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At higher settings of iSAT, there will be no change in the sounds of positive or negative hot
rocks. As the iSAT value is decreased, the sound of positive hot rocks will remain the same
but the negative hot rocks may give a thinner beep sound instead of the boing sound.
Therefore, you can make a decision by listening to the warning tones produced by the
device in the field. If you receive a metal sound, it means that you either detected a positive
rock or a piece of metal. If you receive a strong signal and a stable ID, you can distinguish if
the detected target is a rock or metal by checking the ID. However, remember that weak
signals may produce different IDs and metals under rocks may produce different metal
signals. Therefore, the most appropriate action is to dig up when a metal signal is received.
If you are operating with discrimination modes and you know the ID of the surrounding
rocks, you can use the ID filtering to eliminate the rocks. However, this may not be sufficient
to avoid all rock signals. The device may still receive signals from rocks because soil and
rocks together will form a combined effect and generate a different ID than those of rocks.
Tracking and Effects of Rocks
When the tracking is active, the device may give a warning tone and ID when it passes over
a hot rock because the effect of the rock will be different than the ground's. If you swing
the search coil over the rock, tracking will automatically adjust the setting and the warning
tone/ID will either disappear or diminish significantly. Because there is a slight delay in
tracking, you may hear a strong signal at the first one or two swings until the setting is
adjusted. Then the sound will get weaker and disappear. This will not happen with metal
targets because metals will prevent the device from ground balancing. Therefore, in
tracking, if you are getting a constant signal over a target after repeated swings, there is a
high possibility that the target is a metal. Moving from over a rock back to soil, the device
may give signals to the ground for a few swings until the ground balance setting is
updated again. This is normal and should not mislead you.
Tracking is not recommended to eliminate rocks under normal conditions. It is
recommended for use in areas with changing soil types.
Metals Under Rocks
RACER 2
increases the possibility of detecting metal targets under mineralized rocks
through the proper adjustment of your settings. The combined effect created by the rock
and metal together is lower than the effect that the metal creates by itself and the
displayed ID will be different than the metal's expected ID. The displayed ID is formed by
the combination of rock and metal together and gets closer to the ID of the rock if the size
of the metal is smaller in relation to the rock. Keep in mind that metals under hot rocks will
never appear with their own metal ID. For instance, a gold piece under a brick may produce
an iron tone and ID.
Remember this very simple principle as it will save you lots of time: “If the target you detect
is not a stone, it can be metal”.
The key to detecting targets under mineralized rocks, particularly when positive rocks are
in question, is the knowledge of the maximum ID value produced by the surrounding
positive rocks.
