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Grounding The Antenna

post #1 of 27
Thread Starter 
Do I need to ground my old outdoor antenna on the roof? What about the antenna rotator I'm going to install? Where would I actually run a ground wire, and what would I ground it to? I have no idea where to start here.
post #2 of 27
Quote:
Originally Posted by mrwatkin View Post

Do I need to ground my old outdoor antenna on the roof? What about the antenna rotator I'm going to install? Where would I actually run a ground wire, and what would I ground it to? I have no idea where to start here.

in most of the USA it is building code that the antenna and mast/tripod be grounded. it is best practice as well.

the mast and tripod have a ground wire running to a grounding rod. the coax goes to a grounding block, this grounding block has a wire that also runs to that grounding rod. the antenna grounding rod is then connected to where your house electrical system is grounded (either a water service pipe or a grounding rod).
post #3 of 27
cold water pipe
post #4 of 27
Check local codes. CW pipes are against code in some areas.


DISCLAIMERS:
Coax enters house at grounding block.
NOT to scale.
Only shown to illustrate connections needed, not their locations.
YMMV.
post #5 of 27
The above illustration is not the best to show the desired installation. It only shows a specific case (where the antenna mast ground wire comes down near an external electrical meter) and is misleading.

It doesn't show the coax going into the house which is misleading. It shows the grounding block mounted high, it should be just before the coax enters the house (this is not shown) and near the ground. I understand that this illustration may show just grounding connections but it should be labeled as such and state that it is not to scale, if you take the diagram literally and to scale you will be mislead.

the antenna mast ground should go to a ground rod in the shortest distance possible, this could be your electric service ground rod but should be separate if not close. the antenna coax should be connected to this antenna mast ground rod. if the antenna mast ground rod is separate it needs to be connected to your house electrical grounding electrode (either a grounding rod or your metal water service pipe) with 6 AWG wire (in the USA). it is important to go to that grounding electrode or the connection between your fuse/breaker box and that grounding electrode and not just any grounded wire or metal plumbing.
post #6 of 27
Thread Starter 
Here is a picture of the side of my house:



Can anyone point out where I need to attach the wire?
I am looking at solidsignal for a ground wire long enough. I found this:

http://www.solidsignal.com/prod_disp...?prod=WRGND100

Is this good enough? How much should a ground wire cost me?
post #7 of 27
Quote:
Originally Posted by mrwatkin View Post

Can anyone point out where I need to attach the wire?

By the green arrow below would be good.

Use a ground clamp. If you can't get the clamp around the conduit, use a ground strap like this one.
post #8 of 27
There is a little corner clamp made to let you connect your ground wire directly to the box that the meter is in. They cost under $3.
post #9 of 27
And another alternative:
If everything there (power, telephone, etc.) is grounded to a ground rod directly below, ground your antenna to the ground rod.
post #10 of 27
Thread Starter 
What about the Copper Ground Wire #10 Gauge - 100 Ft from the link I sent at solidsignal? Is it good enough to be used as the grounding wire on my antenna/mast. I didn't know the coax needs grounding, so I'll try grounding the 4-way splitter before any bad current goes into the house.
post #11 of 27
Yes, the coax should be grounded too, using a grounding block the ground screw on a splitter, if available.
post #12 of 27
Quote:
What about the Copper Ground Wire #10 Gauge - 100 Ft from the link I sent at solidsignal?

Don't you have a home depot or other electrical supplier near by?
post #13 of 27
Home Depot doesn't carry 10 gauge solid insulated, but the mast ground doesn't have to be insulated. The coax outer conductor ground must be insulated, but the code doesn't specify its gauge. I know of some cable companies that use 12 gauge solid insulated copper to ground their coax outer conductors, and you should be able to buy that by the foot at Home Depot or Loews.
post #14 of 27
Quote:
Home Depot doesn't carry 10 gauge solid insulated,

The ones around here do. It doesn't need to be solid or insulated anyway.
post #15 of 27
Quote:
Originally Posted by duvetyne View Post

The ones around here do. It doesn't need to be solid or insulated anyway.

The mast ground doesn't have to be solid or insulated. It just needs to be 10 gauge copper, 8 gauge aluminum or 17 gauge copper clad steel.

I haven't bought a copy of the Model NEC since 2002, but as recently as then, the coax outer conductor had to be grounded with a solid, insulated copper wire approximately equal in current carrying capability to the outer conductor, which is ridiculous since, at high frequencies, the electrons travel on the skin and the current carrying capability of the outer conductor is roughly equal to that of a solid copper wire that size.

One electrical inspector with nothing better to do actually issued me a low voltage license and required the coax outer conductor ground to be 6 gauge. He said that while it didn't equal the current carrying capability of the outer conductor, there was no point in making it any larger since the code explicitly said I could use 6 gauge from my auxilliary ground rod to the system ground electrode, so there was no benefit to making the coax ground larger than that.
post #16 of 27
I am finishing 'properly' grounding my antenna this weekend. All I have to do is route a #6 cable from the ground rod to the electrical service ground (house). In my location, there is a a seperation of about 10 feet between a new ground rod I buried last weekend and the house electrical service. Is it permissable to dig a trench and bury the ground cable between the ground rod and the electrical service ground? I wanted to do so for asthetic reasons.
post #17 of 27
I believe you can put the ground wire inside that gray electrical PVC they sell at Hardware stores and bury that. Not sure about burying bare wire without some coating. It might deteriorate.
post #18 of 27
Quote:
Originally Posted by mrwatkin View Post

Here is a picture of the side of my house:



Can anyone point out where I need to attach the wire?
I am looking at solidsignal for a ground wire long enough. I found this:

http://www.solidsignal.com/prod_disp...?prod=WRGND100

Is this good enough? How much should a ground wire cost me?

Just to satisfy my curiosity, where is that splitter in the pic grounded? It has that orange tag on it, but it looks like it goes under the house. Your ground point may be a cold water pipe if that is so.
post #19 of 27
Quote:
Originally Posted by Bozzmonster View Post

Is it permissable to dig a trench and bury the ground cable between the ground rod and the electrical service ground?

Yes.
post #20 of 27
Quote:
Originally Posted by Bozzmonster View Post

In my location, there is a a seperation of about 10 feet between a new ground rod I buried last weekend and the house electrical service. Is it permissable to dig a trench and bury the ground cable between the ground rod and the electrical service ground? I wanted to do so for asthetic reasons.

have it down 1.5 to 2 feet to keep it from being damaged. also not a bad idea to put some protection around it, like mentioned laying a straight length of PVC conduit and running the wire through, is good protection; then just bring up bare at the grounding rods.
post #21 of 27
Much thanks. I feel much more secure both legally and safety-wise with a properly grounded antenna. Another question... can a properly grounded antenna assist in reception? I was thinking in terms of drawing away locally generated static via unshielded autos, neighbors kitchen equipment, etc that may interfere with reception. In particular, I have two local stations moving DTV to VHF hi in June. VHF is a bit more sensitive to electrical impulse interference than UHF.
post #22 of 27
Quote:
Originally Posted by Bozzmonster View Post

Another question... can a properly grounded antenna assist in reception? I was thinking in terms of drawing away locally generated static via unshielded autos, neighbors kitchen equipment, etc that may interfere with reception.

That noise should be rejected by a good tuner.

With grounding your antenna the coax shield is connected to the earth. If the center wire of the coax goes through a lightning arrestor then it will take high voltages to the earth, noise and signals will go to the tuner.
post #23 of 27
Quote:
Originally Posted by johnpost View Post

That noise should be rejected by a good tuner.

Not necessarily. I have had VHF (both hi & lo band) impulse noise problems on many different tuners. Preamps seem to make the problem worse, but where I live, a preamp is necessary for multiple splits.

I currently have DTV VHFs on chs 9 & 10. In the previous market I lived in, there were DTV VHFs on 5 & 12. All have had impulse noise problems, but ch 5 (of course) was the worst.

The farther away you are from the transmitters, the more likely this may be a problem.
post #24 of 27
Thread Starter 
I've located the cold water pipe in the basement of my house. There is a grounding clamp already there, but the ground wire was clipped. I have no idea why, but maybe someone was trying to prevent something bad from happening. Won't grounding on the water pipe electrify the water when someone is in the shower when lightening hits? It seems kinda dangerous and I guess clamping to the soft padding of the electric service meter would make it a little safer, right?

Can someone give me a little more guidance here?
post #25 of 27
Quote:
Originally Posted by mrwatkin View Post

I've located the cold water pipe in the basement of my house. There is a grounding clamp already there, but the ground wire was clipped. I have no idea why, but maybe someone was trying to prevent something bad from happening. Won't grounding on the water pipe electrify the water when someone is in the shower when lightening hits? It seems kinda dangerous and I guess clamping to the soft padding of the electric service meter would make it a little safer, right?

Can someone give me a little more guidance here?

house electrical systems on city water often used the water service entrance pipe (on the incoming side of the water meter if it was metal) as a grounding electrode.

you metallic plumbing system should be grounded for safety and to be to building code in most places in the USA.

if a new grounding electrode (a grounding rod) was put in then the water service pipe would no longer be the grounding electrode but the metal plumbing on both sides of the water meter should still be connected to grounding system.

you need to investigate further. was this clamp used to ground a previous antenna and that was disconnected? is your metal plumbing system grounded and connected to your house electrical system ground? do you have an electrical system ground? if you don't know enough about this and what is required then you need to get someone who knows, hire an electrician or have someone that knows electrical help you out. Not having an electrical grounding system could be fatal or lead to fire, your description isn't such that i could guess if it was safe or not. you need to give more details.
post #26 of 27
I'd also offer that if you run a mast the whole way to the ground, that counts as a grounded mast. This also has the added benefit if you mount the mast to the outside wall of the house of being pretty frakkin strong. You'd still need to ground the antenna separately.
post #27 of 27
Quote:


I'd also offer that if you run a mast the whole way to the ground, that counts as a grounded mast.

according to the code in most places in the USA it is grounded if a grounding electrode goes 8 feet into the earth. if your bare metal mast went 8 feet into the earth it would be grounded. if your mast went into a concrete base that alone would not be grounding according to code I would think.
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