You can still approximate the size of a target by raising the coil and swinging it at the same time. Eventually the target will null out. A smaller target will have the coil null out at a lower depth then say a larger rusted tin can. A coin sized object might null out at say at around 10 inches, and the tin can will null out at about 20 inches. Your combined practice + trial and error will eventually allow you to guess a fairly accurate targets size. Using the depth, conductivity reading on the screen plus your experience should really help you digging deep targets with the DD coil.
And yes, if your soil is quite mineralized, the 10" x 14" PROformance Power DD" coil would be the proper coil to use over the others. Another trick to know about the DD coils, is that they all like rusted bottle caps, and will read them as a quarter. To save you lots of digging, do this:
On a quarter reading target in the top 6-7 inches, stamp real hard with your foot on the target. Now, check it again. A silver or copper coin will still give a signal reading in the coin range, where as a bottle cap will now sound at the left part of the screen, under the iron. This same trick works on all Garrett coils/machines.
Good luck with your new coil and let us know how it works in your higher mineralized area.
John-Edmonton
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