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Recovering the Target

  It is essential to carry at least one of the following 

digging tools with you while detecting: 

– a pick with broad scraping blade (essential)
– a crowbar (for very deep objects in hard ground)
– a small, strong digging spade or shovel (for soft soils, 

sand, etc.)

Back-fill Every Hole You Dig

Always refill any holes, and scatter leaves and surface debris, before 
leaving the area. Help restore the area to its original condition 
to help give electronic prospectors a good reputation, and also 
disguise your secret hot-spot! Any rubbish you recover should be 
taken away with you and disposed of properly. 

Refilling holes and removing rubbish will help detector users 
maintain a good reputation. This should lead to more areas being 
readily accessible for prospecting.

1  Clear the area of loose surface material and  

check that the target signal is still there. If it is not, 
the target should be amongst the moved  
surface material. 

2  Remember if there are other signals close to your 

target. This is important so when you come to dig 
your hole you do not heap the loose dirt on top of 
another target already in the ground.

3  If the target signal is still present use your pick to 

dig to a depth of approximately 50mm (2"). 

4  Sweep the coil over the hole to determine if the 

target has been dug. If the target signal is not 
heard then the target should be in the pile just dug. 
Otherwise dig a little deeper and check again. 

5  Start digging approx. 100mm (4") in front of 

the target to reduce the chance of damaging it. 
Damaging a nugget may reduce its value.  

6  If the target signal disappears from the hole  

sweep the coil over the loose dirt and pinpoint its 
exact position. 

7  Take a handful of the dirt and pass it over the coil.
8  If there is no signal place the handful carefully in a 

new pile, pinpoint the position of the target again, 
and repeat with another handful of soil. 

9  Once the target is in your hand, transfer half of the 

dirt to the other hand. Test each handful of dirt 
across the coil.

10  If the target is too small to see drop the dirt onto 

the top of the coil and with your finger move any 
suspect objects. A target signal will only be given 
when the target is moved.

Note: Your hands and  
wrists must be free of any 
metallic jewellery and 
watches when passing dirt 
over the coil.

Note: When digging,  
avoid sharp edges to the 
hole as they can produce 
false signals, potentially 
masking the target. Slope 
the edges of the hole to 
avoid any problems. 

Note: The GPX-4500 is a 
‘motion’ detector. This 
means it must be moving 
over a target to detect it. 

Summary of Contents for GPX-4500

Page 1: ...terference The tuning process takes approximately 60 seconds Do not move the coil or pass metal objects near the coil during the tuning process Whilst lowering and raising the coil between 25mm and 10...

Page 2: ...marks apply The World Leader in Metal Sensing Technology From our origins in 1985 Minelab have specialised in advanced electronic technologies Our competitive advantage was created almost immediately...

Page 3: ...Technology DVT Smart Electronic Timing Alignment SETA and the latest in high tech analogue components combined with advanced digital processing The GPX 4500 will locate gold in all types of ground es...

Page 4: ...ce Procedure for Specific 60 Special Soil Timings 61 Manual Tune Reducing Electrical Interference 63 Changing Search Modes 64 Motion Adjusting Sweep Speed 66 Rx Gain Adjusting the Sensitivity of the D...

Page 5: ...tector s immunity to highly magnetic rocks and soils Through a process of dynamic noise compensation SETA ensures that the threshold stability is improved and maintained allowing you to operate the GP...

Page 6: ...6 7 List of Parts...

Page 7: ...sure it is loosened 2 Compress the spring loaded pin of the lower shaft Slide the lower shaft into the upper shaft until the pin reaches an adjustment hole The pin will spring out and clip into place...

Page 8: ...in the armrest cover and then slide the cover over the armrest Connecting the Control Box to the Upper Shaft 1 Place the detector on a flat surface with the handle facing upwards 2 Position the armre...

Page 9: ...audio level when a correctly wired speaker is used The new Minelab Lithium Ion battery will automatically detect if headphones or a speaker is in use and adjust the audio level accordingly See wiring...

Page 10: ...omfortable Detecting pg 16 Attaching the Bungy Cord 1 Create a loop in the bungy cord 2 Undo the plastic wingnut and remove the bolt from the clamp 3 Push the bolt back through the clamp and loop to s...

Page 11: ...ough 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...

Page 12: ...socket 3 Switch the wall socket on Vehicle Charger Adaptor The vehicle charger adaptor will charge the battery from the accessories socket cigarette lighter of most motor vehicles The socket must be...

Page 13: ...ruct 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...

Page 14: ...th and target response to small objects A variation in coil height at the end of each swing may cause confusing sounds and reduce detection depth an even flat sweep is desirable Practise sweeping the...

Page 15: ...automatically scans a range of frequency channels to help reduce electrical interference Coil Connector Connects the coil to the control box Smart Point is a connection point for the Quick Trak button...

Page 16: ...ectronics of the detector The On Off switch is located on the rear control panel To turn the detector on or off Press and release the On Off toggle switch Many of the GPX 4500 functions are accessed t...

Page 17: ...LCD menu These are Patch Factory Preset Selection Hi Mineral Hi Trash Test A This allows a total of six separate search modes which can be set up for different circumstances The Main Menu functions ar...

Page 18: ...is mode will help to stabilise the detector in highly mineralised soils yet still remain sensitive to small and deep targets You may need to adjust the Rx Gain setting to suit your particular location...

Page 19: ...ore performing the Auto Tune process When the process is complete simply return the Motion speed to its original setting The detector may be affected by electrical interference from powerlines radio t...

Page 20: ...vel 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 T...

Page 21: ...desired target sizes Soil Timings can make a big improvement to your finds Certain Timings have a particular affinity to certain soil conditions magnetic alkaline neutral etc and on different target...

Page 22: ...is changeable or when you want to cover a large area quickly and efficiently Fixed Fixed holds the last Ground Balance setting In ground where conditions allow Fixed will provide greater depth sensiti...

Page 23: ...odically test that you are still in harmony with the ground by stopping then raising and lowering the coil If the Threshold remains stable then you are still Ground Balanced If there is a change in th...

Page 24: ...the coil to test if you are still in harmony with the ground stop then raise and lower the coil If the Threshold remains stable then you are still ground balanced If there is a change in the Threshold...

Page 25: ...ry close to the coil It is recommended you use the left edge of the coil to pinpoint shallow targets Cancel This setting provides a receive field that is particularly stable in areas of electrical int...

Page 26: ...tings from accidentally being erased whilst allowing the LCD menu Deep Mode and General Mode settings to be quickly restored to factory settings Function Select Setting On Off Hold for FP On Off Hold...

Page 27: ...t Slow Medium Off All Metal Off All Metal 7 Off All Metal Main Menu Range Universal Functions Factory Preset Special Salt Coarse Sens Extra Sharp Sens Smooth Sens Extra Manual Tune 0 255 128 Search Mo...

Page 28: ...etting control accesses a settings adjustment screen The Function Select control scrolls through a list of functions Navigation Arrows Indicates which way the menu can scroll Title Indicates what type...

Page 29: ...odes can be saved with different settings AutoTune Search Mode Soil Timings Ground Balance Coil Rx Cancel Tracking Special Deep Custom Enhance Fixed Double D M N G Threshold Coil Smart Point AutoTune...

Page 30: ...e the advantage of holding power through most of the life of the charge before going into a rapid shutdown LCD Backlight In low lighting conditions the LCD can be backlit You can select how long the b...

Page 31: ...ly be very limited A low volume will be more comfortable on your hearing but will increase the risk of missing small targets Try using a large and small target to adjust the Volume Limit to a comforta...

Page 32: ...evious Minelab models In Tracking General Ground Balance GB samples variations in the ground mineralisation and sets a continuously changing average of the Ground Balance level General GB is ideal for...

Page 33: ...e Factory Preset Salt Coarse Sens Extra Sharp Sens Smooth Sens Extra You can select which timings will be activated by the Special switch on the control panel Salt Coarse The effect of alkaline salt m...

Page 34: ...ough the channels This is normal and will not be present when the control is turned slowly Manual Tune Reducing Electrical Interference Auto Tune pg 33 Range 0 255 100mm 4 Note A slower Motion speed p...

Page 35: ...or your Custom Search mode then while detecting in General or Deep you can quickly change to Custom to pinpoint a target Tip If you wish to quickly compare settings you can change the search mode swit...

Page 36: ...ou are using a Fast Motion and the Threshold is too unstable you can either select Quiet Audio Type pg 68 or reduce Rx Gain pg 67 Range Very Slow Slow Medium Fast Rx Gain Adjusting the Sensitivity of...

Page 37: ...erference are somewhat filtered out Boost This is a more aggressive Audio Type Boost will provide very sharp target signals but will also increase any signal caused by ground noises or electrical inte...

Page 38: ...he optimal position of the stabilizer is one number below the point where the threshold begins to chatter The effect of the Stabilizer could be seen as having a similar effect to that of the Rx Gain c...

Page 39: ...are using the Target Volume to control ground signals and adjustments to the Rx Gain are required due to a change of coil or location make sure the Target Volume is returned to the Factory Preset set...

Page 40: ...arge deep targets use the Response function to invert the pitch Normal When Normal is selected and a small target is detected the pitch normally rises to a higher pitch and then falls to a lower pitch...

Page 41: ...nce pg 41 whenever necessary Ground Balance Tracking Fixed Medium In ground conditions which make operating in Fixed impractical the factory preset Medium setting provides a good compromise between ef...

Page 42: ...l give a non ferrous response until the signal becomes stronger i e due to a hole being dug and the coil getting closer to the target The Iron Reject function is designed this way to allow maximum acc...

Page 43: ...could be mistaken as a ferrous target This setting should only be used in very high trash areas or when using the detector in lower mineralisation when searching for coins and relics Range Off All Met...

Page 44: ...alance Coil Rx Cancel Tracking Special Deep Custom Enhance Fixed Double D M N G Threshold Coil Smart Point Function Select Setting On Off Hold for FP Function Select Setting On Off Hold for FP 1 3 4 3...

Page 45: ...noloop M Setting with DD coil Strongest Signal To pinpoint a detected target sweep the general area with the coil taking note of where the strongest signal is received By shortening the length of the...

Page 46: ...our pick to dig to a depth of approximately 50mm 2 4 Sweep the coil over the hole to determine if the target has been dug If the target signal is not heard then the target should be in the pile just d...

Page 47: ...a signal from one direction and no signal on the return sweep If you are not sure if the sound is ground noise or a target signal you should always investigate Scrape a shallow hole about 30mm 1 deep...

Page 48: ...eady become a favourite for many operators 18 Round Monoloop Superb depth and good sensitivity in low to medium mineralisation This coil will find targets in heavily worked areas where other operators...

Page 49: ...s necessary for Iron Reject to work In high trash concentrations a smaller coil is preferable Search Pattern A Double D coil will typically provide a blade like detection pattern from the toe to the h...

Page 50: ...shape of two D s one reversed The characteristics of a Double D coil are stability especially in heavily mineralised ground good depth and sensitivity and a very thorough search pattern Electromagneti...

Page 51: ...rch coil windings to determine the exact position of the detected target Rx Receive Refers to the response or electromagnetic field which is received back by the coil and is used by the control box ci...

Page 52: ...ape may result in some loss of sensitivity Do not expose the detector to high temperatures or leave it in the sun for longer than is necessary Shading will help protect it Do not leave the detector in...

Page 53: ...t Volume 1 20 Response Normal Inverted Tracking Slow Medium Fast Iron Reject Off All Metal 1 10 User Preferences Main Menu Range User Preferences Backlight Off 1 8 Volume Limit 1 20 GB Type General Sp...

Page 54: ...Ltd regional distributor within 14 days of the original purchase date If you need to return your detector to Minelab for service please fill out the Minelab Service Repair Form Please supply your name...

Page 55: ...cut out or photocopy Please explain how we can replicate the problem in order to repair your detector Today s Date Detector Model Serial Number Purchased From Purchase Date Part s Sent Owner s Name Ad...

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