1. Introduction
Thank you for choosing the BUUBO MD-4050 Metal Detector. This device is designed for detecting various metals underground, making it suitable for treasure hunting, relic recovery, and general metal detection activities. Please read this manual thoroughly before operating your detector to ensure proper use and optimal performance.
2. Safety Information
- Always obtain permission before searching on private property.
- Avoid searching in areas where underground cables or pipes may be present.
- Exercise caution when digging, especially in public areas.
- Keep the detector away from extreme temperatures and moisture.
- Remove batteries if the detector will not be used for an extended period.
3. Package Contents
Ensure all the following items are present in your package:
- 1 x BUUBO MD-4050 Metal Detector Unit
- 1 x Operation Manual
4. Assembly
Follow these steps to assemble your MD-4050 Metal Detector:
- Attach the Search Coil: Connect the search coil to the lower stem. Ensure it is securely fastened with the provided bolt and nut.
- Connect the Stems: Insert the lower stem into the middle stem, and then the middle stem into the upper stem. Adjust the length to a comfortable position and secure it with the locking collar.
- Mount the Control Box: Slide the control box onto the upper stem. The armrest should be positioned for comfortable use.
- Wrap the Cable: Carefully wrap the search coil cable around the stem, ensuring it is not too tight or loose, and plug the connector into the control box.

Figure 4.1: Exploded view of the MD-4050 components for assembly.

Figure 4.2: Labeled components of the MD-4050 for easy identification during assembly.
5. Battery Installation
The MD-4050 requires two (2) 9V PP3 batteries (not included). To install:
- Locate the battery compartment on the control box.
- Open the battery compartment cover.
- Insert two 9V PP3 batteries, ensuring correct polarity (+/-).
- Close the battery compartment cover securely.
Note: Always use fresh batteries for optimal performance. Remove batteries if the detector will not be used for extended periods to prevent leakage.

Figure 5.1: View of the control box underside, indicating battery compartment location.
6. Operating Instructions
6.1 Control Panel Overview

Figure 6.1: Detailed view of the MD-4050 control panel.
- POWER (OFF/ON): Turns the detector on or off.
- SENS (Sensitivity): Adjusts the detector's sensitivity to targets. Higher sensitivity increases detection depth but may also increase false signals.
- DISC (Discrimination): Allows the detector to ignore certain types of metal. The MD-4050 can discriminate between aluminum and silver, while still detecting all other metals.
- NOTCH: Used to selectively eliminate specific metal categories from detection.
- VOLUME: Adjusts the audio output level.
- PHONE (Headphone Jack): For connecting 3.5mm headphones for private listening and clearer audio signals.
- View Meter: Displays target information and battery status.
- Speaker/Buzzer: Provides audible alerts for detected metals.
6.2 Basic Operation
- Power On: Turn the POWER knob clockwise to the 'ON' position. The detector will emit a single tone, indicating it is ready.
- Adjust Sensitivity: Start with a medium sensitivity setting. If the detector is unstable or produces too many false signals, reduce the sensitivity. Increase sensitivity for deeper detection in clear areas.
- Discrimination: Use the DISC control to filter out unwanted metals. For example, to ignore iron, adjust the DISC setting until iron signals are no longer detected. The MD-4050 has preset ground balance.
- Sweeping the Search Coil: Hold the search coil parallel to the ground, approximately 1-2 inches above the surface. Sweep the coil slowly from side to side in overlapping motions.
- Target Indication: When a metal object is detected, the view meter will indicate the target type, and an audible tone will be emitted through the speaker or headphones. The MD-4050 provides a single tone audio response.
- Pinpointing: Once a target is detected, narrow down its location by sweeping the coil in a cross-pattern over the area.
6.3 Low Battery Indication
The detector features a low battery indication via an LED light. When the LED illuminates, it is time to replace the batteries to ensure consistent performance.
6.4 Waterproof Search Coil
The 16.5cm search coil is waterproof, allowing for detection in shallow water. However, the control box is not waterproof and must be kept dry.
7. Maintenance
- Cleaning: Wipe the detector with a damp cloth after each use. Do not use abrasive cleaners or solvents.
- Storage: Store the detector in a dry, cool place when not in use.
- Battery Care: Remove batteries during long storage periods to prevent corrosion.
- Cable Inspection: Regularly check the search coil cable for any signs of damage.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No power | Dead or incorrectly installed batteries | Replace batteries, ensuring correct polarity. |
| Erratic signals / False signals | High sensitivity, electromagnetic interference, mineralized ground | Reduce sensitivity. Move away from power lines or other electronic devices. |
| No audio from speaker/headphones | Volume too low, faulty headphones, loose connection | Increase volume. Test with different headphones. Ensure headphone jack is fully inserted. |
| Poor detection depth | Low sensitivity, low battery, highly mineralized ground | Increase sensitivity. Replace batteries. |
9. Specifications
- Model: MD-4050
- Detection Depth: Up to 16 cm (depending on target size and ground conditions)
- Search Coil: 16.5 cm (6.5 inches) waterproof
- Power: 2 x 9V PP3 batteries (not included)
- Audio Output: View meter with speaker/buzzer, one tone audio, 3.5mm earphone socket
- Discrimination: Discriminates between aluminum and silver, detects all metals
- Ground Balance: Preset
- Low Battery Indicator: LED light
- Net Weight: Approximately 0.9 kg (2 lbs)
10. Warranty and Support
For information regarding warranty coverage or technical support, please refer to the purchase documentation or contact your retailer. Specific warranty terms may vary by region and retailer.





