Hi Robertk,,,,,,,,,,,,,,I think you made two mistakes in your testing or the deep silver program. #1,,,,You freshly buried a coin in the ground without putting a teaspoon or water in the hole then tamping down the dirt firmly to remove all the air spaces. Targets buried a few years have the benefit of the dirt settling down tightly, which will somehow allow them to be heard quite a bit deeper with a detector. #2,..,.. You tested for a clear ground area without running your discrimination down to zero, which it would take to hear a small tack, pin or other tiny iron piece. If this was the case, and the coin was buried say, six inches, but the tack was buried just above the coin at three inches, you would have the Dankowski effect in which you would hear neithet the coin or the tack. These are two common problems experienced by may detectorists. I hope this could be of some help in testing the depth of detection in various programs in the future. Hope your threasure hunting is going well and haveing good luck......How.