6
connected the headphones, the detector is ready for use.
First ensure that no metal is in close proximity to the coil. It is also
advisable to carry out the tuning and setting up of the Nexus away from
other detectors or potential sources of electronic interference.
Click the
On-Off switch
on the control box to turn the Nexus on. A tone will
be heard and the meter needle will kick. The tone will fade after 2 -3
seconds. If the initial tone sets for much longer than 3 seconds that will
indicate
Low Battery Condition.
Holding the Nexus with the coil well above ground level, adjust the Gain
control knob to minimum. Adjust the Threshold knob to obtain a minimal
tone setting. Adjust the Volume knob to set a comfortable level. Lower the
coil to the ground and sweep slowly to ensure that there are no metal
targets in the place you are tuning the Nexus. When you are satisfied that
no metal is in the ground where you are standing, the procedure for tuning
can be started.
Position the coil about 2” above and parallel to the ground surface. Raise
the coil gently to about 10” above the ground and lower back to 2” above
ground several times. Note whether the threshold tone remains the same
or if it increases or decreases while raising and lowering the coil. If the tone
rises when LOWERING the coil towards the ground, then adjust the
Ground Balance knob slightly in an anti-clockwise direction. If the tone rises
when LIFTING the coil away from the ground, then adjust the Ground
Balance knob slightly in a clockwise direction. Repeat this procedure to
ensure that an accurate assessment of the tone is obtained. If the tone
remains constant, then the ground balance is set properly. To achieve the
best ground balance tuning, it is essential that the coil be held parallel to
the ground surface at all times during the procedure. If the Ground Balance
is not properly adjusted the Meter needle will move to the left or to the right
in some cases. If the Meter needle moves while raising and lowering the
search coil to the ground, that indicates inaccurate Ground Balance
adjustment.
The next stage is to adjust the sensitivity to suit the site conditions. From
the minimum setting of the Sensitivity knob used in the initial ground
balancing procedure, adjust the Sensitivity knob clockwise to increase the
sensitivity.
Repeat the procedure of raising and lowering the coil between 2” and 10”
above the ground surface, as for ground balancing. If there is no change in
tone while doing this, then the sensitivity may be increased further. For best
