When I first got my MXT I was confused about ground balancing. The little manual that came with it just wasn't very clear. So, I came across a book by Jeff Foster, "THE MXT EDGE" In this book he very clearly explains the proper way to ground balance this metal detector. I hope this helps you like it did me.
To ground balance the MXT make sure the (TRAC) toggle switch is on the (GROUND) position. Then, lower the search coil to the ground and repeatedly raise it a few inches and lower it back a few times. The ground balance tracking in the MXT is so fast that only one or two pumps are usually needed. This process will cause the MXT to sniff out the grounds VDI number and automatically adjust the ground balance system to lose sensitivity to targets with the VDI number of the ground.
CONFIRMING THE GROUND BALANCE
Whenever the MXT has been ground balanced, it is best to confirm that it worked properly. Confirming that the ground balance is set properly is a basic skill that all MXT users should know how to perform. The first thing to do is to confirm that the area of ground, which was used for the ground balancing procedure, is free of any metal. Pull the (TRIGGER) all the way back and move the coil back and forth on the spot on the ground. If there are readings from that patch of soil, with the (TRIGGER) held in, search around to find an area of ground that is free of any targets. Now that there is a known clean area of ground, repeat the ground balance procedure there.
Now check the ground balance. To do this, raise the search coil to waist level (away from any objects), squeeze, and hold the (TRIGGER) switch. While holding the (TRIGGER) switch, lower the coil to the ground. There should be little, if any, change to the threshold sound. (A modest increase is OK) This is the reason for ground balancing!! It causes the MXT to ignore, as best as possible, the mineralization in the ground.
Happy Hunting!!
