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Thread: Radio Station Grounding Reply to Thread
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Topic Review (Newest First)
02-15-2019 08:30 PM
edprof It is also standard practice for ham operators to disconnect their coaxial lines whenever the radio is not in use so the antenna does not collect lightning to bring into the shack.
02-15-2019 07:30 PM
spork1 not sure if its been posted yet. W8JI has a lot of info on grounding if you search his old posts on eham and qrz forums. He also has a web site. He takes a lot of hits without damage to his radios.

https://www.w8ji.com/station_ground.htm

As others have already mentioned your service entrance ground is the best place to bond your coax and enter the house. From what I've read most of the protection comes from proper bonding and I think a strike is further discharged through the power companies wiring and ground setup.
02-04-2018 03:25 PM
tatkinsh
Quote:
Originally Posted by Armordude View Post
PSY

Consider using this guys entrance panels http://www.kf7p.com/KF7P/EntrancePanels.html

Well made, copper backing plate predrilled for lighting arrestors. I use this and its great.

http://www.kf7p.com/KF7P/Gallery.html#1

If the entry box shown is metallic then there is a way to improve that installation. That is to use a longer copper plate that will cover the bottom of the box as well. Bend the copper sheet to fit. Use all stainless steel hardware to mount the copper plate in the box with a small gap between the copper an the box's shell to avoid galvanic corrosion. Remove a rectangular window in the bottom of the box shell but leave a wide enough lip to place a strip of stainless steel on each edge between the copper and the box shell. Then use bulkhead arresters which mount in a hole through the copper. I ADMIT IT! That is a "Gold Plate" installation.

Much less expensive is to use a plastic box exactly as shown. If a metal box is needed for damage resistance you can go the extra expense and use a stainless steel box with bulkhead connectors through the "floor" or bottom facing flange of the box. You can also use a common steel metal box and place bulkhead connectors through the bottom of the box and a short jumper to the arresters mounted on a stainless steel or copper back plate.

So why am I obsessing about how the coaxial cables get through the wall of the box? If the box is non-stainless; or mild; steel it needs to be effectively bonded to the cable shields at the wall of the box. The mild steel will serve as a choke at wall of the box and the cables may be damaged. Stainless is not completely immune from induced currents but the effect of the magnetic fields is drastically reduced and the arresters can be mounted through the wall of the box so as to bond the shields to the box shell quite effectively. Bonded = no voltage difference = no destructive current flow between the cable shields and the box shell.

Tommy
02-04-2018 02:16 PM
tatkinsh
Quote:
Originally Posted by Damonte View Post
4' is better than nothing. As much as you can get down in the ground. How much of the top you leave exposed is entirely up to you (mine is completely under the grade).

In a perfect world, you would also bond that ground rod to the house main electrical ground rod as well. Ideally, that bonding wire would be buried.
The alternative to driving the ground rod straight down is to drive it at a 45 degree angle but that still means that you need ~5.6 feet above hard-pan to drive it into. If you have less than ~30 inches of an eight foot rod still exposed when you hit rock bottom then driving at a 45 degree angle is certainly worth a try. If Rock Bottom is shallower than 5.6 feet the most practical remedy is dig a trench that is ≥ (at least) 30 inches deep and bury the rod. Tamp the soil well, remove large rocks, If you have access to any type of water loving clay use it as 2 feet of the back fill depth.

In order to leave the connection between the rod and the Grounding Electrode Conductor (GEC) accessible for inspection use a Ground Box, as previously suggested, and buy a 10 foot rod at an electrical supply house. Using a 1 foot deep plastic ground box You bend the rod to extend up to 2 feet from the bottom of the trench which will leave about 6 inches exposed in the ground box for inspection of the connection.

Should you resort to mechanical equipment, such as a back hoe, make the trench just as deep as the excavator will reach. Below the average water table would be ideal. Also if you have basement water leakage problems expose the exterior of the affected wall while you are at it and get the waterproofing; and maybe even external insulation; put in. EXERCISE EXTREME CAUTION TO AVOID UNDERMINING THE FOOTER! Undermining the footer can cause structural collapse!

If you are going to take the OP's advice and run a bonding conductor to the Electrical Service Grounding Electrode System (GES) run it outside the building; if you possibly can; in a ≥ 30 inch deep trench, if possible, use a wire that is ≥ #2 AWG. If you can afford 2/0 AWG so much the better but better still would be 4 inch wide copper ribbon; think copper roof flashing. The thickness of the copper ribbon chosen won't change the initial effectiveness much but it will effect how long it will last especially in some soil types. If you have un-guttered roof edge which creates a drip line cut the trench in that line.

Again if you use a mechanical excavator go as deep as practical without going below the top of the footer. If the foundation is shallow; such as the turned down edge of a slab on grade; keep the trench well away from the footer.

Even though this is an RF ground it will be affected by lightning. Any substantial difference between Grounding Electrodes will cause a current to flow between them, possibly through the Ground traces on the equipment circuit boards. The AC power supply; whether inside the radio or separate; is connected to both the electrical safety Equipment Grounding Conductor (EGC) and the RF grounding electrode/s.

Remember that once the magic smoke escapes from the equipment you will have to replace all the components that no longer have magic smoke in them or send it to a repair shop to have the emptied components replaced.

--
Tommy
01-29-2018 11:07 AM
franklin ARRL has an excellent book on grounding and bonding for you station.

https://www.amazon.com/Grounding-Bon...grounding+book

Well worth the investment.
01-29-2018 09:46 AM
RobertSWMissouri Thanks for the clarification ! Robert
01-26-2018 07:20 PM
Explainist
Quote:
"Ground" is poorly understood by most........................
I have been an electronics tech since 1964, you would not believe where I have worked and what I did, I have been a ham for 30 years, and I don't pretend to understand ground.
01-26-2018 04:46 PM
Juan rivera If you have an outside antenna then you need to ground that outside the structure. A lightening protection device needs to be install outside on your antenna feed and tied into the antenna lightening ground. The National Electrical Code specifies that the antenna ground needs to be bonded to the electrical ground via ground run outside the structure.

In your shack AC powered equipment needs to be tied in to the house wiring ground. Generally this is accomplished through three prong outlets but on older rigs the chassis should be tied in to ground. This is a safety ground required by National Electrical Code.

Then we have grounding of the radio equipment to reduce noise. These can be grounded a number of ways but generally a bus bar with all equipment connected and a single ground wire from that to a ground rod. (Some people tie this into the electrical system ground rod. If you do this attach the ground run as close as possible to the actual electrical ground rod.)
01-26-2018 02:07 PM
RobertSWMissouri I am not sure I understand: I read "Polyphaser white paper on amateur radio station grounding and protection"

I clearly read in the above threads, and see in the white paper, that she common ground bar in the shack is tied to BOTH an external ground AND the house a/c ground. In an early post, it was mentioned running a large ground wire from the ground bar in the bus.... but this is not in all posts...

Do I run a ground from the shack ground bus to the house common ground, AND run a ground to an independent ground rod outside (which seems to defeat ONE ground point giving me two paths to ground), or, do I run a ground from the bus to an extra ground rod, then loop from that ground to the farm common ground ?

I can put another ground rod 6' or so outside the shack. The nearest point to the outside farm grounding system is a ground rod about 12' away around a corner. This rod grounds some OUTDOOR equipment (the controls for the wind generator and the PV), and is tied in one direction by #2 bare copper buried 6' deep to the main service entry ground rod (12' rod) at the other end of the house, AND is buried 6' deep the other direction 140' to the base of the tower, where it bonds to 3, 8' ground rods AND the tower AND it radiates out in 3 directions 90' each leg (buried only 2' deep) to an 8' deep ground rod at each guy anchor (and it tied to the guy cables there as well).

This may be the same issues as my electric fence: 8000v pulsed high frequency. I needed 5, 8' ground rods on the North side of the barn (damp area) to get a good fence ground. I had always been strongly told ONLY ONE ground point per building, so I tied this ground array to the service entrance for the barn (which ties to the main power pole, where service goes to barn, house and well house). NOISE on EVERYTHING from the phone to the TV to the radios. I disconnected the fence ground from the service entrance to the barn, and all noise quit.

Thanks for guidance,

Robert
06-18-2017 03:10 PM
tatkinsh
Make it a single system.

Quote:
Originally Posted by Damonte View Post
The key with RF grounding isn't the absolute value of the ground, it's about bonding all the equipment to a common ground.

Do not confuse RF ground with electrical ground.
Conversely do not confuse an effective RF performance ground with adequate lightning and surge spike protection.

Read the more recent articles from QST magazine. Read the Polyphaser white paper on amateur radio station grounding and protection. Be willing to actually do the job rather than just "installing some extra copper and stuff." Check the lightning frequency for your area and make an intelligent and informed decision about what to install for lightning protection. I have worked with electricity my entire adult life as a radio system support installation and service technician, communications wireman, electrician, and a power production equipment installer. Even though I have been involved in literally dozens of radio site build outs I still look very carefully at every single radio installation that I am involved with.

Have a single entry point for all of the conductors that enter the radio station area and bond all of the grounds, including the AC power ground for the radio equipment, to that one entry point. If you cannot bring all metallic pathways for power, cable, and telephone in at that same place on the house then bond all of those Grounding Electrode Systems together into a single grounding system outside the building. Yes that may mean digging trenches half or even all the way around the building but if your metallic entry pathways are that spread out then that is what you will have to do.

When you bond all of the electrodes together don't miss the chance to make that system more effective by using conductors which have a cross sectional area which is at least as large as a Number 2 American Wire Gauge conductor and burying it at least 30 inches deep. If you resort to a back how or trencher go as deep as it will reach and drive additional electrodes through the bottom of the trench until there is only enough left to attach the bonding conductor to. The additional driven rod electrodes should be no closer to each other than twice their own length.

Once you put in Twenty or more feet of Number 2 or larger copper bonding conductor buried at least 30 inches deep and connected two or more rods driven through the bottom of the trench then you will have built the equivalent of a Ground Ring Electrode for a smaller building and only a Concrete Encased Electrode or a full Ufer Grounding grid in the building's floor and footing are likely to be more effective.

If you have to operate during lightning storms consider buying an isolation transformer large enough to run the equipment that you actually need to use during the storms. That allows you to create a new power system at your station with it's power source Grounding Electrode System collocated with your antenna lead ins and Station Grounding Electrode System.

You can rent electric demolition hammers with Ground Rod Cups to drive your ground rods in at most tool rental stores. You can also rent a miniature back hoe that can be pulled into position on the side of your house without tearing up everything in the yard.

I'm happy to answer questions if anyone has them.

--
TAtkinsH
01-28-2017 02:00 PM
MoKan Thanks RT,
I think that I'll cut a counterpoise for 80m and then cut that wire at each band and use power poles so that I can adjust the length to match. Kind of a pain but I don't plan to band hop a lot.
01-18-2017 10:09 PM
Rockwell Torrey It called for a length of wire, length was dependent on the frequency, ran it along the baseboard. The MFJ 931. They also make a combo ground/tuner, MFJ 934.
01-17-2017 04:34 PM
MoKan RT, do you recall what you ran for counterpoise?
01-17-2017 07:51 AM
Rockwell Torrey
Quote:
Originally Posted by MoKan View Post
I've been reading up on artificial grounding as an option.

Any experience or ideas about that?
Thanks
Mixed resulte. Lived in a second floor apartment back when, an MFJ artificial ground was the only viable option. Had to use low power, no more than 50 watts and I had good results.
01-17-2017 06:50 AM
MoKan I've been reading up on artificial grounding as an option.

Any experience or ideas about that?
Thanks
01-15-2017 10:38 PM
MoKan I own. I just have a good spot in this room that affords me a lot of what I need.

I'm actually operating out of it tonight using an MFJ 935B loop tuner. Not optimal, but it's actually working pretty good for contenental contacts.

No RF ground.

I'm pretty sure that once I get my vertical set up I'll do much better. But I think that RF grounding will be more of an issue. Thanks for any ideas!
01-15-2017 10:06 PM
Damonte @MoKan

Do you own your home? Is it a condo or an apartment?
01-15-2017 11:27 AM
MoKan I am wanting to set up my rig in an upstairs room. I will be using a ground mounted vertical. I am concerned about RF grounding but I would really like to use that room. What can I do?
12-22-2016 10:45 AM
William Warren
Quote:
Originally Posted by PSYOP Soldier View Post
... in fact, in a few minutes, i am going to hang off flag pole in front of home ...
I'd recommend using the flagpole as a vertical. You can hide both your ground system and your feedline underground, and a little decorative wooden or plastic fence will keep little Robbie F. Burns from getting too close.

William Warren
12-17-2016 08:54 AM
PSYOP Soldier Outpost...

funny you mention that cause oi got in my 4:1 unun which i plan to use to connect to neighbors gutter system.....

his pop was an operator and he is ok w my tinkering as long as i don't fry his stuff....
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