Abandoned Well Casing Steel Ground

[NoCoFire]

I was thinking of some time in the near future putting a amateur radio antenna at my residence. I would like your opinions on using a drilled well casing as the ground. This well casing is 6" steel pipe and goes about 27 feet into the ground before it hits bedrock, once at the bedrock the well (not the casing) continues another 68 feet. The well is "abandoned" (long expensive pita story) and before I fill it with grout and cut it off below the surface I was thinking of using the steel casing as a ground. I really don't want to use the "active" well (15 feet away) as I would rather steer lighting away from my new expensive pump. Any thoughts or is this a ridiculous idea?

[mmckenna]

It should work pretty well, no pun intended. You'll just need to find a way to connect to it without corrosion degrading the joint over time. Ideally, welding on a stud and attaching there would work, but drilling a hole from the outside, bolting the connection and sealing it as well as you can.

This should be a decent set up, but depending on the exact type of antenna, you may need to add an additional network of ground rods.

Not sure how far down the ground currents would travel during a lightning strike, but 15 feet between this well and your working well is nothing considering that bolt of lightning just travelled several thousand feet through the air. Proper protection on the pump circuit would be important, no matter what.

[jeatock]

Originally Posted by mmckenna

It should work pretty well, no pun intended. You'll just need to find a way to connect to it without corrosion degrading the joint over time. Ideally, welding on a stud and attaching there would work, but drilling a hole from the outside, bolting the connection and sealing it as well as you can.

This should be a decent set up, but depending on the exact type of antenna, you may need to add an additional network of ground rods.

Not sure how far down the ground currents would travel during a lightning strike, but 15 feet between this well and your working well is nothing considering that bolt of lightning just travelled several thousand feet through the air. Proper protection on the pump circuit would be important, no matter what.

I second that.

"Exothermic Welding" the ground wire (#4 or bigger) is best but hidiously expensive. Welding a stud or drilling a bolt will work quite nicely, provided the connection doesn't corrode over time. Soldering the whole thing together will work. If you just have a mechanical connection a liberal coating of Harger HCAJC8 copper compound will help.

[wb4wdu]

I know of a broadcast tower about 1000 feet tall that they had problems getting grounded good. Kept getting eat up with lightning. I think they had 2 wells drilled, dont know the depth, and bonded the caseing to the tower. There engineer has told me they have had very little problems with lightning since then.

[rfradioconsult]

Exothermic welding is the way to go to connect the conductor to the casing but what are you trying to accomplish with your "ground connection"? How far is it away from your proposed operating position, would this be a RF ground, safety ground, lightning ground; what is your plan.

[prcguy]

Unless you are going to use the radio equipment at the well you would want to bond the well casing ground to your house ground to keep them at the same potential during a strike. It would also be required to meed code in all areas.
prcguy

[LtDoc]

If you have it available why not use it in conjunction with your 'other' grounds. If you had to drill that 'well' then I doubt if it would be worth the trouble at all. 'Deep' isn't all that beneficial, although it doesn't hurt. If you had that drill casing on top of the ground I can think of several better uses for it, masting for example!
- 'Doc

[reconrider8]

Originally Posted by LtDoc

If you have it available why not use it in conjunction with your 'other' grounds. If you had to drill that 'well' then I doubt if it would be worth the trouble at all. 'Deep' isn't all that beneficial, although it doesn't hurt. If you had that drill casing on top of the ground I can think of several better uses for it, masting for example!
- 'Doc

My thoughts exact be one dern good mast mount lol

[rfradioconsult]

If you are serious about getting into ham radio you might consider welding a piece of 1 1/2 pipe that would be about 2 foot above grade and when you get your license stick a Multi-band HF antenna on it.

[ab3a]

There are two reasons to ground things: First, for protection of your gear and the electrical distribution systems. There should be a ground that is bonded to your breaker panel in your home. If lightning strikes, you NEED that ground to be bonded to whatever else is in your station. You will want to ride that ground reference as the local ground potential goes up and down.

The other reason is to act as a counterpoise for your antenna system. This is a situation where you may not want to use the household ground system because it may be too far away electrically. If the ground wire is a significant portion of a wavelength it may not be a good ground reference anyway.

If you set up a tower, you really should bond it to a system of ground rods right next to the tower with heavy ground wires (#8 AWG or larger) to the ground rods in as nearly a vertical straight line as possible.Your coaxial cable should leave the tower at a right angle and it is preferable to bond the shield of the coax to the tower right where it makes that bend (assuming you have a balun at the top). I have seen tower systems with similar grounds and antennas and they survive direct lightning strikes without a hiccup.

If you're setting up a ground mounted vertical antenna, a ground system isn't quite as important. What IS important is that you have radials. LOTS of radials. Medium Wave (AM) Broadcast stations use about 120 radials for their antenna system. You could easily do well with less, but you do need to have some form of radial system.

Nevertheless, you should isolate your coaxial feed line from the antenna system so that it doesn't radiate in the building or pick up common electrical fields from inside your home. The further the antenna system is away from everything, the better off you'll be.

That's a very quick overview of grounding issues. People write extensive books about this subject. For a very complete technical reference, I recommend Antennas by Krause. However, this is a book that few will understand without a significant education or experience in RF Engineering. The ARRL antenna book is better, though their explanations are sometimes oversimplified and therefore somewhat cryptic or confusing. Another great book is from Jerry Sevick, on baluns. There are some very good explanations of what a Balun is and how to isolate antenna systems from the home. There is also a nice appendix on short (compared to a quarter wave) vertical antennas.

That said, the well casing is probably a good ground, provided that you get a clean, high conductance bond to it. Exothermic welding is often the preferred method, but I have seen decent results with a bug clamp too, provided it is protected with electricians putty from the elements. If the well casing is close to your home foundation, you may want to add it to your electrical ground system. If you erect antennas above that well casing, that ground could be used to dissipate lightning strikes. Note that if there are higher structures around your antenna, it is unlikely it will be hit directly. That said, if anything in the vicinity of your antenna IS hit, you will see the ground voltage potential rise up thousands of volts. Unless you are carefully bonded to your home electrical system or carefully isolated from it, you will see significant damage.

Read your local electrical codes and consult with a master electrician before doing any of this. The rules and codes differ from place to place. Unless you're experienced in this sort of thing, this technology can seem arcane and bizarre.

[NoCoFire]

Originally Posted by rfradioconsult

Exothermic welding is the way to go to connect the conductor to the casing but what are you trying to accomplish with your "ground connection"? How far is it away from your proposed operating position, would this be a RF ground, safety ground, lightning ground; what is your plan.

RF, this is about 50' from my house and about 80' from my proposed operating area in the basement of my house. I wanted to use this for a VHF/uhf icom dstar mobile I have that I took out of my truck a couple of years ago. I wanted to see if I was to put up a short mast if the well would be a ideal ground to work local repeaters. Thanks for your help.

[NoCoFire]

Thank you all for you help. I will have to research exothermic welding. And yes I agree it would make a solid foundation for a mast.

[mmckenna]

Originally Posted by NoCoFire

RF, this is about 50' from my house and about 80' from my proposed operating area in the basement of my house. I wanted to use this for a VHF/uhf icom dstar mobile I have that I took out of my truck a couple of years ago. I wanted to see if I was to put up a short mast if the well would be a ideal ground to work local repeaters. Thanks for your help.

Exothemic welding can be expensive, but it does work well. If it's steel, then getting someone to come in a weld a stud on for you would be cheaper.

As for the location, 80 feet is a long way. It'll work, but you'll need to invest in better coaxial cable. Remember that coaxial cable has loss, and that loss goes both ways... you will lose transmit signal and you'll also loose received signal. By the time you spend the money on 80 feet or more of good coax, you might spend more than just putting up a pole closer to your operating position and driving a new ground rod. While the well casing will make a great ground, it's not going to be so much better than an 8 foot ground rod that it would be worth the extra bucks.

Just my opinion...