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Old 1-Nov-2018, 4:36 PM   #1
athiktos
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Grounding Question

I live in a 50-year old house that has an existing antenna tower outside. I have used my DB4e antenna inside and would like to install it outside, on the tower with another VHF antenna, for better reception but I understand proper grounding is very important.

I've been reading as much as I can and see that most recommend you ground to your home's electrical service ground. This is where my question comes in...

My home's ground is in the basement and it goes directly from my breaker panel and attaches to the water line coming into the house through the basement wall. I've had a few grounding issues at the house and have someone coming by to take a look at it.

After speaking with a few electricians I know, they recommend I ground my antenna/tower to a ground rod instead of the house ground on the water line. Good idea, bad idea? I really don't want to put the house at risk and would appreciate the feedback.

For clarification: I will be installing two separate antennas (DB4e and MCM-2476) on a tower (not directly on the house). The past owners dug a pvc line underground and into the basement wall from the bottom of the tower for the coax feed; I figured I would use that instead of drilling through the side of the house. Given the information, I planned on mounting the two antennas on the tower, joining them with a combiner, grounding them to a ground rod after the combiner (if that's OK), grounding the tower to the same ground rod, then pulling the coax line in after that.

Also, would it be wise to attach my grounding blocks to the antenna tower since it is about 5ft away from the house? Feel free to pick these ideas apart. I appreciate the info.

Last edited by athiktos; 1-Nov-2018 at 8:10 PM.
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Old 1-Nov-2018, 8:08 PM   #2
rabbit73
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Grounding your mast and the coax shield to a separate ground rod does not meet the code requirements of the NEC unless the ground rod is connected (bonded) to the house ground with 6 gauge copper wire.



However, the code is only a suggestion. The local AHJ (authority having jurisdiction), who is usually the electrical inspector, has the final say. His interpretation of the code becomes the local law, and is binding on you and the local electricians.

The purpose of bonding the ground rod to the house ground is to eliminate any difference in potential between the two for electrical safety.

I'm not an electrician, but my personal opinion is that if the cold water pipe meets the local law for the house electrical service, it should be suitable for your antenna system.

But, it's your antenna system and your choice.

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.



Another viewpoint:

http://www.reeve.com/Documents/Artic...quirements.pdf

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

The latest device to connect other services to the house ground is the IBTB. It has a lay-in connection for the house ground wire so that it is not necessary to disconnect the house ground to make a connection. Disconnecting the house ground, even for a moment, isn't safe. In the past, a split bolt has been used to connect to the house ground wire.









Based on my personal experience, grounding the coax shield to the house ground with a grounding block is the most important, because I have had three close calls with electrical shock.

The coax is connected to AC operated equipment. If that equipment becomes defective, you can be exposed to shock from leakage current if the coax shield isn't grounded.

see also

http://www.hdtvprimer.com/antennas/basics.html

Scroll down to Grounding Outdoor Antennas for pros and cons
Attached Images
File Type: jpg Separate Ground Rod_1.jpg (99.0 KB, 174 views)
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Last edited by rabbit73; 1-Nov-2018 at 9:03 PM.
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Old 1-Nov-2018, 9:48 PM   #3
athiktos
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Thanks. I'll read some more with the links you provided. I saw the back-and-fourth between you and another forum member here: http://forum.tvfool.com/showthread.php?t=16526

So, a ground rod ALONE, basically will not suffice? I have also seen people do this with their towers:
http://4.bp.blogspot.com/_Ri8FW252Vh...r%20ground.gif
http://wf0gm.fpage.com/images/Tower/Base.jpg

But I assume that something like this would still have to be connected to the house ground to pass NEC?

So what is the purpose of a separate ground rod if you still have to bond it to the house ground? I know you said you bond it to eliminate any difference in potential between the two for electrical safety...but if a rod alone doesn't pass code, why have one?

If I were to connect the antenna to the house ground, should I connect it directly to the water line, or should I connect it directly to the breaker panel in the basement that is connected to the water line?

Sorry if I am asking stupid questions. It's my first outdoor install and I would prefer to ask more questions than less.
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Old 1-Nov-2018, 11:38 PM   #4
rabbit73
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Quote:
Originally Posted by athiktos View Post
Thanks. I'll read some more with the links you provided. I saw the back-and-fourth between you and another forum member here: http://forum.tvfool.com/showthread.php?t=16526
Yeah, I didn't add any more comments. There are many ways it can be done, but I didn't want to get in an argument about the "right" way. The right way is the way that the electrical inspector says it should be done.

Quote:
So, a ground rod ALONE, basically will not suffice? I have also seen people do this with their towers:
http://4.bp.blogspot.com/_Ri8FW252Vh...r%20ground.gif
http://wf0gm.fpage.com/images/Tower/Base.jpg

But I assume that something like this would still have to be connected to the house ground to pass NEC?

So what is the purpose of a separate ground rod if you still have to bond it to the house ground? I know you said you bond it to eliminate any difference in potential between the two for electrical safety...but if a rod alone doesn't pass code, why have one?
A ground rod is sufficient for the tower, but there is also a feed line. When a tower is involved, the setup is more controversial, which is why I added the link to a pdf:
http://www.reeve.com/Documents/Artic...quirements.pdf

Quote:
If I were to connect the antenna to the house ground, should I connect it directly to the water line, or should I connect it directly to the breaker panel in the basement that is connected to the water line?
If the water pipe is OK for the inspector for the house ground, I would think it would be OK for the antenna system too. Do not connect your antenna system ground to the electrical panel, that is definitely wrong.

Quote:
Sorry if I am asking stupid questions. It's my first outdoor install and I would prefer to ask more questions than less.
Your questions aren't stupid. Grounding has a lot of gray areas; I'm not confident that I can give you precisely correct answers about your particular area.
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Last edited by rabbit73; 2-Nov-2018 at 12:16 PM.
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Old 2-Nov-2018, 3:32 PM   #5
athiktos
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Thanks for the help. One, non-grounding, question.

As mentioned earlier, I'm combining the two antennas (DB4e and MCM-2476). I've always had an RCA preamp. I'm sure it will not hold up as well outside as say the Channel Master 7777 would, but I'm starting with that and the RCA has a separate input for VHF and UHF.

I assume this means I will have no need for a splitter/combiner. But, I also know that the RCA preamp can be fickle. Do you know if the RCA preamp will combine my two antennas using the standard inputs without issue or should I prepare for something else before I start this process?
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Old 2-Nov-2018, 3:56 PM   #6
rabbit73
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The correct device to combine a UHF antenna with a VHF antenna is not a splitter in reverse, it is a UVSJ (UHF/VHF Separator/Joiner), also known as a UHF/VHF combiner or a UHF/VHF Diplexer. A UVSJ looks like a splitter, but it is very different inside.

The RCA TVPRAMP1FR has separate UHF and VHF inputs, so you do not need a UVSJ, just set the switch to separate. That switch has a history of causing problems; sometimes it doesn't make good contact with the VHF antenna in the separate position. If that happens to you, set the switch to combined, and combine the two antennas with a UVSJ before the preamp input.

The quality control for the RCA preamp isn't very good, and some fail early because of power adapter problems. The one that I have been testing for the AVS Forum is now giving me different voltage and current readings than when it was new. I have ordered another one, even with the new higher price, to try to figure what is normal for that amp.

I only recommend it for people that understand it isn't as reliable as other preamps.
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Last edited by rabbit73; 2-Nov-2018 at 4:02 PM.
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Old 2-Nov-2018, 5:16 PM   #7
athiktos
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I did know to get a UVSJ instead of a standard splitter from a prior thread I opened. Which is great, because it does look identical to a typical splitter.

Hopefully the preamp works because I couldn't find a UVSJ at any local shops now that RadioShack is no longer a thing here.

Time to get the bucket truck out and play around a little bit. Thanks!
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Old 2-Nov-2018, 5:39 PM   #8
rabbit73
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Quote:
Originally Posted by athiktos View Post
Hopefully the preamp works because I couldn't find a UVSJ at any local shops now that RadioShack is no longer a thing here.
They are getting hard to find:

https://www.radioshack.com/products/...itter-combiner

with weather enclosure:
https://www.antennasdirect.com/store...Combiners.html

Channel Master is now making a preamp with separate inputs, but it is more expensive; the Amplify+, 7778HD:
https://www.channelmaster.com/Amplif.../cm-7778hd.htm
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Last edited by rabbit73; 2-Nov-2018 at 5:44 PM.
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Old 2-Nov-2018, 9:33 PM   #9
rabbit73
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TWO Defective RCA TVPRAMP1 Preamps

My first RCA TVPRAMP1R preamp had these measurements:
Voltage out of power inserter without preamp: 19.5 VDC
Voltage with preamp connected: 9.5 VDC
Load current: 70 mADC
Gain 23 db

I thought it was strange that the voltage out with no load was so high because the power inserter contains a voltage regulator, but it worked.

Recent measurements of first TVPRAMP1R:
No load voltage: 13.5 VDC
Voltage under load: 7.37 VDC
Load current: 18 mADC
Gain: 0 dB; Uh-Oh!

Second (new) TVPRAMP1E measurements:
No load voltage: 9.11 VDC
Voltage to preamp under load: 9.11 VDC
Load current: 75 mADC

well, that looked good so far, but
Gain: 5 dB; not so good

I thought there was something wrong with my signal level meter, so I substituted a CM7777HD at low gain:
Gain: 17 dB; right where it should be.

My meter is OK, the RCA preamp isn't OK.

I can't recommend the RCA TVPRAMP1 preamp.
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Last edited by rabbit73; 2-Nov-2018 at 10:58 PM.
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Old 4-Nov-2018, 10:47 AM   #10
ZippyTheChicken
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Posts: 58
Hey Rabbit

heh i can tell you one thing don't do

use a CM7777 injector to power a 7777 and a RCA TVPramp1

Burnt out my RCA doing that

But I run two 7777s off my one injector about a 50 foot run and through a power passing splitter that combines both my antennas

and then I snapped the connector off my 7777 when I attached some coax heh

I just resoldered that with a new connector yesterday and tested it last night.. works. Got lucky

haven't measured the power at the amps/antennas .. probably should .. but its working for now


hope all the regulars are doing well here.. i get here once in a while but I am mostly on Reddit .. hope the site is doing well . and the owner... never really heard that story..

anyway just passing by heh


Quote:
Originally Posted by rabbit73 View Post

I thought there was something wrong with my signal level meter, so I substituted a CM7777HD at low gain:
Gain: 17 dB; right where it should be.

My meter is OK, the RCA preamp isn't OK.

I can't recommend the RCA TVPRAMP1 preamp.
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Old 7-Nov-2018, 3:37 PM   #11
athiktos
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I've been told by my electrician friend that my house, currently grounded from the breaker box to the main water line, should be upgraded to a ground rod.

He said, the idea initially was that a water line was better because of the distance it was under ground. However, an anomaly in the plumbing (especially in an older house) can turn the ground into a live wire through a faulty appliance. Which is exactly what I experienced when my sump pump shocked the crap out of me through the washing machine water (sump pump since replaced).

However, my main service is not located on my house...it is located on the utility pole that feeds the line into my house. I think they did this because we live on a farm and they wanted to connect it to the large barns we have on the property via underground lines.

My electrician friend recommends having him or someone else come over and install a ground rod and connecting to the breaker box; which I would then connect my grounded antenna system to.

I can locate the ground rod by the utility pole on my main service, but it is about 100ft away from my antenna tower. Would it be better to stretch a buried ground system with multiple rods to reach the main service 100ft away or attach the tower to my newly installed house ground attached to the breaker box?

Last edited by athiktos; 7-Nov-2018 at 8:25 PM.
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Old 7-Nov-2018, 3:56 PM   #12
ADTech
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I would recommend following the advice of the electrician friend assuming he's going to assume the liability for any work he does and that it will meet all national and local (if any) codes.
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Old 8-Nov-2018, 6:22 PM   #13
Tower Guy
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Here's my 2 cents.

Are both the house and barn fed using triplex from the pole? If so, they are considered two distinct systems, each of which need their own ground which is best done at the house using a ground rod PLUS the water pipe.

If the feed goes from the pole to the first barn and then to the house you should have a 4 wire connection from the barn to the house with both a ground rod and water pipe connection at the house. In this case the breaker panel in the house should have TWO buss bars inside, one for the white neutral wire and another for the bare ground wire, ground rod, and water pipe. The 2 buss bars MUST NOT be connected to each other. The neutral buss bar must be insulated from the steel backing of the breaker box.

Either way, the tower should be grounded directly at the base of the tower with its own ground rod and then the coax should be connected to the house ground as soon as it enters the house.

Local codes may have a different take.

Last edited by Tower Guy; 8-Nov-2018 at 7:14 PM.
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Old 12-Nov-2018, 2:16 PM   #14
Nascarken
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Tower's and installed the right way have a place too hook up your grounds too!!! And if not use a ground rod next to the tower for best results.
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