Instruction manual

When it comes to sweep speed, the X-TERRA is a very forgiving
detector. You can operate with a relatively quick sweep in wide open
areas, and slow down when targets are abundant. But to gain a better
understanding of how sweep technique may aect the quantity of
our nds, let’s rst analyze the eld of detection for both the X-TERRA
Concentric coils and the Double-D coils.
Based on my eld analysis, with the center of the coil as the “hot spot”,
I nd the eld of detection for a Concentric coil will go “straight down”
until you reach approximately 55 - 60% of the maximum depth for a
specic target. In other words, if you are capable of detecting a target
at maximum of 10 inches, you will nd the circular eld of detection
begins to narrow at the 5.5 to 6 inch depth level (see Concentric
diagram). The deeper the target, the more closely centered (under the
coil) it must be, to provide a target response. As such, if you are not
overlapping your Concentric coil by half the width of the coil, you risk
missing those deeper targets that are not directly centered under the
coil as you pass over them. By overlapping your swath by half the width
of the coil, you’ve increased the eld of detection “coverage” at any
given point, maximizing the opportunity for a solid target response.
Double-D coils are designed to help neutralize the eects of
mineralization. Part of those design characteristics place the “hot spot”
of the coil directly down the center, from the front tip to the rear heel.
Don’t be misled into thinking that the eld of detection goes straight
down, from front to back, until the maximum depth is achieved.
Treasure Talk 
X-TERRA...
Controlling the search coil
Tuesday, January 04, 2011
52Understanding your X-TERRA - Coils
Concentric coil
Inner winding (receive)
Outer winding (transmit)
Inner winding (receive)
Outter winding (transmit)