The original wasn't defective, it was designed to work with a high sensitivity on the 1500/2500 to increase depth. But, at real high sensitivity, it became so sensitive that a sudden light tap would sound off the coil to belltone. Of course you could compensate for that by going over the target again to see if in fact there was a target or if it was some falsing. It can be compared to driving your car down hill at 150 miles an hour, and it starting to shake a bit, but not necessarily out of control. Also, the original coil windings in the coil were set in some foam type material to protect the windings, but at the same time could allow the windings to move with a sudden hard jerk, which would sound off the detector.
The engineers at Garrett figured out a way to make the coil thin, still maintaining the Imaging Feature, and now keep the windings in place with a new resin which is very strong and doesn't allow the windings to move at all. The result......a much more stable coil at higher sensitivity, which gives added depth. Hope this helps....
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