Minelab GPX-4000

Search
Mod
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Soil
/
T
imin
g
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Ground
B
alanc
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Coil
/
Rx
Ca
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ce
lTrackin
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Sa
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D
eep
Pa
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S
ensitiv
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Fi
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Double
D
M
N
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Set the front panel switches to the following positions:
Threshold
Auto Tune
Ground
Balance
Tracking
Fixed
Threshold
On/Off
Hold for FP
Press the On/Off button on the rear control panel. (pg. 25)
Turn the Threshold control up until a tone is audible
through the headphones.
(pg. 34)
Raise the coil off the ground and Press the Auto Tune
button to reduce electrical interference. The tuning
process takes approximately 60 seconds. Do not move the
coil or pass metal objects near the coil during the tuning
process.
(pg. 33)
Whilst lowering and raising the coil between 25mm and
100mm (1" and 4") from the ground, change the Ground
Balance switch to Tracking. Any variations in the Threshold
will smooth out within 3-5 seconds.
(pg. 40)
Adjust the Threshold to a very faint but still audible level.
It should be smooth with only minor fluctuations.
(pg. 34)
You are now ready to start searching!
Quick Start
Search
Mode
Soil /
Timings
Ground
Balance
Coil /
Rx
Patch Sensitive Fixed Double D
NG

Minelab GPX-4000 Specifications

General

Search Modes	Multiple
Ground Balance	Automatic and Manual
Type	Pulse Induction
Technology	Pulse Induction
Target ID	Yes
Audio Output	Speaker, Headphone Jack
Headphones	Yes
Weight	2.5 kg
Battery	Rechargeable NiMH
Power Supply	Battery

Summary

Quick Start

Set the front panel switches to the following positions

Configure initial switch settings for the metal detector.

Press the OnOff button on the rear control panel

Power on the metal detector using the rear control panel button.

Turn the Threshold control up until a tone is audible through the headphones

Adjust the Threshold control to achieve an audible tone in headphones.

Raise the coil off the ground and Press the Auto Tune button to reduce electrical interference

Use Auto Tune to minimize electrical interference by raising the coil.

Whilst lowering and raising the coil between 25 mm and 100 mm (1 and 4) from the ground, change the Ground Balance switch to Tracking

Set Ground Balance to Tracking while moving coil to stabilize audio.

Adjust the Threshold to a very faint but still audible level

Fine-tune the Threshold for a smooth, faint audible level.

Introducing the GPX-4000

Gain

Adjusts the overall sensitivity level of the detector for varied conditions.

Timings

Features improved timings for enhanced performance in different ground conditions.

Ground Balance Type

Offers Normal and Specific options for optimal ground balancing.

Response

Inverts target response pitch for easier identification of deep targets.

Motion

Matches detector response to coil sweep speed to reduce noise.

Assembly

Attaching the Coil to the Lower Shaft

Connects the search coil to the lower section of the detector shaft.

Attaching the Lower Shaft to the Upper Shaft

Joins the lower and upper sections of the detector shaft together.

Attaching the Handle to the Upper Shaft

Secures the detector handle onto the upper shaft.

Attaching the Armrest to the Upper Shaft

Mounts the armrest components onto the upper shaft.

Adjusting the Detector for Comfortable Detecting

Holding the Detector

Proper grip and arm positioning for comfortable detector operation.

Adjusting the Position of the Handle

Setting the handle position for optimal grip and comfort.

Adjusting the Length of the Lower Shaft

Modifying shaft length for comfortable coil swing and balance.

Adjusting the Battery Harness

Fitting the battery harness for maximum comfort during long detecting sessions.

Adjusting the Bungy Cord Clamp (Bow Knuckle)

Positioning the bungy cord clamp to relieve coil weight.

Charging the Battery

Vehicle Charger Adaptor

Instructions for charging the battery using a vehicle's accessory socket.

Mains Charger Adaptor

Details on charging the battery via a standard AC power outlet.

Turning the Detector On

Auto Tune

To Perform an Automatic Tune

Step-by-step guide for conducting an automatic tuning process.

Ground Balance Procedure for Tracking

When there is no longer a change...

Ground Balance re-set in Tracking

Ground Balance Procedure for Fixed

Whilst keeping the coil parallel...

While moving the coil...

Release the Quick-Trak button...

Ground Balance re-set in Fixed

Tracking Speed

Initial Very Fast Ground Balance

Sensitive SoilTimings

Ground Balance Type

General

Specific

Ground Balance Procedure for Specific

Find a clear area of ground without any targets

Change the Ground Balance switch to Fixed

Hold the coil 300 mm-450 mm (12-18) above the ground

Change the Ground Balance switch to Tracking

When the low pitch tone begins...

Continue moving the coil up and down...

Change the Ground Balance back to Fixed...

Manual Tune

Hold the coil vertical and 100 mm (4) above the ground

Access the Manual Tune screen via the menu

Slowly increase or decrease the numbers, pausing after each change to test the stability

Listen to each channel in the range until you hear the least noise

Gain

Pinpointing

Locating the Target

Double-D Setting

Monoloop (M) Setting (with DD coil)

Recovering the Target

Clear the area of loose surface material and check that the target signal is still there

If the target signal is still present, use your pick to dig to a depth of approx. 50 mm (2)

Sweep the coil over the hole to determine if it has been dug

Start digging approx. 100 mm (4) in front of the target to reduce the chance of damaging it

If the target signal disappears from the hole, sweep the coil over the loose dirt and pinpoint its exact position

Take a handful of the dirt and pass it over the coil

Detecting Tips

For Maximum Gold Recovery

Techniques for optimal gold recovery including coil proximity and sweep speed.

Identifying Target Signals

Choosing the Right Coil for the Job

Troubleshooting

No sound

Checks for power, connections, and volume settings when no sound is detected.

Threshold but no target signal

Steps to take when the threshold is present but no target signal is heard.

Random noise

Solutions for persistent random noise, including tuning and coil settings.

Battery will not charge

Troubleshooting steps for a battery that fails to charge.

Battery not holding charge

Coil Overcurrent screen appears

Taking Care of Your Detector