Special / Soil/Timings; Manual Tune / Reducing Electrical Interference - Minelab GPX-4500 Instruction Manual

Special
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Soil/Timings (Continued)
Sharp
Sharp is similar to Normal but it puts out a more
powerful detection field. It is capable of an
improvement in depth, but it is more susceptible
to interference and will also increase the severity of
false signals in difficult grounds.
This timing is best used in quiet conditions and can
work well in combination with Deep Search Mode;
with a reduced Rx Gain setting. Sharp is an excellent
tool for pinpointing faint signals due to the very
"sharp", aggressive signal response.
Choose Sharp in the menu and select it by switching
into Special on the front panel.
Note: Sharp will work best with DD coils in most
gold field locations.
Sensitive Smooth
Sensitive Smooth is optimised for an improved
response on smaller, shallow nuggets in severe soils.
There is a slight loss of depth on bigger targets; so
you should not use this setting when seeking out
large, deep nuggets.
Sensitive Smooth allows the use of monoloop coils
in highly mineralised areas. It eliminates most false
signals from hot rocks, and ground mineralisation,
whilst retaining excellent sensitivity to small targets.
Note: Sensitive Smooth is best suited for use with
monoloop coils in difficult soils.
Manual Tune
Reducing Electrical Interference
(Auto Tune, pg. 33)
Range 0–255
Manual Tune allows you to scroll through and select
a particular channel.
Manual Tuning through the full range is time
consuming. We recommend that you use the
Manual Tune for fine adjustments after performing
an Auto Tune
You may find that you can select a channel at one
end of the scale, or the other, if detecting in a quiet
area with no interference. Low numbers are lower
frequency channels and high numbers are higher
frequency channels. High frequency channels can
be slightly more sensitive to smaller targets close to
the surface. Low frequency channels can give a little
more depth to larger targets, but the difference is
only marginal.
1 Hold the coil vertical and 100mm (4") above the
ground making sure there are no large targets or
obvious electrical interferences close by.
2 Access the Manual Tune screen via the menu.
3 Slowly increase or decrease the numbers, pausing
after each change to test the stability.
100mm
4 Listen to each channel in the range until you hear
(4")
the least noise.
Note: If interference persists after tuning try reducing
the Rx Gain setting, but in high interference areas you
Note: A slower Motion
may need to use Cancel on the Coil/Rx switch.
speed (pg. 66) will also
If the setting control is turned quickly you will notice
reduce instability due to
noise caused by rapid movement through the
interference.
channels. This is normal and will not be present when
the control is turned slowly.
(pg. 33).
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