Minelab Eureka Gold Metal Detector User Manual
1. Introduction
The Eureka Gold's primary feature is its constant, automatic ground balance, ensuring optimal performance and reducing user fatigue while extending the search range.
To accommodate a wide range of targets, the Eureka Gold offers three operating frequencies:
- 6.4 kHz
- 20 kHz
- 60 kHz
Another advanced feature is the pitch change in target signals, which helps reduce noise. The detector comes standard with a 10-inch (25cm) Double-D coil. Please note that the equipment and options may vary by model and country of purchase, so the manual's descriptions or diagrams may differ from your unit.
2. Package Contents
Please check that all the following items are included in your package:
- Eureka Gold Control Box
- 10-inch (25cm) Double-D Search Coil and Coil Cover
- Two-piece Shaft Assembly (including lower fiberglass shaft)
- Two-piece Aluminum Armrest (with bolts and nuts)
- Mounting Bracket for Control Box
- NiMH (Nickel Metal Hydride) Battery Pack
- NiMH Battery Charger
- Neoprene Armrest Cover
- Two-piece Armrest Straps
- 'Teardrop' Washer
- User Manual
- Detector Stand
The following accessories are also available as options:
- 12V NiMH Car Charger
- 11-inch (28cm) Circular Double-D Search Coil
- 15-inch (38cm) Spider Coil
- Minelab Logo Cap
- Minelab Polo Shirt
- Minelab Jacket
- Padded Carry Bag
3. Detector Assembly
Follow these instructions to assemble your detector. Refer to the figures for parts confirmation and assembly locations.
3.(1) Armrest and Upper Shaft Assembly
a) Attach one armrest (④) to each side of the upper shaft, aligning the bolt holes.
b) Insert nylon bolts (⑪) through the bolt holes and loosely secure with nylon wing nuts (⑫) by turning them two or three times. Do not tighten fully yet.
Figure 2: Armrest/Upper Shaft Assembly - Illustrates the connection of the armrest to the upper shaft, showing components like bolts, nuts, and the armrest itself.c) Insert the detector stand (⑦) into the groove on the armrest and hand-tighten the wing nut.
d) Attach the armrest straps (⑥) using the push-button clips on the armrest.
e) Thread the armrest straps through the holes in the armrest cover (⑤) and attach the cover to the armrest.
3.(2) Lower Shaft Assembly
a) Remove any tape from the lower fiberglass pipe.
Note: Be careful not to lose the washer after removing the tape.
b) Remove the black nylon wing nut (⑫) and bolt (⑪) from the search coil (⑨).
Figure 3: The Coil and Lower Shaft Assembly - Depicts the search coil, lower shaft, and the hardware used for their connection, including washers and nuts.c) With the teardrop washer (⑲) in place, insert the lower fiberglass pipe (③) into the coil bracket, aligning the holes.
Note: Ensure the black nylon spring clip near the top of the fiberglass pipe faces the rear of the coil.
d) Insert the black nylon bolt (⑪) from the cable entry side of the coil into the coil bracket, insert the washer (⑲), and hand-tighten the wing nut (⑫).
3.(3) Completing the Shaft Assembly
a) Insert the assembled lower shaft (③) into the aluminum upper shaft (②).
Note: You may need to loosen the nut (⑱) on the lower shaft to align it correctly.
Figure 4: Completing the Shaft Assembly - Shows the final assembly of the shaft sections and the attachment of the control box.b) Secure the black nylon spring clip in an adjustment hole to set the shaft length, and tighten the plastic nut.
3.(4) Mounting the Control Box
a) Position the control box so the recess (①) on its back aligns with the edge of the mounting clip (⑧). Push the front of the control box upwards until it clicks into place (see Figure 5).
b) Wrap the cable around the shaft approximately 17-20 times to reach the control box.
Note: Leave some slack in the cable near the coil for easier adjustment of the coil's position.
Figure 5: Mounting the Control Box on the Shaft - Illustrates how the control box is attached to the detector shaft.c) Connect the coil connector (⑬) to the plug (⑭) on the back of the control box.
d) Secure the cable to the shaft using the magic tape, ensuring proper positioning between the coil and shaft.
Note: A waterproof hip pouch is available as an option for protection in wet weather. It allows the control box to be used while mounted on the shaft.
3.(5) Mounting the Control Box to the Rear of the Shaft
The control box can also be mounted on the rear of the shaft, below the armrest. This provides an alternative mounting position.
Figure 6: Mounting the Control Box to the Rear of the Shaft - Shows an alternative method for attaching the control box to the shaft.a) Loosen the wing nut from the armrest and remove the detector stand.
Note: Leave sufficient slack in the coil cable for easier adjustment.
b) Insert the mounting bracket on the back of the control box.
c) Tighten the nylon wing nut on the armrest.
d) Insert the control box into the rear mounting bracket.
e) Wrap the cable around the shaft axis with magic tape.
f) Connect the coil connector (⑬) to the plug (⑭) on the back of the control box.
3.(6) Hip Mount / Armrest Mount
Using a hip mount reduces arm strain and allows for longer detecting sessions without fatigue. A hip mount bag is available as an option.
a) Ensure the battery pack is charged.
b) Place the control box into the hip mount bag with the controls facing outwards. (See Figure 7)
Figure 7: Hipmounting the Control Box - Illustrates the control box placed inside a hip mount bag.c) Position the bag as desired, worn on a belt or over the shoulder.
Note: If wearing the device on the chest, use the belt loop to secure the bag around the chest.
d) Wrap the cable around the shaft approximately 5 times, minimizing excess cable.
Note: Leave sufficient slack in the cable near the coil for adjustment.
e) Secure the cable with magic tape at the base of the shaft, near where it enters the control box.
f) Wrap excess cable around the hip mount bag's belt bracket before connecting to the control box. (See Figure 8)
Figure 8: Hipmounting the Control Box - Shows the process of wrapping the cable for hip mounting.g) Connect the coil connector to the socket on the back of the control box and tighten the nut.
4. Battery
The Eureka Gold uses a 12V NiMH battery pack and charger. A 12V car charger is available as an option.
4.(1) Installing the NiMH Battery Pack
a) Ensure the NiMH battery pack is fully charged.
b) Place the battery pack at the rear of the battery compartment (A). Push the front of the pack in to seat it (B). Two battery clips will secure the pack.
Figure 9: Installing the Battery Pack - Shows the correct orientation and method for inserting the NiMH battery pack. Figure 10: Replacing the Battery Lid - Illustrates how to close and secure the battery compartment lid.Note: NiMH batteries are factory sealed and cannot be opened.
4.(2) Installing Alkaline Batteries
An optional battery pack for 8 AA alkaline batteries is available and useful for backup power.
a) Ensure the unit is switched OFF before opening the battery compartment.
b) Slide open the battery pack lid.
c) Insert 8 AA alkaline batteries (16) into the base of the alkaline battery pack (15), ensuring they are oriented as shown in Figure 10 and the compartment.
d) Close the battery compartment lid.
e) Insert the base of the battery pack into the rear of the battery compartment (A). Push the front edge of the pack firmly to seat it (B). The battery clips will secure it.
Note: Genuine alkaline batteries provide approximately 10-15 hours of operation.
4.(3) Low Battery Warning and NiMH Battery Recharging
When the battery is low, the Eureka Gold emits a sharp "beep" approximately every 30 seconds. This is followed by a continuous tone that can be adjusted with the Threshold control. When this occurs, recharge the NiMH battery pack or replace alkaline batteries. Recharging can be done with the supplied charger or the optional 12V car charger.
Note: Pay attention to the charger's output voltage. Use the correct charger for your country.
4.(4) Using the NiMH Battery Charger
Connect the charger to the NiMH battery pack socket, connect the charger to power, and switch it on. The car charger has a red light indicating power. A fully discharged battery requires about 12-14 hours to charge. A green light indicates a full charge. A fully charged NiMH battery pack provides 15-20 hours of detecting.
Figure 11: Car and Mains Battery Chargers - Shows the connection of both the mains charger and the optional car charger to the battery pack.5. Eureka Gold Control Panel
The Eureka Gold's control panel is designed for easy access to frequently used controls. (See Figure 12)
Figure 12: The Eureka Gold Control Panel - A detailed diagram labeling all the controls on the detector's main unit, including Volume, Threshold, Sensitivity, Frequency, Signal, Mode, Tone, and Balance switches.5.(1) Volume Control
The Volume control also functions as the On/Off switch. Turning it fully counter-clockwise turns the unit OFF. Turning it clockwise turns it ON. This sets the maximum signal audio output. Lowering the volume can suppress signals from larger targets while keeping smaller target signals audible.
Figure 13: Volume Control (The maximum audio output (volume) can be limited) - Illustrates how adjusting the volume affects the audio output, showing full volume and low volume settings.5.(2) Threshold Control
This control is used to maintain a constant background hum or "threshold" sound, also known as the "working sound." Set the control so the sound is just audible without being distracting. Too high a threshold can mask faint signals.
Figure 14: Threshold Control Settings - Shows graphical representations of different threshold settings and their impact on detecting small targets, illustrating audible signal levels and noise.The dotted line in Figure 14 indicates the audio output level. If the signal is below this line, it is inaudible. A correctly set threshold allows detection of faint signals just above the noise floor. Setting it too high makes it difficult to distinguish small variations in signals. Setting it too low results in no background noise and the inability to hear faint signals.
5.(3) Sensitivity Control
This control affects signals from small/shallow targets, large/deep targets, and mineralized ground. Unlike the Volume control, it affects both large and small targets equally. It is recommended to set the Sensitivity control to maximum for normal ground conditions.
Figure 15: Sensitivity Control - Illustrates how sensitivity settings amplify the audio output, showing maximum and minimum sensitivity.The sensitivity control generally does not reduce interference from electrical noise, high ground mineralization, or ironstone, except to minimize it.
5.(4) Frequency Switch
The Eureka Gold has three operating frequencies: 6.4 kHz, 20 kHz, and 60 kHz. 6.4 kHz is best for deep, large gold nuggets, while 60 kHz is for shallow, small gold nuggets. 20 kHz is suitable for general detecting or intermediate conditions.
After changing the frequency, there is a 2-second delay. Ground balance may also shift slightly, but the detector will re-balance automatically. If you are concerned about losing targets, perform manual ground balancing (see pages 16-18).
5.(5) Signal Switch
This switch offers three audio levels: Normal, Fine, and Boost. Normal has no effect on target signals. Fine is for detecting small targets near the surface, especially in mineralized ground; it amplifies and filters signals. Boost amplifies signals for maximum depth in uniform ground but may produce false signals. It is useful for faint signals.
5.(6) Balance Switch
This switch selects between Auto-Fast Track, Auto-Slow Track, and Fixed ground balance. The two automatic positions make the Eureka Gold an automatic ground balancing detector, constantly adjusting to ground conditions for optimal depth. Fast Track responds quickly to ground changes, while Slow Track responds at half the speed. Fast Track is useful for highly mineralized or rapidly changing ground. Slow Track is better for stable ground. Fixed mode is recommended for stable ground or to re-acquire a target after ground balancing. If a target is lost, switching to Fixed mode can help re-acquire it.
Diagram showing the Balance switch positions: Fixed, Fast Track, Slow Track.5.(7) Mode Switch (Discrimination / All Metal)
The Discrimination mode switch activates the built-in discrimination mechanism. It has two positions: All Metal and Discriminate. In All Metal mode, the detector responds equally to all target types. Discrimination mode allows distinguishing between ferrous (iron) and non-ferrous metals. The effectiveness depends on target size and depth. Iron targets are typically discriminated by the audio signal becoming silent.
Diagram showing the Disc Mode switch: Disc, All Metal.5.(8) Tone Control
This control adjusts the "tone" or "pitch" of the signal. Set it to the most pleasing audible tone. Experiment with different target depths to determine the best tone.
Diagram showing the Tone control.5.(9) Headphones
The headphone jack is located on the bottom right of the front panel. Use low impedance headphones (8 ohms or higher). It accepts standard 1/4 inch (6.4mm) mono or stereo headphone jacks. When headphones are plugged in, the speaker is automatically muted. Using headphones can help distinguish signals in noisy environments and conserve battery power. For headphones with stereo/mono switching, select stereo.
Diagram showing the headphone jack.6. Coil Search Pattern
The Eureka Gold is designed to be used with Minelab-approved search coils. The included 10-inch (25cm) coil is a Double-D type, optimal for deep searching in mineralized ground. Its "blade-like" pattern ensures sensitive coverage across a wide area, making target identification easier and requiring less overlap.
Figure 16: Coil Search Pattern - Illustrates the search pattern of a Double-D coil, showing areas of maximum sensitivity at various depths.Optional coils include an 11-inch (28cm) circular coil and a 15-inch (38cm) spider coil, designed for deeper detection of large gold nuggets.
7. Basic Operation Procedure
Follow these steps for basic operation:
- a) Turn on the unit using the Volume control.
- b) Set the Volume control to maximum.
- c) Set the Sensitivity control to maximum.
- d) Adjust the Threshold control to just audible.
- e) Set the Tone control for the best sound.
- f) Set the Mode switch to All Metal.
- g) Set the Signal switch to Normal.
- h) The Discrimination control does not function in All Metal mode.
- i) Frequency switch: Use 6.4 kHz for deep/large targets, 60 kHz for small/shallow targets, and 20 kHz for general detecting.
- j) For highly mineralized ground, select Auto-Fast Track (refer to section 5.6).
- k) Sweep the coil up and down over ground without targets to perform ground balancing. The threshold hum should remain stable.
- l) Begin searching.
Minelab encourages users to thoroughly read this manual to understand the true function and purpose of each control. This will enable you to achieve the best possible settings for various situations.
7.(1) Best Settings
Gold Prospecting Settings:
- Signal: Normal
- Frequency: 20 or 60 kHz
- Mode: All Metal
- Threshold: Audible limit
- Sensitivity: Maximum
- Volume: Maximum
- Balance: Fast Track or Slow Track
Other Settings (Coins, Relics):
- Signal: Boost
- Frequency: 6.4 kHz
- Mode: Discriminate
- Threshold: Audible limit
- Sensitivity: Maximum
- Volume: Maximum
- Balance: Slow Track
- Tone: User preference
- Disc. Control: Minimum
Note: The settings above are recommended starting points. Understand each function to optimize settings for your specific working environment.
8. Signals
The detector emits seven types of signals:
- Threshold Signal: A faint hum heard when the coil is in motion, even when no targets are present.
- Target Signal: A signal whose volume and pitch change, indicating a metal object.
- Iron Signal: In Discriminate mode, iron targets produce a signal that cancels the threshold hum.
- Overload Signal: A high-pitched squeal indicating a very large target or severe mineralization.
9. Basic Detecting Techniques
The Eureka Gold is a motion-type detector; the coil must be kept moving. If the coil is stationary for a few seconds, the signal disappears. It is designed to be sensitive to various targets and discriminate between ferrous and non-ferrous metals. Keep the Threshold control set so a faint sound is always audible. This sound will change when a metal target is present. Sudden changes in ground mineralization can also cause signal changes; experience helps distinguish these.
9.(1) Coil Movement
Proper coil movement is crucial for effective detecting. Sweep the coil like a broom, overlapping each sweep to cover the ground thoroughly. Ensure each sweep overlaps the previous one to cover the ground completely. Maintain consistent coil height above the ground, avoiding lifting the coil at the end of sweeps. Consistent coil height is vital for clear signals and maximum depth. Hitting rocks can cause noise. Keeping the coil in contact with the ground can improve sensitivity to small targets and increase depth.
Figure 18: Sweeping the Coil - Demonstrates the correct sweeping motion of the search coil, showing overlapping sweeps and consistent ground clearance.9.(2) Pinpointing the Target
Once a target is detected, pinpoint its exact location for recovery. Switch to Fixed ground balance. Continue sweeping the coil, noting where the signal is strongest. Gradually reduce the sweep area to narrow down the location. Mark the spot. To pinpoint, sweep the coil from different directions (e.g., 90 degrees to the previous sweep) and imagine a line of strongest signal. The intersection marks the target's location.
Figure 19: Pinpointing the Target - Illustrates the process of pinpointing a target's exact location by identifying the point of strongest signal from multiple sweep directions.9.(3) Automatic Ground Balance Adjustment
Figure 20 illustrates how the Eureka Gold's Automatic Ground Balancing (AGB) system allows for maximum detection depth. Unlike manual balancing, AGB continuously adjusts to ground conditions, preventing reduced detection depth caused by mineralization. This ensures consistent performance.
Figure 20: Automatic Ground Balancing - Compares manual ground balancing (which can be affected by mineralization and reduce depth) with automatic ground balancing, showing how AGB maintains optimal detection depth.10. Discrimination
When the Discrimination control is set, the Eureka Gold can distinguish between ferrous (iron) and non-ferrous targets. The detector automatically adjusts discrimination based on ground mineralization, offering deeper discrimination in moderate ground and shallower discrimination in highly mineralized ground, without reducing overall detection depth or sensitivity. Smooth coil movement is important, as stationary coil periods can increase discrimination sensitivity, potentially causing false signals in "hot" ground. For best discrimination results, use frequencies in the order of 6.4 kHz, then 20 kHz, then 60 kHz.
10.(1) Discrimination of Ferrous Targets
For gold detection, use 20 kHz or 60 kHz with Fast Track or Slow Track. For 6.4 kHz, use Fixed mode to check for iron content in targets.
10.(2) Discrimination in Mineralized ("Hot") Ground
When using Discrimination mode with Fast Track or Slow Track, precise discrimination requires specific techniques. Fast Track provides accurate discrimination with the first sweep over a target, while Slow Track requires the first two sweeps. To avoid digging unwanted iron, if a target is discriminated, re-balance the detector on soil free of targets, then set the detector to Fixed mode. Sweeping the coil over the target multiple times in Fixed mode will allow for accurate discrimination.
10.(3) Discrimination in a Hole
Do not insert the coil into a hole to discriminate. Keep the coil moving smoothly over the target. Inserting the coil can cause false signals (e.g., iron appearing as non-ferrous). Soil samples from holes can also give false "non-ferrous" signals, especially in highly mineralized soil. Discrimination is most reliable on undisturbed ground. Large targets near the surface can overload the detector, indicated by a "chirping" sound. Lift the coil to reduce the signal. In "hot" ground, if the coil passes over a target multiple times, the automatic adjustment mechanism may cause iron targets to be discriminated incorrectly. This is normal for detectors with auto-adjustment.
11. Tips for Success
Learning to identify important signals and ignore others requires practice. The Eureka Gold excels at reducing ground noise, providing excellent depth. However, ground noise can persist in highly mineralized soil.
11.(1) Mineralization and "Hot Rocks"
Highly mineralized ground can produce signals similar to deep targets. These signals are usually broad, not very loud, but can be sharp. "Hot rocks" (mineralized rocks) can cause strong signals. The Eureka Gold handles these strong signals well. If a strong signal is suspected to be a deep target, sweep the coil in a circle around the target area, avoiding the center. Then, change the sweep direction by 90 degrees and repeat. If the signal is confirmed from both directions, start digging. Gold can be found among rocks; break rocks apart and pass the coil over the fragments. "Hot rocks" or "holes" can sometimes cause negative signals (signal dips).
11.(2) Clay Deposits
Clay deposits ("clay domes") are common in gold-bearing areas. Their signals can be broad and mistaken for deep gold signals. To distinguish: Pinpoint the target. Remove about 4cm of soil. Smooth the area. Sweep the coil close to the ground from multiple directions. Listen for signals that become clearer or stronger when the coil is closer. Signals usually come from one direction and weaken on the return sweep. If unsure, dig deeper and re-evaluate. Ensure the hole edge is smooth; sharp edges can cause false signals due to changes in distance between the coil and ground.
11.(3) Charcoal
Charcoal near the surface can produce signals similar to large metal targets. Experience is needed to interpret these. Charcoal signals are broad and may be intermittent when digging. The Fine setting can help distinguish these signals.
11.4 (Gold)
Search in areas where gold has been found previously. Gold can range from dust to nuggets. Gold deposits are often the result of eroded gold veins. Experienced prospectors learn to "read the ground" for signs of gold. Metal detectors offer advantages over traditional prospecting. A common issue is the presence of ironstone, which can interfere with detection, especially in areas like Australia and North America. Gold and ironstone often coexist.
12. Eureka Gold Care
Follow these precautions for proper care:
- Remove alkaline batteries when the detector is not in use to prevent leakage and damage.
- Avoid prolonged exposure to direct sunlight or high temperatures. Protect the unit from heat.
- The control box is water-resistant, not waterproof. Avoid unnecessary wetting. Keep away from gasoline and oils.
- Keep the detector clean and dry. Prevent sand from entering the shaft. Do not use solvents for cleaning. Clean with a soft cloth dampened with water.
- Use only Minelab-specified batteries. Recharge NiMH batteries promptly when the low battery warning sounds. Use genuine alkaline batteries and replace them when the low battery warning appears.
- Use only Minelab chargers.
- Ensure coil cables are in good condition and not strained.
- Rinse with fresh water if exposed to corrosive substances like salt water.
- Use a padded bag or case for transport to prevent damage.
- The optional hip mount bag protects the control box from dust, rain, and impact.
- The detector is sensitive to external noise sources like other metal detectors, high-voltage transformers, and power lines.
- Do not attempt to open or modify the control box; this voids the warranty.
13. Troubleshooting Guide
No Sound: Check battery connections. Ensure the coil plug is secure. Adjust Sensitivity dial counter-clockwise. Disable Fixed ground balance. Check headphone connections. Ensure no sand is between the coil and cover.
Unrelated Noise: Check battery connections. Ensure the coil plug is secure. Adjust Sensitivity dial counter-clockwise. Disable Fixed ground balance. Check headphone connections. Ensure no sand is between the coil and cover.
No Target Response: Ensure the unit is powered on. Check battery charge and connections. Check coil connections. Check headphone connections. Re-adjust ground balance.
14. Product Warranty
A 2-year warranty covers electronic control box components, manufacturing, and workmanship. A 1-year warranty covers the coil and shaft. Contact your dealer for warranty or repair issues. Note: The warranty is non-transferable. The registration card must be sent within 14 days of purchase for the warranty to be valid. The warranty does not cover accidents, misuse, neglect, unauthorized repairs, or modifications. Refer to the "Product Warranty Card" for full details.
15. Product Specifications
Specifications are subject to change without notice.
- Length: 710mm (packed), Minimum 1190mm, Maximum 1350mm (in use)
- Weight: Control Box: 740g, Total (excluding battery): 2.2 Kg
- Battery: Rechargeable NiMH 12V 1000Ah
- Charger: 110/240V Mains Charger
- Coil: 10-inch Double-D, with coil cover
- Frequency: 6.4, 20, & 60 kHz
- Ground Balance: Automatic, 2 speeds, Fixed
- Search Mode: Discriminate, All Metal
- Ground Balance Adjustment: Fast, Slow, Fixed
Controls:
- ON/OFF Volume: 1-turn control
- Threshold Control: 1-turn control
- Sensitivity Control: 1-turn control
- Tone Control: 1-turn control
- Balance Switch: 3-position switch
- Frequency Switch: 3-position switch
- Signal Switch: 3-position switch
Accessories:
- Alkaline Battery System (8 x 1.5V)
- Car Charger (12V Cigarette Lighter Plug)
- Gold Search Coil (11-inch Circular)
- Hip Mount (Waist) Bag
- Headphones (32 ohms)
