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Old 18-Jun-2016, 9:23 PM   #1
Maykinit
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Antenna Recommendation please?

I am looking for an antenna recommendation among other questions I have but I'll start there. I am hoping you'll be so good as to have a look and comment? My install will be on the roof making use of a Direct TV mount for my install. The roof of the house is approximately 20 feet off the ground and I intend to add another 8 feet with a chain link fence top rail added to that mount.

http://www.tvfool.com/?option=com_wr...e2cb7aa1301b6c

Thanks so much,

-M
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Old 18-Jun-2016, 9:27 PM   #2
Maykinit
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Sorry...

My House Report for antennas:
http://www.tvfool.com/?option=com_wr...e2cb7aa1301b6c
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Old 19-Jun-2016, 1:00 AM   #3
rabbit73
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Welcome to the forum, Maykinit:

It looks like you got approved. Many people have waited for weeks. Some, like Bobsgarage, never were approved and had to join another forum.

Thanks for the signal report. There are a few problems that have to be dealt with and might require some experimentation. I am not able to offer a guarantee.

The first thing that I see is that WZME is so strong that it might overload your tuner if you aim an antenna at it. Since you are so close to the transmitter, the signal might not be as strong as indicated if the strongest part of the beam is well above your location. You will not be able to use a preamp if you want some other signals that are a lot weaker because the preamp will be overloaded.

You will need an antenna that has a good front to back ratio aimed NNE to help reject WZME coming from the rear. If that doesn't work, you will need a custom filter to attenuate WZME on real channel 42.

The antenna that I suggest is the Antennas Direct DB4e. It is a UHF antenna, but might be able to pick up WTNH ABC on real channel 10 that is very strong. If not, add the VHF dipole kit.

Some of your important channels are 2Edge because of terrain interference and need the extra gain of the DB4e. If you click on the callsign in your report you can see the terrain profile. The transmitter is on the left and your location is on the right.

WVIT NBC
http://www.tvfool.com/?option=com_wr...dALLTV%26n%3d5

WFSB CBS
http://www.tvfool.com/?option=com_wr...dALLTV%26n%3d7

If you add a mast to the Direct TV mount, it will need braces or guys unless the mount already has diagonal braces.

If the antenna is outside, the coax shield should be grounded with a grounding block that is connected to the house electrical system ground with 10 gauge copper wire for electrical safety and to reject interference. For further compliance with the electrical code (NEC), the mast should also be grounded in a similar manner to drain any buildup of static charge, but the system will not survive a direct strike.

I made reject interference in bold type to keep WZME from getting directly into your TV cabinet.



I hope there aren't too many trees in the signal path; trees kill TV signals.
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Last edited by rabbit73; 19-Jun-2016 at 2:01 AM.
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Old 19-Jun-2016, 12:42 PM   #4
Maykinit
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Question Ground

Excellent! Thanks for that. Antenna is now on order! The house ground is on the opposite side of the house. It would be one helluva run of #10 Wire. If I sink another grounding rod closer to the location of the antenna, do I accomplish the same? May be a stupid question but I have to ask.
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Old 19-Jun-2016, 2:31 PM   #5
Maykinit
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Quote:
Originally Posted by Maykinit View Post
Excellent! Thanks for that. Antenna is now on order! The house ground is on the opposite side of the house. It would be one helluva run of #10 Wire. If I sink another grounding rod closer to the location of the antenna, do I accomplish the same? May be a stupid question but I have to ask.
Uhh, just weighing the pros and cons. Reading further I don't think the second grounding rod is a viable option short of connecting that second rod to the house's main ground.
Is this an alternative? The distance from the antenna mast to the house ground is roughly 100 feet. That implies 200 feet of solid copper core #10 wire assuming two separate runs for coax and mast.
Can I... ground the antenna via a ground included coax wire run to a cold water pipe and do one run of #10 copper core wire to the house ground?
I would like to tackle this today and am hoping I get a prompt response here. Thanks so much for the expertise here.
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Old 19-Jun-2016, 2:43 PM   #6
Maykinit
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Would bare copper wire be appropriate for the ground?
http://www.lowes.com/pd/10-Gauge-Sol...e-Foot/4294403
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Old 19-Jun-2016, 5:28 PM   #7
rabbit73
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Quote:
May be a stupid question but I have to ask.
Not a stupid question; very logical. As you found out, the code requires a 6 gauge copper wire between the ground rod and the house electrical system ground to eliminate any difference of potential; verrrry expensive.

The code is written for electrical professionals, and is difficult for the rest of us to understand. And it changes every few years. And the local inspector (AHJ, Authority Having Jurisdiction) has the final say, if you dare getting him involved.

Every location is unique; all you can do is the best you can. Many people put an antenna up without any grounding, but I think you should at least ground the coax shield to reject interference and for personal electrical safety. The coax is connected to AC operated equipment that has leakage current even when operating properly. I have had three close calls with electrical shock, so I'm probably more cautious than most.

CECB Leakage Current, post #1022
Getting A/C voltage on converter box's antenna input !
http://www.digitalhome.ca/forum/81-o...ml#post1457594
Equipment Leakage Current, post #1025
http://www.digitalhome.ca/forum/81-o...ml#post1457668

In our apartment, the electrical panel ground wire is connected to the copper water pipe, so I use that pipe for my coax ground. Recent construction now uses some plastic pipes, so you need to check if your cold water pipe is really grounded.

If your cold water pipe is also used as a house electrical system ground, you can connect your coax grounding block wire there. Do not disconnect your house electrical system ground, even for a moment, when connecting your ground wire.

So, to me, the coax ground is the most important. The code also requires a separate ground wire for the mast, which would be difficult for you to do. Dish installers use the "piggy back" method and run a wire from the dish mount to the grounding block; the grounding wire from the grounding block to the house electrical system ground does double duty.

Quote:
piggy-back method
There is an alternate method used by dish installers, called the "piggy-back" method, but it doesn't meet code. It uses coax that has an attached 17 gauge copper clad steel messenger wire. That coax runs from the antenna to the grounding block, with the grounding block connected to the house electrical system ground with 10 gauge copper wire. The steel wire runs from the mast to the grounding block.
Satellite System Grounding
Part 2 - NEC Overview
Presented by Todd Humphrey

http://www.dbsinstall.com/diy/Grounding-2.asp

Todd Humphrey doesn't speak for the NFPA that publishes the NEC code, but he has some ideas that are helpful. The local electrical inspector (AHJ, authority having jurisdiction) has the final say if you are willing to get him involved. Some inspectors are more friendly than others; a local electrician could tell you.

Are there any ground connections left from the dish installation?
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Last edited by rabbit73; 19-Jun-2016 at 5:57 PM.
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Old 19-Jun-2016, 5:30 PM   #8
rabbit73
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Quote:
Originally Posted by Maykinit View Post
Would bare copper wire be appropriate for the ground?
http://www.lowes.com/pd/10-Gauge-Sol...e-Foot/4294403
That would be suitable; it can be bare or insulated.

Attached Images
File Type: jpg grounding block2.jpg (31.9 KB, 6184 views)
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Last edited by rabbit73; 19-Jun-2016 at 5:35 PM.
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Old 20-Jun-2016, 12:44 PM   #9
Maykinit
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RE: Ground

Rabbit... thanks so much. My antenna arrives today. Amazon prime is amazing! So another install question. Not to beat this to death but... I will be coming down the mast with my coax and taking the most direct route I can to the main television in the house and into my new Tivo OTA. Another ground question if you don't mind and if you've already covered it, please forgive me. I will use a grounding block on the coax and run the ground to the house ground which is approximately 100 feet away. The question I am left with is grounding the mast itself. I'm trying to understand why the code calls out the need for a second ground wire run. Why can't the same wire be used to ground both the mast and the coax? The cheapest solid core wire I've found is non insulated. My first choice would be to run both wires the same path to the house ground. And having said that I find myself wondering if they are not insulated why the need for the second run at all when they would be in contact with each other were I to run two wires. Help me understand please? As an aside, on my way to work this morning I found myself looking for antennas on house roofs and even when looking for them found none! If only more people knew what they were missing. Having said that I know I am fortunate to have the line of sight that I do.
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Old 20-Jun-2016, 2:03 PM   #10
ADTech
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Quote:
I'm trying to understand why the code calls out the need for a second ground wire run
It doesn't say that two grounding wires are needed. It simply says both the mast and the grounding block must be grounded. A reasonable interpretation of the code's lack of detail would be that a continuous daisy chain connection would meet both the letter and the intent of the electrical code. Of course, the AHJ, if any, has the final say and they are not obligated to be reasonable.

NEC 810.21 (I) (2014 version) Specifically states that "Common Ground. A single bonding conductor or grounding electrode conductor shall be permitted for both protective and operating purposes."

BTW, do not confuse the antenna system's grounding for a lightning protection system, that's a different animal completely that has its own set of rules.
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Last edited by ADTech; 20-Jun-2016 at 2:12 PM.
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Old 20-Jun-2016, 2:13 PM   #11
Maykinit
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Would I be grounding both mast and coax properly if I came off the mast with #10 ground wire and joined it to the coax ground on the grounding block? The grounding block then grounded to the house ground via #10 solid core wire...




Thank You
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Old 20-Jun-2016, 2:17 PM   #12
rabbit73
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I understand your confusion. I'm not an electrician, and the NEC requirements are so convoluted and full of references to other sections that I have trouble with it. You can go to your library reference shelves and read section 810 of the NFPA National Electrical CodeŽ to see for yourself.

Why they want separate grounding wires for the mast and the grounding block is a mystery to me, but that is the way the code is written. My guess is so that there are separate paths to drain any buildup of static charge to discourage a strike, but your system will not survive a direct strike.

Even dish installers connect the mast (or mount) grounding wire to the grounding block.

My concern is for personal electrical safety, which is why I want the coax grounded.

You could hire a local electrician to help you. He would know the local requirements in your area, if you want to adhere to the code.
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Old 20-Jun-2016, 2:27 PM   #13
rabbit73
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Quote:
Would I be grounding both mast and coax properly if I came off the mast with #10 ground wire and joined it to the coax ground on the grounding block? The grounding block then grounded to the house ground via #10 solid core wire...
I think you are covered with that method, but as ADTech stated, the local AHJ might say NOT. Electricians in my area say that some inspectors (AHJs) can be arbitrary and unreasonable, but their interpretation is the law and must be followed, or the work will not be approved.
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