I need some grounding-strap guidance, if'n you please
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I need some grounding-strap guidance, if'n you please
 
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Good morning, folks, I'm eagerly awaiting Wednesday's arrival of my KX-1 kit, tricked out for four bands plus the auto tuner. The last two kits I built (back in the day) were Heathkit's HW-8 and 2036A synthesized 2-meter transceiver. That was largely before static-sensitive ICs. I will be building the kit in my workshop, which occupies one corner of our garage (unfinished interior walls, unpainted cement floor). I'm not clear where I should hook up the other end of a wrist strap or mat. One thought that occurred to me involved any bolts holding down the wall framing to the cement foundation. But there may be a more elegant approach. I'd be grateful for any guidance! With best regards, Pete -- Peter N. Spotts -- KC1JB http://www.kc1jb.net (under construction) Email: [hidden email] | Skype: pspotts QRP-ARCI # 4174 | North American QRP CW Club # 2446 Flying Pigs QRP # 1983 | SKCC # 4853 | QCWA #34679 W5JH Black Widow paddle #601 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: I need some grounding-strap guidance, if'n you please
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Pete,
Work carefully with the KX1 - especially the KXB3080 low pass filter - the manual is correct, but follow it *exactly* and keep your work neat - use small diameter solder and do not apply too much. Get flush cutters if you do not have them already. Those bolts around the foundation are not likely to be grounded - most are not. If you have modern wiring in that garage, ground the wrist strap and anti-static mat to the center screw of the receptacle plate. Before doing that, get one of those inexpensive receptacle test devices from your hardware or DIY store (the ones that just plug in and have 3 LEDs as fault indicators) to be certain the receptacle is wired correctly. If you do not have the modern grounded wiring, is the electrical breaker box located in the garage? If so, run a wire to its enclosure. If no electrical box, then run a wire through the wall to the ground stake outside at the electrical service entrance. Older homes may have *all* copper plumbing out to the service entry or well, and can be used for a ground connection, but then consider that the plumbing may have plastic splices that defeats a continuous ground path. 73, Don W3FPR Peter N. Spotts wrote: > Good morning, folks, > > I'm eagerly awaiting Wednesday's arrival of my KX-1 kit, tricked out > for four bands plus the auto tuner. The last two kits I built (back in > the day) were Heathkit's HW-8 and 2036A synthesized 2-meter transceiver. > That was largely before static-sensitive ICs. > > I will be building the kit in my workshop, which occupies one > corner of our garage (unfinished interior walls, unpainted cement > floor). I'm not clear where I should hook up the other end of a wrist > strap or mat. One thought that occurred to me involved any bolts > holding down the wall framing to the cement foundation. But there may > be a more elegant approach. > > I'd be grateful for any guidance! > > With best regards, > > Pete > > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Don offers generally good advice. I would argue with the statement that the j-bolt sill anchors aren't grounded, however. They may not make a good safety or made ground, but for anti-static purposes, they should be fine.
Wes N7WS --- On Mon, 8/31/09, Don Wilhelm <[hidden email]> wrote: From: Don Wilhelm <[hidden email]> Subject: Re: [Elecraft] I need some grounding-strap guidance, if'n you please To: "Peter N. Spotts" <[hidden email]> Cc: [hidden email] Date: Monday, August 31, 2009, 7:43 AM Pete, Work carefully with the KX1 - especially the KXB3080 low pass filter - the manual is correct, but follow it *exactly* and keep your work neat - use small diameter solder and do not apply too much. Get flush cutters if you do not have them already. Those bolts around the foundation are not likely to be grounded - most are not. If you have modern wiring in that garage, ground the wrist strap and anti-static mat to the center screw of the receptacle plate. Before doing that, get one of those inexpensive receptacle test devices from your hardware or DIY store (the ones that just plug in and have 3 LEDs as fault indicators) to be certain the receptacle is wired correctly. If you do not have the modern grounded wiring, is the electrical breaker box located in the garage? If so, run a wire to its enclosure. If no electrical box, then run a wire through the wall to the ground stake outside at the electrical service entrance. Older homes may have *all* copper plumbing out to the service entry or well, and can be used for a ground connection, but then consider that the plumbing may have plastic splices that defeats a continuous ground path. 73, Don W3FPR Peter N. Spotts wrote: > Good morning, folks, > > I'm eagerly awaiting Wednesday's arrival of my KX-1 kit, tricked out > for four bands plus the auto tuner. The last two kits I built (back in > the day) were Heathkit's HW-8 and 2036A synthesized 2-meter transceiver. > That was largely before static-sensitive ICs. > > I will be building the kit in my workshop, which occupies one > corner of our garage (unfinished interior walls, unpainted cement > floor). I'm not clear where I should hook up the other end of a wrist > strap or mat. One thought that occurred to me involved any bolts > holding down the wall framing to the cement foundation. But there may > be a more elegant approach. > > I'd be grateful for any guidance! > > With best regards, > > Pete > > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: I need some grounding-strap guidance, if'n you please
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Wes,
I have built several houses myself, my father was a masonry contractor, and I have seen many installations of J-bolts in foundation sills - I have never seen any of them grounded - they are simply stuck into the concrete filling the blocks. It may be different with poured foundations where the rebar is tied before pouring and it may be different in commercial structures, but for residential structures, I would never consider the J-bolts as an adequate ground for anything at all. 73, Don W3FPR Wes Stewart wrote: > Don offers generally good advice. I would argue with the statement that the j-bolt sill anchors aren't grounded, however. They may not make a good safety or made ground, but for anti-static purposes, they should be fine. > > Wes N7WS > > --- On Mon, 8/31/09, Don Wilhelm <[hidden email]> wrote: > > From: Don Wilhelm <[hidden email]> > Subject: Re: [Elecraft] I need some grounding-strap guidance, if'n you please > To: "Peter N. Spotts" <[hidden email]> > Cc: [hidden email] > Date: Monday, August 31, 2009, 7:43 AM > > Pete, > > Work carefully with the KX1 - especially the KXB3080 low pass filter - > the manual is correct, but follow it *exactly* and keep your work neat - > use small diameter solder and do not apply too much. Get flush cutters > if you do not have them already. > > Those bolts around the foundation are not likely to be grounded - most > are not. > If you have modern wiring in that garage, ground the wrist strap and > anti-static mat to the center screw of the receptacle plate. Before > doing that, get one of those inexpensive receptacle test devices from > your hardware or DIY store (the ones that just plug in and have 3 LEDs > as fault indicators) to be certain the receptacle is wired correctly. > > If you do not have the modern grounded wiring, is the electrical breaker > box located in the garage? If so, run a wire to its enclosure. If no > electrical box, then run a wire through the wall to the ground stake > outside at the electrical service entrance. > > Older homes may have *all* copper plumbing out to the service entry or > well, and can be used for a ground connection, but then consider that > the plumbing may have plastic splices that defeats a continuous ground path. > > 73, > Don W3FPR > > Peter N. Spotts wrote: > >> Good morning, folks, >> >> I'm eagerly awaiting Wednesday's arrival of my KX-1 kit, tricked out >> for four bands plus the auto tuner. The last two kits I built (back in >> the day) were Heathkit's HW-8 and 2036A synthesized 2-meter transceiver. >> That was largely before static-sensitive ICs. >> >> I will be building the kit in my workshop, which occupies one >> corner of our garage (unfinished interior walls, unpainted cement >> floor). I'm not clear where I should hook up the other end of a wrist >> strap or mat. One thought that occurred to me involved any bolts >> holding down the wall framing to the cement foundation. But there may >> be a more elegant approach. >> >> I'd be grateful for any guidance! >> >> With best regards, >> >> Pete >> >> >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.409 / Virus Database: 270.13.72/2337 - Release Date: 08/31/09 05:50:00 > > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Re: I need some grounding-strap guidance, if'n you please
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Ron is correct - never trust an outlet box ground without testing it
first. The small 3-lamp testers available are something everyone should have in their toolbox. That being said, what I have done is to take a conventional U-ground cord cap purchased at a local hardware store and fit it with a single banana jack (in place of where the SC cord would normally exit). This (green) jack is connected to the U-ground pin. When this plus is inserted into a (tested) 120V AC socket, the ground is available for other uses. I then plug the end of the ground wire from my Pomona anti-static mat into the ground connection, and I am ready to work on electronics with much less chance of a damaging static discharge. And, the setup is easy to move to another work area should that be needed. - Jim, KL7CC Ron D'Eau Claire wrote: > Take a look inside one of your outlet boxes. > (snip) > I never trust a ground without checking it. > > Ron AC7AC > > > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Don Wilhelm-4
There is really no need to get to "earth" ground. The risk is that the
potential between parts and people is of sparking and ESD values. All that is needed is for the assembler and the assembly to be at nearly the same potential. Much ado about nothing... 73 jim ab3cv ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Don Wilhelm-4
Don,
For ESD purposes, we usually have a megaohm or so between the wrist strap/ESD mat to ground. In the overall scheme of things, a J-bolt stuck in concrete is at worst a few more ohms in series with the current limiting resistor. I almost added this in my prior message but thought better of it. I guess that was a mistake. Here is a thought experiment (Don't actually DO this). Put one had on the J-bolt and the other on the hot side of the AC line and report back as to whether the J-bolt is grounded or not. A Ufer ground is nothing more than that tied rebar you mention and it's entirely encased in concrete. The concrete is the connection to the earth, not the steel. A way I often look at things is to consider the opposite condition. What if I wanted that J-bolt to be insulated from ground? What steps would I have to take to make it so? Something other than sticking it into wet concrete, that's for sure. Regards, Wes N7WS --- On Mon, 8/31/09, Don Wilhelm <[hidden email]> wrote: From: Don Wilhelm <[hidden email]> Subject: Re: [Elecraft] I need some grounding-strap guidance, if'n you please To: "Wes Stewart" <[hidden email]> Cc: "Peter N. Spotts" <[hidden email]>, [hidden email] Date: Monday, August 31, 2009, 4:25 PM Wes, I have built several houses myself, my father was a masonry contractor, and I have seen many installations of J-bolts in foundation sills - I have never seen any of them grounded - they are simply stuck into the concrete filling the blocks. It may be different with poured foundations where the rebar is tied before pouring and it may be different in commercial structures, but for residential structures, I would never consider the J-bolts as an adequate ground for anything at all. 73, Don W3FPR ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I have installed quite a few power poles, you may call them telephone poles, but they carried electrical power. That ground wire that goes down the side of the pole is simply coiled (I think they called it "flaked" in sailor terms) in a spiral fashion at the bottom of the pole. That's it. Once on a trouble call for low voltage we found that both sides measured 120 VAC unloaded at the transformer and at the entrance box. with load it dropped a few volts with a heavy load it dropped about 5 volts. eventfully we discovered that there was a hidden break in the ground wire and the house was getting close to proper voltage with the lousy ground at the bottom of the pole and the house ground rod. Go Figure!
Not only does that illustrate how a lousy ground can carry quite a bit of current, but also why it is important to have a good ground rod at your house. I would NEVER place a ESD ground strap on the ground of a power outlet or even the metal case of the outlet. (I think I read somewhere in a Navy manual that this was forbidden.) I have seen to many not grounded even though they have a grounding outlet and ground wires not terminated at the fuse panel, AND fuse panels not bonded to a ground rod - simply relying on the center tap of the ac feed, and I just told you how that is grounded at the pole. DON'T DO IT! Your cheap hardware store testers will be fooled. You are only trying to neutralize static electricity, not ground lightning. |
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Re: I need some grounding-strap guidance, if'n you please
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In reply to this post by n7ws
On Mon, 31 Aug 2009 18:34:20 -0700 (PDT), Wes Stewart wrote:
>In the overall scheme of things, a J-bolt stuck in concrete is at >worst a few more ohms in series with the current limiting resistor. Not so. I recently poured a tower and buried three 2-inch wide pieces of copper in the concrete base at widely separated places in the base (which was roughly 30 inches square by 48 inches deep). The DC resistance between those straps was on the order of 100 ohms when I measured with a Simpson 260 more than a month after pouring. I completely agree that a ground like that is plenty good enough to discharge a wrist strap, but it's a LOT more than "a few ohms." The purpose of the wrist strap and the anti-static mat is to pull you and the work to something approximating a low potential with respect to earth by discharging any potential that may be on you, the parts, or anything else. Hundreds of kOhms is probably good enough to do that -- our bodies are typically tens or hundreds of kOhms from one point to another unless we're wet, and/or grasping conductors quite hard, and WE are a big part of what we're trying to discharge! :) 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: I need some grounding-strap guidance, if'n you please
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In reply to this post by Rich
On Mon, 31 Aug 2009 21:14:50 -0500 (CDT), Rich wrote:
>Not only does that illustrate how a lousy ground can carry >quite a bit of current, but also why it is important to have >a good ground rod at your WRONG! The earth connection on power systems is a lightning discharge path, and it typically has a fairly high resistance to earth, especially with lousy soil. The EARTH connection does NOT CARRY POWER CURRENT. The HOT and the NEUTRAL do that. The "coil" at the base of the pole sounds like lazy electricians to me. The ground rod at the power system entrance IS very important. See http://audiosystemsgroup.com/publish and study the tutorial on Power and Grounding for Audio and Video. It explains a lot about how power systems work. I'm nearly finished with an international version. BTW -- I also wrote the Grounding section in K7LXC's new book on towers. Ken Kopp said: >As others have said .... NEVER use the "U" hole in the >outlet for a wrist-strap or anti-static mat connection! "Others" are wrong. BY LAW, the U hole must be a solid ground carried from the power system service entrance. As long as that connection is there, it is PLENTY good enough to discharge static. >Mine goes to the station ground buss ... 2" wide CU >strap ... that's connected directly to a number (12) >of 8' ground rods that are all bonded together with #8 >CU wire. There is no connection between this ground >system and the power company's entrance ground. And you are DEAD WRONG. BY LAW, ALL GROUNDS MUST BE BONDED TOGETHER. To do otherwise is UNSAFE. >There is often measurable potential between the white >neutral wire, the green "ground" wire and a ground rod. There MUST be measureable potential between the white (neutral) wire and the ground wire -- the neutral carries the current of the load, the green ground wire must NOT carry that current. >In some parts of Canada there is just one wire used in >the power distribution, especially in rural areas. The >earth is the other side of the distribution circuit. That's also done in Australia, but only for HIGH VOLTAGE distribution (tens of kV) (which has proportionally lower current for the same power), not for local distribution. The earth is FAR too lossy (resistive) to do that for low voltage (120V/240V/480V). >This was the case for rural phone lines in the US in the past. Not quite. The use of the earth was for signalling (ringing), and was balanced (called simplex, similar to "phantom power" used to power professional microphones on balanced cables). An audio frequency loop with a single wire and earth as a return would be VERY buzzy, because it picks up the magnetic field of the power system and the 3-phase noise current in the earth. W8IHY and I did that around 1957 between our houses that were about three city blocks apart (in Huntington, WV). It was very buzzy. :) Many major misconceptions have been thrown around in this thread. Some of you guys need to study my power and grounding tutorial. 73, Jim Brown K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: I need some grounding-strap guidance, if'n you please
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Coiling the down-the-pole ground wire in a concentric
circle on the bottom end of a power pole is the accepted method of achieving "ground" and isn't because of "lazy electricians". "Electricians" don't erect power lines, "linemen" do. (;-) I'm a retiree from the Montana Power Company, FWIW. 73! Ken Kopp - K0PP [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Thanks!!!
I have lived in 7 states and the Linemen/women have done it that way in every one of those states! Even the railroad does it that way! You would also be quite glad your neutral was grounded at your house and the pole transformer had a ground when you lose a neutral wire (some call it a ground wire but in my first post I was trying to keep out the technical stuff). I have been at houses where this happened, the refrigerator or some heavy 115 VAC appliance kicked on and wiped out all of the appliances on the other side. Happened at the customers fuse panel so he was responsible for all the damages. The story I gave earlier had a happy ending because of the low ground (earth, dirt) resistance.
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In reply to this post by Jim Brown-10
"One measurement is worth a thousand expert opinions"
I just used my Simpson 260 to measure from a J-bolt (that I placed when I built half of my house) to a cold water pipe that is bonded to both a ground rod and an AWG 4 bare copper wire buried next to the foundation around the building periphery. The resistance was ~10K. So this would increase the ground strap resistance to ground by 1%, that's a few ohms in my book. Regards, Wes N7WS --- On Mon, 8/31/09, Jim Brown <[hidden email]> wrote: From: Jim Brown <[hidden email]> Subject: Re: [Elecraft] I need some grounding-strap guidance, if'n you please To: "Elecraft List" <[hidden email]> Date: Monday, August 31, 2009, 11:39 PM On Mon, 31 Aug 2009 18:34:20 -0700 (PDT), Wes Stewart wrote: >In the overall scheme of things, a J-bolt stuck in concrete is at >worst a few more ohms in series with the current limiting resistor. Not so. I recently poured a tower and buried three 2-inch wide pieces of copper in the concrete base at widely separated places in the base (which was roughly 30 inches square by 48 inches deep). The DC resistance between those straps was on the order of 100 ohms when I measured with a Simpson 260 more than a month after pouring. I completely agree that a ground like that is plenty good enough to discharge a wrist strap, but it's a LOT more than "a few ohms." The purpose of the wrist strap and the anti-static mat is to pull you and the work to something approximating a low potential with respect to earth by discharging any potential that may be on you, the parts, or anything else. Hundreds of kOhms is probably good enough to do that -- our bodies are typically tens or hundreds of kOhms from one point to another unless we're wet, and/or grasping conductors quite hard, and WE are a big part of what we're trying to discharge! :) 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Jim Brown-10
--- On Tue, 9/1/09, Jim Brown <[hidden email]> wrote:
The "coil" at the base of the pole sounds like lazy electricians to me. Nope, it's SOP in the utility business. And no end of trouble in the RFI "business". My rural electric co-op uses aluminum wire for the above-ground part of the grounding system, either for cost, copper theft, or both reasons. They also love staples and drive them at too frequent intervals up the pole to secure the ground wire. Unfortunately, a green pole shrinks considerably in the 6% RH typical here in the summer and the ground wire then arcs to the loose staple. So the fix is to drive them deeper. I've then seen the wire cut when the pole expands again when the RH increases. This nearly undetectable break then arcs and generates lots of intermittent noise. The same thing happens at the crimp they use to connect the aluminum to the copper; that's a physically weak point that can break and cause the same trouble. This used to be a much worse problem before they replaced thousands of epoxy insulators that crazed in the Arizona sunshine and had 100's of mA of leakage current; a lot of it flowing in these ground wires. They actually had some insulators catch fire from the heating. Regards, Wes N7WS ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: I need some grounding-strap guidance, if'n you please
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In reply to this post by Pete Spotts
You assume wrong. :) Concrete is a conductor, and metal that makes
contact with it forms a Ufer ground (that is, a ground electrode). By virtue of having a lot of surface area in contact with the earth, the Ufer ground can have a fairly low impedance to earth. The tower is bonded to that copper and to ground rods that surround the tower. Thus, the total impedance to earth is the parallel combination of all of those electrodes. Again, the fundamental principal is that all grounds MUST be bonded together for lightning safety. In the event of a lightning hit, the potential of all rise together, so it is much less likely that something bad will happen in the building. We say "less likely" because those bonding conductors have resistance and inductance, so the potential difference won't be zero, but it will be lower than if there were no bonding. 73, Jim Brown K9YC --Original Message Text--- From: Ken Kopp Date: Tue, 1 Sep 2009 06:47:39 -0000 Hi Jim, I assume the straps in the concrete were an experiment to measure the resistance of concrete and -not- intended to be for lightning grounding. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: I need some grounding-strap guidance, if'n you please
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In reply to this post by Ken Kopp-3
Ken,
Perhaps I misunderstood your description of the practice. Are you saying that the bare end of this wire is buried in the earth in a coiled concentric circle? That does sound like good practice to the extent that it puts a lot of copper in contact with the earth, but lazy to the extent that the coil adds inductance to the discharge path. Or if you're the accountant for the power company, "efficient." 73, Jim K9YC --Original Message Text--- From: Ken Kopp Date: Tue, 1 Sep 2009 06:43:50 -0000 Coiling the down-the-pole ground wire in a concentric circle on the bottom end of a power pole is the accepted method of achieving "ground" ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: I need some grounding-strap guidance, if'n you please
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In reply to this post by Pete Spotts
On Mon, 31 Aug 2009 09:20:51 -0400
"Peter N. Spotts" <[hidden email]> wrote: > >snip< Many thanks to all! My original question was prompted by an experience I had as a teenager visiting my uncle in the mid 1960s (oops, the gray hairs are showing). I was working in his garage, using a metal-housed electric drill in bare feet on a dry concrete floor. (No cracks about natural selection at work, please!). I got a jolt about 2 volts shy of a hairstyle by Boston Edison! (Although this was in a St. Louis suburb.) So that's what led me to wonder if an anchor bolt embedded in concrete would constitute a sufficient ground. It sure seemed to for that drill! Thanks again for the helpful advice! With best regards, Pete -- Peter N. Spotts -- KC1JB http://www.kc1jb.net (under construction) Email: [hidden email] | Skype: pspotts QRP-ARCI # 4174 | North American QRP CW Club # 2446 Flying Pigs QRP # 1983 | SKCC # 4853 | QCWA #34679 W5JH Black Widow paddle #601 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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