Techniques for identifying sources of EM interference?

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plexi59

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So I moved my guitar stuff to another room, and it seems that there's only a couple of spots in that room where I don't get a ton of 60Hz hum. I still get some, it's just not horrible. Does anyone have tips on how to nail down the source? The strength of the hum changes as I move around the room, and as I turn around. It's not the guitar either, it's happening (to a different extent) with all of them, and the main one is a Suhr Modern, it doesn't get much better than Suhr. My Steinberger (with EMGs) has the least hum, but I don't play it very often.
 
My friend had this happen and it was a ceiling fan light below the room we were in. Try turning lights off one at a time and anything else that may be on.
 
markmusicman said:
My friend had this happen and it was a ceiling fan light below the room we were in. Try turning lights off one at a time and anything else that may be on.
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I don't think there's any wiring below the floor, the room is in the basement. But I'm not sure.
 
I use the Tricorder app on my Android phone but I guess CBS had Google remove it from the app market, so it's no longer available. See if you can find another magnetic flux sensing app on the market.

If it's line noise, you need a Power pedal 2 + with a toroidal xfmr or a nice power conditioner from Furman :)

Also, shield your guitars or get noiseless pickups from Kinman.
 
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maybe start by turning off the light switch. a process of elimination, one thing at a time could help to identify the culprit.
 
First, here are two of the most common sources of EMI: light dimmers, and those curly florescent bulbs. Try turning those off in the house first.

To locate the source of the EMI, you can turn off every circuit in the house, and power the Axe from the one circuit that's still on. If the EMI goes away, turn the breakers back on, one by one, and listen for the noise to come back. If the EMI doesn't go away, plug the Axe into a different circuit and repeat.
 
For the OP: 1:1 ratio isolation transformer. An invaluable investment for many reasons. I use them and they're a cure for just about anything in the circuit before the transformer. After the isolation transformer it is much easier to nail down culprits. In my case all I had to deal with after I started using them was my phone too close to my computer monitor.:)

If you consider this route buy one according to the wattage your gear consumes with some headroom.
 
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swass said:
For the OP: 1:1 ratio isolation transformer. An invaluable investment for many reasons. I use them and they're a cure for just about anything in the circuit before the transformer. After the isolation transformer it is much easier to nail down culprits. In my case all I had to deal with after I started using them was my phone too close to my computer monitor.:)
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Isolation transfomers are a great cure for some types of hum, but they won't touch EMI.
 
Sorry, I should have explained more clearly. There's no problem with the Axe. it's the guitar that's picking up 60Hz hum (hence the change in loudness as I move around the room). Google seems to suggest to use an AM radio for identifying the source by proximity. Will try that tomorrow. Come to think of it, I could use the guitar itself as a "radio" too, just crank the gain a bit and triangulate along the walls and ceiling.
 
plexi59 said:
Come to think of it, I could use the guitar itself as a "radio" too, just crank the gain a bit and triangulate along the walls and ceiling.
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This. Don't just move your guitar around; twist it, turn it, make it face the ceiling, the floor, and everywhere else. You'll sometimes find the noise is loudest when your guitar is facing the source.

If that doesn't find it for you, the circuit-breaker trick mentioned above would help you narrow it down pretty quickly.
 
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