Help with understanding noise

[Rob Strand]

So with NO AC in my house, and the security system off (but some of the wireless sensors are still working because they run on batteries) I only have EMF by the house AC panel, and at the water stand pipe coming into the house.

I have underground power lines.

Thanks for elaborating on the details.   
(I missed some details you had already posted in the previous posts).

I like the idea of the guitar/headphones walking around. I tried it outside on driveway and seemed to get same noise. Curious once I get the EMF meter to see what I find out, if anything. 

I had some hum while standing in front of electrical panel, typical since there is power there even with house breaker off. And also around a chest freezer. I started to turn on beakers one at a time but was still hard to determine cause. But you can really here a increase in hum standing at electrical panel and turning each breaker on.

Initially I was thinking there maybe some issue with alarm system scanning but now I don't think that's the cause. 

The noise around your freezer points to mains.

To me, the fact you are getting noise on the driveway is starting to point to the underground power cables, or perhaps an RF source.    Another possibility is there is a significant current flowing into the ground, perhaps due to some fault, that could spread the noise all over the place.  If it's current through the earth rod you might be able to measure a current down the earth rod with a clamp meter.   If there's an underground fault then it might not show up going down the earth rod.     I would be tempted to put a few loops of wire around the earth rod and feed it into a cheap battery powered amp(maybe not your I phone).   If the loops in air are significant higher than the loops around the earth rod it could be an indication of a fault.

One thing you could try is to connect the centre pin of the 6.5mm jack to a 300mm length of wire and see if the HF noise is still present and also how strong it is compare to the guitar.

I am getting a 31 band eq next week for $50.00. maybe I can get closer to cutting the specific freq.

Another way is to record the noise then play around with the wavefile.  You can filter/EQ  signal to remove the low frequencies, listen to frequency bands and look at the spectrum.

[pinkjimiphoton]

I also put copper tape inside the cavities on the guitar and made sure I have conductivity.

MAKE SURE THAT ITS ALL CONNECTED TO GROUND! including the cavity cover.

YOU are likely the source of the noise, we're like huge freekin antennas for all kindsa noise. USUALLY proper grounding/shielding will help, but it also comes down to phasing.... everything i think has a bit of a theremin aspect to it, and how close/what angle you are to your gear can definitely effect him and noise.

pretty much i think what you describe originally is fairly normal. its just the nature of magnetic pickups and magnetic fields. thats why some positions are quieter than others, depending on your alignment with the magnetic fields, you either buck the hum, or reinforce it. hendrix exploited this, i think


i'm probably wrong, but that's my answer n i'm sticking to it.

[caspercody]

Thanks Jim

I do have the cavities grounded all together.

That is exactly what it is. Depending on the position I am in will determine quieter noise (or move a little this or that way) and the noise gets louder. Also, I think the magnetic field is picking up a some stray frequencies and then they are being amplified.

I have been to two different locations besides my house, and these locations both had no noise. One location was just with the iPhone set up, abut the other location I did have my guitar, amp, and pedals. Same cables and all the gear that I am using at my house. So I know my amp set up is cable of not creating this noise.

[caspercody]

Found the source of the noise, it is my water pipe. When I remove the ground connection from the water pipe, noise is gone. When I reattach noise is back. Now I need to someday contact our city utilities and see what they can find out. Also when I remove the wire my EMF sensor shuts off, when the ground wire is connected the sensor goes off and turns red. I did check this grounding wire to the ground on the closest receptacle and I do have continuity

[Rob Strand]

Found the source of the noise, it is my water pipe. When I remove the ground connection from the water pipe, noise is gone. When I reattach noise is back. Now I need to someday contact our city utilities and see what they can find out. Also when I remove the wire my EMF sensor shuts off, when the ground wire is connected the sensor goes off and turns red. I did check this grounding wire to the ground on the closest receptacle and I do have continuity

It sounded like that type of thing.    It's still not clear where the problem is though.

If you have access to a clamp meter (AC current meter) it would be worth seeing if you have significant current going down the earth wire that connects to the water pipe (the one you disconnected).  If you see significant current that means something in the house is leaking to ground.   It's something to take  seriously, if your earth connection fails a whole heap of stuff in the house could go live.

If you don't see significant current then that means there's a fault outside of the house maybe a faulty power utility cable.    The fact you get noise out in the driveway points more to this.

[PRR]

The water company is happier if not connected to electricity. It's not their business.

However you are *required* to bond house electric to all accessible metal, and specifically underground metallic piping.

And that should not be a problem.

The fact that is is means there is a REAL problem with your *electric* supply. You want both the power company and your own electrician looking at this. Un-bonding from dirt is NOT safe.

[caspercody]

Thanks for the replies. I am fortunate that within our company we have a electrician that has been helping me talk about this problem. I turned off all the power in my house and still had the EMF at the water pipe, and the water pipe is in a separate room from the electrical panel and about 15 feet away. So I know it is a issue coming from the pipe. 

[EBK]

Very strange question:  Does the noise change if water is flowing through the pipe?

[Rob Strand]

Thanks for the replies. I am fortunate that within our company we have a electrician that has been helping me talk about this problem. I turned off all the power in my house and still had the EMF at the water pipe, and the water pipe is in a separate room from the electrical panel and about 15 feet away. So I know it is a issue coming from the pipe. 

Hmmm, maybe someone else in your area has the serious earth leakage problem.

[EBK]

Is there a water meter in line with the pipe that has the ground wire?  If it goes earth-->meter-->pipe-with-ground-wire, then the meter could be the problem (really the location of the ground wire would be the problem--also, there should be a redundant ground connection to a long metal spike hammered into the ground outside the house, which might be missing here *gasp*).  Just another guess....

(Also, I'm an engineer, not an electrician, so I am talking out of my ass a bit here rather than spouting actual wisdom.   ).

[Rob Strand]

Is there a water meter in line with the pipe that has the ground wire?

I'm don't know how the water meters work in the US at all.   

Strange thing is about month ago our water meter was changed out since it was
reaching the end of its service life.   I spoke to the guy about various meters.

In AU the majority of meters are just mechanical.   I believe none of the meters are mains powered.   Electronic, remotely readable meters are very uncommon and are only used in special cases where people have large dogs or security for entry.  How the remotely readable  meters were powered was not known.  I suspect a battery is required since you can't guarantee the water to be flowing when the meter is read but it's not known if the water can charge the battery (maybe not as it would add to the expense.)

[caspercody]

The meter was replaced earlier this year, but I had this noise even with the old meter. This new meter is plastic so it breaks the connection to the main water line in the house. Out of ground is pipe then meter than main water line into house. The ground wire is connected by a clamp and screw to the ground pipe and also to water pipe after meter. The electrician from my work asked me to verify I have a ground outside next to my panel, I do. Then is the wire at the meter location connected to my electrical ground, it is. My DMM wires are not long enough to reach from the meter to the electrical box, but there is a electrical outlet right next to the meter and at this receptacle I verified connection to the groung wire.

I left a message with our cities utilities and they will call me back next week. When I described my issue on the phone to the lady she was not to shocked of my situation.

[EBK]

Well, I'm left guessing it's a secret underground military installation and/or highly radioactive water in your pipes.   

[amptramp]

You could drive additional grounds into the soil.  Ham radio operators do this all the time and have methods of adding ionic material whether salt or fertilizer to the soil to keep it conductive.  It sounds like your house could not pass code for electrical or lightning protection as it stands, so this could be your best bet.

[caspercody]

I will wait to see what the city says. According to our work electrician the utility companies legally need to provide clean power

[PRR]

Water meters can be mechanical, or remote with battery (they normally have to see the meter every 5 years to be sure you are not cheating it, so they can replace the battery then), and a few are water-powered (inline turbine and generator with storage battery). NONE of these can be leaking enough to make trouble.

If the meter is plastic, there sure as heck should be a jumper-wire around it, or some very good reason why not. A classic water-man death is to remove a meter for service, grab the two stub-pipes, and take a heavy leakage shock. With plastic meter you don't even have to pull the meter to be shocked. Things are changing now that many pipes are plastic- but my last house had a foot of copper into the ground before going plastic, and that could be enough dirt to pass a dangerous shock.

Random dirt-rods are not an answer. First they don't make great contact except in salt-swamp. Second, there is potential between your land and all the rest of the land the power wires come through, so you could actually make things worse. There are National Codes for dirt-rods. Follow them.

One much too common problem: thieves steal the copper grounding-wires off of power poles. If someone hit my street, I might only be connected to dirt a mile or three away. Because my neighborhood is all 1-phase, there is significant voltage drop in the 20KV "neutral", easily 100 volts per mile. If I had a perfect dirt connection it could absorb 100 Amps of stray current. Since I can't get much under 25 Ohms in this thin soil, only 4 Amps (at like 80V)-- in fact I measure about 0.2A mostly due to my last 500 feet of line (most of the street-grounds are OK). But every situation is different.

That small residual ground-current here caused visible "hum bars" in cable TV and buzz in phone until I inspected the several service ground connections. Power and communication rods were in the same patch of dirt but not copper-connected together. After study of Code, I established interconnects at pole and in cellar and hum was reduced a lot.

An astonishing number of power companies figure if the meters turn, all is well. There are many cases of 240V on "neutral" and some horror stories of 80,000V leaking from an underwater cable next to a swimming-dock.

[Rob Strand]

If the meter is plastic, there sure as heck should be a jumper-wire around it, or some very good reason why not.

FWIW, the guy that replaced our meter did just that.  The jumper cable had two very large clips, like those on car jumper cables.

[caspercody]

there is (1) ground wire coming from the electrical panel and connected by a clamp on one side of the plastic meter, and then clamped on the other side (the side from the ground) of the meter.

I remove the side that is clamped to the ground when I play, and when i remove the wire I see a little arc from the wire to the clamp, and again when i connect it.

[PRR]

> i remove the wire I see a little arc

This is very dangerous. Don't get yourself killed. Show/tell it to the electric gurus.

The line from the street to the service panel should already have N at ground. There may be a few stray volts from line resistance; I have as much as 3 volts. That won't arc. You have A Problem.

[Rob Strand]

This is very dangerous.

Indeed.

In this era because a lot of devices use switch-mode power supplies and the lines filters leak a bit of current to earth.   However that current should flow down to the neutral connection and *not* through the earth stake.

It seems you have some sort of problem.

Dodgy wiring or water heaters can leak current to ground.  You need to measure the current to determine how big it is.