1. At what depths can a detector find treasure?
It’s impossible to predict with complete certainty how deep a specific detector can be expected to find metal. This is because there are a variety of factors that affect a detector’s performance. For example, the amount of minerals in the soil, the type of metal that’s being detected and the quality of the detector itself impact how deep your detector will hunt. The size and surface area of a target also affects detection. For example, the larger a metal target, the easier and more deeply it can be detected.
Generally speaking, a quality detector equipped with an 8” or 9” searchcoil can be expected to detect:
Small jewelry (e.g., necklaces, thin gold rings) at 3 to 6 inches
Large jewelry (e.g., class ring) at 6 to 12 inches
Small coins (e.g., dime, penny) at 4 to 6 inches
Large coins: (e.g., quarter, silver dollar) at 6 to 12 inches
Mason jar lid at 9 to 16 inches
Coffee can at 1 to 2 feet
Cannonball, helmet, etc. at 2 to 3 feet
Using a searchcoil larger in diameter can also help a detector achieve greater depth. A 12.5” searchcoil produces a more extensive magnetic field that penetrates the ground more deeply to find objects at depths that a smaller size searchcoil can’t reach.
2. How do I pinpoint a target?
Slowly and methodically sweep your searchcoil from side to side, keeping it one to two inches above the surface. Overlap each sweep by advancing the searchcoil by about one quarter to one half of its diameter. Scanning in a straight line helps to keep the searchcoil level and the overlap sweeps uniformly while reducing the likelihood of lifting the searchcoil after each sweep. Listen for a peak in the audio sound. Hold the searchcoil one to two inches off the ground and slowly sweep it back and forth in an X pattern. Note where the sound becomes the loudest. The target should be located in the center of the imaginary X. Many of today’s modern metal detectors are equipped with an electronic pinpoint button. Read your owner’s manual for complete electronic pinpointing instructions.
3. What do I need to know about my detector’s batteries?
NiCads (nickel/cadmium) and nickel metal hydrides are rechargeable batteries that last between 8 and 12 hours and cost up to 10 dollars each. Alkalines are disposable batteries that last between 25 and 30 hours and cost about two dollars each. Because extreme temperatures can drain battery power, it is recommended that you always carry a spare set of batteries. In cold weather, attaching the battery pack to your belt under your jacket can help keep batteries warm and dry.
4. What is discrimination?
Discrimination refers to a metal detector’s ability to reject a target, such as a pull tab and foil or accept a target such as a coin or piece of jewelry based on its metallic composition. With features like Target Imaging and Tone ID, your detector can tell you what your target is before you ever dig.
5. What’s the difference between Coin Depth and True Depth?
Most detectors only offer a basic coin depth reading. Coin depth and true depth are similar to human depth perception. A person’s vision is seriously impaired with the use of only one eye because his field of vision is much smaller with only one eye than it is with two. Coin depth is the equivalent of seeing a target with only one eye. True depth, which can only be found on Garrett´s GTI and GTP detectors, is made possible with additional receivers in a metal detector that offer added depth perception much like having two eyes open.
6. What is True Size?
True size is obtained in much the same way as true depth. Multiple receivers, within a GTI metal detector, add additional dimensions of target ID, not just material ID. Ultimately, however, it´s how multiple receivers relate to one another that provides these true measurements, not just merely having them. True size and depth are Garrett exclusive features and are only possible with Garrett GTI detectors, which were designed to give treasure hunters the most accurate information about a target before they dig.
7. Is overall depth compromised when searching with discrimination?
Yes. To achieve the greatest depths when searching for large, cache sized-objects, many professionals hunt in the All-Metal mode and use a large searchcoil.
8. What is the significance of a detector´s Operating Frequency?
A metal detector transmits magnetic energy into the ground and senses distortion in the magnetic field due to the presence of a metal object. The frequency content, temporal form and amplitude of this magnetic energy can affect detection capabilities and overall performance characteristics. There are two primary detection technologies used in today´s metal detectors: Single Frequency (also known as Continuous Wave) and Multiple Frequency (e.g. Pulse Induction and Dual Frequency). Each technology has its own detection characteristics, understanding these will enable you to choose the right detector for your treasure hunting needs.
9. Do I really need headphones when treasure hunting?
For maximum success when treasure hunting you should use headphones. They are essential in noisy areas and enhance audio perception by bringing the sound directly into your ears.
10. Do I need more than the one searchcoil?
The searchcoil is a vital part of your metal detector. It is the flat, typically circular disk, which generates a magnetic field and senses metallic targets in the surrounding environment. It is located at the end of the stem and is connected to the control housing via a cable that is wound around the stem. The size, depth and energy output (power) of the magnetic field is determined by the shape and size of the searchcoil. Understanding the purposes behind the various sizes and shapes of searchcoils will empower you with the ability to choose the best searchcoil for the right application.
11. Are there any laws surrounding treasure hunting?
Every square inch of property is generally owned -- by an individual, group, corporation, governmental body, etc. And, there are definitely laws that have been written to apply to various treasure hunting situations. Each state has its own statutes concerning where you can and cannot search and whether you may keep the treasure you find. You must learn these laws, and remember that they can be changed at any time.
12. How far should my searchcoil be off the ground when I´m hunting?
You should hunt with your searchcoil a couple of inches off the ground (about the height of freshly cut grass) and scan at a pace of 2 to 3 feet per second.
13. Are there online forums or treasure clubs I can join?
There are countless online forums where treasure hunters share their own tips, help other hobbyists with their detector, and of course, show off their latest treasure. You can also contact your local dealer, he or she can point you towards all the exciting clubs and events that other treasure hunters are hosting right in your own backyard!
There are some common issues that many hobbyists experience that are universal to all makes and models of metal detectors. Here are a few proven remedies to some of these common symptoms.
1. Ensure batteries are installed in the correct position.
Erratic sounds or Target ID
1. Ensure your searchcoil is securely connected and the coil is tightly wound around the stem
(NOTE: Iron targets may cause erratic sounds or Target ID Cursor movement. You can identify iron targets in an All-Metal Mode)
Intermittent signals typically mean you've found a deeply buried target or one that is positioned at a difficult angle for your detector to read. Increase the sensitivity on your detector and scan from different directions until the signal becomes more definite. In the case of multiple targets switch to the All-Metal Mode or press PINPOINT to precisely locate all targets.
(NOTE: Iron targets may cause Intermittent Signals. You can identify iron targets in an All-Metal Mode).
I'm not finding specific targets
Ensure you are using the correct mode for the type of hunting you are doing. If you are hunting for coins, ensure you are in the COINS mode. You may also use the All-Metal mode, which detects all metal targets to ensure desired targets are present.
Target ID Cursor bounces
If your Target ID Cursor bounces erratically, chances are you've found a trash target. However, a Target ID Cursor may bounce if a good target (such as a coin) is not parallel to the searchcoil (e.g. on edge). It may also bounce if there is one or multiple "junk" targets laying next to the good target. Scan from different directions until your Target ID Cursor becomes more stable.
Click on the Detector for the required Manual.
Ground Search Detectors
The searchcoil is a vital part of your metal detector. It is the flat, typically circular disk, which generates a magnetic field and senses metallic targets in the surrounding environment. It is located at the end of the stem and is connected to the control housing via a cable normally wound around the stem. The size and depth of the magnetic field is determined by the shape and size of the searchcoil. Understanding the purposes behind the various sizes and shapes of searchcoils will empower you with the ability to choose the best searchcoil for each application.
HOW SEARCHCOILS WORK
Searchcoils generally consist of two internal sets of coiled wires, a Transmit Coil (TX) and a Receive Coil (RX). Mono coils can be different in that one coil acts as both the TX and the RX. When the detector is turned on, the TX coil generates a magnetic field in the surrounding space. When a metallic object is within this generated magnetic field, it will create a distortion in the magnetic field. The RX coil will sense this distortion and send a signal to the control housing. A searchcoil’s detection pattern is determined by the combination of the TX’s generated field pattern and the RX’s sensing field pattern.
The transmit coil (TX) creates a magnetic field while the receive coil (RX) senses distortion in this field and signals the control housing.
Download the complete Searchcoils Tech Sheet for a full explanation of the workings of Seachcoils including:
- Searchcoil Depth
- Sizes and Shapes
|All-Metal Mode||A metal detector setting that detects all metal objects, no discrimination|
|Audio Threshold||The background audio level produced when no target is being detected - it is best to adjust the audio threshold to the lowest audible level, and recommended the operator use headphones when treasure hunting|
|Audio Tone||The pitch or frequency of the sound made by a detector. The tone on the GTI 2500, 1500 and GTP 1350 detectors can be adjusted on a treble to bass scale.|
|Cache||Larger deposits of treasure that generally consist of money and valuable objects|
|Classifier||A filtering device, typically found at the head of a sluice, which helps prevent rocks and other large debris from falling into a gold pan.|
|Coin Shooting||Hunting for coins regardless of location or era of coins targeted|
|Composite Digger||Trowel made of durable plastic that helps prevent coin damage during recovery. Ideal for soft terrain|
|Control Box||Contains the detector's main circuitry, controls, speaker, batteries and microprocessor chip|
|DD Searchcoil||A special configuration of the transmit and receive coils to minimize the effects of ground minerals|
|DSP||(Digital Signal A highly advanced computer chip used in Garrett detectors and other sophisticated Processor) electronic equipment|
|Discrimination||The ability of a metal detector to reject a target, such as a pull tab and foil or accept a target such as a coin or jewelry based on its metallic composition|
|FastTrack||(See Garrett's exclusive technology that analyzes ground mineralization and adjusts to "cancel" Ground Balance) its effects in a matter of seconds|
|Frequency||The number of times per second the energy transmitted from a detector's coil changes direction (e.g. 7.0 kHz = 7000 times per second) - higher frequencies are typically used to find targets such as gold nuggets, while lower frequencies are best for general purpose hunting.|
|Gold Pan||A bowl-shaped, shallow container that traps gold flakes|
|Gravity Trap™||A patented gold pan made by Garrett which has 90 degree riffles to trap small gold Gold Pan|
|Ground Balance||An adjustment made to "cancel" or ignore ground mineralization; may be done manually (See GroundTracking) or automatically|
|Ground Tracking||The ability of a metal detector to continuously measure the ground's mineralization and automatically adjust the detector's ground balance setting for optimum performance|
|GTA||(Graphic Target Exclusive Garrett technology that visually identifies a target's conductivity or ID and also Analyzer) shows the discrimination pattern|
|GTI||(Graphic Target Exclusive Garrett technology that measures and displays a target's true size and depth Imaging)|
|LCD||(Liquid Crystal A graphical display that indicates target information, detector settings, etc... Display)|
|Multiple Frequency||See Pulse Induction and Multiple Frequency article|
|Microprocessor||Computer chip that performs digital functions that make many features such as Target ID and Discrimination possible on today's Garrett detectors|
|Mono Searchcoil||Refers to searchcoils with one ring where both transmitter and receiver antennae are located|
|Motion Mode||Refers to the setting where coil motion is needed to detect targets|
|Notch||Discrimination Targets above and below these discrimination settings|
|Pinpoint||A mode of operation that allows the operator to detemine the precise location of a target still in the ground|
|Pulse Induction||Used primarily for heavily mineralized environments such as the beach or the gold fields of Australia and is found in many of today's specialty detectors (See also Multiple Frequency)|
|PowerMaster||Exclusive Garrett feature that increases the detector's ability to detect deeper and wider - up to 20 percent|
|Probe||A long screwdriver-like device made of brass used to penetrate the ground and physically locate a detected target before digging it up|
|Prospecting||Hunting for valuable metals such as gold|
|Relic Hunting||Hunting for targets with historical value, such as old battlefield items or family heirlooms|
|Salt Elimination||A detector's ability to eliminate the interference of salt mineralization, which adversely affects detection depth and target ID capabilities|
|ScanTrack||A unique Garrett feature that automatically adjusts to the operator's scan speed to achieve optimum performance|
|Searchcoil||Also referred to as the "coil", the searchcoil is the flat, typically circular disk swept over the ground to sense the presence of metal|
|Sensitivity||Synonymous with Depth, the adjustment that determines how deep or small a target can be detected - the higher the sensitivity, the greater the detection depth|
The adjustable stem that connects the control box and the searchcoil
|Single Frequency||Offers greater potential depth capabilities, better discrimination and enhanced target ID under most common soil conditions where most treasure hunting occurs (See Multiple Frequency article for more information).|
|Super Sluice™||Large 15" gold pan with 1/2"deep riffles. Traps small gold nuggets up to one ounce and larger in size|
|Surface Elimination||A detectors ability to ignore all targets located on or near the ground's surface, which is useful in heavy trash areas|
|Surface Mount PC Board Technology||The latest trend in constructing electronic circuit boards|
|Target||Any metallic item sensed by a detector|
|Target ID Cursor||A graphical indication of the target's probable identity (e.g. coin, gold, pull tab) based on its electrical properties|
The ability to adjust the loudness of the audible response produced by the detection of a target
Garrett Metal Detectors makes every effort to ensure its products are safe for use. Extensive research by Garrett has produced no information which would indicate that its products have any adverse effects on medical implants, pregnancy, recording media or magnetic strips. Garrett makes every effort to cooperate with medical device manufacturers and to communicate with agencies such as the United States Food and Drug Administration and Health Canada as a means of assuring product safety. The electromagnetic fields produced by Garrett products are similar to those encountered in the daily environment and meet U.S. and International standards for electromagnetic emissions.
Garrett recognizes that certain medical devices may have additional requirements which may require special care. Users of medical devices should follow specific information provided by medical device manufacturers and medical practitioners. This information is often in the form of informational booklets and information cards. If, for any reason, (e.g. doctors orders, etc.), a patron objects to being scanned with a metal detector, it is recommended that alternative procedures be used.
Additional information may be obtained by contacting medical device manufacturers directly or by searching topics such as Metal Detectors, Security Systems, and Travel on websites such as:
The following should be considered when developing a security checkpoint screening plan.
Traffic Flow: Traffic flow should remain consistent and encourage unrestricted traffic flow as a means of minimizing the time a person remains within the archway of a walk-through metal detector.
Alternative Screening: Alternative screening methods such as scanning with a hand held metal detector, hand searching or denial of access should be clearly defined in checkpoint screening procedures as approved alternatives to screening with the walk-through metal detector.
Personnel Training: Security screening personnel should be instructed in the care of persons with special medical needs and use of alternative screening methods that meet the requirements of medical practitioners or medical device manufacturers