MINELAB GP 3500 Contact Details: Minelab USA 871 Grier Drive, Suite B1 Las Vegas, Nevada 89119 UNITED STATES OF AMERICA email: minelab@minelabusa.com tel: +1-702-891 8809 Minelab Electronics Pty Ltd PO Box 537 Torrensville Plaza South Australia 5031 AUSTRALIA email: minelab@minelab.com.au tel: +61-8-8238 0888 Minelab International Limited Laragh, Bandon Co. Cork IRELAND email: minelab@minelab.ie tel: +353-23 52101 www.minelab.
l GP 3500 l the Minelab An IMPORTANT MESSAGE from MINELAB page i GP 3500 We ask YOU, as a responsible detector operator, to take all due care regarding the environment. Minelab cannot stress enough the importance of being responsible when recovering targets. BACKFILL EVERY HOLE YOU DIG. If care and consideration is taken, during and after the removal of targets, especially with respect to the back filling of holes, this should ensure the continued access to areas for prospecting and treasure hunting.
page ii l contents l l contents l table of contents 1. introduction table of contents 1 5. detecting 35 Introducing the Minelab GP 3500 1 Detecting techniques 35 Unpacking your GP 3500 [easy reference] 2 Prospecting techniques 39 Identifying target signals 40 Recovering the target 42 2. assembly 3 List of pre-assembled sections and parts 3 Complete assembly instructions 4 3. batteries Battery and charging 6.
page iv l 1 introduction l l contact l page 1 introducing the Minelab GP 3500 contact Contact Minelab Minelab is always interested in your opinions so if you have any questions or comments regarding the GP 3500 or any other Minelab product, please feel free to contact us via your local Authorized Minelab dealer, or write to us: The Minelab GP 3500 utilises “Dual Voltage Technology” (DVT), which assists accurate ground balance and increases sensitivity by overcoming the potential problem of super-satur
page 2 l 1 introduction l unpacking your GP 3500 easy reference l 2 assembly l page 3 list of pre-assembled sections and parts K Headphones (16) J H B Armrest Cover (15) Battery (17) & Battery Pack (18) I A Arm Strap (14) Upper Shaft (8) Bungy Cord (21) Bungy Knuckle (22) Battery Power Cable(19) Coil Cable (2) G Velcro Cable Straps (20) Handle with Wrist Strap (9) F Tear-drop Washers (5) Nylon Nut & Bolt (6) E Fibreglass Lower Shaft (4) D 11 inch Double D Coil (1) & Skid Plate (3) C
page 4 l 2 assembly l l 2 assembly l page 5 complete assembly instructions – continued complete assembly instructions Assembling the lower and upper shaft sections You will need to assemble the GP 3500 from all the various components, so we have provided you with detailed assembly instructions. Refer Figure 2.2 Step 1. Slide the lower shaft (4) with coil attached into the end of the upper shaft (8), snap spring clip into place. Attaching the coil Step 1.
page 6 l 2 assembly l l 2 assembly l complete assembly instructions – continued page 7 complete assembly instructions – continued Attaching the Control Box and achieving balance Fitting and connecting the battery pack Step 1. Position the ‘T-section" on top of the control box (10) into the armrest with the Step 1. Fit the battery (17) into the backpack pouch (18). battery plug at the rear. Tighten the nylon wing nuts by hand. Step 2.
page 8 l 3 batteries l l 2 assembly l page 9 batteries complete assembly instructions – continued Adjust for your own comfort The Battery Step 1. Adjust the bungy cord (21) from the knuckle (22) on the shaft to the correct length to take some of the weight when prospecting. The 6V rechargeable battery can provide enough power to operate the detector for 14-15 hrs, when fully charged. Step 2. Adjust the hand strap on the handle (9) for your own comfort. Step 3.
page 10 easy reference l 3 batteries l batteries – continued l 4 controls and operation l page 11 detector sounds Mains battery charger The mains battery charger will charge the battery from local mains (AC) power outlets. Step 1. Connect the mains charger to a mains outlet. DETECTOR SOUNDS - Explanations Step 2. Connect charger to the battery using the power cable. In the course of operating your detector, there will be various noises and sounds that you may hear.
page 12 l 4 controls and operation l Quick start instructions easy reference page 13 controls and operation rear controls controls and operation – continued TRY OUR WAY FIRST! Step 1. Set the Coil switch to Double D. Step 2. Set Soil switch to N (Normal). Step 3. Set Balance switch to Fixed. Step 4. Set Iron Discriminate knob to All Metals. Step 5. Set Boost to N (Normal) for general detecting. Step 6. Set Volume to maximum and Signal to 2 o’clock. Step 7.
page 14 l 4 controls and operation – rear l l 4 controls and operation – rear l rear controls – continued Figure 4.2 page 15 rear controls – continued Threshold - On/Off Volume NOTE – Always switch the detector Off before connecting or disconnecting the coil or battery pack and when not in use. Sets a maximum loudness of the target signal obtained from a large target. Refer to Figures 4.7 - 4.9. The dotted line in these figures represents the level of volume set by the volume control.
page 16 l 4 controls and operation – rear l l 4 controls and operation – rear l rear controls – continued rear controls – continued Figure 4.10 Tone control page 17 Tone Signal Audio Adjusts the tone of the threshold. The user may set this to the preferred tone, e.g. the tone at which the operator’s hearing is most sensitive.
page 18 l 4 controls and operation – rear l l 4 controls and operation – rear l rear controls – continued rear controls – continued Boost (Shallow/N/Deep) Soil (Sensitive/Normal/Salt) Boost switch selects the type of processing and filtering applied to the detector signals to enhance different target signals in different circumstances. This switch is used to optimise the detector for different soil conditions and targets by changing the signal processing.
page 20 l 4 controls and operation – front l l 4 controls and operation – front l page 21 front controls – continued front controls Smart Point Front Control Functions Smart Point - A quality initiative from Minelab Electronics The Smart Point is an intuitive new feature of the GP 3500. It serves two functions 1) It is the connection point for the Quick-Trak push button to connect with the control box circuitry; (see page 33 - Quick-Trak reset button for more details.
page 22 l 4 controls and operation – front l l 4 controls and operation – front l front controls – continued page 23 front controls – continued All Metal/Iron Discriminate Discrimination - continued Discrimination is the ability of a detector to distinguish between different types of metal objects and to assist the user in identifying a target. Figure 4.18 All Metal / Iron Discriminate switch The GP 3500 is capable of rejecting many iron objects while still detecting non-ferrous metals.
page 24 l 4 controls and operation – front l l 4 controls and operation – front l page 25 front controls – continued front controls – continued Discrimination - continued Discrimination - continued The strength of the target response required for discrimination to occur may be altered by rotating the control knob. There is usually some merging of characteristics between targets, which are clearly ferrous and others that ‘may-be’ ferrous.
page 26 l 4 controls and operation – front l l 4 controls and operation – front front controls – continued l page 27 front controls – continued Coil (Double-D/M/Cancel) Figure 4.22 Coil switch This control changes the sensitivity and search pattern of the coil to allow the GP series of Double-D coils to become multi-versatile with different characteristics to suit different environments.
page 28 l 4 controls and operation l l 4 controls and operation l front controls – continued Figure 4.23 Balance switch (Fixed/Tracking) front controls – continued Balance (Fixed/Tracking) Ground Balancing Procedure The ground you’re searching in contains not only sand, but also many different chemicals, minerals and salts. These extra materials are referred to as ground mineralization. This ground mineralization may often produce a sound from the detector, known as ‘ground noise’.
page 30 l 4 controls and operation l l 4 controls and operation l front controls – continued front controls – continued Operating the GP 3500 in Fixed mode Operating the GP 3500 in Tracking mode In medium to quiet ground you will achieve better depth by operating your GP 3500 in the Fixed position and using the Quick-Trak push button to re-balance when the ground changes and/or threshold becomes erratic.
page 32 l 4 controls and operation l l 4 controls and operation l front controls – continued Tracking Speed Figure 4.25 Tracking speed front controls – continued Tracking Speed Quick-Trak push button If searching in Tracking position, the operator can choose the speed that is best suited to the area. In effect, this gives the operator 4 options to search in: Slow, Medium & Fast plus the 4th being Fixed Balance which is the recommended position subject to variability of the ground mineralization.
page 34 l 4 controls and operation l l 4 controls and operation l page 35 front controls – continued front controls – continued Set the Tune control Tune The Tune function reduces the effects of electromagnetic interference from sources such as power lines, radio transmitters and other metal detectors. There are two controls allowing the operator the greatest flexibility. Tuning should be done initially with the Coil switch in Double D or in M (Mono).
page 36 l 4 controls and operation l l 5 detecting l front controls – continued page 37 detecting techniques After completing the Auto-tune, pick the detector up and with the coil rotated flat, into the search position, listen to see if it is stable. If a slight interference is still present, you can use the manual control to fine tune the selected band.
page 38 l 5 detecting l l 5 detecting l detecting techniques – continued page 39 prospecting techniques Covering the search area • As the user moves forward slowly, the search pattern should resemble a snaking path.
page 40 l 5 detecting l l 5 detecting l page 41 identifying target signals – continued identifying target signals Metallic targets will usually give a 'solid' sounding signal when the coil is swept across the object from any direction. A metallic target generally produces a short, sharp and mostly symmetrical signal. Ground noises usually give a broad uneven signal when the coil is swept from different directions and often may only give a signal from one direction and no signal on the return sweep.
page 42 l 5 detecting l l 5 detecting l recovering the target When you are sure of the location of the target, it is necessary to dig it out. In order to preserve the environment, the hole should be as small as possible. Afterwards, always replace the soil and grass which is removed. It is essential to carry at least one of the following digging tools with you when searching: • small, strong digging spade or shovel. • pick with broad scraping blade. • crowbar (for very deep objects in hard ground).
page 44 l 6 user info l l 6 user info l page 45 troubleshooting technical specifications Use the following table to check for suggested solutions to problems. The GP 3500 Length Weight Maximum 1300mm Minimum 1100mm Complete with 11" coil Fault Suggestion No sound Turn Threshold control fully clockwise. Turn Volume control clockwise. Check power cable and connections. Check headphones. Check battery. Threshold but no target signal Try testing different coils.
page 46 l 6 user info l l 6 user info l service repair form warranty Today’s date: Detector Model: page 47 The GP 3500 control box has a 2 year warranty covering parts and labour. Refer to your warranty card for details. The GP series coils have a warranty for one year against malfunction. Serial No. : Purchased from: Refer to either your supplier or Minelab directly for service. Purchase date: The commencement of the warranty is the date of purchase.
page 48 l 6 user info l l 6 user info glossary of common terms The control box encloses the electronic circuitry of the detector. The control box originates the TX (transmit) signals sent by the coil and interprets the RX (receive) signals detected by the coil. All user selectable functions (knobs & switches) are located on the front and rear panels of the control box.
page 50 l 6 user info l l 6 user info l glossary of common terms– continued Salt page 51 detector care and safety The presence of high salt content in the ground being searched will have a similar but different effect on the metal detector ground balance as does mineralization. Salt content causes a negative (-) response rather than the positive (+) response of laterite soils. The detector needs to therefore use different filtering techniques to overcome this effect.
page 52 l 6 user info l accessories Search coils The GP 3500 is supplied with the 11" Double D coil. This coil has been specially designed to take advantage of the new technology and features of this detector. In addition to this there are also a number of other size coils now available to give improved performance to your detector.
