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Summary of Contents for White's GMT

  • Page 2: Table Of Contents

    Standard Battery Holder ........................4 Using the Standard Battery Holder ........................4 Rechargeable Battery(Opt.) ......................... 5 Battery Check ............................5 Chapter 3 GMT Quick Start ..............6 Quick Start Instructions ............................7 Chapter 4 Controls ................. 8 Gain Control/Power Off ........................8 Gain Adjustment ..........................
  • Page 3: Chapter 1 Assembly

    Chapter 1 GMT Assembly Assembly WASHERS BETWEEN EACH LOOP EAR & CLEVIS METER / DISPLAY CABLE RETAINERS 1/ Iron I.D. % Probability Bar Graph 2/ Type of Minerallization ( 0 to 99 ) CLEVIS 3/ Amount of Mineralization ( 0 to 99 )
  • Page 4: Assembly Instructions

    Chapter 1 GMT Assembly Assembly Instructions 1. Remove all parts from shipping carton and 5. Grip the instrument by the handle, with your check the assembly page to make sure all parts are arm in the elbow cup with strap secure, and sweep present.
  • Page 5: Chapter 2 Batteries

    Chapter 2 GMT Batteries Batteries Using the Standard Battery Holder 1. Slide open the battery holder lid (decal side of battery holder) by applying gentle upward pressure on the tab of the door so that it unlocks. Slide the door away from the battery box exposing the cell positions.
  • Page 6: Rechargeable Battery(Opt.)

    Chapter 2 GMT Batteries Rechargeable Battery(Opt.) Battery Check A rechargeable battery system is not standard equipment with your GMT, however, high quality systems are available. White's rechargeable battery #802-5211, and charger #509-0022 are recommended and offer SORRY! LOW BATT quick charge and overnight charge options.
  • Page 7: Chapter 3 Gmt Quick Start

    Chapter 3 GMT Quick Start GMT Quick Start Iron I.D. Trigger Switch three position-Forward, Center, and Squeeze Audio Signal Boost Toggle Switch-three position-On, Off, and Battery Test GROUND BALACE Toggle Two position switch for setting either Fast AutoTrack or Manual GROUND BALANCE...
  • Page 8: Quick Start Instructions

    With the GMT properly assembled and the batter- If you attempt to demonstrate or test the ies installed, follow the instructions below to start GMT by waving targets in the air in front finding those nuggets! of the search coil, it is ESSENTIAL to...
  • Page 9: Chapter 4 Controls

    This is where the new GMT can help you out. When ground mineralization is too high for the current GAIN control setting, the display flashes "BAD GROUND-REDUCE GAIN"...
  • Page 10: Gain Adjustment (Cont'd)

    GAIN" alert keeps popping up on the display or if ground noises are still a problem reduce GAIN. IRON I.D. BARGRAPH 7. The IRON ID capability of the GMT also functions more accurately when the GAIN is set at a level which allows for smooth operation. Too much GAIN can cause bad ground to distort the proper identification of iron and non-iron targets.
  • Page 11: Audio Signal Boost Toggle

    Chapter 4 GMT Controls AUDIO SIGNAL BOOST BATTERY TEST TOGGLE Audio Signal Boost Toggle The AUDIO SIGNAL BOOST toggle switch boosts the sound (makes it louder) to help "hear" very deep or small nuggets. AUDIO SIGNAL BOOST only amplifies the sound AFTER processing thus it does not cause signal overload.
  • Page 12: Hot Rocks

    Chapter 4 GMT Controls Variable SAT Speed Control The Variable SAT (Self Adjusting Threshold) Speed control knob adjusts the speed that the GMT recovers its threshold "hum" when the search-coil passes over changes in mineralization. Changes in mineralization can cause a rise or fall in the "hum".
  • Page 13: Iron I.d. Trigger Adjustment

    Normal tracking STOPS and IRON I.D. adds each succes- Iron I.D. Tips & Facts sive pass to its memory bank. Unique to the GMT, 1. In extreme ground conditions where Iron we call this feature "TARGET ANALYSIS". Since I.D.
  • Page 14: Threshold Control

    Threshold Adjustment The GMT has an improved microprocessor driven THRESHOLD control that is adjusted with a single THRESHOLD CONTROL turn. It does not, therefore, require a 10 turn pot for “HUM”...
  • Page 15: Ground Balance Fast Autotrac

    As most electronic prospectors have always known, gold usually follows black sand. So with the new GMT you can avoid the problems that GROUND BALANCE varying TYPES of ground mineralization cause by...
  • Page 16: "Manual" Ground Balance

    Chapter 4 GMT Controls Ground Balance Adjustment When you turn the GMT on, The GROUND BAL- ANCE reference number in the upper left portion of the display shows a default value of 77(approximate level reading for a ferrite sample). After performing the "pumping"...
  • Page 17: Chapter 5 Searching

    Chapter 5 GMT Searching Searching Pinpoint Technique Due to the wide scan nature of elliptical searchcoils it can be difficult to locate small targets under the physical center of the loop. Use an "X" marks the spot technique as shown in the diagram to identify the portion of ground the nugget is in.
  • Page 18: Headphones

    Chapter 5 GMT Searching Headphones The headphone jack on the GMT is located on the control box near the plug for the search coil. There is a dust cover on the headphone jack that needs to be removed before the stereo plug from the head- phone is inserted.
  • Page 19: Field Use & Tuning Tips

    Rather than concentrating on all of the controls of can tune the GMT, the more gold you will find. the detector, think of the detector's systems as an If small red “hot rocks” (positive mineralization)
  • Page 20 Perfect Ground Balance: Problems from Low Ground Mineralization: At first you will overcorrect the Ground Balance. The GMT is designed to work in an environment of For example, if the sound decreases as the coil heavy iron mineralization. In some instances there...
  • Page 21: Field Use & Tuning Tips (Cont'd)

    This sometimes visible. The Twin D coil on the GMT also helps in sounds like a "boing" when the ground mineral and eliminating these pests. Wet alkalai washes can be...
  • Page 22 If so, a series of separations will the desired results in your area. Therefore, if you quickly expose the nugget. have been operating your GMT at the full level of GAIN (10) and you determine that this is too high Handful Of Dirt:...
  • Page 23: Field Use & Tuning Tips (Cont'd)

    % Iron Probability Blocking: not get you the Gold in heavy mineralization as In operating the GMT, we have noticed that the % well as lower GAIN and a bit of faster SAT. of Iron Probability Block Graph is very dependable.
  • Page 24 This can also be the case with a pocket of negative mineralization. The more you use the GMT, the more you will come to appreciate the very fast tracking which allows you to work with little effort in the changing...
  • Page 25: Chapter 6 Information

    Chapter 6 GMT Information Information Proper care I. Cleaning III. Storage A. Both the coiland rod are waterproof and can A. When the instrument is not in use, make sure be cleaned with fresh water and mild soap. The it is turned OFF.
  • Page 26: Service

    Chapter 6 GMT Information Service White’s reputation has been built on quality products backed by quality service. Our Factory Authorized Service Centers are factory trained and equipped. They offer the same quality service as the factory. Service before and after the sale is the cornerstone of our customer relations.
  • Page 27: Warranty

    Warranty If within two years (24 months) from the original Duration of any implied warranty (e.g., date of purchase, your White's detector fails due to merchantability and fitness for a particular purpose) defects in either material or workmanship, White's shall not be longer than the stated warranty. Neither...
  • Page 28: Warranty Transfer

    (+) and (-) mineralization. The GMT has made it easier to achieve and monitor ground rejection by utilizing digital microprocessor soft- ware to automatically track out (eliminate) ground mineralization.
  • Page 29: Video And Owner Information

    ® White's Electronics, Inc. 1011 Pleasant Valley Road Sweet Home, OR 97386 USA Distribution: 1-800-547-6911 Factory: 1-541-367-6121 FAX: 1-541-367-2968 Web Site: http://www.whiteselectronics.com ©White's Electronics, Inc. P/N 621-0428 Printed in USA Rev. 8/2001...

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Gmt goldmaster series

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