Instruction manual
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If, however, when I properly ground balance the Concentric coil and
the ground phase number is less than 28, I nd the Double-D coil will
hunt deeper and provide a more stable operation. The TID when using a
Double-D coil is not as accurate as with a Concentric coil. Especially on
the more deeply buried targets. But the Double-D design allows for more
coverage per sweep than the Concentric coil, allowing me to cover more
area in a given period of time.
The biggest “down-side” for me is the weight of the 10.5-inch coils. I’m not
as young and athletic as I use to be. As such, the weight and balance of
these coils is not conducive to a long day of detecting. I’ve tried several
aftermarket apparatus, with mixed results. But by mid-day, I’ll usually
resort back to one of the 9-inch Concentric coils or the even smaller
6-inch coils, depending on the site.
6-Inch Concentric Coil
As I mentioned, the 6-inch coils come in both Concentric and Double-D
versions. The 6-inch Concentric is a 7.5 kHz coil and is extremely hot. In
fact, when I was eld testing these coils, I commented to Minelab that
I thought this one was too hot. The reason I want a small coil is not for
extreme depth. It is for target separation in trashy areas. And the 6-inch
Concentric coil just didn’t let me isolate targets as sharply as I would have
liked. But for working in around weeds and stubble in harvested elds, it
is an excellent choice.
6-Inch Double-D Coil
Fortunately, for extreme target separation, Minelab also produces a
6-inch Double-D coil for the X-TERRA. I can’t stress enough that this small
Double-D coil is an excellent tool for a serious coin shooter. Surprisingly
deep, excellent separation and extremely sensitive to small targets. I’ve
found mine to be a silver dime and Indian Head cent killer.
Understanding your X-TERRA - Coils