I live in WA, along the Columbia River, and my local native soils are highly mineralized. In certain areas my Mojave is more chatty, almost unusable, than my Silver regardless of coil selection; might be EMI but not likely given the rural locations?
I have owned 11 Tesoro models (4 & 5 pin) and tried nearly every coil option over the last 12yrs searching for that perfect combo for my ground.
My Mojave is paired with a 3x18 cleansweep coil 95% of the time and I use it for tot lots & sports fields for shallow drops. I also use the stock 7 and concentric 4 occasionally when I'm curious if other machines have missed a nonferrous target in an iron infested site but feel either the Silver or Outlaw are better suited, in my soil, for iron discrimination-separation.
I will always own one or more Tesoro's; simple beep-dig fun and possibly the best iron separator in my ground.