Lady...it's pretty easy to do.
1 - Make sure you have the sensitivity at preset or just a little higher. Don't do overboard on this setting when first starting to GB.
2 - Set the ground balance knob to the center position.
3- Turn the Threshold knob until you hear the hum. Make it a little louder than normal so when ground balancing, you can distinguish between the rise and fall of the threshold hum when bobbing the coil. But not too loud !
4 - With the coil on the ground, switch to All Metal mode. Sweep slowly around to make sure you do not get any hits due to a piece of metal in the ground on the spot where you will be ground balancing, You don't want to ground balance over a metal target.
5 - Start to raise the coil off the ground about 4 -8 inches and then lower it back to the ground to about an inch over the ground. Keep raising and lowering the coil, and when doing so, listen to what the threshold sound is doing. It will either be getting louder/raising up in sound, as the coil is being lowered the ground, or getting softer/fading to silent as the coil is lowered ( and vice versa when the coil is raised above the ground). This should be happening as you are continually bobbing the coil over the ground. Also...make sure when bobbing the coil that the coil is parallel to the ground.
5 - As you continue to bob the coil, slowly adjust the ground balance knob either clockwise or counter clock wise, until the threshold sound has a continuous, smooth hum, without it rising or falling. You want to make sure you have the threshold sound as close to a continuous, steady hum with no change as you are bobbing. When this happens, your ground balance is set and stop turning the GB knob.
You can now start hunting in All Metal or switch to Discrim mode. You may also want to turn the threshold back a little after doing the GB process ( but you need to make sure you still hear a faint hum). The reason I turn it up a bit louder when ground balancing is that I am beach hunting, and sometimes the waves and wind are loud and I need to make sure I can hear the threshold sound and it's changes when ground balancing.
Also...whenever you raise or lower the sensitivity, you should re-ground balance. In addition, if the machine starts to become a little erratic, it may be due to a need to re-ground balance again. You may have hit a spot where the previous ground balance setting is not cutting it.
I check my ground balance all the time. Since I always hunt in all metal, with a threshold sound, it's easy. Just start bobbing the coil and if there is any slight rise or fall in the threshold sound, slowly adjust the gb knob while bobbing until you have a smooth continuous threshold sound again.
Once you are comfortable with ground balancing, you can then up the sensitivity to max, re-ground again and have a really deep hunting BHID. The machine may false on you with sensitivity at max, and that means the machine is telling you it's running too hot and you have to back off the sensitivity. If you do...remember to ground balance again !!
HAVE FUN.
JC
