Minelab GPX-4000 Quick Start Manual page 21

36 Soil/Timings
Optimising the Detector
for Different Soil and Target Types
Soil /
The Soil/Timings switch has the ability to change
Timings
the electronic 'timing' or pattern of the pulses. This
optimises the detector for different soil conditions,
the type of coil being used and desired target sizes.
Sensitive
Soil/Timings can make a big improvement to your
finds.
N
Put simply, certain combinations of pulse patterns
(timings) have a particular affinity to certain soil
conditions, (be it magnetic/alkaline/neutral, etc.)
and on different target sizes and conductivities.
Salt
By using the Soil/Timings switch, changes to the
timings can be made to improve the performance in
different conditions.
Sensitive
Sensitive
Sensitive timings have been optimised for an
improved response on smaller, shallow nuggets.
There is a slight loss of depth on bigger targets, so
you should not use this setting when seeking out
large deep nuggets.
There are two types of Sensitive settings available
via the LCD, Extra and Smooth
the factory Preset setting and is very different to
previous GP models. It will eliminate most false
signals from hot rocks and ground mineralisation
whilst retaining excellent sensitivity to small targets.
When switching between Soil/Timings, there is a 1
second pause (ie. 1 second of Threshold) to allow the
change in the detectors electronics to take effect.
(pg. 55). Smooth is
Normal (N)
Normal gives you the best performance on a wide
N
range of soil conditions and will provide the best
depth on a wide variety of target sizes. You will use
this setting most of the time. You should always use
Normal in new areas where you are unsure of the soil
mineralisation and the depth of targets.
Salt
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 it is to detect. In these areas,
Normal should be tried first, but if the Threshold
Salt
is too unstable, then better performance will be
obtained in Salt.
Using the Salt setting may result in a slight loss in
signal response to smaller targets. 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 setting can be used to
obtain a smoother Threshold, allowing you to hear
those mellow deep nugget signals.
Always remember to re-Ground Balance
the detector after making any changes
to the Soil/Timings switch.
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