I'm the friend Cal Cobra refers to, who was swinging the Exp. II on this hunt. The park is a park that's given up a lot of silver over the years. And continues to give up oldies, for the current generation of explorer/etrac users who know who to ferret out those "come get me" deep silver/wheatie signals. Ie.: one of those type turfed parks where you pass up clad, and look for 5" or more deeper only type places.
I had 14 wheaties, an IH, a barber and an early merc, as compared to Brian getting a lone wheatie. I had Brian try several of my deepie signals with his etrac, before I dug. In each case, I was able to listen in on what his Etrac with 12" Sunray coil was doing: The Etrac heard them WITH ROOM TO SPARE. So simply hearing the target, was not the issue, apparently. The issue seems to be having an audio difference between those targets, and random shallower clad elsewhere, or flutters, or whatever. In other words, it's as if perhaps he had his settings in such a way as to be TOO hot, and thus loosing all tell-tale clues as to shallow verses deep, verses mono-tone verses fluty/warbly, etc...
Since I'm not familiar with the Etrac controls, I wasn't able to help him much. But I had a different friend in this park last year with the Etrac, and he pulled multiple oldies (silver, etc...) out of this park no problem (while digging probably zero clad).
So if anyone has a "deep turf silver" program they can lend Brian, let us know. It need not be one of those b*lls to the w*lls max power type programs, since perhaps that (too much squirelly power) might have been the problem. It's got to be settings that have the tell-tale differences from when it's a 4 or 5" deep clad dime, verses the 6 or 7" silver dime type audio clues differences. On the Exp. II, those deeper signals I chase in turf have a tell-tale "fluty" tone, which indicates they've been in the ground longer, are deeper, etc... As opposed to more recently lost and shallower stuff, and their tone is a bolder steady consistent "beep" note, and not as "fluty", if that makes any sense.