Been hunting a beach here on the Wisconsin River that is used by a local pub/restaurant for summer volleyball, parties etc. Their season is just getting under way so I've gotten permission to swing the F70 there. Others have hunted there but don't know anything about them or their equipment. Lots of bobby pins, tabs, foil and iron. Found some clad , mostly quarters which seems unusual but considering it is a younger party crowd, I can see that would be the more common coin to loose. The thing I've noticed about the spirited F70 is there seems to be a relationship between the coin signals that seem to get kinda chirpy or distorted, and the presence of iron signals.. Like falsing. I have my mode 1 set to autotune for a quick comparison to what I am seeing in my mode 2 channel also for a better ground balance. Mode 1 is set at 65 sensitivity, and 0 threshold. Mode 2 is 65 sensitivity, 6 discrim. 0 thresh. delta pitch or 4H with nothing notched out. I use 6 discrim. because the Wi. River has lots of iron in the water and 6 will cut down on the low tones a lot. I found totally by accident while in autotune, I was hearing some 1/2 volume groans. They were so weak that there was no VDI at all. I switched to discrim. mode to try a comparison and there was nothing there. I turned up the sensitivity to 75 and threshold to +3 and there was still nothing there. Yes I am using headphones. I switched back to autotune and did a pinpoint which said about 8 inches. So I dug to 8" before the pro point finally started to pick it up. Determined to find out what the heck was going on and not having to worry about a mess, It ended up being about 10" to a clad Oklahoma quarter and water standing in the hole. If I am running so much gain that I am creating falsing from iron signals, how am I ever going to hear the deep targets? This is why I use autotone a lot. Does any one else find themselves switching back and forth between autone and discriminations modes? Or am I doing something wrong?------Larry