I headed out yesterday with the S-5 still on and went to a spot with heavy soil, hot rocks, minerals, iron, and RF noise. Yea, it's one of those dream spots that has everything going for it. Up until the GT none of my machines could handle this spot without going so low in sensitivity that they had the effective depth of a Garrett (shun intended
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) and even then target ID and audio wasn't all that great. As I've said before the only machine that could do any better at this spot was my Explorers which did manage a few silvers/indians/large cents, but even with those target ID/audio was only about 70% "there" and I got them by digging the best of the iffy signals. This is the spot where the 15x12 and GT popped out a standing liberty quarter a few weeks back that gave a perfect ID and tone at around 7" or so, and I was even hunting in auto sensitivity. I've gridded that area from several directions with my Explorers so I know I didn't miss that coin but somehow the GT got it while the Explorers didn't.
Anyway, the S-5 coil handled well in the area and managed a few copper (non-wheat) pennies next to trash or iron that were deep enough for me to know that they've been there for years and so I missed them with other machines. I also popped several round tabs at about 4 or 5" that I had missed with other machines before. I know I did because this was around a large oak tree where some of my better finds had come with the Explorer (not just coins) and so I had dug everything that gave a remotely good signal with it, regardless of target ID being a possible "tab" or any other signal for that matter. These round tabs on the GT and this coil give perfect hits, though I did dig a few that would only ID one way and would null the other. That's how bad the ground and iron is at this spot, and these targets were non-existent with other machines prior to this. While I didn't dig anything old other than one ornate piece of metal (hair clip?) that I have to investigate yet, I was pleased with how the GT and this coil gave me solid target IDs at good depth even in auto at a spot that I thought had nothing left to offer due to the harsh conditions.
My next testing of all three coils (S-5, 10" Tornado, SEF 15x12) should be of interest to some people. I plan to mask coins in various ways with mostly iron but other trash as well to the point where they can just hardly be ID'd properly with the S-5, and in some cases where the S-5 can no longer see them despite any sweep angle. Once I've got an assortment of various masked coins in many ways, and a mix of those that the S-5 can see and can not see, I'm then going to glue them in place right where they sit on some cardboard without moving them at all. This will insure nothing left to error when I switch to the other coils and see how well they can unmask the targets to compare. I plan to make a picture chart with the findings to make things as easy to compare as possible, and will also include photos of each masked target for each slot in the chart for quick reference.
I'm going to go out on a limb here and not just state the obvious, that being that the S-5 should probably unmask the most targets. What I'm also going to bet is that based on my experience with the SEF 15x12 coil I think it may in fact unmask coins that the S-5 wasn't able to in some situations, and I also bet the SEF will do as well and probably better than the 10" Tornado with all targets tested. The S-5 will probably reveal the most coins but I'm real interested to see if the SEF can get ones that even the S-5 can't based on both it's ultra thin detection line and also it's unique hybrid coil dynamics.
While conducting these tests I also plan to compare Iron Mask ON to OFF and also Auto Sensitivity to max stable sensitivity. I'm curious as well about these functions, and if say auto might do better or worse than max stable setting. It might due to the coil being less "hot" and so seeing less of it's surroundings, or also because it does a good job of resetting the threshold and allowing the target to break through. Yesterday after playing with auto/manual on some iffy coin signals (due to nearby iron) I found that auto provided slightly more consistent and stable IDs to the targets. Reasons why are up for debate, but I've got the above theories to work with.