Minelab GP 3500 User Manual

front controls – continued
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GP 3500
Tune
The Tune function reduces the effects of electromagnetic interference
from sources such as power lines, radio transmitters and other metal
detectors. There are two controls allowing the operator the greatest
flexibility.
Auto push button
Pressing and releasing the Tune button starts automatic tuning. The
tuning process takes approx. 60 sec. and completion is indicated by
three sharp ‘beeps’. Once pressed, the GP 3500 scans through a wide
range of search bands, testing each one for it’s susceptibility to outside
electromagnetic waves in the same or similar bands that would cause
interference. On completing the search, it selects the most stable band
for operating in the environment of operation.
NOTE – Interference in some locations can change during the
course of the day so you may need to re-tune from time to time to
maintain a smooth threshold as you move around the area.
Figure 4.27
Tune control & button
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l 4 controls and operation l
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Set the Tune control
Tuning should be done initially with the Coil switch in Double D or in M (Mono). If the
interference is still severe after completing the tuning operation, change the Coil switch to
Cancel and then re-tune the detector again.
• Hold the detector at waist height and the coil vertical and slowly rotate through a
half-circle (eg: from East to West, or from North to South).
• Listen for any increase in interference as you move and when the interference is loudest,
stop moving. Lay the detector on the ground, facing that position, and keeping the
coil vertical.
• Press and release the Tune button.
• The detector will then scan through the available range of transmission frequencies and
automatically select the frequency that results in the greatest reduction of noise from
electromagnetic interference.
• The end of the tuning process (which takes approx. 60 sec.) is announced by three beeps.
NOTE – While the detector is selecting the preferred frequency, the coil must be
kept motionless and clear of metal objects. If you move the coil or allow it
to sense a metal target, the testing for the quietest band will be influenced.
When tuning the detector in close proximity to other detectors, each
operator needs to take turns tuning.
Do not try to tune two detectors at one time
.
Figure 4.28
The Tuning
Process
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GP 3500

Minelab GP 3500 Specifications

General

Brand	Minelab
Model	GP 3500
Category	Metal Detector
Language	English