Critterhunter
New member
I'm a GT user but I figured you guys might find this of interest. The 15x12 did not go as deep as the stock 10" Tornado coil in my medium to high mineral land sites. It did show greater depths (2 or 3") in the sand, though, well into the mid teens or so on a coin. The thing I can't figure out is why it got deeper in my mineralized beaches than the stock coil but didn't on land. Either way, I figure the 15x12 is just too big to see through the fog on land for me to provide greater depths. Don't get me wrong, it's depth was still decent on coins in the 8 or 9" range but I've dug coins 2 or 3" deeper with the stock coil on land.
Otherwise I loved every other aspect of the 15x12. Better pinpointing using the base of the "V" at the tip or tail of the coil. Using the outer front or back portion of this coil I feel it separates better width wise than coils as small as 8 or 9" on other machines, and I felt it was better than the stock coil in that respect too. The DD detection field of this coil feels compressed in the left/right perspective to give excellent separation and pinpointing. The very center is more like a concentric and puts out a signal roughly the size of a medium soup cap, though it's separation is still excellent there as well. I just prefer to use the tip or tail to investigate targets and feel it gives even better separation that way. The stability of this coil is unreal in high minerals or iron. It runs smoother at higher sensitivity settings than the stock coil and seems to provide better audio as well. Still, as I found with my Explorers and now my GT running at max stable sensitivity in my soil doesn't provide best depth. Often something much lower is where I've found I get the best depth and target ID. My normal routine is to bury a silver dime at fringe depth and then calibrate sensitivity over it to provide best response. Often higher than that (though stable) can degrade or even null out a coin just like too low can.
Beyond all that, the coil also seems to unmask coins on edge or in trash better than conventional DD or concentric designs. In every respect I feel it out performs the stock coil, and that's saying a lot because the stock 10" Tornado is one of the best coils I've used on any machine. I give the 15x12 a 9 out of 10 and it would have been a perfect 10 had it shown me greater depths than the stock coil on land. It's better depth on my mineralized beaches and it's awesome coverage in wide open areas or at the beach makes it a winner as well in my book.
My only caution to people considering a coil for max depth on land is to go by the amount of mineral content you have. If it's medium to high then I would expect the 15x12 to not show greater depths than the stock coil even if it's running stable at higher sensitivity settings. I've just traded the 15x12 for a 12x10 and I would highly suggest that you put some deep thought into which to buy based on the kind of minerals you have in your soil. Down the road I plan to pick up another 15x12 just for my beach hunting or when covering wide open areas such as open fields. It's a great coil.
Also, an interesting theory I have about size to depth ratio when it comes to rough ground. We all know the fog in headlights theory so I won't re-hash that, but onto my point...As I've said these SEF coils seem to "ride" on less ground than a conventional DD coil of roughly the same size. For that reason even if you feel that a 12" coil is past the point of no return in terms of getting better depth in your soil, you might still want to consider the 12x10. I have a feeling that the compressed left/right signal of these SEF coils have less "bleed off into space" of your typical DD. For that reason it may very well in fact be that the 12x10 is seeing less ground than a 12" or even 10" standard DD coil. If things follow suit then I expect the 12x10 to feel like a 8 or 9" coil to me much like the 15x12 did in terms of it's stability and left/right separation. For that reason maybe you've tried a Sunray 12" coil and found it to not show greater depths in your rough soil, but I'd still consider the 12x10 in that it might be seeing less ground "fog" than coils in this size range (10 to 12" round coils).
If not for anything else even if this coil doesn't show me greater depths then stock I'm sure I'll still be happy with it. The SEF's ability to hit coins on edge or masked in certain ways over conventional DD and concentric designs is something to behold. It's stability at higher sensitivity settings, improved separation, and ability to run smooth as silk in iron or rough ground is also amazing. Just think about which of these coils will probably offer you the best depth. If your minerals are high then I'd lean towards the 12x10. If they are low or you do a lot of beach or wide open field hunts then the coverage of the 15x12 is simply outstanding.
I'll be conducting depth, separation, and other tests on the 12x10 versus the 10" Tornado as well as how it compares to the 15x12 at the same sites. One thing I want to see is just how high I can raise sensitivity on it at a specific site compared to my 10" coil. While I don't run at max sensitivity, it is useful to note it's performance in that respect for those of you who have soil that permits you to get best depth at the fringe of stability. These field trials will be posted in the Sovereign forum over the next few weeks are further down the road as well.
One other minor note about the 15x12- It's sensitivity to tiny little things like earring backings is very good. Also, it's weight was never an issue for me since I got rid of the coil cover (3.6oz) and sprayed the bottom of the coil with spray on liner. With that done it was either the same weight or I think lighter than the stock coil with it's cover still on. You can find a chart in the Sovereign forum I put together with the weights of various coils with and without coil covers and some FBS coils are listed as well. The 12x10 will be riding with no coil cover and spray on liner as well for me.
Otherwise I loved every other aspect of the 15x12. Better pinpointing using the base of the "V" at the tip or tail of the coil. Using the outer front or back portion of this coil I feel it separates better width wise than coils as small as 8 or 9" on other machines, and I felt it was better than the stock coil in that respect too. The DD detection field of this coil feels compressed in the left/right perspective to give excellent separation and pinpointing. The very center is more like a concentric and puts out a signal roughly the size of a medium soup cap, though it's separation is still excellent there as well. I just prefer to use the tip or tail to investigate targets and feel it gives even better separation that way. The stability of this coil is unreal in high minerals or iron. It runs smoother at higher sensitivity settings than the stock coil and seems to provide better audio as well. Still, as I found with my Explorers and now my GT running at max stable sensitivity in my soil doesn't provide best depth. Often something much lower is where I've found I get the best depth and target ID. My normal routine is to bury a silver dime at fringe depth and then calibrate sensitivity over it to provide best response. Often higher than that (though stable) can degrade or even null out a coin just like too low can.
Beyond all that, the coil also seems to unmask coins on edge or in trash better than conventional DD or concentric designs. In every respect I feel it out performs the stock coil, and that's saying a lot because the stock 10" Tornado is one of the best coils I've used on any machine. I give the 15x12 a 9 out of 10 and it would have been a perfect 10 had it shown me greater depths than the stock coil on land. It's better depth on my mineralized beaches and it's awesome coverage in wide open areas or at the beach makes it a winner as well in my book.
My only caution to people considering a coil for max depth on land is to go by the amount of mineral content you have. If it's medium to high then I would expect the 15x12 to not show greater depths than the stock coil even if it's running stable at higher sensitivity settings. I've just traded the 15x12 for a 12x10 and I would highly suggest that you put some deep thought into which to buy based on the kind of minerals you have in your soil. Down the road I plan to pick up another 15x12 just for my beach hunting or when covering wide open areas such as open fields. It's a great coil.
Also, an interesting theory I have about size to depth ratio when it comes to rough ground. We all know the fog in headlights theory so I won't re-hash that, but onto my point...As I've said these SEF coils seem to "ride" on less ground than a conventional DD coil of roughly the same size. For that reason even if you feel that a 12" coil is past the point of no return in terms of getting better depth in your soil, you might still want to consider the 12x10. I have a feeling that the compressed left/right signal of these SEF coils have less "bleed off into space" of your typical DD. For that reason it may very well in fact be that the 12x10 is seeing less ground than a 12" or even 10" standard DD coil. If things follow suit then I expect the 12x10 to feel like a 8 or 9" coil to me much like the 15x12 did in terms of it's stability and left/right separation. For that reason maybe you've tried a Sunray 12" coil and found it to not show greater depths in your rough soil, but I'd still consider the 12x10 in that it might be seeing less ground "fog" than coils in this size range (10 to 12" round coils).
If not for anything else even if this coil doesn't show me greater depths then stock I'm sure I'll still be happy with it. The SEF's ability to hit coins on edge or masked in certain ways over conventional DD and concentric designs is something to behold. It's stability at higher sensitivity settings, improved separation, and ability to run smooth as silk in iron or rough ground is also amazing. Just think about which of these coils will probably offer you the best depth. If your minerals are high then I'd lean towards the 12x10. If they are low or you do a lot of beach or wide open field hunts then the coverage of the 15x12 is simply outstanding.
I'll be conducting depth, separation, and other tests on the 12x10 versus the 10" Tornado as well as how it compares to the 15x12 at the same sites. One thing I want to see is just how high I can raise sensitivity on it at a specific site compared to my 10" coil. While I don't run at max sensitivity, it is useful to note it's performance in that respect for those of you who have soil that permits you to get best depth at the fringe of stability. These field trials will be posted in the Sovereign forum over the next few weeks are further down the road as well.
One other minor note about the 15x12- It's sensitivity to tiny little things like earring backings is very good. Also, it's weight was never an issue for me since I got rid of the coil cover (3.6oz) and sprayed the bottom of the coil with spray on liner. With that done it was either the same weight or I think lighter than the stock coil with it's cover still on. You can find a chart in the Sovereign forum I put together with the weights of various coils with and without coil covers and some FBS coils are listed as well. The 12x10 will be riding with no coil cover and spray on liner as well for me.