Minelab F3 Service Manual page 16

F3 Service Manual
If the ground balance button is not immediately released, the F3 will commence the

Within two seconds the threshold tone should return to its correct level.

If the threshold tone does not return to the correct level refer to section
Finding Procedures.
d. Ground Balance Test. This test confirms the detector is capable of ground
balancing against mineralised ground. In doing so, it confirms the correct operation of
the green ground balance button, wiring loom, coil and electronics pack. The test is
conducted as follows:

Ensure hands and arms are free of metallic objects (watches, rings etc), and
that no other metallic objects are near the coil.

Keeping the detector stationary, press and hold the green ground balance
button for five seconds then release the button.
This action will cause the F3 to delete the previously stored ground balance
condition. Unless this is done, the detector will remember its last ground balance
condition regardless of the unit being switched off or the batteries removed.

Slowly move the ground balance test piece from approximately 15cm (6ins)
above the centre of the coil towards the centre of the coil and confirm that a rise
in threshold tone occurs. This confirms that the F3 is detecting the mineralised
content of the ground balance test piece.

Press down and hold the green ground balance button whilst slowly moving the
ground balance test piece from approximately 15cm (6ins) above the centre of
the coil towards the centre of the coil (and touching the coil). Then move the
NOTE
Ground Balance procedure.
Figure 6: Audio Reset.
NOTE
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