White’s Electronics TDI Pro - Manual (Page 26)

26 TDI Pro Owner’s Guide
4. Determine if Ground Balance is necessary-
At this point it is important to fi nd out if there is enough mineralization in
the ground to require the Ground Balancing.
1. Set the FINE GEB to OFF and Pump the search coil 1-6 inches over the
ground;
a) If there is no change in the Threshold as the search coil is
pumped 1-6 inches over the ground, you may leave the FINE
GEB in the Off position and operate the Pulsescan TDI with no
Variable Audio as a straight pulse detector, and dig all targets, or..
b) If you wish to detect with Variable Audio active, you may turn
FINE GEB slightly clockwise from OFF to activate this capability,
and set Coarse GEB and Pulse Delay according to Chart under
Ground Balance Chart “A” on page 23.
2. If there is a change in threshold as the search coil is pumped 1-6
inches over the ground, continue pumping the search coil while adjusting
fi rst the COARSE GEB for no change in Threshold, then the FINE to fi ne
tune for no change in Threshold as the search coil is pumped 1-6 inches
over the ground. Inability to balance requires a slight reduction in GAIN
and try again.
FINAL ADJUSTMENTS AND YOU ARE ON YOUR WAY
If all has gone well to this point, you might see if you can increase the
Gain in small stages. An increase in Gain is desirable in order to increase
depth of detection. Never increase Gain at the expense of the inability to
handle ground minerals or environmental interference. As with the opera-
tion of all metal detectors, too much Gain may not increase depth nor the
ability to hear targets. It will be up to you to fi nd the proper setting.
If you change the Pulse Delay or the Gain, and you are operating with FINE GEB
ON (clockwise from OFF), you must re-adjust the Ground Balance.