Hey everyone. I wanted to check in because I have a much better handle on the situation. And while it is not yet fixed 100%, the hum is more manageable now.
I had a NJ based EMF expert come in and take readings (I live in NJ). Joseph Dumanov of
http://www.spectralanalyticalsciences.com/
He said the entire house was fine regarding EMF readings except, of course, in my studio and in the master bedroom immediately above it. 22 to 58mG readings.
Before I continue, here is some important layout information. As is code here in NJ, a ground line runs from my breaker box to the incoming water line. This is not the main ground, as I have two spikes in the ground for that. There is also a ground jumper that that runs from one side of the water meter to the other on the water pipe.
When I had my 200 amp service put in prior to building the studio, the new water ground wire went direct from the breaker box to the water line. That path happens to be in the ceiling immediately over my head in the live room. The ground wire exits the live room next to the studio door and meets the water line about 4 feet away from the door.
OK, back to the results.
It became apparent to Joseph that the high mG readings were present in the entire path of ground wire. In the ceiling over my head and also where it meets the water pipe. And readings were also coming from the water pipe. As such, electricity was in the ground wire and the pipe. Based on the mG readings, he estimated 15 amps. I then walked out of the live room with my Strat and stood near the water meter. The closer I got to the meter, the worse the hum. It was really bad when just inches away.
The question then became this. Is the electricity coming into the ground line and water pipe from my breaker box? Or is it the reverse? Is it coming from the water main into the house via my water line and into the ground wire?
So my electrician , Rich (the one who has done all my work), came by in mid September. He did not have a clamp meter, but rather a meter that was designed to measure wires and had a small opening. So all he could test was the ground wire, not the pipe.
Rich got a reading of about 1.8 amps initially with fluctuations up to 5 amps. He got similar readings on the ground jumper.
Rich temporarily removed the ground wire from the water pipe just to see where the source of the electricity seemed to be. He then measured both the ground wire and the jumper (the jumper still being connected to the water line). The ground wire went to 0 amps. But the jumper still had readings. As such, it appeared that the electricity was coming from the water line, not from my breaker box.
With the ground removed, the hum on my guitar stopped. And even better, even after Rich reconnected the ground wire, it was gone. About an hour later it returned, but it was much more manageable. More like a normal Strat hum. And to this day, it is still manageable.
We also discovered that turning on electrical devices is increasing the reading. My girlfriend happened to turn on her hair dryer during the testing, and the reading jumped 2 amps from 1.8 to 3.8.
I subsequently purchased a clamp meter so I could take readings myself on both the ground and the water pipe. This happens consistently regarding devices. When nothing is on (no dryer, no guitar gear) the reading is generally about 0.8 amps. Start turning stuff on, and it immediately goes up. As if the electricity is trying to find its way back to the water line and to the source of the problem.
BTW, the water line AFTER the ground wire is fine. So the electricity is coming in through the pipe, diverts to the jumper, goes back into the pipe, then goes into the ground wire.
I made reference to the "source of the problem". It is most likely a bad ground-to-neutral connection somewhere in my neighborhood. This is a 1950's neighborhood, so most people still have metal water lines running to the house and in the street. As such, if someone has a bad ground-to-neutral or other issue, electricity can run from their house via their ground into their water line, out to the water main, and run into all the other houses. I have taken water pipe and ground wire measurements for two of my neighbors, and both have similar readings. So this does seem to be the case.
My electric company, PSE&G, has been very helpful. They do concur that the electricity is coming into my house via the water pipe (meaning there is no issue in my wiring). One of the techs is even a bassist so he is even more interested in finding the source. But it will be very hard and quite possibly they will not find the source. They have tried a number of things in the neighborhood, but so far no luck.
So what are my options? Well for now, the hum is manageable and correspondingly the mG reading seems lower. About 3 mG with nothing on but up to 11 mG with the hair dryer on. But remember, the master bedroom is directly above the live room. So it has similar readings. My girlfriend tends to believe that high EMF fields are bad for your health, and anything above 6 mG is bad. So she is uncomfortable having me leave it as-is.
That leaves one fix. I would need to have the metal water line that runs from the street to my house replaced with PVC. Replacing a small section of pipe would work (a section long enough to avoid "arcing") but replacing the whole thing would be better. This won't help my neighbors, but it will at least fix my problem. Which is the main thing. And of course, that won't be cheap.
