My friend just got an AT PRO and we picked up interference from each other’s machines. How do you avoid that?
From the manual...
"The AT Pro is capable of operating at four slightly different frequencies in order to minimize the interference caused by electrical sources (e.g. power lines) or other metal detectors.
To adjust frequencies, hold down the PINPOINT button and press the (+) or (-) SENSITIVITY pushbuttons to change the frequency to find one with the least amount of interference. The frequency setting (F1–F4) will be indicated on the LCD. Release the PINPOINT button when finished. "