Gold detecting is a fascinating and rewarding activity enjoyed by people all over the world. By getting to know your GPX-4500 you can become one of the many who find gold and valuable treasure.
The GPX-4500 is Minelab's most advanced gold detector. It is a high precision instrument incorporating Multi-Period Sensing (MPS), Dual Voltage Technology (DVT), Smart Electronic Timing Alignment (SETA), and the latest in high-tech analogue components combined with advanced digital processing.
The CPX-4500 will locate gold in all types of ground, especially highly mineralised ground conditions, with greater efficiency than any previous detector.
This manual is designed to help both the beginner and expert prospector get the best performance out of the GPX-4500.
TEC wishes you every success in your quest for gold and treasure!
The GPX-4500 is Minelab's most advanced gold detector. It is a high precision instrument incorporating Multi-Period Sensing (MPS), Dual Voltage Technology (DVT), Smart Electronic Timing Alignment (SETA), and the latest in high-tech analogue components combined with advanced digital processing.
The CPX-4500 will locate gold in all types of ground, especially highly mineralised ground conditions, with greater efficiency than any previous detector.
This manual is designed to help both the beginner and expert prospector get the best performance out of the GPX-4500.
TEC wishes you every success in your quest for gold and treasure!
Holding the Detector:
Thread your arm through the armrest and strap. Grasp the handle of the detector and rest your forearm in the armrest.
Adjusting the Position of the Handle:
Your elbow should sit just above the back of the armrest allowing you to comfortably grip the handle.
Slide the handle into position. Using a screwdriver, tighten the two screws which hold the handle
onto the shaft. Adjust the handle strap to a comfortable position.
Adjusting the Length of the Lower Shaft:
If the coil is too far from your body it will be difficult to balance and manoeuvre while detecting.
If the coil is too close to your body it may detect your pick, the battery, or any other metal which you are carrying; causing confusing sounds.
Rotate the twistlocks of the shafts counter-clockwise to ensure that they are loosened.
Compress the spring pins of the shafts and move them up or down to suit. Once all shafts are clipped into position, rotate twistlocks clockwise onto the shafts until they are firmly clamped.
The correct length of the lower shaft should allow you to swing the coil in front of your body without any uncomfortable stretching or stooping.
Thread your arm through the armrest and strap. Grasp the handle of the detector and rest your forearm in the armrest.
Adjusting the Position of the Handle:
Your elbow should sit just above the back of the armrest allowing you to comfortably grip the handle.
Slide the handle into position. Using a screwdriver, tighten the two screws which hold the handle
onto the shaft. Adjust the handle strap to a comfortable position.
Adjusting the Length of the Lower Shaft:
If the coil is too far from your body it will be difficult to balance and manoeuvre while detecting.
If the coil is too close to your body it may detect your pick, the battery, or any other metal which you are carrying; causing confusing sounds.
Rotate the twistlocks of the shafts counter-clockwise to ensure that they are loosened.
Compress the spring pins of the shafts and move them up or down to suit. Once all shafts are clipped into position, rotate twistlocks clockwise onto the shafts until they are firmly clamped.
The correct length of the lower shaft should allow you to swing the coil in front of your body without any uncomfortable stretching or stooping.
The Lithium Ion battery is specifically designed
for theGPX-4500.
The Lithium Ion battery is not compatible with
non CPX detectors. The GPX-4500 is supplied with a
power lead which has been specifically designed to fit
CPX detectors only. Attempting to use the Lithium Ion battery
pack with other detectors may damage the detector or the battery pack.
Do not try to adapt this battery to other models as it will very likely
cause damage.
• Do not charge the battery at temperatures above 45°C (113°F).
• Do not charge the battery at temperatures below 0°C (32°F).
• Do not leave the battery in hot conditions (e.g. on the dashboard
of your car or rear parcel shelf).
• Do not immerse the battery in any liquid or allow water ingress.
• Do not throw the battery or impact it in any way.
• Do not short-circuit the battery.
• Do not use the battery if it is damaged or deformed.
• Do not disassemble or reconstruct the battery.
• Do not incinerate the battery.
In the event of a fault, you should return the battery to a Minelab
authorised service centre for repair.
The use of non-approved components will VOID YOUR WARRANTY.
There are no user serviceable parts within this battery pack.
for theGPX-4500.
The Lithium Ion battery is not compatible with
non CPX detectors. The GPX-4500 is supplied with a
power lead which has been specifically designed to fit
CPX detectors only. Attempting to use the Lithium Ion battery
pack with other detectors may damage the detector or the battery pack.
Do not try to adapt this battery to other models as it will very likely
cause damage.
• Do not charge the battery at temperatures above 45°C (113°F).
• Do not charge the battery at temperatures below 0°C (32°F).
• Do not leave the battery in hot conditions (e.g. on the dashboard
of your car or rear parcel shelf).
• Do not immerse the battery in any liquid or allow water ingress.
• Do not throw the battery or impact it in any way.
• Do not short-circuit the battery.
• Do not use the battery if it is damaged or deformed.
• Do not disassemble or reconstruct the battery.
• Do not incinerate the battery.
In the event of a fault, you should return the battery to a Minelab
authorised service centre for repair.
The use of non-approved components will VOID YOUR WARRANTY.
There are no user serviceable parts within this battery pack.
Note: The GPX-4500 is a
‘motion’ detector. This
means it must be moving
over a target to detect it.
‘motion’ detector. This
means it must be moving
over a target to detect it.
The GPX- 4500 will per f orm at i ts best wh en the coil
is kept close an d parallel to the ground at al l times.
This will increase the d etecti on d epth and target
response to small objects.
A variation in coil height at the end o f ea ch swing
may cause confusing sounds and reduce detection
depth; an even flat swee p is de s irable.
Practise sweeping the coil over the ground in a
side -to-side motio n, while walking for ward sl owly at
the end of each sweep. Slightly overlap the previous
sweep to e nsure full ground coverage. An average
sweep spe ed is four se co nds from left to right to left.
is kept close an d parallel to the ground at al l times.
This will increase the d etecti on d epth and target
response to small objects.
A variation in coil height at the end o f ea ch swing
may cause confusing sounds and reduce detection
depth; an even flat swee p is de s irable.
Practise sweeping the coil over the ground in a
side -to-side motio n, while walking for ward sl owly at
the end of each sweep. Slightly overlap the previous
sweep to e nsure full ground coverage. An average
sweep spe ed is four se co nds from left to right to left.
Tip: When using a Monolo op coil m ore overl ap is
required to ensure that targe ts at maxim um depth are
n ot over looked (see pg . 9 0 for a diag ram show ing coil
search pat terns) .
required to ensure that targe ts at maxim um depth are
n ot over looked (see pg . 9 0 for a diag ram show ing coil
search pat terns) .
Note: Tuning should be done initially with the Coil switch in Double-D or in Monoloop (M). If the interference is still severe after completing the tuning operation change the Coil switch to Cancel and then re-tune the detector if necessary.
To Perform an Automatic Tune:
1 Hold the detector at waist height, with the coil vertical, and slowly rotate through a half-circle. Make sure there are no large targets or obvious electrical interference sources close by.
2 Face the direction of the most interference and hold the coil steady.
If you have difficulty holding the detector very still for 60 seconds, you can place the detector on the ground with the coil vertical.
3 Press the Auto Tune button. Keep the detector completely still during the automatic channel scanning process.
A single beep indicates the beginning of the Auto Tune. The detector will begin to scan each channel for the least interference. This may take up to
60 seconds.
The detector will select the quietest operating channel identified. The end of the Tuning process will be indicated by three sharp ‘beeps’.
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 the same time.
Any interference is made more obvious with a faster Motion setting (pg. 66). Therefore, you can assist the Auto Tune function in selecting the quietest frequency band by selecting Fast Motion before performing the Auto Tune process. When the process is complete simply return the Motion speed to its original setting.
1 Hold the detector at waist height, with the coil vertical, and slowly rotate through a half-circle. Make sure there are no large targets or obvious electrical interference sources close by.
2 Face the direction of the most interference and hold the coil steady.
If you have difficulty holding the detector very still for 60 seconds, you can place the detector on the ground with the coil vertical.
3 Press the Auto Tune button. Keep the detector completely still during the automatic channel scanning process.
A single beep indicates the beginning of the Auto Tune. The detector will begin to scan each channel for the least interference. This may take up to
60 seconds.
The detector will select the quietest operating channel identified. The end of the Tuning process will be indicated by three sharp ‘beeps’.
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 the same time.
Any interference is made more obvious with a faster Motion setting (pg. 66). Therefore, you can assist the Auto Tune function in selecting the quietest frequency band by selecting Fast Motion before performing the Auto Tune process. When the process is complete simply return the Motion speed to its original setting.
Threshold is the constant audible background tone or 'hum' produced by the detector. The Threshold is your reference point and lets you know what the coil is picking up, whether it may be a target, ground noise, or electrical interference, so it is important to set the threshold so it can be heard.
The level of the Threshold should be set low, but still audible and stable. Ideally it should be a smooth, gentle hum. If you set it so that it can't be heard you may set other detector settings incorrectly.
Small targets or large deep targets may not produce a distinct target signal, but may cause only a small variation in the Threshold. If the Threshold level is set too high or too low these very small variations may be missed.
Listening for a target signal with a high Threshold would be like trying to hear a whisper within a crowded noisy room. A high Threshold may also be uncomfortable to your hearing.
If the Threshold is set too low the target signal needs to be loud enough to become audible. Therefore, very soft target signals, from small or very deep targets, may not be heard.
It is important to reset the Threshold level as conditions change. For example, your ears may adjust to the low levels of audio after an hour or so, or the conditions may have become windy
The level of the Threshold should be set low, but still audible and stable. Ideally it should be a smooth, gentle hum. If you set it so that it can't be heard you may set other detector settings incorrectly.
Small targets or large deep targets may not produce a distinct target signal, but may cause only a small variation in the Threshold. If the Threshold level is set too high or too low these very small variations may be missed.
Listening for a target signal with a high Threshold would be like trying to hear a whisper within a crowded noisy room. A high Threshold may also be uncomfortable to your hearing.
If the Threshold is set too low the target signal needs to be loud enough to become audible. Therefore, very soft target signals, from small or very deep targets, may not be heard.
It is important to reset the Threshold level as conditions change. For example, your ears may adjust to the low levels of audio after an hour or so, or the conditions may have become windy