Advice on grounding an OTA antenna

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Old 12-29-17, 10:31 PM
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Advice on grounding an OTA antenna

Finally cutting the cord, but need advice on how to ground my new OTA antenna.

The only logical and secure place to install the antenna is on my chimney. Unfortunately, the existing coaxial service entrance and grounding rod are about 50 feet from this location. I donít know if such a coaxial length is too much for the antenna.

As an alternative solution, is it feasible to put a coaxial grounding block next to the antenna and run the grounding wire all the way down to the grounding rod (approximately 50 feet)? I would find another (much shorter) way for the coaxial line to enter the home.

Is there any safety concern with running a grounding wire across the roof or under vinyl siding?
What gauge wire should is best?

Unfortunately, I donít really have an elegant way to run any wire or cable from the antenna to the service panel/ grounding rod.
 
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Old 12-30-17, 05:19 AM
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I recommend grounding it with #6 bare copper wire to the ground rod. You may want to also install a coax ground block or intersystem bonding bridge and connect the coax to the ground wire as well.
 
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Old 12-30-17, 06:41 AM
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Method 1. Run a ground wire down to a (perhaps new) ground rod roughly or directly or as closely as possible below the antenna, running on the exterior of the house as much as possible. But you must (1a) also have or run a #6 wire from that rod to the existing ground rod for the panel (along the foundation on the outside as much as possible) (or to an existing similar #6 wire going to a ground rod or main panel neutral bus). Run the coax to the electronics via the shortest practical route.

Method 2. (uour suggestion) Because of requirement (1a) and because some experts say that all the ground rods for the building should be very close together (the second at least 6' from the first), called single point grounding) yes you could run the ground wire from the antenna (exteriorly as much as possible) to the existing ground rod. For example almost vertically down from the antenna as in method 1 but don't put a ground rod there. Continue along the foundation to the existing ground rod etc. Run the coax from the antenna to the electronics via the shortest practical route.

Each joint in the coax line puts a little loss in the signal path. A typical coax grounding block requires screwing the antenna coax (suitably fabricated to length) into the block and connecting the coax (suitably fabricated to length) to the first piece of electronics into that block also. I would, if possible, have a direct run from antenna to electronics running past the grounding block and carefully cut the plastic cover and attach a clamp around the exposed coax braided shield to connect to the grounding block.
 

Last edited by AllanJ; 12-30-17 at 07:12 AM.
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Old 12-30-17, 09:45 AM
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because some experts say that all the ground rods for the building should be very close together (the second at least 6' from the first), called single point grounding) yes you could run the ground wire from the antenna (exteriorly as much as possible) to the existing ground rod.
hmmm, I don't believe those experts. Only cost and labor make an installation of 20 ground rods all bonded and surrounding a home a bad idea. Optimally, you want as much conductor surface area in contact with the earth consistent with the risk at hand.

Saying all this, a single TV antenna on a chimney doesn't warrant heroics for grounding. I would (and do) method 1.
 
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Old 12-30-17, 06:38 PM
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some experts say that all the ground rods for the building should be very close together (the second at least 6' from the first), called single point grounding)
I think the single vs multi point grounding is more relevant in commercial settings where there are multiple paths to building ground (conduit, structural steel, ground wires, etc) and interactions with ground loops. These really aren't issues in a residential setting. As long as all your grounds (and metal) are bonded, you're good.
 
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Old 12-30-17, 08:45 PM
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Method 1. Run a ground wire down to a (perhaps new) ground rod roughly or directly or as closely as possible below the antenna, running on the exterior of the house as much as possible. But you must (1a) also have or run a #6 wire from that rod to the existing ground rod for the panel (along the foundation on the outside as much as possible) (or to an existing similar #6 wire going to a ground rod or main panel neutral bus). Run the coax to the electronics via the shortest practical route.

I'll probably implement this idea, but there is no way I can connect the new grounding rod to the old one. The run would be 60 feet minimum.
With a new grounding rod, the grounding wire from the antenna would only run about 20 feet.

And not to be cheap, but is it feasible to pull the three wires from 12/2 romex, strip and twist them together, put them back into the romex housing and use that as a ground wire? I'm a little hesitant to buy a 6 AWG wire which I'm sure is going to cost a lot.
 
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Old 12-30-17, 08:48 PM
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And what about tucking the grounding wire into vinyl siding? Is that discouraged?

I can leave the grounding wire on the outside of the house, but would like to conceal it as much as possible,
 
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Old 12-30-17, 08:56 PM
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And what about tucking the grounding wire into vinyl siding? Is that discouraged?
I'm curious about this as well. My lightning rod "wires" (mesh turned into a tube shape) are run behind vinyl siding (not my doing). I had to have the wiring for this old farmhouse inspected before the utility would connect power. The inspector caught a glimpse of one of these grounds behind the siding. He said "Whoa, what the *** is this?" then a few seconds later "oh, that's just for the lightning rods" and we proceeded with the inspection. Take that for what you will. We get lots of storms here in tornado alley.
 
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