White’s Electronics MXT Pro - Manual (Page 23)

2
Chapter MXT Pro Controls
“Music Notes” Tone ID. Starting out turned
on, Iron Grunt provides a distinctive grunt for all
targets certain to be iron (80% and higher prob-
ability). If turned off by pressing “music notes”
Tone ID the same VCO audio tone will be heard
for all targets.
TRAC Toggle-
The TRAC toggle selects the type of ground mineral rejec-
tion (ground balance) and automatic tracking to ground
mineral changes best suited to the specific area. Three dif-
ferent positions for a specific ground condition (ground type)
are provided.
The Ground position is used for normal or typical ground
conditions. In this position the MXT Pro will quickly com-
pensate for ground minerals in a few pumps of the search
coil over the ground being searched and automatically track
to any ground changes as you sweep the search coil during
searching. For most operators the Ground position will be
used for over 90% of your searching conditions.
The Lock position monitors, however, doesn’t track to
changing ground conditions. Man made iron decomposes to
the point of tricking the Ground and Salt position tracking
CONCERNING ALL MODES
into thinking it is a mineralized part of the ground. This
can create noise and instability during searching as the
tracking system bounces radically up and down the scale,
always searching for a good ground rejection setting and
never able to find it. This makes it difficult for an operator
to recognize worthwhile targets and/or run at the higher
performance GAIN settings. In these conditions it is recom-
mended to first go to the Ground or Salt position and pump
the search coil over a clean area of ground representative
of the area (free of man made iron) then switch the TRAC
control to Lock. By doing so stability and success search-
ing these trashy areas will improve dramatically. Because
ground changes are monitored during Lock, pressing and
releasing the GROUND GRAB button, or switching back
to either Ground or Salt tracking positions, updates to the
appropriate ground setting (ongoing tracking) are virtually
instantaneous.
Another example of when Lock would be used is if a
particular mineralized rock or patch creates difficulties in
searching an area. A hard rock mine for example with a low
mineralized quartz based rock and random high-mineral-
ized magnetite rocks or patches. Place the TRAC control
in the Ground position and balance “pump the search coil”
over a representative sample of the high mineral rock or
patches. Then Lock in that ground rejection setting “place
the TRAC control in the Lock position”. The entire area can
then be searched without the distraction of the inconsisten-
cies the high mineral patches create.
The Salt position provides an extended ground balance
and tracking range to compensate for conductive salts also
called alkali. Ground rejection against salt/alkali slightly
overlaps the lower end of the conductive target (metal)
range. In other words if you ground balanced against signifi-
cant salts, some loss of sensitivity to lower conducting
metals (metals low on the VDI target scale) can be ex-
pected. The advantage and performance improvements of
rejecting the salt, however, far outweigh any loss. Because
the Salt TRAC setting can track well into the target range it
is not recommended for normal conditions, only for areas
known to contain salt.