Here a paraphrased article by Dave Johnson. He did the MXT as I remember, and is with Fisher now. It's a good read.
Electrical Interference
Because of the high sensitivity of modern metal detectors coupled with the proliferation of sources of electromagnetic interference, you are likely to encounter electrical interference. It is important that you recognize electrical interference when present, and take appropriate measures to deal with it.
Symptoms of electrical interference
Electrical interference can cause a metal detector to
Electrical Interference
Because of the high sensitivity of modern metal detectors coupled with the proliferation of sources of electromagnetic interference, you are likely to encounter electrical interference. It is important that you recognize electrical interference when present, and take appropriate measures to deal with it.
Symptoms of electrical interference
Electrical interference can cause a metal detector to