Today and found five pennies(one ih 1897 and four wheat's). The school closed in the late forty's it's farm ground now.(corn stubble). Found three junk ring's and an asortment of other stuff. Got a question about the ET. When i'am hunting it sound's like it startes to null but then it sound's like the threshold and another tone sound at the same time ????? Part of the time it goes back to threshold hum on it's own but other times i have to bump the coil or hit the detect button......... anybody else have this happening?????