Creative grounding ideas - besides the tree in the cup? - Page 1
Forum section: electronics / rf-microwave

author: cdev
author_rank: Super Contributor
timestamp: December 04, 2018, 05:14:09 am
content: How do you ground your HF setups?Here is what I am wondering.What does the (US) electric code say about connecting (strapping) all your grounds together?Des it require any specific size or kind of strapping?This seems important to me to prevent the problem of a lightning strike hitting the power lines nearby (more likely than any other nearby things, except maybe a tower which I wont have) or antenna and then going through the house and equipment to get to a better ground. I have a set of ground rods at where my electric and phone service enter the house. They are official- electrician installed ground rods, hammered a very long distance into the ground and secured to the pipes and electric service indoors through very thick copper wire. The pipes indoors are also bonded to this. However in my experience this ground is very noisy.I suspect that the terrain in my entire area is all over 'igneous' rock which is nonconductive.* I'm about to set up my first real permanent antenna installation with the aim of getting my amateur license soon and going on the air. This antenna although modest is going to have to meet the electrical codes and also be protected against lightning adequately and ideally, better than just adequately. It may be as much as 60 feet or more up in the air and so I am expecting it will likely get impacted when lightning strikes nearby. Two trees on my property have been hit by lightning within the last decade or so and so I know it happens. One of the two trees is no longer there. the other still is and although scarred its still thriving. It is a beautiful tree. I am kind of on what amounts to a small hill but the slope is very gentle. There are two trees on my lot that are large enough for antennas. one is a midsized pine tree, maybe 60 feet tall, but its at the edge of my lot and so I think I will wait a bit with that one. I would be content to just have one good performing vertical HF antenna. So the other of the two trees is the one I am going to put my antenna into because its both tall and (barely) far enough from the edge of my (very small) lot to support a small radial system. So at its base I will need to install both a good ground rod (at least one maybe more if I can find a cheap source of pipe) and the radials' hub. Also where the coax comes into the house it will need to be grounded through heavy copper, which I am going to try to attach through the thickest wire I can find to the existing two electrical panel grounds via a thick buried wire OUTSIDE THE HOUSE. The antenna I plan to start out with is a "43 foot vertical" attached to a 9:1 unun. Perhaps the unun may be elevated a bit because the tree seems taller than just 43 feet. The unun ground will be connected via thick wire to the ground rod at the base of the tree to ground the antenna -Question -I am also considering connecting the vertical portion of the antenna to ground and its radials via a very high value RF choke made of very thick wire to provide an even larger more direct path to ground for any lightning. (would this inductance nullify the value of the conductor as far as lightning, as its going to be hit by a pulse and during that initial pulse it may look like a high impedance, after all its an inductor, what works best?)Additional ground rods are essential in at least two places. As stated above I will probably put at least two 8 foot additional copper ground rods in - at least two, one as close to the base of the antenna tree as is possible because of its root system, and one beneath where the coax enters the house. (near the back water spigot)That will make three grounds at the house. All of these grounds near the house must be connected together, ideally by soldering them to a thick wire, a very thick wire or strap, (with a blowtorch, probably because of the size of the copper will not allow me to solder to them any other way) - bonded together to make one ground.the antenna base area being a bit of a distance away must get its own ground rod.the coax from the antenna(s) will likely be buried in a shallow trench until it emerges right under the grounding panel-so the lawnmower doesn't hit it.Is this setup the right one? Is there any danger of lightning following the (RG 8, probably) coax into the house?Where are good places to pick up scrap copper? Junkyards? I cant afford to buy it new. Wire and copper rods can be dinged up - even look horrible as sin, as they/it will be buried. Old wire as long as its still wire is fine.I am wondering how big does this wire need to be? What do people do? Does this sound like its enough?

author: boB
author_rank: Frequent Contributor
timestamp: December 04, 2018, 05:24:57 am
content: I don't ground mine.Ground radials at a vertical of course and where needed.boB

author: cdev
author_rank: Super Contributor
timestamp: December 04, 2018, 04:00:51 pm
content: Do you use an inherently non-ground needing antenna?I would still worry about lightning unless the wire is so thin it would burn up before conducting anything powerful anywhere.Loop antennas and balanced antennas clearly don't need grounds, although some are supposed to benefit from them.They may, if you have a good ground but if your ground has noise on it (like mine does) not so much.I think that the soil under where i live has issues as far as its connection to "the one true ground" on some level. (I live in an area that has a volcanic past (basaltic volcanism) and 'igneous' rock is notorious for non-conductivity) Also it was later scraped by glaciation which likely left the 'earth' later above those rocks fairly thin.I wonder is there any way of measuring or quantifying grounding quality?

author: darrellg
author_rank: Unknown
timestamp: December 05, 2018, 11:31:26 pm
content: You would benefit from obtaining and reading this book:http://www.arrl.org/shop/ARRL-Antenna-Book-23rd-Softcover-Edition.

author: cdev
author_rank: Super Contributor
timestamp: December 06, 2018, 03:06:10 am
content: This is my problem, I live in an area surrounded by basaltic/igneous 'traprock'.Which is to to say it is resistive, just as seawater and graphite are conductivehttps://www.eoas.ubc.ca/ubcgif/iag/foundations/properties/resistivity.htmResistivity of Soil:https://sites.ualberta.ca/~unsworth/UA-classes/325/C/325C1-2005.pdfResistivity of Rocks:https://orkustofnun.is/gogn/unu-gtp-sc/UNU-GTP-SC-09-06.pdf

author: tkamiya
author_rank: Super Contributor
timestamp: December 06, 2018, 04:31:18 am
content: Don't ask me to quote the code number because my license is from Japan. But I know this much:Electrical code says you must "BOND" all ground together and enter into any building from one place only. Your house has a main ground where electrical power enters the house. In Florida, a certain ohmage is required but it also says, you can stick two 8 feet rod and call it done.Tower grounding is yet a different matter. That is more for lightening than electrical safety. (well, both....) Typically, tower has large number of rods in footing of the tower for lightening safety. Then, bond a #6 wire or was that #4?? to that grounding system and bond that to house ground. If you REALLY want to be complete, take all coax the same way and enter together after bonding and grounding shield of coax together.Shack ground, well, same thing. Here, we have electrical safety ground, the neutral, the lightening safety ground, and the RF ground.Well, ARRL has a book on this. You better read up rather than listening to me do a memory dump.

author: tkamiya
author_rank: Super Contributor
timestamp: December 06, 2018, 04:42:47 am
content: Quote from: tkamiya on December 06, 2018, 04:31:18 amMy own antenna system is quite simple. A 100 feet wire from house to a tree. I've added 3 grounding rods to the existing two. Bonded all with #4 and buried. Antenna ends right above one of the grounding rods. That's the feeding point. Braid goes to a rod and center goes to antenna. (Yes, I am aware, impedance matching is needed but I don't) Coax comes from a wall to the feeding point via just lying on a ground.Power to the lab comes via a dedicated 40 amp circuit from a circuit breaker panel. I made sure grounding and neutral is firmly attached to the system.It's been like this for few years. Nothing has blown up. As crude as it is as an antenna, electrical safety wise, this is more or less a textbook implementation.I am in Central Florida, the lightening capital by the way. Our grand is sand.

author: LapTop006
author_rank: Unknown
timestamp: December 06, 2018, 01:10:00 pm
content: Quote from: tkamiya on December 06, 2018, 04:31:18 amOr even betterMotorola's "STANDARDS AND GUIDELINES FOR COMMUNICATION SITES"(pdf), in which two chapters are devoted to grounding alone, with much of the rest of the book on other power issues.

author: tkamiya
author_rank: Super Contributor
timestamp: December 06, 2018, 01:31:05 pm
content: Oh yeah! 1/2" thick copper plate and faraday cage, here I come!Seriously though, industy's handbooks are nice but can be quite out of reach and impractical for residential ham applications. Let me also just put a warning here. Don't go solely by internet advise. Codes are different for different part of country. Also, there are so many "experts" on internet, you really don't want to risk your life on their ideas. I've seen some crazy stuff out there.

author: cdev
author_rank: Super Contributor
timestamp: December 06, 2018, 02:33:21 pm
content: My main concern is safety, because I know for a fact we get strong lightning here by the scars on the trees.I think I need to bond-solder some super thick wire to- to tie the two ground rods we had put in when we upgraded our electric service to a 'shack' antenna entrance plate, which must be made out of a big chunk of solid copper. (where to get? - or would the thick copper sheeting that I have (but thin enough to be bendable) be okay? I do have one piece of copper large enough for a bunch of larger antenna connectors (it currently has a bunch of small ones on it already) which I could use for now.I can put in additional ground rods too. I just don't want to spend money to have somebody come out and do it when I can do it myself. Maybe to check it if the code requires that. That would be okay.I'd rather spend the money on more copper pipe to hammer into the ground and wire to connect it all together. Wire between house ground and antenna base ground? That's likely to be long and costly.The tree I am going to put my antenna into has already been struck by lightning once.I live less than a kilometer from a ridge which is one of the main north south 'mountains' in the area and if I lived there I would have a commanding view in all directions of the entire tri-state area. (NY, NJ and CT) Commercial tower providers exist along that ridge, its that good of a view. Unfortunately I am down a fair bit and behind it so I have to go on a hike and up a bit of a hill as well, to enjoy such a view (Or buy a big tower! Too big, price wise for me now.)We don't have the view, but we do get the lightning. And we do have the volcanic rock too. The crappiest grounding anywhere?Maybe not. There is also clay here which isn't so bad from what I have read. The soil here was likely deposited here by glaciation and so its a mix of all sorts of stuff from north of here that was carried southward.But it seems as if its perhaps not so good from the RF noise and failure of my attempts so far to get rid of it fully.tkamiya, have you tried putting a "unun" there where your long wire antenna starts? You might want to give that a shot - a 9:1 unun. Receive especially would definitely be quieter with an Unun- there connecting your (transceiver)and coax to the long wire+ground.

author: tkamiya
author_rank: Super Contributor
timestamp: December 06, 2018, 02:49:01 pm
content: Hi,No, I have not tried un-un or 9:1 impedance transformer. I don't need it! Today's receivers are SO sensitive, overload is more of a concern. Besides, I almost never transmit, so bad VSWR isn't one of my problems.Well, a big chunk of copper will cost you so much money... Most rods are copper-clad. Thicker than plating and mechanically stronger, but very thin. Think of a lightening as RF, so you have skin effects. While it may not do a full cycle, Dy/Dt is so fast, you are working with VHF.If you want to do it right, you can look into use professional lightening protection materials. There are woven wires used for these, and they are probably the best. No aluminum, please. Please be aware, I am NOT talking about those that looks like coax outer shield taken out and flattened. Those rust fast. There is a special type for this application. I called it "Oniyori-sen" in Japanese. Have no idea what the English translation is.Soldering is not good either. Instantaneously, the connected spot will heat to few thousand degrees. It will blow itself away before conducting and dissipating most of its energy. You can braze the connection or you can use mechanical connectors. (screw compression) OR, you can do thermite welding. You can buy a "shot" already to go. I think it's called "Cad welding" in US?For entrance, I think many folks use aluminum plate or copper plate. The idea is not much makes it this far and this is the last place to get rid of lightening energy.

author: cdev
author_rank: Super Contributor
timestamp: December 06, 2018, 03:17:17 pm
content: What about "flashing" copper? Copper sheeting. It's used on roofs around chimneys, etc. because of its flexibility and durability.Its a very good conductor and its flat so low impedance. Maybe in conjunction (soldered to?) a thicker piece for the area right around the incoming coax connectors (so that the nuts holding them had a larger surface to bite into) which can also be connected to the ground(s) via a straight and wide vertical - approximately hand width - copper flashing strap(s).

author: tkamiya
author_rank: Super Contributor
timestamp: December 06, 2018, 07:32:26 pm
content: Copper strips are often used in large installations.Are you going to get it inspected? I think you just want a good ground that works.... if that is the case, I'd use it.As to suitability of flashing copper, if you get a major and direct hit, then probably not thick enough. But it's probably far better than #4 wire I used.

author: cdev
author_rank: Super Contributor
timestamp: December 06, 2018, 08:04:14 pm
content: I think the key issue is having good grounds and bonding them all together with a low resistance conductor that wont come apart in a lightning strike.Quote from: tkamiya on December 06, 2018, 07:32:26 pmHonestly, I don't know the applicable law, if there is any.We do have grounds that conform to the electrical code. I previously had a long wire antenna up but I had taken it down in anticipation of the new one, also the vinyl insulated wire it was made of had deteriorated in the sunshine.I have a new antenna and unun ready to go, as soon as I have this grounding sorted out.I would have to ask my local fire or building department about if any code applies to antennas made of wire lacking towers. There may be.I suppose definitely there would be codes involved if I was erecting some kind of tower. But a wire antenna, I don't know.I suspect what might be required is having a legal grounding setup, and bonding of grounds together so any antenna is properly grounded where any new wire enters.And for an antenna that goes up more than outward maybe additional ground rods at its base.Does an additional thick wire need to duplicate the coax shield between the antennas bottom and the house?I *do* want it to be safe and conform to best practices, fire safety regs, and all applicable rules/laws.I should check out local recycling centers to see if they have any cheap thick wire.

author: coppercone2
author_rank: Super Contributor
timestamp: December 07, 2018, 06:45:31 am
content: can you some how stick a waveguide into the ground or something like that? like i heard of a copper bath tub being buried before. what if it was real big, or like a big metal tower?

author: cdev
author_rank: Super Contributor
timestamp: December 07, 2018, 03:01:38 pm
content: Yes, I've wondered what would work for grounding like that that would be cheap.I think there would be an optimum size that would be large enough to resist corrosion but small or common enough to be cheap!Other metals such as zinc galvanized wire would work, as long as I could make a solid connection to them (soldering would be best) that didn't have the non linear junction problem.Especially, (rectification on) rusty old wires causes noise.A copper bathtub would likely be an antique and worth way too much to bury.Also, one has to think about future owners of the property, I don't want to leave problems for people fifty or a hundred years from now after I am gone.Radials, lots of wire radials, solder or crimp terminal bonded to a central hub and buried just a few inches below the surface are likely the best way to ground an antenna as far as RF goes.A metal tower would also be likely to be more useful as intended than buried simply as a massive metal object. It wouldn't be worth the trouble of moving (except to the scrapyard) unless it was going to be used as a tower.Of course I would love to have a tower but that kind of thing will have to wait as they are insanely expensive new.Quote from: coppercone2 on December 07, 2018, 06:45:31 am

author: ogden
author_rank: Super Contributor
timestamp: December 07, 2018, 03:11:52 pm
content: Quote from: cdev on December 07, 2018, 03:01:38 pmRest assured that grounding systems manufacturers did it for you already. Unless you want to replace your grounding system each couple of years - just take proven solution.

author: cdev
author_rank: Super Contributor
timestamp: December 07, 2018, 03:13:35 pm
content: Could you give me some examples? Have you used any of them?Quote from: ogden on December 07, 2018, 03:11:52 pm

author: ogden
author_rank: Super Contributor
timestamp: December 07, 2018, 03:23:20 pm
content: Quote from: cdev on December 07, 2018, 03:13:35 pmNo, I  did not use any of them. Does it qualify if I suggest solutions used by subcontractors in projects I was supervising?

author: cdev
author_rank: Super Contributor
timestamp: December 07, 2018, 03:26:18 pm
content: Please do!One thing I have to explain though. I am unlikely to be able to go out and buy expensive commercial solutions, because of costs, but I do like to know what went into them because its often possible to do exactly the same things, via some other route, for less.Quote from: ogden on December 07, 2018, 03:23:20 pm

author: rhb
author_rank: Super Contributor
timestamp: December 07, 2018, 03:33:36 pm
content: I've been studying the same issue except different geology.The antenna feed line should be grounded at the closest point on the ground from the feed point to the ground using a gas discharge lightening arrestor in the feedline. A conductive tower should also be grounded to the rod.You should use standard 8' copper plated steel ground rods, longer if you can find one. To drive them, buy or rent an electric jack hammer. I have one from Harbor Freight my dad bought. It's a bear to use, but very handy when you need it. You'll need a ladder to stand on to start it.. You want the rod to go as deep as possible as the deeper you go the lower the resistivity due to the presence of moisture in the ground.The standard copper clamps will bond the wire adequately. No need for solder. I'm dealing with very hard quartzite lenses in the subsurface, so if I hit one of those the rod will either bend or not go in any further. So I may need more than one to get one down 8 ft.For additional protection I plan to place a 2nd lightening arrestor at the entrance to the house with a 2nd ground rod.The NEC rules for grounding for electrical power are for safety, not for lightening protection except at the electrical utility level.

author: ogden
author_rank: Super Contributor
timestamp: December 07, 2018, 03:49:45 pm
content: Quote from: cdev on December 07, 2018, 03:26:18 pmGrounding rods are most common and widely used solution. Most popular are copper-plated rods which are compromise between price and longevity. You can use cheaper "galvanized rods", thou for 1/5 price gain you lose 2/3 of guaranteed operation time. Then there are pure copper or stainless rods which usually are expensive, specific industrial use only. You can buy all the necessary parts in your nearest homedepot. 5/8 in. x 8 ft rods are most popular. Bigger rods needs industrial tools to get them into ground.Around on the internet are tons of information about how exactly you shall do/install grounding - because construction-related things are strictly regulated and standardized. Best you can do - look for information on grounding systems manufacturerswebpages. Usually you can find everything you need for shopping decisions down to planning and installation.Thou I always suggest to do jobs you know so you can earn money to hire professionals who do jobs you don't know.

author: cdev
author_rank: Super Contributor
timestamp: December 07, 2018, 04:20:50 pm
content: I wish I could send all the RFI from local AM radio stations to groundThere is a lot of it here. Must be several volts just by itself.Quote from: coppercone2 on December 07, 2018, 06:45:31 am

author: cdev
author_rank: Super Contributor
timestamp: December 07, 2018, 04:28:45 pm
content: Our electrical upgrade and the installation of the two grounding rods was done ten years ago. Honestly, I don't know what our electrician put in there. Whether they were pure copper or galvanized.I suspect plain copper pipe would be be the best choice. If getting eight feet into the ground proves difficult, more shorter rods bonded together well, would likely be as good, at least where the soil had moisture in it.At least one knows pipe is copper and likely to last a long time. Perhaps the end going into the ground could be hammered so that it would present a spade point and be easier to push downward? Another idea might be to use continuously running water to perhaps make it easier to push the rod down deep into the soil?I should get some kind of awl bit for my drill to make the starter hole in the dirt, and smooth the first meter or so.Quote from: ogden on December 07, 2018, 03:49:45 pmOften we do end up hiring professionals, but its always best to go into those negotiations knowing how best to do something yourself if you need to.All of this stuff does seem important to know - well.

author: cdev
author_rank: Super Contributor
timestamp: December 07, 2018, 04:56:01 pm
content: I guarantee you that if you do try one you'll see improvements. Especially for receive. Thats what I meant. I have no transmitting experience at all, everything Ive learned was from receiving.Using a long wire antenna and ground with no unun and then switching in the unun, my received signals immediately can be seen to have become dramatically quieter and the signals stronger, more consistent.Its remarkable how much less noise I receive with a good unun and a ground there.For a dipole or loop receiving antenna you should use a balun. This is to decouple the antenna from the feed line. You can make your own either balun or unun.You can make a very handy switchable 1:1 and 4:1 balun by using the same design as one sold by Elecraft. Its not weatherproof (at least my version isn't) but the switch makes it very handy for experimentation. I use two #43 material two aperture cores in that one.Quote from: tkamiya on December 06, 2018, 02:49:01 pm

author: rhb
author_rank: Super Contributor
timestamp: December 07, 2018, 05:28:26 pm
content: Quote from: cdev on December 07, 2018, 04:28:45 pmIf you want pure copper get this:https://www.cesco.com/Harger-588C-588C-HARGER-5-8X8-SOLID-CU-GROUND-R/p2058599orhttps://www.cesco.com/Harger-3410C-3410C-HARGER-3-4X10-SOLID-CU-GROUND/p1920430You will not be able to drive a copper pipe very far before it buckles.As you can see there is a good reason that galvanized or copper plated steel rods are popular. Not a big deal to drive a new one in 15 years. The only reason to use this rather than the steel would be soil conditions which would remove the plating either by abrasion while driving or by chemical reaction with acidic ground water.But *do* use a standard product engineered for the application.

author: cdev
author_rank: Super Contributor
timestamp: December 07, 2018, 05:46:30 pm
content: The only reason I am "questioning" how good my grounding is here is that I have found that the house AC ground is very noisy. In the past grounding the shortwave receiver always quiets the signal coming from a long wire antenna. Here a lot of noise rides in on the AC power line and CATV cable. (which are both grounded to their own ground rods)I can tell that by walking around with a small digital AM/FM/SW receiver I have. Basically, it goes nuts when it is brought close to either the power line or the CATV cable.Grounding the receiver doesn't help this HF noise so much. It seems to make it worse.All sorts of junk rides in on those outside wires and the grounds just are not up to the task of removing it like has been the case elsewhere for me in the past.(I've had this receiver for more than 20 yrs, since around 1986-87- so I have lots of experience with its performance.)Maybe my logic is faulty somewhere? Maybe this is just normal now?There is a lot of AM junk here, but there was a LOT more FM and VHF/UHF junk where I lived in SF. (for many years, not that far from the Sutro Tower which is used for TV and FM transmission.)

author: ogden
author_rank: Super Contributor
timestamp: December 07, 2018, 06:07:19 pm
content: Quote from: rhb on December 07, 2018, 05:28:26 pmCopper plated lasts 30..50 years, galvanized as you say around 15 years (10-20).QuoteSingle rod is OK only for small shack that does not need lightning rod. Even 2-bedroom house needs at least 4 ground rods - one for each lightning rod and at least two or even three for mains power earthing.Lookhow much>= 10' rods are needed for wind turbine.QuoteRight. Stainless steel rods for salty ground water sites as well. If you own small island in the ocean - use stainless steel. If you are crazy enough purist to buy pure coppergrounding rods for 400$ each, make sure nobody knows it, otherwise they will be stolen. Imagine - somebody steals copper of your earthing during bad weather and lightning strikes, then his relatives sue you for negligence

author: cdev
author_rank: Super Contributor
timestamp: December 07, 2018, 06:22:47 pm
content: OMG, does it really cost that much?(Need to check prices around here!)No way could/would I ever buy pure copper for that much. Copper piping (which I already have some of) is probably significantly cheaper, but the two pieces of pipe I have - its been years since I bought it. Could have gone up, I suppose.I find it makes a decent RF case, so have used very small pieces of it in projects.Quote from: ogden on December 07, 2018, 06:07:19 pmNobody around where I live has lightning rods on their houses. In my memory I have only seen obvious lightning rods on very large houses with lots of lightning exposure. (houses that stick out on a ridge line and present an obvious target for lightning)Because of CATV and satellite services, few houses in my area now have visible antennas of any kind that stick up. Back in the day when people had TV antennas it was common practice to ground the mast using a thick wire, (but not that thick) to a ground rod.I don't currently have any antennas mounted anywhere (high or not). Its always been my plan to ground them when I did, though. In a cost effective manner.The place I live would probably qualify as a little shack.How would I be able to tell how successful my grounding efforts were?

author: ogden
author_rank: Super Contributor
timestamp: December 07, 2018, 06:32:28 pm
content: Quote from: cdev on December 07, 2018, 06:22:47 pmThere are specific earthing measurement/certification procedures and equipment.Just first google hitI am not expert here. I prefer to hire professionals - you know

author: cdev
author_rank: Super Contributor
timestamp: December 07, 2018, 06:48:49 pm
content: Thank you!This (UK's standards for soil resistance measurement) looks very useful.I've shied away from use of the term "earthing" in searches, because of... well.. "noise" in the returned data.(from whence - or perhaps wince is better ...came the title of this post.)

author: SeanB
author_rank: Super Contributor
timestamp: December 07, 2018, 07:22:15 pm
content: Copper pipe into ground is easy, just put on the non ground end a compression elbow ( probably will be half inch/16mm copper pipe as that is the most common rigid pipe) and connect a hosepipe to the elbow, stand on ladder and turn on hose while pushing down until rod is buried. Water drills the hole and at the same time improves soil conductivity, provided of course you do not live on an outcropping of hard non permeable stone, sandstone, limestone or such.Otherwise standard electric fence grounding rods are galvanised, just use a few in parallel to get lower resistance. They are merely cut lengths of standard reinforcing rod with a plate welded on to make bolting the wire on easy, and are then hot dip galvanised.

author: tautech
author_rank: Super Contributor
timestamp: December 07, 2018, 07:39:12 pm
content: Quote from: SeanB on December 07, 2018, 07:22:15 pmBetter when the ground conditions allow (they don't for cdev) is a full 6M length of 20mm (3/4") threaded galv pipe with 2 90oelbows fitted so the water connection faces straight down, turn on the water full blast and work the pipe up and down using the 'hydraulic hammer' effect to bore it into the ground.Easy to do close to a building so to have a helper on the roof to keep the pipe supported vertical until you have enough of it in the ground for it not to fall over. Have done it with a helper person hoisted high in a tractor front end loader bucket.The weight of the water inside the pipe and the 'lube' it offers against ground resistance allows a 6M length to be sunk full depth in 10-15 mins, less when the ground conditions allow.The greatest benefit of a single long ground peg is to get well into the water table for an 'all season' highly effective ground.Done this ^ a few times for grounds for high power mains electric fences.

author: rhb
author_rank: Super Contributor
timestamp: December 08, 2018, 02:47:00 am
content: I'm a somewhat mongrel PhD level geoscientist. MS in igneous petrology followed by 4 years pursuing a PhD in geophysics before I lost my financial support.The effectiveness of connecting a garden hose to one end of a pipe is highly dependent upon the geology. Works great in fine alluvial fill. Doesn't work at all in glacial till or gravel.I'm 65, I was born in Brooklyn, NY before the merger with Manhattan. To the best of my knowledge I have never lived in a building with lightening rods. I have never seen a single family residence with lightening rods.At work, yes, a rod about every 12-18" all along the perimeter of the roof with heavy copper braid from each rod. I never did see what the braid connected to at the ground as it was all landscaped. Very likely that is where those very expensive solid copper rods get used.It's important to understand that lightening rods are there to dissipate charge differentials. That is why they are pointed. Grounding a lightening arrestor for an antenna is entirely different.An ultra conservative approach would be to drive two 8' standard copper plated steel rods a few inches apart. Attach a piece of 1/4" by 1.5" copper bus bar between them with a hole for bulkhead mounting the lightening arrestor. Drill and tap the ground rods after installation, bolt the bus bar to the rods and then solder after cleaning with sand paper and applying acid plumbing flux.For verifying the effectiveness of the grounding, measure the resistance between the two rods before installing the bus bar. If you do the Reg overkill approach and install a 2nd arrestor at the house entrance, make a 4 wire measurement of the resistance between the feedpoint ground and the entrance ground. If you can't make a 4 wire meaurement, measure the resistance of the wires and then subtract that from the 2 wire measurement.It's important to remember that the objective is to prevent a high voltage pulse being applied to the RF input of your rig. The ham radio club station I used while getting my MS had a bulkhead on the wall. You were expected to connect the appropriate antenna when you started to operate and to disconnect them when you left. The club station and antennas were on top of an 8-10 story building that housed the EE department. This was not a switch. It was a row of PL-259s on the wall bulkhead and a row of labeled cables.Remember, you're trying to protect the radio gear. If lightening hits the antenna, some or all of the feedline is going to be destroyed

author: coppercone2
author_rank: Super Contributor
timestamp: December 08, 2018, 02:55:12 am
content: if you mess with the ground impedance by shorting it with a bunch of wires for some kind of counterposie or whatever, are you more likely to take a lighting strike?same thing if you drive a buncha rods deep for a better ground.I assume the answer for small stuff is unmeasurable but how about really large ground modification systems? and waterlogging of substrate.

author: ogden
author_rank: Super Contributor
timestamp: December 09, 2018, 01:04:57 am
content: Quote from: coppercone2 on December 08, 2018, 02:55:12 amUnless you are doing it for huge areas, it does not change lightning hit probability. Some say that proper lightning rod(s) with pointy spike(s) may slightly decrease hit probability due to corona discharge, but opponents including me, disagree. That corona dissipate gazillion times lower energy than charge of clouds above - how it can help?Ground impedance shorting, let's say low impedance earthing between all the interconnected structures helps to reduce lightning step voltage which occur when it hits nearby structure (tower/building/tree). If you have tower in the field/backyard and cable is going into your radio shack, you would want to make good, common for both, low impedance earthing system. Otherwise ground bus between tower and your shack is RF cable. You would not want that even when lightning does not directly hit your tower. This is why it is so important to do very good grounding of any cable where it enters house BTW. If you fail in this regard then results can be nasty or even deadly. You want to get lightning into the ground as soon as possible so it does not seek path to neutral of the power grid through every appliance & water pipe of your home.

author: coppercone2
author_rank: Super Contributor
timestamp: December 09, 2018, 06:24:47 pm
content: does anyone have any good recommended guides on how to build a lighting protection system for a small house, say 2000 sqft?preferably a nice amusing youtube video. an over built one that people here can agree is good.

author: coppercone2
author_rank: Super Contributor
timestamp: December 09, 2018, 06:55:19 pm
content: anyone got a copy of IEC 62305?fucking IEC want money to tell you how to prevent your cave from burning downhttp://www.zinoglobal.com/wp-content/uploads/2016/12/IEC-62305-1-1.pdfhttp://www.zinoglobal.com/wp-content/uploads/2016/12/IEC-62305-2-1.pdfhttp://www.zinoglobal.com/wp-content/uploads/2016/12/IEC-62305-3-1.pdfhttp://www.zinoglobal.com/wp-content/uploads/2016/12/IEC-62305-4-1.pdfthis tells u what u need to readhttp://www.pts.ir/panel/images/post/tpb85gmi6kIEC%20625611-621.pdfhttp://www.pts.ir/panel/images/post/n53p2z19cqIEC%20625612-378.pdf