pescadore
Well-known member
Let me start out by saying that I realize that VDI numbers are only a reference point and should not be exclusively counted on for reliability. With that being said, wanted some feedback from other X-terra users. I have a chart of VDI reference numbers for different US coins. In air tests I find the chart to be accurate especially with lowered sensitivity. In the field though it is a whole different situation. On the chart a quarter is a 42 but in the field it is almost always a 44 and even can go to a 46. In the field a dime is usually a 40 with a copper penny being a 38/40. On the chart a nickel is 10/12 and in the field that is always a tab but 12/14 is usually a nickel if the tone is good. The silver half I dug recently was a 44/46 not completely unlike a quarter. Is this about what everyone else is seeing. I use the 5x10 HF DD coil usually maxed out in sensitivity or as high as stability allows. Thanks for your help !!