Minelab GP Extreme User Manual Download Page 22

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I r o n   D i s c r i m i n a t e

F i g u r e s   5 . 4 ,   5 . 5

Iron discrimination with the ‘GP extreme’ is the silencing or ‘blanking

of the threshold which occurs when the detector determines a target

is comprised of ferrous metal.

There is no discrimination when Iron Discrimination is set to All

Metal.  Targets will cause the tone and volume of the threshold to

vary. These variations convey no consistent information about the

type of metal detected.

Iron discrimination operates when Iron Discriminate is set to Disc.

Objects must produce sufficiently strong target responses for the detector

to successfully discriminate. Fortunately, most iron rubbish is located near

the surface and should produce the required strong signal response.

NOTE

   When Disc is used, small or deeper targets, whether

ferrous or non-ferrous, will produce a normal target signal.

If a target response is too weak for the detector to discriminate,  it will

internally change to the all metal mode. As soon as the target response

becomes strong enough, the detector will resume discrimination.

Pinpointing is best performed using All Metal.

HINT

  When a target has been located using Disc, the coil should

be rapidly passed back and forth over the target centre several

times. Remember to set Balance to Fixed for this.

The coil should always be passed smoothly over the surface of the

ground, while maintaining the coil height above the ground. This is

especially important when attempting to discriminate a target.

NOTE

   Discrimination will give the best results when used in

combination with the specially designed ‘GP extreme’ coils.

When detecting a piece of iron, a normal target signal should be

heard until the detector determines that the object is ferrous.

At this point, the signal will 'blank'.

The strength of the target response required for discrimination to

occur may be altered by using Level Adjust.

Figure  5.4

A  normal  signal  on  a  non-ferrous

target.

P 0 0 5 1 4 - A

Figure  5.5  Discrimination  target  signal  on  a

ferrous  target.

P 0 0 5 1 4 - B

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Level  Adjust  Control

Level Adjust gives the user the ability to select the sensitivity and

likelihood of a target being discriminated as ferrous when used in

the Disc mode.

This may also affect how the detector responds to ground

mineralisation compared to metal targets when used in Disc. Mode.

There is usually some overlap between signals from useful targets

and some types of iron rubbish. The user may set Level Adjust to

select the amount of discrimination between two extremes:

(Fully anti-clockwise). All targets detected, but some iron will

give a normal signal (as per Figure 5.4).

(Fully clockwise) Little iron detected, but some small non-

ferrous targets potentially mistaken as ferrous.

Turning the control anti-clockwise increases the strength of a signal

required for iron discrimination to be activated.

The Level Adjust also affects the Tracking mode.

When set fully clockwise, it is unlikely the detector will 'balance out'

genuine targets, but some ground noise may still give false signals.

When set fully anti-clockwise, the detector will 'balance out' ground

noise effectively, but some faint, weak target signals may be missed

after repeated sweeps of the coil.

HINT

   It is usually best to dig out all targets and only use the

discrimination function in areas where a large amount of rubbish

makes the digging of everything impractical.

NOTE

   Discrimination functions will only work with strong,

positive target responses. Weak responses will give normal

'all metal' type signals.

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Summary of Contents for GP Extreme

Page 1: ...Minelab USA Inc 871 Grier Drive Suite B1 Las Vegas Nevada 89119 United States of America Telephone 1 702 891 8809 Facsimile 1 702 891 8810 Email info minelabusa com...

Page 2: ...THE MINELAB GP extreme I Minelab GP extreme 4901 0036 Version 0 1 4901 0036 Revision 1 2...

Page 3: ...data or restricted rights data or both Patents and trademarks apply THE MINELAB GP extreme III TABLE OF CONTENTS INTRODUCTION 1 About this manual 2 Introducing the Minelab GP extreme 3 ASSEMBLY 5 Unpa...

Page 4: ...he Minelab GP extreme 50 Troubleshooting 51 Service repair form 52 Warranty 53 Accessories 54 Glossary of common terms 55 Detector care and safety 59 An important message from Minelab 60 7 THE MINELAB...

Page 5: ...ng tips ABOUT THIS MANUAL THE MINELAB GP extreme INTRODUCTION 1 3 Minelab GP extreme is the first detector to use Dual Voltage Technology DVT Minelab have developed this new Dual Voltage Technology DV...

Page 6: ...nternational Limited Laragh Bandon Co Cork IRELAND email minelab minelab ie tel 353 23 52101 Contact Minelab Minelab Electronics Pty Ltd PO Box 537 Torrensville Plaza South Australia 5031 AUSTRALIA em...

Page 7: ...d Figure 2 1 Contents of the GP extreme pack P0501 A easy reference UNPACKING YOUR GP extreme THE MINELAB GP extreme 7 ASSEMBLY 2 LIST OF PRE ASSEMBLED SECTIONS AND PARTS PRE ASSEMBLED SECTIONS Figure...

Page 8: ...COMPLETE ASSEMBLY INSTRUCTIONS Attaching the handle and bungy cord Figure 2 4 refer also Figure 2 2 STEP 1 Slide the handle 9 onto the other end of the upper shaft 8 and set it to a comfortable posit...

Page 9: ...ctor and cause random noises which may be confusing HINT Use only the 6v DC battery supplied CAUTION Attaching the lower fibreglass shaft Figure 2 2 STEP 1 Slide the lower fibreglass shaft 4 into the...

Page 10: ...ww minelab com THE MINELAB GP extreme 13 BATTERIES 3 3 Battery The GP extreme is supplied with a 6v DC rechargable battery pack plus both mains and vehicle chargers This chapter provides details on ba...

Page 11: ...battery in approximately 20 hours The 1000mA charger will recharge a completely flat battery in approximately 10 hours Partially discharged batteries require a shorter period to recharge Allow approx...

Page 12: ...ww minelab com THE MINELAB GP extreme 17 4 CONTROLS 4 Controls It is important to familiarise yourself with the features of the GP extreme control panel A few minutes spent reading this chapter will b...

Page 13: ...oving the coil over the ground Ground noise is caused by the changing chemistry or mineralisation of the ground When the Balance switch is set to Tracking these effects are greatly reduced Tune Indica...

Page 14: ...too high then small variations in audio signal might not be discernible above the threshold level Figure 4 5 An example of this would be to hear a whisper within a crowded noisy room Figure 4 5 Thresh...

Page 15: ...igh low pitch variance to a target is reduced At maximum position the high low pitch variance to a target is increased CONTROL FUNCTIONS Figure 4 12 Signal control Audio Figure 4 13 Reduced pitch vari...

Page 16: ...Cancel Figure 4 21 Changes the sensitivity and search pattern of the coil to allow the GP extreme range of coils to become multi versatile coils with different characteristics to suit different envir...

Page 17: ...Fixed the ground balance remains at the current level When Balance is changed from Fixed to Tracking the detector begins to automatically ground balance through a two stage process that is described o...

Page 18: ...TIONS HINT Take time to read this manual thoroughly to obtain the best performance from your new GP extreme detector THE MINELAB GP extreme 28 O P E R A T I O N 5 www minelab com QUICK START INSTRUCTI...

Page 19: ...extreme 31 O P E R A T I O N 5 DETAILED OPERATING INSTRUCTIONS E Enhance changes the way the coil transmits and receives its signals Operating in enhanced the coil has some of the characteristics of a...

Page 20: ...e detector known as ground noise The GP extreme has the ability to cancel out the effects of ground mineralisation This minimises ground noise and retains maximum sensitivitytometaltargets Cancellingt...

Page 21: ...able use Tracking If the ground is very mild use Fixed and switch back to Tracking temporarily if the threshold becomes noisy Do not test a target by switching to Tracking when the coil is above it HI...

Page 22: ...al should be heard until the detector determines that the object is ferrous At this point the signal will blank The strength of the target response required for discrimination to occur may be altered...

Page 23: ...t response should pause the tracking mode but weak responses may be mistaken for ground mineralisation MAX FULLY CLOCKWISE Almost all iron objects are discriminated but a few small non ferrous items w...

Page 24: ...e coil it is important to keep it parallel to and at the same height from the ground at all times Lightly skidding the coil across the ground can sometimes help in this depending on mineralisation Do...

Page 25: ...ery carefully this is more important than looking SLOW DOWN Do not rush take your time For Maximum Gold Recovery THE MINELAB GP extreme 43 D E T E C T I N G 6 IDENTIFYING TARGET SIGNALS IDENTIFYING TA...

Page 26: ...of the coil if operating with the RX switch set to Enhance or Cancel THE MINELAB GP extreme 45 D E T E C T I N G 6 RECOVERING THE TARGET When you are sure of the location of the target it is necessary...

Page 27: ...TEP 3 Keep testing the target location as you dig deeper STEP 4 Take care that the target is not in the wall of the hole You may dig past it Try pinpointing again to check your hole is in the correct...

Page 28: ...D E T E C T I N G 6 www minelab com THE MINELAB GP extreme 49 USER INFO 7 7 User Info This chapter provides a glossary of terminology user guides technical specifications warranty and repair details...

Page 29: ...7 TROUBLESHOOTING Use the following table to check for suggested solutions to problems No sound Turn Threshold control fully clockwise Turn Volume control clockwise Check power cable and connections C...

Page 30: ...________________ Phone Day ______________________ Home _______________________________________ Fax ____________________________ Email ____________________________________________ SERVICE REPAIR FORM S...

Page 31: ...d by the coil All user selectable functions knobs switches are located on the front and rear panels of the control box Discrimination The ability of a metal detector to estimate if a located target is...

Page 32: ...position of the detected target RX RX refers to the response or electromagnetic field which is received back by the coil and is used by the control box circuitry to detect a metal item in the ground...

Page 33: ...AND SAFETY THIS DEVICE COMPLIES WITH PART 15 OF THE FCC RULES Operation is subject to the following two conditions 1 this device may not cause harmful interference and 2 this device must accept any in...

Page 34: ...filling of holes this should ensure the continued access to areas for prospecting and treasure hunting This will also ensure that the pristine condition of our beautiful bushland forests and dry land...

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