are working just fine for me and are a 'will stay' fit in my Regular-Use Detector Team, to be sure.
I have other Tesoro's and Nokta's that can provide me more depth, if I want and need it, and I am sure a coil swap with the Mojave might nudge that number up a trifle, but as it is, I kept the new 7" coil on the Mojave after trying several coil swaps.
As for search coils of the past, and who designed and made them, look non further than Jack Gifford for the well-known Troy Custom Super 7 Inch. The Shadow X2 was a Jack Gifford design with some small modifications to the Silver Sabre µMAX, and while I liked the Shadow X2, it was mainly because I liked the color scheme change. I still preferred my Silver Sabre [size=small]micro[/size]MAX because it was more 'functional' with the variable Threshold control on the control face rather than a tiny trip pot on the inside.
Troy wanted something different.
Tesoro had a weighted thin-profile 7" coil for their water unit as an accessory option. [size=small](Refer to the Stingray II manual under optional coils.)[/size]
Jack Gifford used that white, thin-profile 7" housing, did it in black, and eliminated the non-buoyant filled design to make the new Super 7 Inch for the Shadow X2. I spoke with him on the phone back then regarding that coil and the design and he told me it wasn't easy to try and get it to work well. We discussed the Tx and Rx internal windings and he gave me the answers I needed for what was sometimes being spoken about back then.
From what I have been told from the folks who ought to know [size=small](Rusty H. and Allan C.at Tesoro)[/size] the new Precision 7" Concentric might be a 7" thin diameter, but it is NOT the same as they designed for the Troy Custom Shadow X2, which was a Jack/Tesoro designed coil and not something Troy designed and made.
Monte