The odd thing is some GM 1000 work great out of the box. Then others have trouble with the small coil. But then you have people like me and a few others have trouble with both coils. It would be interesting to know if Minelab has more than one plant where GM 1000 comes together. Then too if Minelab had to buy their electronics from another company that could of been substandard without knowing it. This wouldn't be the first time a top name company got the shaft unknowing what they were