It's not running at 12 to 15 KHZ........................that is where the good gold ring/jewelry machines are at. Yet some claim it does really well..............Why?? Or is it Hype???? Why would I consider the F5 for this type of hunting.................................hoping to get tips and advice from people who actually own and use the F5. I was told the F70 was superior in this type of hunting, and to stay away from the F5....................yet I'm not so sure . So help me out..................which way should I go..........................Thanks!!!!!!!