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jp2code 9-Nov-2010 5:44 PM

Lightning Fix
 
So, an electrical storm took out my tuner a few weeks back. Lightning did not actually hit the house, but there must have been enough static electricity in the air to damage the tuner.

Now, I have a surge protector to place inline on the RG6 coax coming down from the antenna.

So, where should it go? I have a preamp, and this complicates my selection.
  • After the antenna but Before the Preamp Box?
  • After the Preamp Box but Before the Preamp Power Inserter?
  • After the Preamp Power Inserter and before the TV Tuner?

ADTech 9-Nov-2010 5:56 PM

Quote:

Originally Posted by jp2code (Post 3915)
So, an electrical storm took out my tuner a few weeks back. Lightning did not actually hit the house, but there must have been enough static electricity in the air to damage the tuner.

Now, I have a surge protector to place inline on the RG6 coax coming down from the antenna.

So, where should it go? I have a preamp, and this complicates my selection.
  • After the antenna but Before the Preamp Box?
  • After the Preamp Box but Before the Preamp Power Inserter?
  • After the Preamp Power Inserter and before the TV Tuner?

First choice would be on the input to the pre-amp PROVIDED that you have your pre-amp's case grounded as part of a contiguous and unified grounding scheme (single continuous wire running from the pre-amp case to mast to grounding block to structure's ground electrode system).

Second choice would be to install it on the antenna side of your grounding block and be prepared to sacrifice the pre-amp.

Most in-line coaxial surge suppressors work by diverting surge current from the center conductor to the coaxial shield. If the shield is not properly grounded with a low impedance path to ground, the device will simply shunt the current to the shield and the current will find its own path to ground, most likely through your indoor electronics equipment.

jp2code 9-Nov-2010 7:34 PM

Could you clarify your answer, please?

You said, "First choice would be on the input to the pre-amp."

OK, which part of the "pre-amp system" are you calling the pre-amp, the device that mounts on the antenna mast or the electrical unit that plugs into the wall? Both pieces together comprise the pre-amp system, so I do not know how to interpret your answer.

Thanks for your help.

GroundUrMast 9-Nov-2010 8:07 PM

"...input to the preamp..." means between the antenna and presumably mast mounted preamp.

ADTech is correct to point out the importance of giving static an easy, reliable path to ground.

Consider adding a DC-block in the coax run, just after the grounding block. It will encourage surges to go to ground through the outdoor surge protector / ground block path rather than through your tuner and then to power ground.

http://www.a1components.com/itemdisplayn.aspx?item=4313

http://www.lightningsafety.com/nlsi_...protection.pdf
http://forum.tvfool.com/showthread.php?t=901

jp2code 9-Nov-2010 8:12 PM

Thanks for the static electricity reminder.

Item 4313 is one of the surge protectors I have.

http://www.a1components.com/images/thumbs/SKY16900t.jpg

There will probably be a second internal surge protector that is part of a power strip, which will mainly be to serve the pre-amp.

GroundUrMast 9-Nov-2010 8:37 PM

Just to clarify, a DC-block does not typically include surge protection. It only prevents DC flow on the center conductor of the coax. A surge protector is designed to limit the voltage difference between the center conductor and shield.

Here are a couple of examples of surge protectors... http://www.cabletvamps.com/accessories.htm (Items: TII 210 and TII 212)

kb2fzq 10-Nov-2010 10:56 AM

Quote:

Originally Posted by GroundUrMast (Post 3920)
Just to clarify, a DC-block does not typically include surge protection. It only prevents DC flow on the center conductor of the coax. A surge protector is designed to limit the voltage difference between the center conductor and shield.

Here are a couple of examples of surge protectors... http://www.cabletvamps.com/accessories.htm (Items: TII 210 and TII 212)

Do either of these two devices cause any attenuation to the signal? I consider that I have adequate lightning protection, but have been toying with installing the TII 212, just for added protection...any down side to the 212?

GroundUrMast 10-Nov-2010 3:00 PM

The typical DC-block is just the connectors and barrel with a capacitor in the center conductor path. Loss should be less than 0.5 dB

Surge protectors may be semiconductors or gas tubes typically. In either case, the idea is that voltage between the center conductor and shield must rise to some point above normal operating levels before the device 'turns on' to provide a low impedance path between the center conductor and shield. Loss should be under 2.0 dB.

The gain of a good preamp should be more than enough to accommodate theses in your loss budget.

ADTech 10-Nov-2010 4:23 PM

If you put a DC-block in the coax between the preamplifier and it's power supply, you will have an unpowered preamp. Those don't work very well.

The in-line surge suppressors I've tested, including the one we sell, have negligible insertion loss, usually no more than a barrel splice.

Tower Guy 10-Nov-2010 8:37 PM

Quote:

Originally Posted by jp2code (Post 3915)
So, an electrical storm took out my tuner a few weeks back. Lightning did not actually hit the house, but there must have been enough static electricity in the air to damage the tuner.

Now, I have a surge protector to place inline on the RG6 coax coming down from the antenna.

I feel that you have a grounding problem. I don't think that a surge surpressor will protect you from another nearby lightning strike.

westom 10-Nov-2010 11:35 PM

Quote:

Originally Posted by jp2code (Post 3919)
Item 4313 is one of the surge protectors I have.

So how does that little device stop what 3 miles of sky could not? That is what you (and others) are assuming. As ADTech so accurately noted:
Quote:

If the shield is not properly grounded with a low impedance path to ground, the device will simply shunt the current to the shield and the current will find its own path to ground, most likely through your indoor electronics equipment.
What should be discussed in almost every paragraph? The only thing that does surge protection. Earth ground.

A surge protector does not do protection. Because protector and protection sound alike, then many just know they must be same. They are not.

Protection is where massive energy dissipates. If the post does not discuss where energy dissipates, then it is probably not providing an honest answer.

Protection means energy does not enter a building. If energy does enter and if that energy is sufficient to blow through protection already inside every appliance, then nothing inside will avert that damage. With or without an interior protector, you have same protection. Nothing inside does effective protection. Protection is always about where energy dissipates.

Best protector means nothing in series on a coax cable. How does it stop a surge but not stop radio signals? It doesn’t. Superior protectors are nothing but a direct wire connection. Anything that would 'filter' a surge simply diminishes data signals and does not stop any surge. Best protector per dollar is the single coax grounding block in http://www.cabletvamps.com/accessories.htm
Unfortunately that item is 300% overpriced. Same thing sells in Lowes for about $2.

And it still does not do protection. Its only purpose is to connect a surge within single digit feet of single point earth ground. No protector does protection. That ground block does what a protector does. Either massive energy dissipates harmlessly in single point ground. Or you have no effective protection.

In some cases, the more expensive TII210 or TII212 have purpose. But for most everyone, those do little more. And again, to be effective means a short, with no splices, with no sharp bends, etc wire that connects to protection. Earth ground.

Stop thinking a protector does protection. Too many hype a protector when advertising is their entire science. Learn from what even Franklin demonstrated in 1752. Protection was not about a lighting rod. Protection was about what that lightning rod connects to. Earth ground. Where does energy dissipate? But again the question you always ask. A protector is only as effective as its earth ground.

GroundUrMast 11-Nov-2010 12:31 AM

Sounds like we agree...

http://forum.tvfool.com/showthread.php?t=901

kb2fzq 11-Nov-2010 9:59 AM

Quote:

Originally Posted by GroundUrMast (Post 3932)
The typical DC-block is just the connectors and barrel with a capacitor in the center conductor path. Loss should be less than 0.5 dB

Surge protectors may be semiconductors or gas tubes typically. In either case, the idea is that voltage between the center conductor and shield must rise to some point above normal operating levels before the device 'turns on' to provide a low impedance path between the center conductor and shield. Loss should be under 2.0 dB.

The gain of a good preamp should be more than enough to accommodate theses in your loss budget.

OK, thanks for the info...as said, I have a typical short lead straight down to a copper earth ground, so I feel lightning protection is sufficent, as good as it can get when dealing with lightning, nothing is a guarentee, but even a 0.5 db loss is more then I'd like to give up...thanks.

jp2code 11-Nov-2010 7:12 PM

I have a 2-story house with the antenna on top (obviously).

There is no single point earth ground within single digit feet.

So, if I used a single coax line grounding block like below, it would have to be mounted somewhere inside the house so that I could tie into a single point earth ground (like a copper pipe).

There are vents from the bathrooms & kitchens that come up through the roof, but the bedrooms & kitchen are on one side of the house; the living room is on the opposite side and certainly not within single digit feet.

Where does that leave me?

http://www.cabletvamps.com/images/groundingblock.jpg

GroundUrMast 11-Nov-2010 7:47 PM

Quote:

Originally Posted by jp2code (Post 3950)
I have a 2-story house with the antenna on top (obviously).

There is no single point earth ground within single digit feet.

So, if I used a single coax line grounding block like below, it would have to be mounted somewhere inside the house so that I could tie into a single point earth ground (like a copper pipe).

There are vents from the bathrooms & kitchens that come up through the roof, but the bedrooms & kitchen are on one side of the house; the living room is on the opposite side and certainly not within single digit feet.

Where does that leave me?

http://www.cabletvamps.com/images/groundingblock.jpg

Virtually all of the example drawings of antenna grounding that I have come across (some I have linked to already) show the mast ground and shield ground run outside the building to the same ground point used by the electrical service. The NEC makes allowance for the coax to penetrate up to 5' inside the building to reach the grounding block, apparently as a concession to the real-world. The idea seems clear - If your antenna gets connected to a hazardous source of electrical energy, you want the current to go safely to earth and stay outside your house if at all possible.

My outdoor mast is connected to ground via a #8 bare copper wire that is run as directly and with as few bends as possible, to one of the two ground rods that are part of my electrical service grounding system. The grounding block is on the outside of the building and is connected via a #12 insulated copper wire to the same ground rod. Yes, I spent some amount of money on the grounding of my antenna system, about 2 months of cable fees, but I don't regret it.

westom 12-Nov-2010 2:28 AM

Quote:

Originally Posted by jp2code (Post 3950)
There is no single point earth ground within single digit feet.

So, if I used a single coax line grounding block like below, it would have to be mounted somewhere inside the house so that I could tie into a single point earth ground (like a copper pipe).

Stated was what is required. The antenna must connect to its own earth ground. And the antenna lead must route so make that single digit connection to single point ground. That ground block inside says you still did not grasp what was written.
Quote:

Protection means energy does not enter a building. If energy does enter and if that energy is sufficient to blow through protection already inside every appliance, then nothing inside will avert that damage. With or without an interior protector, you have same protection. Nothing inside does effective protection. Protection is always about where energy dissipates.
Every wire inside every incoming cable must make that short connection to earth before entering. You reroute any cable that does not.

A problem created because too many installers only understand code; do not learn what is also required for surge protection. A utility explains how to kludge a solution only if the superior solution cannot be implemented. How to enlarge a single point ground so that every incoming wire still makes that necessary short connection:
http://www.duke-energy.com/indiana-b...ech-tip-08.asp

jp2code 12-Nov-2010 7:59 PM

Quote:

Originally Posted by westom (Post 3956)
Every wire inside every incoming cable must make that short connection to earth before entering. You reroute any cable that does not.

A problem created because too many installers only understand code; do not learn what is also required for surge protection. A utility explains how to kludge a solution only if the superior solution cannot be implemented. How to enlarge a single point ground so that every incoming wire still makes that necessary short connection:
http://www.duke-energy.com/indiana-b...ech-tip-08.asp

I'm saying that there is no physical way to "make that short connection" that you are referring to. Something tells me I'm not the only one, either.

And I am sorry, but I don't understand what your second paragraph says.

westom 12-Nov-2010 9:38 PM

Quote:

Originally Posted by jp2code (Post 3970)
I'm saying that there is no physical way to "make that short connection" that you are referring to. Something tells me I'm not the only one, either.

That connection is required by the National Electrical code. It must exist.

Now, if there is no physical way, then what are the numbers and obstructions? Useless is a claim without the 'always required' reasons why. It is personally insulting to state something without the always requuired 'why'. Why is that physically impossible especially when it must exist according to code (and your insurance company).

For surge protection, that required connection must be electrically better.

Why is the second paragraph confusing? Again, due to missing reasons 'why', unnecessary posts now exist. What in this simple utility picture is so confusing?
http://www.duke-energy.com/indiana-b...ech-tip-08.asp

John Candle 12-Nov-2010 10:03 PM

Tv Reception
 
GroundUrMast Started This Mess. Now those that think they know the correct thing to do jump in. Westom makes vague statements. Westom like GroundUrMast use scary words like insurance company and code and code enforcers and Fire and explosion. Others will jump in and the mess will get bigger and bigger and bigger and bigger and on and on and and on. To better understand how this lightning safety issue can get out of hand real quick read this http://www.lightningsafety.com/nlsi_...protection.pdf , and if you think you understand and have done every thing 100 % correct , then it is time for you to move on to the home page, http://www.lightningsafety.com

mtownsend 13-Nov-2010 5:18 AM

Quote:

Originally Posted by John Candle (Post 3975)
... use scary words like insurance company and code and code enforcers and Fire and explosion. Others will jump in and the mess will get bigger and bigger and bigger and bigger and on and on and and on.

I hope everyone can keep an open mind here...

Let's just say that insurance company policies and building codes are there for a reason. A lot of people survive just fine without following every rule exactly to the letter. Conversely, just because the probability of a disaster is small, it doesn't mean that bad things won't happen to good people.

I think the information being shared is being volunteered out of good will. Every situation is different, and every person should use their own judgment in deciding what advice to follow. Learn about your options, consider the trade-offs of each choice, and then go with whatever makes the most sense for your situation.


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