Sorry about the posting below. Clicked the wrong thing by accident.
What I was going to say is that no Double "D" coil goes straight down from the tip of the toe to the trailing heel. The penetration doesn't go down in a cone either.
The field patern tapers from the edge of the coil and gradually rounds towards the centre as the depth increases. Due to this, it is still easy to miss targets as there will be zones that do not get full depth detection, even if the coil is overlapped by 50%.
The diagran that Minelab uses to show the coverage of a Double "D" coil is not correct. Look at the pictures in the Garrett catalogue and this gives a more realistic indication of field pattern. This is the reason why targets can still be found in a supposably thrashed out area with any brand of detector. I believe that there isn't any site that has been depleted of targets, if it has only been searched with detectors.
One main thing in target detection is not mainly dependant on the brand of machine being used, but the operator, and this goes for any other hobby or industry one participates in.
Thats just my pennies worth.
Phil
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