Where to run the grounding wire and coax

jim8888

I'm new to antennas this will be my first one so I'm asking around everywhere that I can and trying to find out how to do things correctly!

I want to use a chimney mount to mount my antenna.

The chimney is NEVER used to burn anything in it.

I have a pretty huge hole right behind my air conditioner that the guys that put it in drilled I was going to run the coax cable through there.

The shortest distance to the ground from my chimney is over the gutter though.

This link shows the back of my house

http://snack.freehomepage.com/

I just wanted to see what people with a lot of experience thought about how to run the coax cable and grounding wire on a house like mine?

Thanks

Jim

JB Antennaman

Looks like you have some building issues. The one side of the house is 12 inches higher than the other side. Do you happen to live in Pennsylvania - over some mine subsidance?

It does not look like a chimney mount would work in your situation.

Your chimney does not look tall enough to me to support the wind sheer of a television antenna, mast pole etc. Me personally, I would not use a chimney mount on any chimney less then 4 feet tall!

The proper way to ground your antenna is to use a piece of 8 gauge solid strand wire. It does not matter if it is insulated or not.

What does matter is that you have no sharp bends in the wire. Anything more than a 45* angle and chances are, the lightning will jump off the wire and into the structure.

Yes - I can see your point where you are concerned about running it over the gutter or near the downspout. Might I suggest you use 2 pieces of 12 gauge copper insulated wire and running them down the roof and down the wall and onto a copper ground stake pounded at least 3 feet into the ground and bonded to the stake with a regular copper / brass ground clamp.

You also want to put a ground block terminal outside of the house for the RG 6 and run a second piece of 12 or 14 gauge wire to the ground stake to try to minimize the amount of lightning coming into the house through the RG 6.

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jim8888

Thanks JB Antennaman

I think the house just looks that way on the photo...it's pretty hilly here.

I looked at some diagrams online that show the grounding rod and the ground block and I understand that part.

I'm not sure what you mean about using two pieces of wire?

I couldn't figure out how to get the wire from the antenna to the ground without making a bend in the wire at some point.

Jim

aka.Hooper

Hello jim8888,
As much as I hate to admit it, I have to agree with JB to some degree.

With the chimney in the middle of the roof like it is, I would say wrapping the ground wire around the gutter/fascia with tight bends is not a good idea.

As far as the size of the chimney, that really depends on how big an antenna & how tall a mast you're intending...

I think it might it be better to use a wall or gable mount on one end of the house. Where is your electric service entrance? If to the right in your photo is the garage, and that is where the service panel is, then that end would be a good location. If the elec comes in above ground keep in mind to keep the antenna 2x the mast height away from the electric. If it comes in underground then you can go right at the peak.

You should be using #8 solid ground wire, as JB states, and it should be connected to the main ground rod for your electric service. You want to ground the mast itself, and also use a grounding block for the cable as close to the entrance to the house as possible.

Run the cable to a grounding block, and bring the cable into the attic & split & drop from there. Run the ground wire down the side of the house, making a sweeping bend and come across and connect to the main ground rod as JB suggests.

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JB Antennaman

Several missed points.

First, if you cannot use one strand of 8 gauge wire, for what ever reason, you can replace one 8 gauge wire with two wires of a lesser size with a equal or greater combined size.

You wouldn't want to use two 16 gauge wires for a ground for obvious reasons, mainly that lightning is millions of volts and would burn right through the wire before it ever hit the ground.

Second is the fact that you do not want to make any sharp bends in the wire and you do not want to attach it to the side of your house - like you would your coax wire.

You want the wire to be bonded to the antenna mast and to the ground and that is it.

Third, you would want the ground to NOT be connected to the main ground for the power source for your house.

The main ground for your home's electrical service is not a ground for your antenna. Electricity has a tendency to travel back into the ground - into the electronics and appliances in your home and will burn everything out faster than you could ever imagine.

Furthermore, you want your antenna as far away from the electric lines and the drop coming into the house as possible.

If you read all the posts from people who live in Florida and comes on here for advice on how to improve their VHF signals, their main complaint is the noise that disturbs the signal - when they have a lightning storm, when they use a electric appliance, when they have electric consuming devices like a electric fence near their property.

By hooking your antenna system up to the electric ground, you are making a direct connection between the television antenna and the electric device - you are trying to get away from.

Can you see my point?

A ground rod is a very cheap part of the equation, and even if you have $50 into the whole set up, is still cheaper than replacing the blower motor on your gas furnace, the computers in your home, your refrigerator, your microwave oven etc..

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IDRick

The proper way to ground an antenna is discussed here (scroll down): http://www.hdtvprimer.com/ANTENNAS/basics.html JB is advocating a different grounding approach than the NEC. Building inspectors will be checking to see if you meet NEC requirements not JB's requirements....

HTH,

Rick

JB Antennaman

Not to flame anyone here, but building inspectors only comes to your house when you pay them to, or when a insurance company requests them to.

The NEC has nothing to do with antenna installations - other than if it is required by code for new home construction.

Since a Antenna carries no real power - electricity, there is no real code to go by, only what experience tells us works or doesn't work.

People too cheap or unwilling to spend money on a second ground stake - usually get's what they paid for in the long run.

I live in a company town where all the houses are the same and most all the houses are between 100 and 125 years old and none of the houses that I know of had burned down due to a lightning strike.

Most of the houses had never been hit with lightning either.

One of the reasons for that was because the town was surrounded by Coke ovens. The pollution the Coke Ovens produced, killed all the surrounding vegetation. So there were no trees in my town until about 1950 - 10 years after the coal mine and coke ovens were shut down.

However, my grandfather lived up at the end of the town, on a dead end road and at the end of the run of power lines and there was several large, tall trees in his neighborhood and his house was struck repeatedly by lighting. Maybe as many as 10 times. One time it even blew the chimney clean off the main roof and blew a 6' x 8' hole in the roof.

My grandparents had several televisions that were repeatedly struck by lightning and my dad even ran a steel pipe from the top of the roof to the ground and bonded a ground wire to the mast and could not keep lightning from striking the antenna or television.

My experience with lightning comes from years of experience and not just hearsay evidence.

I would not want to see anyone live though a ordeal of lightning striking their home and wiping out their television and every electrical appliance in the home.

One of my aunt's lived on the other side of the duplex house my grandparents lived in and she would hide under the bed when there was a electrical storm, she was terrorfied of lightning.

__________________
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JB Antennaman

Here is a link from Denny's Antenna Service.

No where in their link does it say that you should attach your ground wire to the main ground for your home.

I do not understand why people are so persistent in trying to improperly connect a ground to a television antenna.

http://www.dennysantennaservice.com/1171010.html

You can also look at the Tower Talk forums - for the Single Point grounding question.

http://lists.contesting.com/pipermai...er/thread.html

__________________
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IDRick

Denny ignores the NEC on his website. That is an error on his part. If you going to give advice, you should advise according to the NEC.

IDRick

LOL! You really need to check things out a bit more before posting JB. There are many people that drive multiple ground rods to interconnect the antenna ground and the house ground. Too cheap is just laughable!

It is not uncommon for a home buyer to request a building inspection. Failure to meet NEC code can result in loss of a sale or require correcting the ground immediately to complete a sale.

jim8888

Thanks aka.Hooper JB Antennaman and ID Rick

There is a lot more to the mounting and wiring of an antenna than I first thought there would be.

Thanks so much for all the links and info. It seems there is different ways that you are supposed to ground an antenna depending on what source that you go to.

One other option that at first I just overlooked is putting an antenna in my attic.

I have a big attic that is empty that could fit a pretty big antenna.

I don't know if you can tell or not by looking at my house if that would be a bad idea or not?

Those are asphalt shingles and it's just wood under them.

Also you don't need to ground an antenna if it's in the attic right?

Jim

IDRick

Jim,

Can you post a www.tvfool.com report for your location? An attic mount may be feasible (generally work best if towers are less than 30 miles away). According to the NEC, an attic mounted antenna is considered an indoor antenna and does not require special grounding. I would make sure that I used surge protectors at your tvs though...

aka.Hooper

And this is where the NEC comes in. If they (the insurance co) find you have things wired not to code, you're in a world of $#%&!

Here's what you want to remember about a ground - it is intended to be the path of least resistance to ground. This is where electricity wants to go - TO GROUND. And it will always take the shortest path - TO GROUND!

I'm sorry I went out tonight, bear with me...

What I'm saying is, if you have your antenna cable connected to a grounding block, and if this grounding block has a better path to ground than does the ground thru your electronic equipment, and your house wiring (say you did a better job, and went a little deeper, hit moister soil - whatever.) then you can see a potential between the grounds.

If you connect the grounds together then they have the same potential, and there is no reason for the current to take either path - because they're all connected it will just take the shortest/best path.

Multiple ground rods that are tied together are all at the same potential, and will essentially act as a single ground rod - because they're all connected.

I know, not my best moment!


As Rick says, post your exact address TVFool report so a determination can be made as to whether or not an attic install is feasible. (Run TVFool and post a link to it - your address will not show, so your privacy is protected.)

LMAO!

__________________
Some details on my DIY antenna builds:
http://mysite.verizon.net/res11d41p/
Some tips for newbies posting to the forum for the first time:
http://www.highdefforum.com/local-hd...ng-advice.html

jim8888

Thanks IDRick and aka.Hooper

Thanks so much for helping me out guys.

I see what you mean about taking the shortest path to ground.

After reading through the info in this thread I thought it might be a good idea to look into the attic as a possible place to install the antenna. That way I do not have to worry about the grounding and coax and wind storms.

Here is my tv fool result for 23 feet that I had saved it might be about 8-10 feet lower if I put it in the attic.

http://www.tvfool.com/?option=com_wr...8ecd80a512e1ec

Jim

IDRick

Jim,

Thanks for posting your tvfool results. There are no guarantees but an attic install appears feasible to me. Your locals are located in a tight band around 156 to 167 degrees (compass heading) and most have very high signal strengths. ABC will be your greatest challenge. It has the lowest NM and is a two edge signal. I would spend my time optimizing signal strength on ABC when evaluating alternative mount locations in the attic.

Are there many trees in your neighborhood? In particular, are there trees in the south/southeast direction from your home. If there are many trees, you may lose ABC since you'll take a 4 to 6 dB hit with an attic install as well as a hit going through nearby trees. Evergreens are worse than deciduous trees.

HTH,

Rick