controls in the front face of the hood (a nice design that puts the controls at eye level). She complained that she sometimes felt a slight electric shock when she touched the cooktop and the hood simultaneously. I brought over my meter and found the potential difference between the cooktop and the hood was 73 volts. The unit worked, so the neutral was OK, but that's not the same thing as having a ground connection despite the neutral being connected to ground at the panel.
220v in US in your home is AC using two legs of 110v so it's a "balanced" system flopping back and forth 60 times a second ...wire running a heating element in a stove or water heater (code did not require for many years)a spare neutral (aka ground wire) due to this fact Im not sure your analysis of the stove is correct
@@steelboymi Could you expand on this a bit more? The electrical shock was undeniably there (I should have mentioned that the difference was present when the cooktop was turned off). It sounds like you're saying the potential difference between the two was normal. I would expect that the cooktop and the hood would share a common ground.
@@pseudorandomly I don't know enough about how they are wired...modem cooktops tend to have 220v elements to heat and microwaves are 110v so microwave is on one of two "legs" that are coming in from power company. I'd be tempted to move the breaker for microwave on slot up or down in the panel (whichever way had slack in the wire) but that me I have plenty of experience with residential panels...there is still live power to the box when main breaker is off so not a job for novice
Jim, you are one of the few people that has a good understanding of bonding, and grounding. You separated grounding from earthing but electrically they are the same. The issue that I think many people face is when they cannot establish electrical equipotential across everything, The cable, transceiver, tuner, amplifier, and the electrical system supplying the station equipment.
First bonding needs to be established to a common point which is the inter intersystem bonding termination and you explained that as good as Mike Holt could have. Ground loops happen where there is a difference of potential not multiple paths to ground. If everything is as equipotential there is no electrical pressure to move electrons so noticeable current to flow.
Never float your equipment, if ti comes with a grounded power supply ground it and provided everything is bonded you should not have any problems electrically.
Also have also said the electrons to not want to go to ground they want to go back to the source and the source is the transformer which created the neutral and bonded the center tap to ground. Electrons will use the ground as a path back if no other patch exist, they want to get back home :) If you do not electrically ground station equipment that path could be you.
RF wise you cannot just dump RF current into the earth, that is not where it wants to go. The electrons was to go back home and home for the returned DC voltage is the transmitter. A properly constructed station should have minimal return voltage provided you have a decent vswr. Once the DC electrons get back to the transmitter the transmitter does not really want them either so it passed them off either through you to ground which goes back to the transformer feeding the station with power or the generator. The other and safer path is using the system bonding connection(s) which would be the path of least resistance taking a majority if not all of the voltage back to the source, the generator or transformer.
Long story short DO NOT LIFT GROUNDS bond everything together to solve issues safely.
Very carefully written and helpful. No matter how you and I might try to explain what goes on, many will just close their minds to learning when it comes to grounding, earthing, bonding. There are a few bullet points that can be used ham radio operators that would make things so much easier. I am working on that draft of bullet points. I am not sure how it will turn out. Perhaps a series of questions would be helpful. This last week I got 2 emails where the writers indicated that their stations were grounded and/or bonded with #6 wire.
To test all of this, I did wrap the room with foil and strips of copper that are about 20awg and 3 to 4 inches wide. I have the frame of my desk tied to the copper and foil. I have 3/4 inch copper pipe in a T configuration under the desktop and connected to the frame. I have short lengths of 1.5 inch wire flat braid from the copper pipe to the equipment. That braid is kept wide over its entire length; even at the connection points. Each piece of equipment has its short piece of that braid. All of that ties to a 1 inch copper pipe in the attic that runs directly to the common ground about 20 feet away. I am still learning and trying to apply where I can. I did this extreme set up as a test. The test is, will it make any difference.
Thanks again. 73, Jim W6LG
Thanks for the video and It is an interesting topic. You’re a brave man for tackling it😉
It looks like you fixed a ground loop on your friends radio. Thank you for this video.
Thank you for another great video. I simply love the calm, non-judgemental way that you express your thoughts and mentor, or "Elmer", others.
In answer to your question about GFCI (aka RCD in New Zealand), I believe that having a separate ground connection should NOT defeat the GFCI. As I understand it, a GFCI continually monitors the current through both the Line (aka "Live" or "Phase") wire and the Neutral wire as a circuit pair. The device is designed to open, or "trip", any time the current flowing through these wires are different from each other. Therefore, if a radio or other electrical device or cable developed a fault that allowed current to go direct to ground, or otherwise bypass the expected path back through the GFCI, then any persons or equipment in the faulty path should be protected. This would be why GFCI breakers in homes were first introduced for external, garage, and "wet" areas within the homes.
For my station I have obtained an isolating power transformer which I am planning to install for my station. I've wanted to do this for a line while. It is partly for safety purposes, but also in hopes to help keep RF off the house wiring.
Thanks again for your excellent videos.
73,
Alan
Hi Alan,
I misspoke or just had a brain short circuit about the GFCI. My only excuse is that the first ones sold here may have been different. In any case, you are correct.
Let's talk about current flowing to the ground wire/terminal. Here we have 120vac (typically a little higher). If say more than 10ma flowed through the ground wire in the 3 conductor cord, would the current in the the neutral and hot still be in balance? If say 1amp were to go to ground, what might happen with the other 8 amps?
Just thinking out loud Alan. Let me know what you think. Thanks & 73, Jim
@@ham-radio Kirchhoff’s Current Law tells me that if part of the current on the Line went to ground then the amount of current on the Neutral must decrease. So, in your example, if the Line (source wire) had 10 amps coming in then 10 amps ***should*** be going back out on the Neutral (return wire). If, say 1 amp somehow made it's way over the 3rd Ground wire, or any other return path, then that law says that the the Neutral wire should only have 9 amps going back. This would put the current out of balance by 1 amp, as seen by the GFCI.
It is important to note that the current bypass leakage may be by a path other than Ground. For example, say we have a very large amp with NO Ground wire, pulling 50 amps, fed by a dedicated GFCI. Let's say that amp has an internal Neutral open fault. The amp would not turn on. Now, let's say we connect a coax cable from that amp to a radio being fed by a separate breaker or GFCI. If the coax, perhaps the shield, completes the lacking Neutral connection through the radio's Neutral wire then a possible overload condition could occur on the radio power circuit.
In this example I guess one would have the choice of electrocution by completing the ground, or by fire from the resulting radio power cord overload.
Back to the original GFCI example, the GFCI should trip as soon as it detects that there is an imbalance between the current in the Line and the Neutral. "As soon as" is relative, as most things are, since how fast it trips and at what level of imbalance it trips will be defined by the design and construction. I believe that in the U.S. the residential GFCIs are designed to trip beginning at 5mA and to do so in something under 1 second.
Incidentally, I'm fairly familiar with U.S. power and general house wiring as I'm and ex-pat and spend most of my life in Texas. As grand as that is, I'm neither an electrician nor a Ph.D, but I've been shocked enough times to know what it feels like.
Cheers,
Alan
I'm not an electrician, but I've done a lot of wiring. For clarification, it should be noted that the two hot wires from the pole (pig) are 120 volts each, which combined give 240 volts. For our purposes, we only use one of the hots for 120 volts. I agree, for safety's sake the equipment needs to be grounded to the main service. The reason that subpanels require four wires (two hots, a neutral and a ground) is so that a short will go back to the main panel, tripping the breaker. A seperate earth rod defeats that purpose. I've read conflicting advice on ham radio earthing/grounding, some say the equipment needs its own earthing rod which is totally separate from the main service earthing rod, others say they should be tied together. I am new to ham radio, so it could well be that a separate earthing rod can reduce interference/noise in some situations. But a separate earth rod dedicated to the ham equipment is electrically dangerous and is a shock hazard.
You'll have a problem when the ground wire is connected to the second earthing rod without a bond to the the ground on the electrical panel. The earthing rod to earth has a high enough resistance that the breaker won't trip. That's one of the reason why the ground wire is bonded to the neutral wire in the main breaker box.
I agree with your comments, and this is the quickest way to start an argument at a ham club! This was our tech talk topic a few months ago at our local ham club, and we soon discovered that the recommendation of having a separate ground system for radio equipment was against our local building code, saying that everything must be connected together.
Just seeing this now, 3 years later... my understanding is that that "separate ground" isn't supposed to be separate. The ground rod outside the shack (if you place one) is supposed to be bonded to the ground rod for the electric supply for the house (at least so many feet apart and using a wire of such and such a gauge, etc.)
You can have two ground rods if you tie them together to equalize the voltage in the system, otherwise you have two separate circuits and run the risk of creating a voltage potential in one with a lightning strike. I recommend the ARRL book “Grounding and Bonding for the Radio Amateur“.
In the last image with the red X over the neutral, the GFCI is still going to trip regardless of the earth rod. GFCI outlets and breakers work by comparing the current on the hot wire versus the neutral wire. With the X on the neutral, the hot is going to have current flowing while the neutral is not. GFCI trips.
I agree, and there is one other item worth mentioning here and that is the "earth grounding" of the antenna tower. The tower should be grounded at the base and not back at the main panel. Having two "earth grounds" that are not bonded together and are separated by a distance (varies but lets say 30') can easily have a different potential between the two but, what are the chances you will be touching both at the same time? It is a difficult question and requires much thought due to the number of variables present in a given situation.
Thank you Jim, being a relatively new ham I have discovered that your videos are the best out there. We're actually fairly close neighbors me being just outside of Sacramento. Next up is my General test. Your videos are invaluable. Thanks again!
Dan, Hi and thanks! Do you know anything about Rocklin? After 40 years here, I will be moving closer to doctors and relatives. 73 Jim
@@ham-radio Rocklin is a very nice area, There are good medical facilities nearby. I have to worry as well about that too. Sutter Roseville which isn't too far would be a good choice. I hope you're doing well.
Jim, I recently had a bad RFI situation on 160 meters when running my AL-811H linear amp. Everything I touched on the radio, mic, amp etc. resulted in RF burns. I started using a small neon bulb to touch the radio, mic, etc. to test for RF to avoid the RF burns. The bulb would light up so bright, that it was glowing with blue highlights.
So I hard grounded the AL-811H amp to a nearby water pipe (under the kitchen sink). Amazingly, that fixed ALL of that RF problem, and I can't get my little neon bulb to light, and no more RF shocks no matter what power level I run.
Thinking about what you said about it being a violation of the NEC to run multiple ground rods, I did an experiment. Instead of 'hard grounding' the amp to the water pipe with my piece of solid #14 wire, I put a .001 uf 7KV (coupling) capacitor in series with the ground wire, and viola, it also worked!.
So you ,might want to mention that, - by putting a "capacitor" (of suitable voltage rating) in series with the ground wire to the secondary ground rod, you maintain the original AC & DC ground path while having a secondary ground rod for the needed RF path. This will satisfy the NEC.
Also, you've made mention about running everything back to the service entry ground point (and service entry ground rod). Only problem is, that this is impracticable, and the long distances from the ham shack and the service panel is what is causing these situations in the first place.
Ferrite beads and what not are all good things, but when you have serious RF (from 160 meters), the only remedy is a close by ground rod, or water pipe, and the way to stay in compliance with the NEC is to put a RF coupling capacitor with the ground wire to the ground rod (instead of hard-grounding the equipment to the ground rod).
Thanks. Someone how, this morning, I am not fully understanding the placement of the .001 cap. Can you send a private email to me with a drawing or perhaps a different way to describe what you did? Also, what is the SWR, feedline and antenna. You sure have a lot of RF in the room and I am wondering why that is happening. Thanks, Jim
Thanks for responding Jim...
My feedline is Belden 9913 (foil shield). SWR leaving the shack is basically 1.1:1, and the antenna is a "loop", or modified inverted "ell".
The principal is simple, and you said something in your video which set up the solution perfectly. You (correctly) said that 'we're dealing with DC paths, AC paths, and RF paths".
Hard bonding ham equipment to local/nearby ground rods (or water pipes), bonds ALL of those paths (AC, DC & RF), when in fact we're only interested in shunting the RF path. And that's we're we get in trouble with the N.E.C.
Much like the way it's done in RF (linear) amps, the "RF" component is shunted to the desired path (the output Pi network) via a coupling "plate" capacitor which passes the RF current, but blocks the DC (and AC) voltage.
The solution is to simply put a capacitor (of suitable voltage rating) in "series" with the ground wire going to the local ground rod(s) or water pipe.
I made a quick video demonstrating this situation, and can be seen here :
ruclips.net/video/inZlg5B7FgQ/видео.html
You (or anyone) can correspond via e-mail via my ARRL e-mail forwarding address which can be found on my QRZ page for call sign: N4MRN
73's for now Jim,
Steve / N4MRN
Hello Jim. I remember living in a house with the old BX cable with the 2 wires wrapped up in paper and 2 prong outlets. The metal outer cover acted as the earth ground, I believe. The house I have now has modern wiring and gfi system. My shack equipment is not grounded to an earth rod. I have read up a little on this and have come to the conclusion that my rig is modern enough that the chassis is earth grounded through the lower prong on it`s 3 prong plug, and outlet. All of my electric power tools have the same 3 prong plugs. I believe it is known a double insulation. Thanks and I will be waiting for the next one.
Hello again Jim,
Good explanation about grounds. An even more complex situation is an HF radio on a boat with optional connections to shore power. Boats have "water" connections as well as shore power ground which is alway a few volts different than the water.
Anyway, one note about GFIs. They do not use the mains earth ground to detect a fault. GFIs will work exactly the same without an earth ground connection. I have tested this.
GFIs measure the difference between the hot and return currents. If they are the same, all is well. If they are different, then some current is going somewhere else and it trips. The GFI cannot directly sense current to ground. If only knows that some of the current flowing out through the circuit isn't making it back.
Ya, I had that wrong. I had different type many years ago and for some reason that stuck with me even though things have changed. GFCI can be installed in an older home with 2 wire AC lines to each convenience outlet because they don't need that third wire. Thanks. 73, Jim
Thanks Jim ... I agree with you. My situation is exasperated by being off grid. I had a situation where dc ground had a voltage difference between ac ground. Ground is a reference voltage .. be careful what your reference is and make sure the whole system agrees on that reference.
Like you said, rf grounding is variable compared to AC/DC. I’ve always been told to run a ground rod 8’ along with a single radial under earth. BUT, here’s where I get confused, if your equipment is grounded via the 3rd prong, wouldn’t that make it bonded upon plug in? I also see most people saying to bond the rf with the ac ground. Well, wouldn’t that create a loop through the outlets and box ? It’s so confusing that I just give it to you guys to figure out. Lol. Look forward to each video.
Defined Horizons the ac ground is earth grounded right?
I will point out that a GFI does not care where the current is lost. It measures the current difference between the hot lead and the return neutral lead, if it’s more than 5 milliamperes it opens the circuit.
A neutral wire and a ground wire is bonded at the main panel. But the difference is the neutral is a current carrying conductor at all times. The ground is reserved to carry a large enough current to trip circuit breaker. It is a redundant path.
If you could imagine a washing machine with no ground system. A hot lead breaks loose inside and falls against the frame of the machine. Now the frame is electrified. Anyone touching the frame of the machine and a cold water source could be shocked to death. Now that same system is grounded. The exterior frame is now connected to the ground. That wire falls inside and touches the machine frame and is grounded to the surface. It immediately creates a large current that trips the breaker and eradicates the electrical hazard. This was the system before GFI’s.
JIM W6LG:
Thank you for all your videos.
I am a new HAM and your videos help me a lot.
73s
Josef Charles Wiehr
K8JCW
THANK YOU for covering the topic.
As an FYI, my GCFI/GFI breakers do not have a ground connected to them, but they do have a neutral passing through it near the hot. How mine work is they sense a difference of current between the hot and neutral (black and white) wires and trip the breaker if the current in both does not match. Your breakers could be and are most likely different than mine.
I don't like the idea, but they thing the reasoning behind it is that if the current is different from the black and white wired, then it must be traveling through the ground wire.
That’s what I have heard too. There’s a solenoid in the outlet such that as soon as there is a discrepancy between the hot and neutral the breaker will trip. The reasoning being that if is isn’t in the neutral, it’s not where it is supposed to be.
Technology connections put out a great video on this.
Hi, Jim hope you're well, can I say first I was watching your videos long before I was a Ham and they helped me so much so thank you for producing these videos, Here in the UK from what I have read we run two different systems new houses run PME where we have a series of ground rods from the property to the substation. If I were to add another rod outside and ground my equipment to it, and if there was an issue with my electrics and any residual current was sent to ground my little old earth rod could pick that up and send it straight to my equipment and potentially me :) The other issue I have is my shack is on the 3rd floor of my house. So if I was to run an earth wire from the 3rd floor to the earth rod at ground level; I have just potentially just created an antenna if when any stray RF gets into it. So I created an artificial earth on the 3rd floor using random cut radials and a MFJ-931. allowing me to tune the random wires to the band im using This dealt with any stray RF, and reduced my noise floor. 73 regards David
Good video, Jim. I like your production style and easy manner. I've subscribed. I'm an SWL since 1970 and a new ham. I have to say, I've never seen ANY subject with so many conflicting opinions and guidance. Certainly, there must be ONE answer to the subjects you raise here. (No wonder you waited so long to bring this up!) I eagerly await the next video.
Thanks for the video Jim, glad to see you're back.
Really confusing topic as the ARRL book on Bonding and grounding says you should tie your equipment to a common ground and out to a ground rod. Great video as usual and a topic that is so relevant!! Thanks -73- W1KPS
Wonderful to see you back on. Hope all is well for you. Hope to hear you on the air soon.
My background is in process control in a pulp and paper mill. I typically worked with shielded balanced wire from field equipment to a DCS (distributed control system) and coaxial communication lines between DCS's. I also worked with high voltage single phase and three phase electrical systems. Shielding and grounding issues were a big part of my job.
In my understanding, a typical USA residential breaker panel, has two hot legs (black wires or a red and black wire) and a neutral leg (white wire) measuring between either hot leg and the neutral leg there should be 120 volts AC. Measuring across the two black legs there should be 240 volts. That is because the transformer (pig) is dropping the higher line voltage (my residence the incoming voltage is 25KVAC) dropping to 240 volts. The transformer primary windings are at 25,000 volts AC, the secondary windings are generating 240VAC. The neutral is center tapped in exactly the center of those secondary windings supplying the 120 volts between the neutral and either hot leg.
The voltage at the breaker will measure line voltage. The neutral will measure zero volts. But the current (amperage) on the hot wire and the neutral will be the same! The bare copper safety (ground) wire should not carry any voltage or current unless there is an electrical fault.
The reason the safety ground (bare copper) wire from the grounding rod(s) is bonded at the neutral buss is to bring the neutral buss to earth ground at that specific location and to establish a zero voltage potential as referenced to earth ground.
Earth ground is electrically active! I have personally measured between two earth grounding systems approximately a quarter mile apart and seen more than 50 volts combined AC and DC! The induced electrical current caused huge noise problems in my equipment! The same will happen to radio communication if grounding isn't taken seriously.
Excellent video, it all makes sense, except for one thing. We add ground rods at the tower and at the entry point of the shack for the lighting/static arrestor's on the coax and this will take the equipment chassis to ground. Is this different because of the braided shield in the coax. Wow, I'm confused.
Excellent point you make. I am working on that answer. Honestly, I have had little time to spare since we are selling the house and moving closer to our oldest son because of my health. I have drawn the graphics in Photoshop, gotten some graphics and help from the expert, Mike Holt and his company. Tomorrow is my 70th birthday and I will try to take some time to do the voice-over for the next video answering the question. The short answer is, in my view, my opinion as verified with experts, dangerous to have that second ground rod separate from the ground rod, Ufer, or water pipe at the main panel. You can have a fault that does not trip the breaker. Thanks for asking. Stay tuned! 73, Jim Heath W6LG
Hello. Thanks for the video. I enjoy watching your content. I will soon be designing my first shack and have been thinking about grounding/bonding. Would it be an issue if you were to tie the grounding rod to the house ground. Grounding rod attached copper plate to where the coax enters the house, that is then connected to the bonding strap (piece of copper pipe) located behind the components, finally, the pipe is connected to the house ground via the outlet grounding plug. The antenna ground, bonding strap and house ground are all connected.
Well Jim you sure open Pandora’s box with your take on grounding.
When living in Florida in the 70’s we had Florida Power & Light give a talk at our Hamfest.
After the hour long talk someone asked when, “when do stop with all this grounding”.
His answer was, when you run out of money. 😳
At that time he suggested connecting your radios ground to your ground rod and have that rod connected to the ground rod that’s connected to your meter.
Had my electric meter replaced in 2004, and they placed two rods to the meter 10 ft apart.
?????
73
Wd4dda
I'm not an engineer or a phD But MFJ has a grounding plate for radios to help ground the system and reduce noise.
Jim, see Dave Casler's episode 8. He advocates a common ground. His reasoning is that the green ground in the house wiring is too far away from the outside pole ground. It seems that there are multiple opinions on this subject. I even see a real PhD responded in comments here and was also ambivalent regarding grounding. Great video and I really appreciate your sharing of knowledge.
Hi and thanks. I don't watch Dave's videos. I believe he presents good information. I just don't want to inadvertently copy his material or ideas. So, I purposely don't follow Dave. I did send a letter to him a last year but that did not go anywhere. There is another guy in CA who's videos are contain a lot of incorrect information. I have watched several of his and I am shocked by the lack of knowledge. Back to your question, in the other 2 videos I do try to follow the NEC and the CA electric code. I do recommend a single point ground of all equipment. I don't recommend a daisy chain. I do recommend a very low impedance conductor. Everything must go to the Intersystem Bonding Termination. My view is that using the "green" (it can be another color) wire is too great an impedance. Watch the two videos from May and see what you think. Mike Holt is the expert that I relied upon and his recognized in the US as the leading expert on the subject. Back to Dave, Dave is a good guy and provides good videos with lots of solid information. As I said, I just don't want to accidentally copy his material or ideas. I hope that at some time in the future Dave and I can communicate frequently. Thanks, Jim
Wow! I’ve been misled all these years. Everything I’ve been told is the way I have my station grounded. I have NO RFI issues at all. I have one 8ft ground rod drilled thru my garage floor to earth. I have a 3/4” copper water pipe running the length of my bench. All of my equipment is connected to that pipe and the pipe is connected via 1” thick copper braid. The connection from my equipment to the water pipe is via 3/4” copper braid. Should I connect the ground to the ground rod at my panel or start all over? Confused! Thanks for the video I think?
Thanks. Many have asked the same question. I plan on a "to the point" episode with my view of the NEC requires and what works for us. A short answer to your question, is the ground rod, in my view, should be connected to the main panel grounding buss bar. Any fault at the equipment must return to the main panel (sub panel is another issue to be discussed). The path of the current must flow to the panel so that the breaker can trip. As you know, current will flow through several paths depending on the resistance/impedance. If you had a short through your body and most of the current flowed to your low impedance ground connection, the breaker might not trip. RFI and the rest is another issue. Basically, you keep that RF out of the shack. All of the instruction books for transmitters that I have ever looked at have the same connection that you describe. You can have an antenna ground and cable ground for example. They too, in my view, must connect to the main pane. I hope that helps a little. It is very confusing. 73, Jim W6LG
So NOW I'm wondering how could things have run so perfectly and cleanly for decades - using only an old lead water supply pipe for ground/Earthing?
I just acquired a full system for an older gentleman that he no longer wanted. When I was taking apart his system there was no ground wire attached to anything. I'm wondering how he pulled that off.
Jim! Glad to see you're doing well :) I've been subscribed to your channel for a couple years now. We've talked on the air briefly once. I hear you out there often. I was at a hamfest today and acquired a High Sierra screwdriver antenna based on looks (and price) alone. I had very little knowledge about them, other than that they look well made and online many were making comparisons to the Tarheel. Lo' and behold my internet searches have revealed that this is an antenna that you used to produce! What a wonderful discovery! I'm excited to get this antenna in operation. I hope it works as good as the internet says it does!
Jim w6lg what a interesting hobby to get in to ham radio
Jim, I am a Ph.D. and a retired university professor. I have worked with all sorts of laboratory electronics, radio transmitters, high voltage and high current sources. I watched electricians install wiring in new homes when I was only five years old. I replaced a light bulb socket on a lamp as a nine year old.
Electricity, AC or DC, in the right place is great, but in the wrong place, deadly and destructive. The same with RF energy.
We are blessed to have voltage sniffers that detect AC voltage on live electrical lines, voltmeters, etc. Better to use a meter than your body to find electricity or RF. Think before you move. Read a lot and ask good electricians, electronic technicians, RF engineers, etc.
I am still learning!! N0QFT, Glen
This is it seems the most controversial subject in radio ! I’m not an EE but I started by grounding at the antenna - to keep the lightning out of my house, then I added a specialized and grounded Balun where the coax came in the house - to keep the RF out of the shack, the I added braided grounding straps to my antenna tuners - and I noticed that my noise floor came down a bit. I haven’t seen any ground loops yet but I cant help but think that the way to deal with that would be to bond all of the ground rods together so they came to equal potential. I’ll bet that older houses - perhaps with rotten ground rod for the mains - are the ones seeing the ground loop problems ?
I hope this series is eventually going to teach me how the heck to ground my ham antennas against lightning. I'm out in the middle of the desert and putting up even a dual-band stick would make it the tallest thing for _miles_. Worse, I have a multiband vertical that is *not* DC-grounded and I've no idea how to protect that should I erect it.
You just never know when you will take a strike. Read all the books, even took a class. Then one day we had a sever lighting storm rolled in. Tv's, surge protectors, all took a hit. The only sure way is to disconnect the power and RF. I had removed the RF lines from my radios but forgot to unplug the power supply. Went thru surge protector, then power supply, then one of my radios. Learned the hard way.
@@jeep146 Even unplugging won't stop everything. I learned that lesson the hard $7000 way back in 1993. I always unplugged antennas and power cords when not operating. Always! I crawled under the desk and unplugged the power strip that had everything on the bench plugged into it. One plug disconnected all AC power to the bench. Then while under there, I disconnected the incoming coax from a coax jumper that went up to the equipment on the bench. All fine and good, except I left the power plug and coax jumper laying about 18 inches away from the incoming coax connector. I took a direct strike on my tower. I was coming down the road on the way home and actually SAW the strike hit my tower. When I came in the shack, it was full of smoke and that smell you get when you know it's a major hit. What had happened was the lightning jumped the 18" gap between the antenna coax and the plug on the power strip cord. Everything was toast. There was a burned spot several inches wide and 18" long from where the destroyed coax connecter laid and where the destroyed power plug laid. The insurance adjuster crawled under the bench to take a picture because he said he had never seen anything like that and no one would believe him if he didn't have a picture. So, when you rely on disconnected cables, make SURE they are well away from anything that is close enough to arc to. I know from experience that 18" is not far enough. I've not had a strike since, but I disconnect my antennas outside the shack now. I have read, but not verified, that if you have an open ended coax going back outside and just laying on the ground, you can connect a disconnected antenna coax to it and the lightning strike will be further directed back outside the shack. I'm not sure enough of that to trust it. I'd rather just have it not come in the shack to begin with. One thing I've learned over the years that if lightning wants in, it's going to come in regardless of what you do. However, my new shack is an all-steel building with no windows and all metal doors. If it gets in here now, it's because the building came apart somewhere, in which case damaged radios is the least of my worries. I watched a tornado pass within less than a quarter mile of my place a week ago today, so it could happen.
If am running all my HAM related equipment off DC/battery (say two different batteries) do I still need to ‘ground’ any of the equipment? I noticed the avail grounding studs off my of my equipment…do I need them in this situation/setup is the question. Thanks in advance.
I have been zapped by appliances before that were improperly wired, or an outlet improperly wired. The reason having that third ground prong is important is this:
A properly wired appliance will have that third wire go to cabinet/chassis ground. That's it's intended purpose. An A/C appliance such as a washer/dryer/fan/stove will very happily continue to work if the hot and neutral leads are reversed. I have had appliances that had the entire cabinet carrying a voltage of 120 volts A/C and worked fine. The unique property of A/C motors that they will run happily reverse polarity makes cabinet grounding essential. I had an electric dryer with a 3 prong outlet (now 4 prong are mandatory) that was improperly wired at the hookup point. Again, 120 volts into the cabinet and 120 volts to one heating coil and the neutral/ground to the other coil. The motor ran fine, but it didn't get very hot! Having a dedicated chassis ground wire is the ONLY way to assure that a hot power lead is not running to the chassis/cabinet because if it is, you will immediately have a short. If you don't have a GFI outlet you might even have some fireworks!
Yes, exactly. Some guys don't quite get the neutral versus ground wire and what that can mean. In short, it means trouble that could kill someone. Maybe you mentioned this, but one famous ham recommends cutting off that pin that you point out is very important. He says he is a Phd. I wonder. Thanks, Jim
I had a situation with an outlet where hot and neutral were reversed. So if you touched the metal chassis on one appliance and touched another on a normal outlet, you could get a shock.
Neither of these appliances used a third pin.
@@jeffkardosjr.3825 Yes, this can definitely happen.
Glad to see you back! 73, K2SCH
Sorry about the typo and incomplete note.I proposed running an additional grounding wire from my new ground rod the fifty feet or so feet to the existing service ground to maintain continuity. There is the matter of an RF ground for antennas as well as equipment grounding for the transceiver, etc. while the service outlet presents a neutral wire that is also grounded at the service panel. It all seems like one leg of a circuit to me. No GFIS at my operating position either.
Understanding Entropy and its use of voltage to return matters to an even state is my key to understanding grounding. Charge carries energy. Flowing charge is current .Current is a means to even out potential differences. These differences are voltages. Entropy manifests itself through current in an unrelenting way to eliminate the voltage anyway it can. Entropy is inevitable and unavoidable. It will happen, current evens out the potential difference. The neutral wire parallels the hot wire. The circuit spot between neutral and hot is where the load goes. The load is a light bulb, a power supply, toaster, computer, televisions. A limit is placed by means of an overcurrent protector in our electrical panel box in serie with the hot wire creates a "controllable" power deliverable. The current which trips the breaker is well beyond that which our bodies can tolerate, particularly once our skin is compromised.We operate on less power than a 50 Watt bulb. The inline overcurrent protector is the means to prevent fire, it does not prevent an electric shock to a human being. That over protection is the means to stop the flow. Everywhere a load is between neutral and hot energy is dissipated and voltages are evened out. Entropy likes that.. We are harnessing the energy transfer between hot wire and neutral to do our bidding. Meanwhile entropy continues to lurk in the background seeking a way to even things out without any regard for intended use. Entropy has many agents, they include circuit boards, the shielding around the conductors, and the metal case around the equipment. All places where a short can occur. A wire connecting the equipment case to the ground provides current a path independent of the unfortunate equipment operator who touches an energised case , and provides a means to allow sufficient current to bleed out the energy and maybe trip the overcurrent protector before the power delivered starts a fire or finds a path through us. Not a fail safe by any means, but an additional level of protection. Now that path to ground is also now doing Mr Entropy's bidding, and will probably find some nefarious way to even out some other Voltage difference, and allow the flow of current in other places where one does not want it and that is the rub.....KD2RBF John
Hey Jim, are you saying just to bond your equipment together, and not run it to earth rod ? I'm a new Ham and putting my station together.
Had an interesting discussion with a friend who’s an electrician. His biggest concern was creation of a ground loop. My proofed idea was to drive an additional ground rod near my operating point and use it primarily as an antenna ground. Seems different to me even though I x tgat werd fretting lossy eartvnvolved
Bad presentation, typos, etc.
Just to clarify for some asking or wondering on comments below. Circuit breakers/fuses protect the wires and devices of an electrical system. GFCI (ground fault circuit interrupter) protect you. 50mA thru the body is considered lethal. GFCIs trip (open) at 7mA. Any current from the hot (Black or Red in a dwelling in the USA) conductor to ground in access of 7mA will trip the GFCI regardless of load on any other conductor on the circuit.
Thanks Sal. I know about the mistake I made in the video. Thanks for the clarification and help. Regards, Jim PS I got across 3KV DC and woke up across the room on the floor with burns. I was a teenager then. Tough lesson!
It depends on the class of GFCI.
They're not all rated at the same mA.
@@jeffkardosjr.3825 correct. it also differs in what part of the world you are. household GFCI's here trip at, or below 30 ma. medical devices require 5ma or less to trip. This coming from Ireland.
Hi Jim, what do you think about connection the ground lugs of all your "units" together but not to earth. Will it help to reduce noise and still be safer? Carl AB1ZI
I have a 5-gallon bucket of water in the corner of my shack. I run a wire from the ground tabs on the back of my gear to a piece of junk steel that I tossed into the bucket of water. Seems to work great.
You are a master. The more I learn the less I know. Can you help me understand why as on almost all of my gear there is a ground post. I have them all connected to common ground bar with tinned copper flat strap. From there about a 5 foot run to the 8foot rod with solid copper flat strap. The FT 950 is feed by 30A supply . They are on 15 amp non GFI circuit . Every thing else including the 600W solid state amp is on a 20A GFI for now. My question is two part. Do they need to be earth grounded and does that need to be bonded to the AC earth ground. What could happen either way. You presentation are very honest and over flowing with decades of real experience. Not theory. I admire and respect that. Waiting for my General ticket to be posted. Do you have any connections.😉
Thanks and yes I can. If you had 10 boxes on your operating desk/table and there was a ground wire run from box 10 to box 1 and then to a common point, box 10 would have a different voltage above ground from box 1. And, you could have a ground loop or hum. Each box needs to have a ground STRAP to a common point. A driven rod separate from the electrical panel, depending on some other factors, may be unsafe. And, it may be a violation of the NEC. I know the ARRL promotes that idea and I believe they are sadly mistaken. Additionally, there is no such thing as a RF ground. RF does not magically flow into the ground. If there is a fault, you want the current to flow back to the main panel or sub-panel. If some of the current flows into the ground during a fault, the breaker may not trip. I would make certain that your GFCI is indeed rated for 20 amps and has the appropriate wire size; probably should be #12AWG. 73, Jim
@@ham-radio Humm. Well they all are common point connected to a bus bar definitely not in series. So you are saying both AC earth ground and station earth should be bonded? Also your quick response reminds me of when people actually cared. Thanks so much.
Power Plant Electrician for 35+ years. Do what ever it takes to protect you and your equipment from voltage on the wrong path, but remember as a ham we also have to keep our noise level down to the lowest value... The best ground as in RF would be on a large steel ship in sea water. The ocean is the best counterpoise, but ships have the ground and neutral isolated for electrolysis reasons. You should get voltage from the nuetral to the ground on the whole ship. The radio grounds are wide copper strips that connect to the ships hull. More later, Thanks Jim. Corey Wade KG6TVJ or on my boat it might be a ship FCC Call letter system.
I have seen that. Some guys think that 6AWG as called out in the NEC is the answer. Flat and wide copper is good. As I am starting from zero, grounding will be step 1. Thanks Corey! 73, Jim
Great video as always, wondering if I'm going to see you at dayton hamvention this year? 73
i have a seperate ground rod for the high tv mast on a metal roof up on the mountain here. the mast and metal roof are bonded together with 4 g solid bare wire i skrounged off a 40' pole and hammered a seperate ground rod from the two i have for the house elect system. im just grounding the mast, do you think i should ground the threaded ring on the feedpoint connector? because that will go back to the pannel via chassis ground. also i was thinking of grounding the (skin effect) static discharge of the 3 conductors of the fan dipole. what do you think?
Your (radio station) ground rod should also be connected to your electrical panel. My ground cable comes inside the house, connects to my station's single point ground and then continues to the ground on the electrical panel. If not connected you could have a potential difference between the grounds. Check out the ARRL book on grounding and bonding.
Please watch all of the Parts to this discussion. You may want to follow the ARRL. Or, you may want to do as shown and enforced by most jurisdictions using the National Electric Code. You can have a potential difference between ground rods if incorrectly installed and incorrectly bonded. Thanks Chuck. Regards, Jim
@Jim W6LG I'm sure you're busy as you prepare to leave Wolf Mountain. I apologize if I am intruding.
I too am leaving California. The high taxes and gasoline and everything else and the political climate has caused me to just want the heck out. I'm looking at a 25-acre parcel in Alabama where they get regular thunderstorms.
The home that is there already is somewhat awkward although solar-powered and their water heater is wood fed. Not quite my cup of tea. I'd like to have it pulled down and put a nice log cabin in there.
I have read of people that have dug a trench all the way around their house at about 6 inches deep and they put I believe it was half inch or maybe even only quarter inch copper pipe all around the house and it dead-ends just below the service panel. The various antenna towers could be tied to this also but that's beyond my knowledge level.
To the point, if this type of grounding were used and tied to the central ground point of the electrical system would this provide improved ground protection especially in thunderstorm alley?
Thanks for the video. I watched your video and now I don't know what to do. Should I use a Earth Ground Rod or not? And if not, then do I just plug all my equipment into my house outlets and be done with it? I've been a ham for over 30 years now and only operate on the 2m and 70cm bands with local repeaters. But do use HF during Field Day events. Now I'm looking to purchase a flagpole antenna, but this video is now discouraging me on if I should jump into the HF world with not grounding my equipment properly. I don't want to use my new gear; when I purchase it, and get electrocuted or destroy my new gear from improper grounding. What do I do or what should I do?
*Very Interesting!* Thank you Jim.
Thank you for the video and information. What about RF ground? Would that tie into the same electrical ground or is that supposed to be a separate ground? It appears to be connected to the electrical ground via the SO-239 connectors and case of the equipment but it kinda makes sense that you might have noise from that setup. Maybe that's where the "Bucket Load" of ferrite chokes comes into play. :-) This topic is confusing but fun! 73's
Jim, Thanks for the video -Great info
You raise some interesting points, thanks!
Holy hockey sticks. I’m a BSME with plenty of practical experience in DIY electrical work. You throw this sacred cow out on the tracks and say, “see you later”. I had an in depth experience working with the Franklin Research Institute on hardening Automotive wiring and airbag ignition systems. Good ground to the vehicle ground was one crucial element in removing spurious RF from wiring systems. There were many more. I don’t understand why you wouldn’t want to clear off any spurious RF noise from your transmission and receiver instruments. They are in metal cabinets but there are many high frequency sources out there hat will go right through the gaps and openings in the units. I don’t see the use of ferrite beads or similar devices at each critical component too protect points where spurious RF inputs would cause problems. Help me understand. It sounds like your friends problem was that the ground circuit was acting as an RF antenna and back feeding into his transmitter. Please excuse my electrical naivety but seeing those giant copper plates in some grounding systems would give me the feeling that some sort of wide band diode is required on elaborate ground systems.
I'm a elctrician, retired. I've never had access to a device that could measure the difference of potential between two parallel grounds. Say from a far bedroom outlet and an outlet next to the panel. Maybe NASA of MIT does. Just my 2 cents. So l just followed the drawings. 😊
Hi again Jim this is without doubt a complex subject, there is a video around where someone is encouraging the lifting of the safety ground from equipment and therefore relying on the interfacing cables to handle fault current. I know it is tempting (and it does work at fixing earthloops) but it is a dangerous practice. I probably would not lose any sleep over taking the safety ground off of a few of my rigs but definitely not from an amplifier with a 3200v B+. As an incidental piece of useless info the current transformer in many RCCBs is often only half wave rectified, so a sudden fault may cause a trip on the next half cycle of the supply. There is no guarantee at all that if I grab hold of the B+ that it will trip at all. RCCBs do have the merit that they will still operate even if our radios are "grounded" by multiple paths. FWIW how many pleasure boats get around groundloop issues when connected to shore power (it can aggravate electrolytic corrosion) is to use a back to back diode arrangement in the ground wire. This arrangement allows the "grounds" to float a volt or so apart. I think a similar arrangement might be useful in our hobby but we all know what will happen when significant RF currents flow through the diodes! Potentially (no pun intended) it could be useful at reducing groundloop issues but of course the diodes need to be up to the job.
Hello! I think that I follow most of what you are describing. Yes, it was Doctor X who has a video wherein he clips the ring that provides a path to ground. So his example is that the equipment is connected only to the neutral and the "hot". His recommendation is, well, dumb. Even more than dumb for a supposed PHD. I would sure like to see his thesis.
Today and yesterday I have been chasing a problem that may be close to what you described. I found (the hard way) that when a (so far not found) wall wart is connected other devices connected to the large power supply have roughly 24 volts on the plus side. There are about 15 devices running on approximately 12vdc. It appears that one of them has a "hot" ground. It is 0330 local and i got up to disconnect all devices and slowly reconnect with a volt meter connected to the rails of a the large power supply.
Enough about that! Just an FYI, I have 3 inch wide copper running around the room. As of yesterday, I have a large diameter copper pipe under the ham desk. That copper pipe is now connected to the 3 inch ground strap. Today I will run flat wide straps from that copper pipe to the transceivers, linears and miscellaneous stuff. Since I really don't think there is an RF since the impedance from a typical ham station to a common ground is way too high to do anything at HF. To test that, I have this room wrapped in foil and copper, tied to the desk frame & pipe, all connected to a wide copper strip to the common ground about 20 feet away. I will let you know if there appears to be any affect connected versus disconnected to the extensive ground. Thanks and I hope this makes sense. I am making lots of typos. 73, Jim
Jim W6LG hi, fwiw I have seen very similar to what you describe, a standard 13.8v power supply was the cause. A pass transistor had a speck of swarf bypassing the insulating kit causing the can (the collector with about +24v on it) to be connected to the chassis of the supply. Good luck with your fault finding, 73
P.S the ham advocating lifting safety grounds etc was someone extremely well known. Not great advice to give to beginners...
Oh..good to know. That is what I am reading at the power supply. Now I am going to back under my desk with a voltmeter. I watched a little of the news on the satellite TV. 73, Jim
Yes and for 10 years I was across from them at Dayton. Enough said. Their videos don't get many views given the effort and years on RUclips. Mostly I don't watch others videos. I did watch a few recently and was shocked, gobsmacked. One guy with 100k subscribers is giving some really screwy advice and purports to be an RF engineer. 73, Jim
Jim w6lg I like your utube videos
So that's what the ground lug on my power supply is for? Should I just jump my radio ground over to that or is that the danger you're describing here?
All cabinets must be bonded together and grounded to your home's green electrical ground wire. Right? Antenna must be earthed separately from equipment cabinets but together with coax shield (if it's a vertical). Right?
So Jim. I live in an older house about 70 miles from you in Pittsburg. I do not have GFCI breakers. I do however have a separate Ground (earthing) rods for just the Ham equipment. Your saying either bond both grounding systems together or just use the house AC grounding system? You didnt get into lengths of grounding or earthing wires. Can they become resonate and give you other problems? Is the shorter the better? Love your videos Jim, love to hear you on the air one day. Where can i find you on the air? Sal KI6UNF.
Hi Sal, I am still in the building phase after the move. So I am not on the air. I recommend that you follow the NEC. Mike Holt has a website with really good information. Low impedance path to ground is better. I would put the all together. My big station was on the second floor, with several amplifiers, towers and antennas. I had no ground on the station other than the wall outlets. I was there for 38 years. 73, Jim
So if I understand this video correctly, you’re talking about connecting a round to the actual ground wire in my house outlet then?
This is my question as well. Hope we get answer 😔
howdy Jim, I've been out of radio for a very very long time. I blew the dust off my old mobile and hooked it up in the house. So I have ?'s. I mechanically connected the antenna pole to an earth ground, I used a MFJ-270 lightning surge protector and connected the ground wire from it to the earth ground the pole is connected to. I put another earth ground at the entry window and mechanically connected a wire from there to the earth ground of the antenna pole. At the window i used a so-239 3 in. long for entry and grounded that to the earth ground at the window. One of my questions is does this seem to be the right way? The other question is should I connect these 2 earth grounds to the 2 earth grounds I have for the AC entry at the electric meter?
QUESTION: If your antenna is grounded properly (8' copper clad iron rod), is your equipment then also not grounded to earth via the coax shield?
QUESTION 2: Is it not best to use braided wire as grounding and bonding medium in order to prevent the buildup of RF and/or to prevent it to travel?
At one point in my life I constructed my shack on the second floor of my house, which created all sorts of RF issues that had to be addressed. I would tend to agree with most of your reasoning. But ground is ground. And shield is ground in most situations. Is it not? No wonder this subject is avoided more often than not.
😉
My radio room was on the second floor above the garage. Other than the electrical ground, there was no RF ground. Many RF engineers believe that there is no such thing as an RF ground. I did work from there with high power and big antennas. I had 8 active elements on 20 meters with 10db gain.
Your Q2, what do you mean by RF build up? Braid is not the best. Those little wires that make up the braid can be trouble.
Your Q1, what is properly grounded? For example, how would a dipole be properly grounded? It is a balanced antenna.
If you have lots of RF in the radio room, I wonder about the kinds of antennas that you have. Are you using an 'end fed'? Thanks for asking great questions. 73, Jim
@@ham-radio Well...that was many years ago when I was first licensed. I was running mostly on a home brew 10 meter ground plane. Which of course the ground plane was grounded to earth ground via solid copper wire to 8' copper clad rod along with ground radials in earth. Quite the setup. Worked the world on 25 watts via a Uniden President 2510. Loved that little rig.
I actually did managed to eliminate the RF issue in the shack (a vacant bedroom) by grounding all of my equipment with baided copper grounding jumpers (made from old coax shielding) to a grounding block, which was then grounded to earth via heavy duty braided wire. I was advised that RF has less ability to build up on braided wire becasue the braiding causes RF to cross itself out. Though I have heard of people who actually make the shielding in their coax resonant. (true?)
Mind you, that I lived in an old century home at that time which had the old knob and post through most of the house, and certainly no grounded outlets. In fact, some rooms only had one electrical outlet as I remember. Hardly to code by todays standards. I believe that much of my RF issue came from a home brew dipole, and two beams that I had up at the time. I eventually built an actual shack on the first floor with upgraded electrical and GFI. But that was three homes back in life.
Thanks for your input Jim.
Steve
If you have a situation where you're Ham equipment is Separately earthed , here we got earth leak detection or something like that in a normal installation where a breaker would trip if it detects current from the Earth connection killing power but, what if your ham equipment earth is taking all this current , maybe because it's closer to earth or has a larger cable connected to the earth rod and your main supply doesn't get enough current to trip ? so could this have the potential to keep your faulty equipment live ?
I have a separate ground to earth from station bus panel but I tied this to the ac panel ground rod. Each mast is also earth grounded and those are tied together to the common earth ac panel ground. Is this correct or over kill?
Jim w6lg your utube videos are interesting
Grounding and bonding is indeed one of the most controversial topics in ham radio. I have read many articles and watched videos on the subject. None seem to agree with the others. Then I found the ARRL book "Grounding and Bonding for the Radio Amateur". ALL WHO ARE CONCERNED WITH GROUNDING SHOULD READ THIS BOOK. One thing the book and the National Electrical Code requires is that all ground rods should be bonded together with heavy copper wire or strap. Your final drawing does not show bonding of the two earth rods. My transceiver is not connected to the AC ground through the DC power supply, only to the station RF ground. My old tube boat anchor is of course grounded to the AC ground. Also the GFCI outlets should not be connected directly to the RF ground, only the AC ground. With the bonding of the AC ground rod with all RF ground rods, all equipment is at the same ground potential. Any accidental contact of AC to any chassis will trip a GFCI or circuit breaker. 73 K9AEE
Excellent. The second diagram is my idea of what should not be done. In the another episode, I will have a recommendation. Thanks, Jim W6LG
@@ham-radio Glad to hear that Jim. I was worried for a minute. 73 K9AEE
Hi Jim
Great video! I have a question. I have a relatively NEW Samsung refrigerator that produces almost s9 static across all amateur bands when the inverter inside of it runs.. Is this due to grounding or earthing within the building or is it just interference I can expect from an inverter?
I have suffered for along time with this interference. I know it's the fridge because when I turn the power point off the noise completely disappears. Is it caused by a leaking socket or something, here power outlets are 240V AC at 50Hz.
I would like to know your thoughts. Would be good to fix my only interference.
Jordan
VK2LPF
Hello Jim,
Please name your videos with the actual topic identified at the beginning of the title. We know it is "Ham Radio Basics" and we know you "Jim W6LG". We expect the video will "Talk About" something.
When I look at your video lists, I cannot tell what the topics are without opening them to see the whole title.
It might be better to say "Grounding, Bonding, Earthing, Shielding and Protecting - Jim W6LG". That way, when the title gets truncated to ~32 characters, I can still know what it is about.
"Grounding, Bonding, Earthing, Shielding and P"
is better than
"Ham Radio Basics--Jim W6LG Talks About Gro"
BTW, great videos. I have just subscribed. : )
Ok. Good point that I never thought about. Thanks. I look into that tomorrow. 73, Jim
Great video - stimulating and thought provoking. Are you saying that all HAM Radio transceivers should have built in power supplies because they would be safer because they would be grounded through their electrical connection?
Michael VA6XMB
A lot of hams through the years have said don’t bond everything through your ac ground! Have separate grounds for Radio & antennas etc. KJ7TBR
If the neutral does float the green wire becomes the carrier to the panel to blow the breaker but this will also cook your radio if your bonding using the ac bond rather than a separate non connected to ac ground!
I.e bond for ac house system don’t connect radio ground to ac bond use separate non connected to ac ground rods!
Thanks Jim, grounding/earthing etc is a very controversial subject; I happen to agree with you :-) By the way, great to see you again. 73 Rob VE6XMB
Thanks Rob. I will discuss the some of the reason for being QRX for a few weeks soon. Then I will do a series of videos on buying a home. 73, Jim ...thanks, always nice to hear from you Rob!
What about your antennas? Should they be grounded or earthed?
Thanks, Jack. That's my question as well.
Well, I like your reasoning, but I think there is a flaw. 1. The ground doesn’t bypass GFI. If the neutral current doesn’t equal hot current then the GFI trips, disrupting the hot, shutting everything off. 2. Assuming a nonGFI outlet, if the radio is earthed properly, then wouldn’t the current flow through the earthing system rather than the person, following the path of least resistance. If not earthed, a person would be creating a primary path for current to flow to the earth -> electrocution, but in an earthed system a less resistive path already exists, and so the person is spared.
I am an Electrical Engineering student, not a PhD or anything. I could easily be wrong, but that’s my understanding as of this point.
I think you are correct and I was wrong about the functioning of the newer GFCI outlets and breakers. As I read the NEC and others, they want the ground lines to all lead back to the main panel or sub-panel (if the sub is on another building). I am currently working on the next video when there is time and I feel up to it. It makes good sense to me to have all current flow through the panel and not straight to ground. Thanks, Jim
A 110 volt 3 wire system - you have 2 safety wires, the white & green, no way will I cut the ground prong off my cord connectors - antenna I do go to some trouble to grd. my antenna, & mast, for lightning protection - But I keep separate from my equipment ground. Just my 60 yrs in the electrical field. Different people all have different solutions for earthing/grounding.
I have only used one of those ground prong isolaters once and it was because the ground from my oscilloscope probe was shorted to the ground lug and was shorting out the negative side of my low voltage power supply. I do prefer to have when possible multiple grounds. But if needed to use an isolation transformer instead of the two prong adapter.
Look at our ham radio symbol, antenna, circuit and grounding. Three important part
In my opinion there is no need for all the grounding at the station, the only necessity for grounding is at the antenna outside before it enters the house to protect against static and lightning.
Most homes built within the last 30 years and maybe before should already have adequate protection from earth faults and to guarantee protection there should be RCD protection which all the ham equipment should be plugged into in the shack similar to what you would use for electric garden equipment, lawnmowers etc.
In my opinion , apart from grounding the antenna there should be no need to ground anything in the shack separated from the house electrical protection circuitry because that’s what it’s there for in the first place.
I’m not an electrical engineer so my views are purely personal if in doubt ask an electrical professional.
Hey Jim, you spoke of your store in one of your videos. What's the website URL to find it?
No reply over these two weeks so I guess Jim doesn't look at comments posted by follower.
@@jimyohe100 His store has been down for some time now due to health issues.
I'm beginning to think an RCD built into a socket would be a very good idea ? if there's any earth fault at all with the equipment it will cut the power.
My indoor radio is entirely powered by battery with no connection to the home's electricity. How does this change how I ground?
Why do you feel like you need a ground? Please explain Vincent so I can help you. Thanks for asking a very good question my friend. 73, Jim W6LG
Good topic. Now your diagram has issues. 1-If it's a GFCI breaker, the neutral goes terminal on the breaker, not the buss bar, there's a pig tail on the breaker to go the neutral bar. GFCI: Good point on the ground current GFCI have been known to trip in the presence of RF because of the FET. 2- those receps are wired incorrectly. The "hot" and the neutral need to be pig tailed like the ground is. By hooking one hot to one screw and "out" to the other screw that little tab between the two screws is carrying the current of the rest of the circuit. That's why you'll see recps go dead but the breaker doesn't trip, but recep has burned in half. I'll paraphrase the code in as that it says. A device must be able to be removed from circuit with out interrupting the circuit. The reason for the two screws is to be able to break that tab so to accommodate two circuits, ie one switched and one constant hot. But never from different legs to prevent the possibility of 240 vac being there.
The "white" is considered a current carrying conductor and the buss bar is "bonded" to the panel via a bonding screw that ties the buss to the case. A broken neutral is looking for a path, the ground isn't or shouldn't be.
Just saying. I'm was an electrical contractor of 22+ years and retired electrical supervisor for the state. 73 W9DLP
Thanks Dave. Do you have time to talk? I'd like to discuss the drawing with you via cell phone. You can get my email from Q...com. 73, Jim W6LG
@@ham-radio Sure. I'll email in the morning. It's 3am here and just got the HHH net on 7.190
Jim w6lg I have a learning disabilty in math I need help in studying for my ham license
At this QTH I am Grounding, Bonding, Earthing, Shielding and Protecting with ARRL insurance 😉
Hello Jim. I saw your title about grounding and thought I'd watch because it's always interesting to read what people think and what their ideas are about grounding. All grounds are not created equal as you talked about at the beginning of your video. ruclips.net/video/3vvvv5QVZoA/видео.html . Mike Holt explains grounding and bonding better than anyone I've watched.
What if i am in a situation where i run equipment off battery? Should i get a separate ground for those equipments?
At 12V there is no need to worry about electrical ground. Although you might still need to consider lightening and RF ground.
Yes anything help when comes to reducing noise. I am thinking use a 4ft electric fence ground rod. The full size 8ft is little difficult. The other thing about lighting is usually your equipment isn't distroyed by a direct hit , direct hit is rare unless you live on a peak or have a really high tower. Power surges from powerline can result from a lighting somewhere down the line, that can cause some damage. Just disconnect everything when storm hits.
But Jim! Kristen McIntyre, K6WX, ARRL First Vice President, has just announced that ground is a myth! So we don't need to worry about any of this! No RF ground references, no tower/lightning safety grounds - we can so much money now! 🤣
Jim w6lg my hobbys are painting pictures and lisining to shortwave and ssb iam thinking about getting my ham license
GFI looks at the current going out the hot and the current coming back on the neutral. If there is a difference the GFI will trip! Don't matter if it comes back on ground wire or if it finds another way to ground! Any difference between what goes out the hot and coming back the neutral will trip it. It is only mileamps
That is correct. And, I think it is something like 20ma where it trips. 73, Jim W6LG
A good reason to buy a transceiver that works of a 12 volt battery
In the US I don't know of a Ham radio that is not capable of working off a 12 volt battery(ies). If fact it's more of a problem running off AC as you need a power supply to convert to 12 v dc. I believe Jim leaves it out for simplicity.
My radio is grounded to a earth rod. Not to house earth or water pipes etc.
When the ground wire is removed i get a increase in noise level by 3 s points .
I have been told never connect to electrical mains earth.
And why is that?
@@samgrieg some houses are are pme so there is no earth here in the uk.
I live in a old hose so all could be fine but its the way i was told to do it when i did my foundation course.
As now the weather is getting better time to sort antenna earths etc.
I got hit off my laptop after earth - ing all my equipment. I got hit and my computer blew.
Definitely not a good idea to use those three prong adapters without the ground tab. If you ever get a short of hot to equipment cabinet and you touch the cabinet while its shorted to the cabinet you get electrocuted. Whereas with the tab screwed to a grounded outlet box the device short should cause the circuit breaker to trip from over current in the short and that saves your life. Sometimes people with Phd's don't have any common sense!