minelab 7000 gtz,having owned twelve detectors,since 1976,consider myself to be experinced operator,have purchased a 7000 gtz, spent the last four days detecting the golden triangle victoria,25 + hours,NOTHING,found three good signals ,lead shot, lost all three signals trying to locate target,went over the same with gtx 5000 found all three targets, contacted minelab today,they were most helpfull,i think the ground balance of the gtz 7000, balances out the signals, as it continully ground balances.on a .3 grm. gold test piece it will pick up at 1-2 inch, no signal at four inches,all the tests were carried at factory recomended settings,the only exception was i had the sound turned up, due to hearing loss.minelab have given me a few tests to do,,i really want this detector to work, not looking for a refund at this point,minelab have not put out a dud detector, but in this case im not so sure.my three detecting friends have cancelled there orders of the gtz7000.two of the most experinced operators from inglewood victoria have returned there 7000 for a refund, all have said stay away from them,just hope that minelab fixes this problem,all the minelab people have said they are a great machine. i think i would like to see a independent test....ps minelab have asked after the test if it fails, the last one had a faulty coil just my luck. regards bob hillier.