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Old 2-Oct-2018, 8:29 PM   #1
Smityyone
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Antenna advice

I need advice on what type or types of antennas I should buy based on the attached TVFool chart. I've decided roof mounted is the way to go atop my single story home south of Omaha. Most of the stations I'd like to get are within 20 miles, but the towers are in different directions, and my home is surrounded on all four sides by tall trees.
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Old 2-Oct-2018, 9:12 PM   #2
jrgagne99
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It looks like your TVFool Report is missing some data (namely CBS KMTV and Fox KPTM). Rabbit ears says the major networks (all but Fox) can all be received from Omaha at around 330 deg:

CBS KMTV on Real 45 (virtual 3.1)
NBC WOWT 22 (6.1)
KETV 20 (7.1)
PBS KYNE 17 (26.1)

FOX KPTM 42 (43.1) is at 252-deg (repacking to Ch 26 in 2019).

These are all UHF and all fairly close and all fairly strong. I recommend a DB4e or equivalent 4-bay aimed at 290-deg or so. Get it as high as reasonably possible to avoid the trees. Start simple with short (50-ft), new RG-6 coax and one TV. Add complexity later.

More-complete advice may be obtained by specifying the precise stations you are after (with call letters) in a "must have", "nice to have", and "could live without" format.
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Old 3-Oct-2018, 2:03 AM   #3
Smityyone
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jrgagne99, thanks for the info. What does it mean Fox 42 is repacking to channel 26? Will I not be able to receive it after that? And I'll look into that DB4e antenna too.
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Old 3-Oct-2018, 11:46 AM   #4
jrgagne99
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In a nutshell, the "Repack" is an FCC plan to clear bandwidth in the higher TV channel numbers for more cell service. They held a reverse auction and some stations decided to get paid for moving to a lower channel number. Cell providers then bought up the newly free airspace. TV stations need to vacate their channels by 2020 I think, depending on their location.

Anyway, 26 is still UHF, so the DB4e (or any decent UHF antenna) should still get it.

Last edited by jrgagne99; 3-Oct-2018 at 11:48 AM.
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Old 3-Oct-2018, 3:41 PM   #5
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Let's keep this all in the same thread. Here is the post from the parallel thread you just opened:

Quote:
Originally Posted by Smityyone View Post
I'll likely order a BD4e antenna based on recommendations from here. I know getting the antenna as high as possible will give me the best results, but I'd prefer not to install it on my roof peak, instead wanting to use a J-mount (or https://www.youtube.com/watch?v=Uas1t68hW8E) attached to my fascia. My roof has a very shallow pitch, so I'd only be losing about 5 or 6 feet in height. What is the tallest mast I can attach to these mounts, what diameter pole, and where to buy? Although I would prefer not to, I could add two supporting braces if that would allow for an even taller mast. Where would I get these supporting braces if needed?
Depending on windiness, I wouldn't go much over 5 feet on an J-mount with a DB4e. Lots of places sell these as kits with the 1.5" or 2" mast and all necessary hardware. Solid Signal comes to mind, Antennas Direct sell them as well.
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Old 4-Oct-2018, 12:30 AM   #6
Smityyone
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Of course I won't know how good or bad my reception will be with a 5 or 6 foot mast and DB4e until I get them and hook everything up and test it. But remember I've got trees to deal with. If it turns out that I need to go higher, are "extensions" available to add to the height of my existing mast? I assume you'd recommend adding guy wires for additional support if that were the case, right?
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Old 4-Oct-2018, 12:54 AM   #7
Nascarken
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To go with a solid signal HDB91
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Old 4-Oct-2018, 2:55 PM   #8
Smityyone
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Where does the grounding wire attach?

I intend to ground my TV antenna wiring to my plumbing system, about 8 feet from where my distribution “panel” (actually a 4x4 sheet of plywood) is located. Here’s my intended wiring scheme; roof-mounted antenna, single RG6 wire comes through roof into attic. If a pre-amp is required, it would be powered in the attic. The RG6 continues straight down into the utility room located directly below, which is where my plumbing (main water line, meter, shut-off, water heater, etc.) is also located. There are already several grounding attachments fitted to the copper pipes located there. I intend to use one of those attachments to terminate my grounding wire. This utility room is also where I intend to branch the RG6 from a 4-way splitter/amp, then distributed to the four TVs. But where along this scheme does the grounding wire first attach? At the antenna itself? At the splitter in the utility room? The total length of RG6 from antenna to splitter is less than 20 feet.
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Old 4-Oct-2018, 3:02 PM   #9
rabbit73
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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 which will tend to discourage a strike, but the system will not survive a direct strike.

Cold water pipe is OK if no plastic pipe between attachment point and earth.





http://www.dbsinstall.com/diy/Grounding-2.asp
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Last edited by rabbit73; 4-Oct-2018 at 3:08 PM.
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Old 4-Oct-2018, 3:54 PM   #10
Smityyone
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I probably should have been more clear with my question. Where is the best place along the RG6 run that the grounding block should be placed? Anywhere between the antenna and the first junction? Before or after the pre-amp? I assume definitely before the splitter. Also, to use the electrical system and/or a grounding rod, the grounding wire run would need to be 5 times farther away than using the nearby plumbing system, which is already grounded and has several grounding attachments already in place.
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Old 4-Oct-2018, 4:36 PM   #11
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Quote:
Where is the best place along the RG6 run that the grounding block should be placed?
Electrical codes states "at or near the point of entry" to the structure.
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Old 5-Oct-2018, 2:49 AM   #12
Smityyone
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Where does the grounding wire attach?

The diagram provided by rabbit73 show both the coax cable and the antenna and/or antenna mast both being grounded. Do I need to ground the antenna and mast as well as the RG6 cable? My intention was to ground the RG6 cable only. Sounds like I'm beating a dead horse, but I'd rather do it right the first time.
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Old 5-Oct-2018, 1:31 PM   #13
jrgagne99
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You're supposed to ground both the mast and the coax shield. Both are accomplished with the bronze-colored grounding block that Rabbit posted. The grounding wire from the mast and a jumper to the copper stake go under the set screw.
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Old 5-Oct-2018, 1:39 PM   #14
rabbit73
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The NEC put out by the NFPA is only a suggested guideline, not a law.

I have posted it for your guidance, to be compete. I don't want you to be caught off guard and have you say: "Why didn't you tell me?" The local AHJ (Authority Having Jurisdiction), who is usually the electrical inspector, is free to decide how it should be done. His decision then becomes the local law and is binding on you and the local electricians.

The code is written in esoteric language, best understood by an electrical professional, which I'm not.

The code not only says that the mast and the coax shield should be grounded, but they should be connected with separate wires to the house electrical system ground.

The ground for the mast is to drain away any buildup of static charge to discourage a strike and to shunt any current to ground if a hot wire contacts the mast. The grounding block grounds the coax shield to help reject electrical interference and to shunt any voltage to ground if the shield becomes energized by defective electrical equipment connected to the coax.

The last reason is most important to me because I have had three close calls with electrical shock. The coax is connected to AC operated equipment. All AC operated equipment has leakage current, even when operating properly. If the equipment has a 3-wire power cord that is connected to a properly wired 3-wire outlet, any leakage current will be shunted to ground. If your equipment has a 2-wire power cord and becomes defective, you are at risk from electrical shock.

I bought a leakage current tester to check my equipment and any equipment that I was giving to other people.





Some of the dish installers use a piggy back-method of grounding. The coax between the antenna and the grounding block has an external grounding conductor of 17gauge copper clad steel that grounds the mast (or dish) and is connected to the grounding block. Then, there is only one 10 gauge wire from the grounding block to the house electrical system ground.
http://www.dbsinstall.com/diy/Grounding-2.asp

If the ground connections to the cold water pipe were done by electricians, that indicates to me they would have satisfied the local laws.

You get to decide how you want to do it.
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Last edited by rabbit73; 5-Oct-2018 at 2:01 PM.
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Old 5-Oct-2018, 1:53 PM   #15
jrgagne99
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Quote:
Originally Posted by Smityyone View Post
Of course I won't know how good or bad my reception will be with a 5 or 6 foot mast and DB4e until I get them and hook everything up and test it. But remember I've got trees to deal with. If it turns out that I need to go higher, are "extensions" available to add to the height of my existing mast? I assume you'd recommend adding guy wires for additional support if that were the case, right?
It sounds like you should consider using gable-end brackets and a mast located at the peak of your roof (like in the picture in Rabbit's grounding example) rather than a j-mount. This may let you go a little higher.
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Old 10-Oct-2018, 3:37 PM   #16
Smityyone
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Ideally that would be my preferred option, but unfortunately, my home doesn't have end gables. Even if I could gable-mount the antenna, although it would offer the shortest route to ground, it would provided the longest route for the RG6, adding no less than 35 additional feet.
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Old 10-Oct-2018, 11:49 PM   #17
jrgagne99
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An extra 35-feet of length is not big deal if it lets you put the antenna higher and shoot over the trees. It sounds like you stand to gain many dB in signal strength by going up, versus maybe a 1 dB loss over 35-feet, which would be moot if you are using a pre-amp.
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Old 11-Oct-2018, 12:05 AM   #18
Nascarken
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Keep the ground out side buy using a ground rod??
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