Ground Balance is basically the detector's ability to compensate for the adverse effects of the ground. The numbers represented by setting the GB do not really represent the actual mineralization of the ground. They might better be thought of as a pre-established number, representing the ground phase required by the X-70 to compensate for the effects of mineralization. The most positive GB setting on the X-Terra 70 is the setting of 1. And, this represents the most highly mineralized ground compensation setting achievable by the X-Terra 70. As the ground phase levels decrease, you will be able to use less-positive GB settings up to a point you might reach the least positive GB setting of 90.
There are many variables in Ground Balancing a detector. A larger coil will "read" more of the effects of mineralization, than a smaller coil. DD coils are designed to compensate for higher mineralization than concentric coils. And, you may find certain coil frequencies are more affected by a given amount of mineralization than another coil frequency. But don't let the numbers or the terminology we use become confusing. Our X-70 can do most of the thinking for us. By setting the GB properly for the coil and the soil you are hunting, you are compensating for the adverse effects caused by the various components that we typically call mineralization. Once a proper GB is maintained, you can run the Sensitivity as high as you like. I like to keep mine just "short" of creating false signals or causing chatter. If your X-Terra starts out quiet and then begins chattering after you have hunted for awhile, you have probably wandered into an area with some sort of interference or it may have a different GB requirement than where you started. Your first instinct might be to lower the sensitivity. Don't. Try readjusting the Noise Cancel setting or GB level instead. You will likely find that you are able to maintain the higher level of Sensitivity when you readjust the NC or GB for the specific area you are hunting. If your detector still provides unstable operation, even though the NC and GB are set as "perfectly" as possible, you might have to lower the sensitivity. But for me, lowering the Sensitivity is the last option. HH Randy
