White’s Electronics TDI - Manual (Page 27)

PulseScan TDI Owner’s Guide 7
#4 - DETERMINE IF GROUND BALANCE IS NECESSARY
At this point it is important to find out if there is enough mineralization in the
ground to require the Ground Balance control to be activated. Since in the
initial setting recommended above, the Gnd.Bal. toggle is set to off there is no
active ground balance, and the Pulsescan TDI has only its inherent ground
rejection ability working for it.
When the search coil is swept over the ground and there is no ground noise, (the
detector runs quietly and smoothly) then there is probably not enough ground to
balance. At this point you have two options as already described on Page 22.
a) You may leave the Gnd Bal toggle 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 switch the
Gnd Bal toggle to the On position and activate this capability, and set ground
balance according to Chart on page 22.
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 the depth of
detection. Never increase Gain at the expense of the inability to handle ground
minerals or environmental interference. As with the operation of all metal detec-
tors, too much Gain will not increase but decrease depth, and the ability to hear
targets. It will be up to you to find the proper setting.
If you change the Pulse Delay or the Gain, and you are operating with Gnd Bal
toggle on, you must readjust the Ground Balance.
(With Gnd. Bal. Toggle OFF as on Chart A.)