Congratulations, I believe you have found that the MXT can punch through really bad ground as we all here said it would, the fact that you read the nickel and while hunting also found a few coins and digging some hot rocks means you are getting it right ! You can be sure if you had put your coil over a 1/2 gram picker you would have heard it. Now it's just a matter of covering more ground and learning to read the lay of the land, look for depressions, move some bigger rocks aside if possible and if you can find some exposed bed rock get that coil over the sand filled low areas and fractures on the bedrock. Be sure to take a flat blade screw driver and small paint brush for cleaning out those spots. There are many other handy tools that will allow you to better clean a fracture of its contents, I think you have learned a lot in a short time and are well on your way now, just remember slow and low is always better. Hope to cya out in the field, Jimmy