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Does this make any sense?

Posted by catherinet (My Page) on
Wed, Apr 14, 10 at 14:17

I'm definitely at a disadvantage, not knowing much about electricity or electronics, etc., but this doesn't sound right.
For several years now, when it gets hot in the summer, my TV gets so much interference from around 2p.m-6p.m. that we can't watch it. (on all the TVs connected to the antenna). Now that its digital, we just lose all our signals. But if I turn a certain breaker off, we get all the signals back.
I had a TV guy out today and he insists that its not an electrical thing.........that its not a short in some wiring in our extremely hot attic. He said its a signal issue.
So we're getting a new antenna (ours has several broken arms), a new amplifier (said it could be that its old....13 years), and he's going to raise the antenna up by about 5'.
I'm having a hard time not thinking its an electrical issue. Plus, today after he left, I started to watch a video that I had taped yesterday (and it was fine), but it too was getting really bad interference on it (just like the TV was).
I called him and he said we probably just needed new fittings on our coax.
He wasn't high pressure or anything. And he has nothing bad about him on the BBB website.
I know I'm not an electrical person, but can these strange interferences on the TV be merely a reception issue??
Something I mentioned to him and he discounted was the fact that even a TV we have that is not on a coax to the antenna has all this interference.
I'd be alot more concerned if we didn't probably need these various new things, but I have the feeling I'll have to call an electrician when he's done.
I'll be really happy if he's right......but it just doesn't make sense to me.
What do you think?


Follow-Up Postings:

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RE: Does this make any sense?

What's on that breaker that you turn off?

2 to 6pm in the summer is a bad time for any signal. It's not that it's hot but the sun is closer to you and creates more interference. Reception is alway a lot better after sundown.


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RE: Does this make any sense?

"2 to 6pm in the summer is a bad time for any signal. It's not that it's hot but the sun is closer to you and creates more interference. "

The sun is not closer to you in the summer. If that was the case, everyone would have summer at the same time. It is actually the angle that the earth is tilted that determines the seasons in a particular section of the planet.

"But if I turn a certain breaker off, we get all the signals back. "

Sounds like you have diagnosed the problem even if the tv guy hasn't. It isn't necessarily a short or anything dangerous though. All it takes if for the cable to be looped around a current carrying wire and you will create signal issues. The alternating current creates magnetic fields which induce corresponding currents in adjacent cables. However, if you are getting the same problem in TV's not connected to the antenna, then I would start checking for problems in the grounding of the "magic" circuit that makes the problem go away.


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RE: Does this make any sense?

bill.....are you saying that we should be checking out the circuit breaker's ground? Sorry, I don't know much here. Or do you mean checking the grounding of all the things that run off that breaker?
There are an assortment of things on that breaker, and I'm sure there are things that I haven't even figured out yet. There is a radon fan (already tried unplugging that and it didn't change the interference), outside flood lights, closet and bathroom lights, etc. Nothing big.

I don't feel good about this TV guy's knowledge......but I think he will be okay for putting up a new antenna and amplifier. But I still think I'll need an electrician after that.
One of the problems is that it gets to be 100-140 in that attic in the summer, and I always hesitate asking anyone to be up there for anything. But I figured its best to have them check things out during this time. Hopefully there will be a cooler day for an electrician.
I know its impossible to say, but you think its not a dangerous situation? Its been going on for about 8 years and the house is still standing.
I think its one of those problems that will be very hard for anyone to figure out!
Thanks.


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RE: Does this make any sense?

Just in a basic trouble shooting scheme....

If you have 2 TV - 1 connected to an antenna and 1 not - and both have the same problem, then it isn't coming from the antenna.

If the problem can be fixed by turning off a circuit, then the problem is probably coming from the circuit.

There are really only 3 electrical paths in a 120V circuit - live, neutral and ground. If you have problems with the live or neutral, that keeps power from flowing, so you would notice that immediately in lights etc. Grounding problems tend to be more subtle. In terms of safety, grounding only comes into play when something else goes wrong. You'll never notice any big problems with improper grounds, but that safety feature won't be there to protect you.

As for the TV's guys solution - it might well work. He's not really diagnosing the underlying problem. He's just going to improve the signal coming in so that (hopefully) whatever interference is taking place won't degrade the signal so much that your digital TV can't decode it.

Personally, I'd still have an electrician take a look. You obviously are uncomfortable with the situation as is.


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RE: Does this make any sense?

I don't think there is anything dangerous going on here.

My guess is that the antenna wire is running close to that circuit wire somewhere along its path. The antenna guy should be able to check for this.

You wouldn't happen to have an attic ventilator fan on this circuit, would you? Or an air conditioner?

Tell me about the video tape: was it recorded with the interference already on it or does it play back normally at other times of day? Is the VCR in line with the antenna wire or is it a separate input on your TV?

You can also get one of those plug-in circuit testers from HD or Lowes and go around to each outlet to confirm the presence of ground, hot and neutral. In case something is missing.


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RE: Does this make any sense?

Alright, my first thought when I read about TV interference is "grounding".

The circuit you're turning off is obviously related to the problem. Coincidences happen, but not repeatably and predictably. It's on that circuit.

My experience with ground-related interference relates to cable TV, but antennas are supposed to be grounded too, and I'll assume yours is.

Identify everything on that circuit, and turn it all off by other means. Unplug whatever you can, unscrew light bulbs, etc. Does that ALSO make the problem interference go away? If so, restore things one device at a time until your problem comes back.

My guess right now is that something is leaking to ground, and this is interacting with the antenna's ground connection. This probably means your antenna is grounded to something it shouldn't be (ie, whoever installed it just ran a wire to the nearest grounded object), and if your current TV guy replaces that, your problem may very well disappear. Something, somewhere, will still be leaking current to ground, however.


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RE: Does this make any sense?

BTW: the only thing at my house that runs in hot weather from around noon to 6pm is my attic ventilator fan.

YMMV.


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RE: Does this make any sense?

Actually in the Northern Hemisphere, the sun is FURHTER away in the summer.
As pointed out, it's the amount of sunshine (due to the earth's tilt) that makes the seasonal difference.


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RE: Does this make any sense?

I agree with the others. The problem is on that circuit you are turning off.
If you are going to let him put up a new antenna ask him if he will guarantee it will fix the problem and what he is going to do if it doesn't. I don't think it will.


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RE: Does this make any sense?

I really appreciate everyone's input. I wish I knew more, in order to question the things he says. He's pretty good at talking.
About the ground for the antenna......where would I find that?
We have an old rusty rotor on the antenna that doesn't work. The control box isn't plugged in. The coax comes from the antenna and goes into the attic from there.
What should I ask him about that ground?
I've heard that you can get these problems if someone has wired one of the outlets backwards. We added on to our house about 13 years ago and this started up around 8 years ago. I'll check all the outlets in the new addition with a tester.
Also....he said that there's no way anything anywhere is causing a short. Is this true?
I just don't know enough about electricity to even talk about it intelligently.

Okay......I went out with my binoculars and took a good look at the setup. There's a wire from the dead rotor taped to the coax from the antenna and they go to a connector, which takes them into the attic.
At that connector, there is a wire that comes down the house and into the ground.
Does any of that sound weird? I have no idea if the ground wire is connected to anything, but it does go into the ground where our septic line exits the house.
Can you extrude any relevant info from that? At least it might help me tell the TV guy what to look at.
And I have the feeling that in the attic, the coax/rotor wire doesn't cross any other wires until it gets to the splitter and then the amplifier. The splitter and amplifier are about 10' apart, I think from what he said.
Thanks for your help!
Oh....about the VHS tape......it was a perfectly fine, clear video before I re-watched it yesterday, during the time when there was interference, and it had exactly the same interference on it as the TV had. I told the TV guy about this and he said we probably need better fittings on the cables in the back of the TV.
My head is spinning. Reality is getting a little weird.
I don't know much about alot of things, but I do seem to have the ability to know when someone is on the wrong track.


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RE: Does this make any sense?

The antenna should be independently grounded, but who knows how it was installed. The wire coming from the antenna should go to ground (as in true ground, not just the ground). The original installer might have mistaken your waste pipe for the incoming water pipe. This could be a safety concern. If the antenna needs to be replaced anyway, just make sure the installed is going to ground the thing properly. After all, it is big piece of metal and the highest point on your house. If it gets hit by lightning, you want the electricity to go from the antenna, down the wire, and away from you.

As for testing the outlets, I'm not sure you are going to do that successfully on your own. The little 3 light tester basically is going to tell you if all the wires are in the right place and the outlet "works." They aren't going to detect small problems. The voltages for your TV signal at really tiny compared to the 120V coming from the wall.

As for "shorts" - I guess it is a bit of technicality. A short is when the live wire comes into contact with something with very low resistance (like ground) and the current spikes dangerously. Your circuit breaker would trip if something were shorting. A bit more subtle problem is when you get a tiny "leak" of current from live to ground. The current isn't spiking dangerously, but a small amount of power is escaping. It won't make any noticable difference for most big things (lights, motors etc) but it can mess up sensitive electronics.

If you aren't comfortable trouble shooting this yourself, you should have a pro look at it.


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RE: Does this make any sense?

Thanks bi111,

What should the ground wire be connected to?
I did wonder about lightening strikes, when the antenna is going to be 5' taller. Fortunately, there are lots of taller trees around, but I still want to be grounded properly.
Its not enough to just go into the ground?
I hope this guy knows how to properly ground it. I really think he does.......but who knows for sure.
Why would it be a safety concern to have the ground attached to the waste pipe? Is there anything else it shouldn't be grounded to? Should it be a certain distance away from anything?
I appreciate your help!


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RE: Does this make any sense?

Hi,

My first reaction would be to say electrical interference over the AC power... something like an attic fan. But, is the antenna amplifier located in the attic as well? Maybe plugged into that same circuit as the breaker controls? Maybe mounted on a west facing wall that gets really hot in the late afternoon?

If you have access to the amplifier, try unplugging it when the problem appears. It is quite possible that a heat related failure is occurring in the amplifier that is inducing interference or even voltage into the feed to your TV.

If that does not do it, I would suggest disconnecting the antenna feed from the wall to your TV or whatever device it first enters when the problem occurs. Did the interference stop? Since you lose your signal you may want to disconnect while watching a previously known good recording. If it stops, it coming down the antenna line - if it doesn't it's on the AC.

Regarding your grounding question on the antenna, there are actually 2 grounds that must be installed. One is from the mast and provides for ground in the event of lightning or if the antenna comes into contact with a live conductor. The other is a static discharge that goes in line with the coax. This discharges the static that can cause "sparkles" on your TV or can cause worse damage. The static builds up from the passing air currents. Also these 2 grounds must be separate but both run to an appropriately bonded ground point at the entrance.


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RE: Does this make any sense?

Most likely the fitting you saw is a grounding block. The ground wire from it should be solidly connected to a ground stake driven deep into the earth, and that wire should also be connected to the antenna mast. This is a lightning protection ground.

Are you by any chance using the RF output of your VCR to view that tape? Any noise coming in on the antenna input to the VCR might well be passed through the VCR.

Another possibility is that you're getting power line noise. You might try plugging the television set into a good quality computer plug strip with noise suppression. Note that a "good quality" plug strip doesn't usually sell for $10 or $20 at the hardware store. One example below.

Here is a link that might be useful: Tripp Lite Isobar


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RE: Does this make any sense?

Hmmmmm.....I just did what I should have done before I even called the TV guy..........I turned off the breaker, and walked around and saw what didn't work any more. The door bell is on that circuit too! Its in the sun in the afternoon.
Could it just be that???? Dang, and the TV guy is on his way with hundreds of dollars of stuff.


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RE: Does this make any sense?

P.S. How would I disconnect the transformer to the doorbell? When I take the lid off, there's a white and a red wire connected to screws. Would I just detach those?
Am I barking up the wrong tree, or is it possible if the doorbell button outside is heating up and malfunctioning, that it could somehow cause interference?


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RE: Does this make any sense?

I'm going to say the doorbell is probably not the problem...

Let's go forward with whether or not your attic fan and possibly antenna amplifier (if you have one) are on that circuit.

I hadn't thought about a malfunctioning/overheating amplifier but that's certainly a logical possibility.


Your description of the grounding configuration doesn't sound like your antenna is connected to your electrical service ground at all. I think it's supposed to be, but don't quote me on that - wait for someone else to post definitely first. My local cable company always ties to it, therefore so do I, but I can't say for sure that Time-Warner Cable is always right.


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RE: Does this make any sense?

I don't have my code book here. But when I used to install television antennas in a former life, we always sank a 8-10' ground rod exclusively for the mast and lightning arrestor. Never bonded it to the electrical ground that I can recall.

That was in the days of vhf and 300 ohm twin lead. Hmmm, I guess about 40-45 years ago. Still done that way today? No idea.


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RE: Does this make any sense?

Well, we have a new antenna and rotor. The guy talked me out of a new amplifier. He said it tested fine the other day. (Hmmmm....he had a slightly different assessment the other day).
Of course, we still have the interference $700 later. I was positive it wouldn't correct the problem. But when a person doesn't know that much about something, she has to trust people. Mistake, I know.
We have a whole house fan in our ceiling (between attic and living space), and its on that circuit, but we never use it.
The reception is no better now than with our old antenna. So other than the rotor, I believe I just threw good money away.
In fact, now I have to use the rotor to get a certain PBS channel, when I didn't before. :(
I don't think he intentionally scammed me. I just think he didn't have the knowledge he needed to have to not waste my money.
The only ground is into the ground and not to the service. The antenna is on the opposite end of the house from the service. Would it have been put through the attic if I had one?
I would prefer not to interact with him again, but my remote control to the rotor control box isn't functioning properly. I point it to the control box, but instead of letting the antenna move smoothly around, it stops and starts and jerks the antenna.


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