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Author Topic: Grounding my station  (Read 2247 times)
AF6WI
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« on: February 13, 2004, 06:07:47 PM »

Hi, guys,

I'm unable to find a lot of information on specifics. My station is on the third floor of my town house. Running a ground wire down the side of the building is not in the CC&Rs, so I'm looking at alternatives. The two relevant threads that I've found here say that using the house's mains ground is not a good idea and that I should do it right because it's worth ti.

Any other clues? I find it hard to believe that I'm the only person who doesn't run a rig out of the basement with a 10-foot copper rod pounded through the floor with a 1-foot wide copper braid soldered to it.

Phil
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WB2WIK
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« Reply #1 on: February 13, 2004, 06:14:47 PM »

Hi Phil,

I'd first ask, "What's the ground for?"

Normally, if you can't provide a pretty good answer to that question, then you actually don't need one.  (No joke.)

If you have outdoor antennas, possibly they should have a "lightning protection" grounding system to help divert lightning energy away from your home, and to earth instead.  However, if outdoor heavy-duty ground cables are not an option, then the whole idea of lightning protection is moot -- you just can't do it.  Here in Los Angeles, where I live, almost nobody has any lightning protection systems, since lightning is very rare.  In fact, in 15-1/2 years here, I've only actually "seen" lightning three times, and "heard" thunder once, and in all cases, it wasn't close by.  Very different from when I lived on the east coast!

If you're going for a "station ground" just because you've heard it's a good idea, I'd have to say that a lot of what you (or we) may have heard is nonsense.  I operate twelve bands from 1.8 MHz through 432 MHz, with kilowatt power levels on most of those bands, with large outdoor antennas, and I have no station ground of any kind.  Nor do I seem to need one, since everything operates perfectly, no feedback, no burns, no RFI, no nothing.  I don't have any "symptoms" that might point toward grounding as a solution, so I've simply never installed a ground of any sort.  Many stations haven't, including many very "big" ones.

So, I guess I'd have to ask, "What's the ground for?" in your particular case.

WB2WIK/6
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AF6WI
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« Reply #2 on: February 14, 2004, 12:01:46 AM »

<<What for?>> I am asked. :->

I have a radio with a ground screw on the back and a manual that says to ground it. I have a 'rig runner' type device to spread power between the FT817 and the FT8900R, and it has a ground screw on it. "Everyone" says stations should be grounded, so I'm thinking I should ground it. I just don't have a good option on the third floor.

(My antennas are in my attic and I live in the San Francisco Bay Area, so my lightning here is similar to yours: no big deal.)

Phil
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WB2WIK
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« Reply #3 on: February 16, 2004, 01:28:44 PM »

Regardless, I would once again ask, "What's the ground actually *for*?" and if no good answers surface, forget about it.

All my rigs have ground terminals; they're nice and shiny and new looking, since I haven't used any of them!

This is silly.  Kind of like covering AC wall outlets that aren't being used, so the electricity won't leak out.  Smiley

WB2WIK/6

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K7IHC
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« Reply #4 on: February 23, 2004, 04:30:10 AM »

The info in the ARRL Handbook indicates that a station's radio(s) equipment should be bonded together and grounded externally (ground rod) and the antenna support structure should be grounded (ground rod).  The antenna feedline(s) should also have suppressors inline and be bonded to the ground setup.  All these auxiliary ground rods should then be bonded to the structure's AC mains ground rod.
That's what the book sez...

I live in coastal N. Calif.  We see a few storms every year with local lighting activity.  I have had small monopoles up before, with no grounds.  My current roof-mounted monopole (10ft tri-band VHF/UHF/1200) is not higher than adjacent trees or the roof peaks of the nearby two-story houses.  So my lightning strike risk is minimal, but possible.
I plan on grounding the antenna support mast and the inline PolyPhaser suppressor to a #6 wire that will terminate in a new ground rod next to the house.

All my station equipment is run off of an Astron RS-35M power supply.  All the power leads are fused twin wires to the various radios from a two-row (+ and -)junction strip fed by the power supply.
I'm not sure if I really need to ground all the equipment chassis to a common ground and another separate ground rod outside of the shack area.
I do plan on getting a better quality (not hardware store) surge suppressor for the power supply.  
If I only ground the power supply, I'm not sure if I really need to ground the equipment chassis, too.
The antenna/suppressor lightning ground seems to be good sense, but most of the other grounding stuff seems to be excessive if I'm not currently having any problems.
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WB2WIK
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« Reply #5 on: February 23, 2004, 04:53:13 PM »

Interestingly, the only ham I've ever known who had his station blown to bits and his basement set on fire due to a lightning strike also had the most elaborate, 100%-to-all-codes lightning protection and grounding system I've ever seen.  His 120' tower was grounded with numerous rods in radial circles around the base of the tower (outside the concrete block) interconnected with about #00 copper wire.  He had arrestors everywhere, on everything.  He had the famous "single point ground," following NEC to the letter.   And his station, in lightning-prone southern New Jersey, blew up.

The lightning, in his case, came via the AC power line, not via any of his transmission lines, and jumped everything in its path.  I think the resulting insurance claim was over $30,000, just for the ham gear.  Thankfully, as I recall, he really did collect on the insurance claim.

I've never had a grounded station, and also, in almost 40 years of hamming, have never had any lightning damage to anything -- this, after having stations installed at sixteen houses over this time, often having multiple tall towers with a lot of antennas.

My impression is there's no substitute for really good insurance, and hoping not to be home if the big one hits.

WB2WIK/6

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K7IHC
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« Reply #6 on: February 23, 2004, 10:03:41 PM »

That's interesting about the lightning surge entering via the AC mains line.  I've been eyeing those whole-house surge/spike suppressors that install at the service entrance.  I would think that it would be a good idea to protect ALL the electrical equipment in my house.  I've also heard about utility company surges damaging customer's home electronics. I haven't checked out the cost of one of those units, though. My neighborhood is all undergrounded utilities.

As I said before, I'm in coastal N. Calif and electrical storms are rare.  I think I'll go ahead with the antenna/mast protection grounding anyways.
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AF6WI
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« Reply #7 on: February 28, 2004, 01:37:45 AM »

The whole house units themselves are not that expensive --  a couple of hundred dollars. I don't know what it costs to have one installed though. It's on my list of things to have done this year.

Phil
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KG4RUL
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« Reply #8 on: February 29, 2004, 11:58:29 AM »

In Ladson, SC, our local electric co-operative will install the unit and add the cost as monthly payments on your electric bill.

Dennis / KG4RUL
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AF6WI
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« Reply #9 on: March 03, 2004, 02:09:25 AM »

> ... our local electric co-operative will install
> the unit and add the cost as monthly payments on
> your electric bill.

Nothing like a life-time stream of income to the electric company. I'd compare the cost of installation of a purchased unit to the rental fee and see how long it would take to pay for an installation.
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K5UJ
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« Reply #10 on: March 09, 2004, 02:56:36 PM »

KG6ILU asks a reasonable question.  He is probably relatively new to the hobby, may be having problems that are to him, bewildering, and may have several other things going on needing attention.  With this, needing help, he asks this question, probably hoping for a fairly simple straight answer.

If you are having problems it is not something to be too surprised about.  You are, like the rest of us, attempting to set up a radio station that should not only receive, but transmit, not on one frequency, but on many bands across the HF spectrum.  And all this from a site that was not constructed with this in mind.  When you look at it that way, what you are accomplishing is more difficult than setting up a commercial MW broadcast site that only transmits, on one frequency, from a site designed from the ground up with this in mind (but broadcasters do have other problems to deal with).  Further, for us nonprofessionals, RF can do weird things which we'll never figure out, and no two ham stations are exactly alike necessitating adapting general solutions for specific situations.  So, don't feel bad.  In fact, if everything worked great out of the boxes, THAT would be unusual!

There are three kinds of grounds:  Safety, lightning and a shack RF ground.  You are asking about the last one.  You may or may not need it.  Try operating your equipment hooked up to your antennas etc. and see what happens.  If you are operating on exciter power only, and you don't feel any RF tingling on your mic and equipment cabinets and no one reports distortion in your audio then you are probably okay.  One point of a shack ground is to give your equipment a low resistance path to dissipate undesired RF that might wind up in places where you don't want it, such as on cables and cabinets.  Often, this is a low inductance connection to a buried electrode which is why it's called "ground" but it doesn't have to be that.  It can be a tuned circuit.  Usually for shacks high above dirt (2nd floor on up) a ham needing a ground will just use insulated wires cut to 1/2 w. at each band he operates on and attached to the ground lug on his transmitter, or a single wire for the lowest frequency with a LC matching circuit at the tranmitter ground post to tune out the reactance on the higher frequencies (e.g. MFJ "artificial ground").  For more information see:
http://www.radioworks.com/nbgnd.html

Rob Atkinson
K5UJ
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WB2WIK
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« Reply #11 on: March 12, 2004, 08:05:13 PM »

K5UJ, nice response!

But I think you had a typo towards the end.  A counterpoise wire not actually connected to earth shouldn't be "1/2w" (one half wavelength) long, it should be 1/4-wavelength long.  As I'm sure you know, a half-wave radial terminated in "nothing" provides "nothing" back to its source, and thus acts as if it weren't there.

WB2WIK/6
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K5UJ
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« Reply #12 on: March 12, 2004, 10:35:54 PM »

Thanks & Thanks 4 correction--73
Rob/K5UJ
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K1CJS
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« Reply #13 on: March 21, 2004, 01:02:35 PM »

A proper station ground (RF) is actually part of the antenna system also.  Some stations may have situations that would necessitate a ground point to improve transmission and reception.

With that being said, Phil, are you getting out and receiving OK?  If so, you may not need a ground for your station.

One other point that nobody has touched on as of yet--is there a cold water pipe near your station setup?  If there is and you can check to see if it is actually at ground potential, you may have what you're looking for.  If the townhouse you live in is an older building and the piping is metal (copper) that may give you the ground path you want.

To check, attach a wire to a known earth ground (never use an outlet ground--you may regret it) and meter the resistance between that wire and the point you will be attaching the ground clamp.  If the resistance is very low or none, you're all set.  If the resistance is high or infinite, the possible benefits of using the piping as a counterpoise of sorts are far outweighed by the possible consequences of doing so--such as getting shocked while using your equipment or the actual damage that may happen to your equipment.

Good luck!
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KG4RUL
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« Reply #14 on: March 22, 2004, 02:05:19 PM »

NO, not a rental but an interest free payment plan.  No 'stream of income' here.

Dennis / KG4RUL
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