.................In normal hunting, swinging the coil back and forth my Sovereign is great, threshold is easy to adjust and the tones are easy to hear and interpret!!................HOWEVER.............as soon as i get a target and lay the detector on the ground so I can dig the target..............the tones and threshold goes crazy like a Xylophone...................this continues until I pick up the detector and start searching again...............the tones and threshold all go back to normal until I lay down the detector again for another target to dig!!.................Any ideas on what can be causing this??.......I have also changed Batteries and it continues to act up like this ..................no matter if it has used or fresh batteries!!..............JOE