Ground Balance Procedure For Specific - Minelab GPX-4500 Instruction Manual

Ground Balance Procedure
60
for Specific
When moving to a new area the first Specific
Ground Balance must be done with the Ground
Balance switch — not the Quick-Track button.
1 Find a clear area of ground
without any targets.
2. Select Specific in GB Type in
the Menu.
3 Change Ground Balance switch
to Fixed.
4 Hold the coil 300mm–450mm
(12"–18") above the ground.
5 Change the Ground Balance
switch to Tracking. You will hear a
high pitched tone that only lasts
one second.
Ground
Balance
3 4
Fixed
Tracking
6 When the low pitch tone begins
immediately start lowering and raising
the coil over the ground. Try to lower
the coil parallel and as close to the
ground as possible without touching it.
Continue moving the coil up and down
until the audio has stabilised and any
ground noise has stopped. When there
is no longer a change in the Threshold
the detector is 'Ground Balanced'.
7 Change the Ground Balance back to
Fixed and commence detecting.
Ground
Balance
Fixed
5 6 7
Tracking
Special
Soil/Timings
Ground
Balance
Fixed
Tracking
Time
Range Salt-Coarse, Sens Extra, Sharp, Sens Smooth
Factory Preset
Sens Extra
You can select which timings will be activated by the
Special switch on the control panel.
Salt-Coarse
The effect of alkaline salt mineralisation is vastly
different to the effect of ironstone and mineralised
clays. Anyone who operates on dry salt flats will
know how difficult they can be to detect. Normal
should be tried first in these areas, but if the
Threshold is too unstable then better performance
will be obtained in Salt-Coarse.
Using the Salt-Coarse timing may result in a slight
loss in signal response to smaller targets. However,
the response on larger items remains relatively
unaffected and ground noise is usually minimised.
Therefore, when searching for large deep nuggets in
highly mineralised soil, the Salt-Coarse timings can
be used to obtain a smoother Threshold allowing
you to hear those mellow deep nugget signals.
Sensitive Extra
This timing may increase the signal from certain
hot rocks near the surface, but can actually help
smooth out the Threshold in certain ground types;
particularly with Double-D coils. In mild ground
conditions Sensitive Extra will provide the best
signal response on a small, deep target.
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