A Look at Used Metal Detectors

Metal detectors are high-tech, but before you know where to start, it might help to get a better idea of what they do. They find metal objects by detecting their electromagnetic field.

A metal detector consists of three main parts: the antenna, the detector head and the control unit. The detector head and control unit work together as a transmitter and receiver; when an object comes into contact with the magnet part of the detector (detector head), it disturbs an electromagnetic signal sent from one coil in the transmitter to another coil in one receiver that converts this signal into a detectable current or voltage. The current or voltage is sent to the control unit where it calculates the position of the object in the ground and sends signals to one or more motors that turn over the plated flat section (coil) of the detector head. Most detectors can only shift up and down, so there is a motor that will turn over a different coil. These coils are aligned to locate an object under 10 feet in 30 seconds or less.

When hunting with a metal detector, you'll want to know three things: strength and depth, depth only, and depth plus target sounder. The first item determines how accurately your detector will detect what you're looking for. The second item determines how deep you can dig. The third item lets you know exactly where you are with respect to the ground, which is important when plowing fields or hunting in thick cover.

• Strength and Depth. On strength and depth you'll want to consider your expectations for the first use of your detector. What level of target penetration can you handle? And how deep will it go?

• Depth Only: Use this when looking for relics. You want to dig deeper than usual – up to a foot or more – to avoid finding things such as nails and screws that might be in the soil too deep to normally find. "Depth only" is also used for looking for coins, jewelry or glass bottles.

• Depth Plus Target Sounder: This is the most common approach for hunting. You'll dig deeper than usual, but as you dig you'll be able to hear what's below. It's like listening to a mini-radio station without actually having a radio in your hand.

• Working Depth: This option makes digging more efficient by using modulated signals and electronic controls that adjust the depth of your search based on signal strength, target strength and other variables.

• Point Search: Use this when hunting for specific targets such as coins, jewelry or large bags of "stuff. " Use this when you have the option of digging a straight line, and it's easier to locate objects near the surface.

• Zero-Loss Mode: This is when you're searching for something that is down in the ground. The signal does not bounce off of anything, so it's a very precise method for detecting objects such as coins and jewelry as well as relics.

• High Limit: This limits how deep you can dig when using a "zero-loss" mode. If your target equals maximum depth (1 foot or greater), then go no deeper than that level until you find your desired target.

• Low Limit: Use this option when hunting on land or in water less than 6 feet deep.

• Pinpoint Mode: This is a unique option that limits the target's location to an exact number of centimeters; then you click a joystick in the direction of your target.

• Coin Depth: This option is for when you are only interested in finding coins. It allows you to set a specific number of centimeters at which to stop searching and dig.

• Gold Tone Reject: This is used when finding gold rings, jewelry or gold-colored items. It eliminates any objects found less than 4 inches deep, causing them to be rejected so they do not show up on the screen and slow down your search.

• Discrimination: This option can be used alone or in conjunction with other settings. It will reject any target that is larger than a quarter, smaller than a dime, not ferrous (not metal), or at the wrong depth. For example, you can tell your detector to ignore targets or parts of targets below 10 inches in depth.

• Ground Balance: This option sets the control unit to eliminate ground noise and interference that might occur due to your soil's mineral content.

• Sensitivity (also called Discrimination Level): This operates similarly to "ground balance" but it sets the detector head rather than the control unit to cancel out any interference from mineral deposits in your soil.

• Sound: You also have options for what you hear when a target is found. The tone of your unit can help you to learn where objects are buried.

• Pinpoint Indicator: This indicates to you where an object is located. It locates the target within a few inches, in one pass over the ground; then the target's depth is displayed on the screen so you know how to dig it up. This option helps speed up your search.

• Automatic Ground Balance and Automatic Sensitivity: These two options work independently or together to speed up your hunt and make finding targets easier by focusing on only those that are at a certain depth and more easily detected by lowering sensitivity and raising balance levels.

• Adjustable Slow Response: This allows you to tune in only to targets that have been detected.

• Audio Reject: This setting ignores low-level audio signals and allows you to concentrate on "beeps" as you hunt.

• High Frequency Discrimination: This is helpful when detecting objects made of titanium or iron, or when hunting in mineralized ground. It will help with discrimination to reject iron, foil, nails and other such items that are usually rejected by the detector's standard settings.

• Notch Discrimination: Use this option to ignore high frequencies such as those emitted by gold chains and other metal jewelry. It can help with discrimination for when hunting for gold coins and jewelry.

• Multi-Notch Discrimination: This allows for two sets of notch discrimination, which makes it easier to ignore small items such as foil and screwcaps, while still detecting valuable items.

• Sync Discrimination: This is used to avoid rejection of a gold ring that is within 10 inches of another gold ring; it sets up the detector so that both rings will be detected and so you can choose which one to dig up.

If you are an experienced metal detector user, you may be thinking "This is a lot of information!" And it is. That's why Bounty Hunter has given us several options for making our search easier, faster and more effective. Let's look in more detail at keeping your search complete with these options.

Conclusion

Metal detectors are machines, and machines have components. These components will wear out with use, so you should always be prepared to troubleshoot the problem or swap out parts or the entire unit if necessary.

As a Bounty Hunter owner, you are expected to keep your detector in good working order and aware of how that "good working order" is achieved. It's your responsibility to read your manual and understand how to operate your machine—beyond what we've discussed here. As a metal detector user, you're also a beginner and intermediate archeologist, who must understand how to hunt efficiently and responsibly.