Metal detector coils are an important part of any metal detector, possibly the most essential tool for any detectorist. They work to create a magnetic field that helps detect metal objects underground, in a number of different terrains. Coils come in a variety of different sizes and shapes, and each is designed for a specific purpose. In this article, we will help you understand what metal detector coils are, what they do, and how they work. By the end of this article, you’ll feel comfortable knowing which metal detector coils you should be using and if they are interchangeable.
Are Metal Detector Coils Interchangeable?
Yes, some metal detector coils are interchangeable. And I use the word ‘some’ with emphasis.
Before you get excited and think you’ll save some money on buying extra search coils, you should know that while some metal detector coils are interchangeable, many are not interchangeable, regardless of whether or not it’s made by a good brand.
Some manufacturers will often create an entire series of metal detectors that are designed to work on a single or even many different (but the same) frequencies, and these metal detectors will use the same basic search coils.
This means that while the metal detector may have different features for different uses, the search coil is usually compatible with the majority of those metal detectors.
For the wide view of things, you generally won’t find two different companies making metal detectors that allow interchangeable coils with each other.
For instance, a Bounty Hunter Gold Digger coil will not be interchangeable with Minelab Vanquish 340. Not only are they different brands, but you also have to be aware of what sort of technology each metal detector is using.
While the Bounty Hunter is optimized for a coil operating on a 6.6 kHz frequency, the Minelab Vanquish is a Multi-IQ metal detector.
A Multi-IQ metal detector is able to metal detect on a number of different frequencies at the same time, which opens up a whole new world of metal detecting opportunities (and complications).
All that said, there are some companies that do make metal detectors that have interchangeable coils. For instance, the Garrett AT Pro and AT Max metal detectors both use the same DD coil.
For more information on the Garrett AT Pro, be sure to check out our list of best metal detectors for beginners.
Talking more about the differences in technology, PI or pulse induction metal detectors are not going to have interchangeable coils with VLF metal detectors.
This is because they work on different metal detecting principles. A pulse induction metal detector uses a single metal detecting coil that emits a magnetic field, which then collapses suddenly. This generates an electric current in the target object, which is then detected by the metal detector.
A VLF metal detector, on the other hand, uses a metal detecting coil that emits multiple metal detecting pulses into the ground.
These metal detector coils are typically round or elliptical in shape, with varying field widths, depending on what type of metal detecting you are doing.
The differences in these technologies go a long way for metal detecting in different environments and for different types of metals.
What Is a Metal Detector Coil?
A metal detector coil is an instrumental part of a metal detector that directly impacts the metal detecting capabilities of the metal detector.
Metal detectors use metal detecting coils to emit a magnetic field into the ground, which is then used to detect metal objects underground at varying depths and makeup.
Each metal detector coil referred to as a search coil, uses a specific pattern and type of metal detecting pulse or frequency to help find different types of metal. This means that smaller metal objects will typically not be detected by metal detectors using pulse induction metal detecting coils, for instance.
In addition, the metal detector coil will have different effects based on the size and shape of the metal detecting coil that is used. Again, it’s worth repeating that while metal detectors are designed to detect metal objects at different depths and locations, it is the metal detector coils that can have the biggest impact on those detection abilities.
Metal Detector Coil Types
Metal detector coils can generally be classified as concentric metal detector coils, double D (DD) metal detector coils, mono metal detector coils, or imaging metal detector coils.
Concentric metal detector coils are metal detecting coils that consist of two winding coils in a circle. One outer coil that sends out the seeking current surrounds the other inner coil which performs the task of receiving the return current.
Because of this type of transmit/receive kinship, a concentric coil is usually considered a great metal detecting coil for accurate detection and working well in many environments.
A double D (DD) metal detector coil is a metal detecting coil that, true to its name, is in the shape of two uppercase D’s standing back to back. This is important to note because the overlapping shape is what makes this coil ideal for tough environments where there exists a lot of interference.
This could be due to high mineralization in the soil, sand, or water.
In addition to the designed stability that the DD metal detector coil provides, it also has an excellent depth range capability, metal detection sensitivity, and discrimination ability.
For those looking for a superior experience when treasure hunting, a double D metal detector coil will give you an edge.
A mono metal detector coil is a metal detecting coil that has a single winding coil in the shape of a circle or even semi-elliptical. This is different than the concentric metal detector coils which have two metal detecting winding coils surrounding each other.
The single coil is used as both a transmitter and receiver of signals, which makes the magnetic field created a perfect option for depth. For example, mono coils are used on PI or pulse induction metal detectors, which are metal detectors that are usually used to find metal at extreme depths.
In addition to incredible depth range, mono coils also excel in sensitivity measurement. The sensitivity of a metal detector coil is great for identifying the size of an object and even the type of metal it is.
The one big drawback to a mono metal detector coil is that it can have challenges with metal detecting in tough environments with high mineralization.
This is where an imaging metal detector coil comes into play.
An imaging metal detector coil is a metal detecting coil that uses multiple coils to send and receive signals. This creates a three-dimensional view of what is underground, which allows a metal detector to have the ability to pinpoint metal objects with greater accuracy.
This metal detecting coil is ideal for searching in tough environments where mineralization and interference are high, as it can easily cut through these kinds of challenges and paint a picture of the true size of the object.
This advanced imaging system that allows for better target size and depth indicator allows detectorists to sift out the trash from the treasure before even taking out their digging tool. The only downside is only Garrett offers an imaging metal detector coil.
Big Coil vs Small Coil Metal Detector
There is a lot of debate when it comes to metal detector coils, especially when it comes to size.
Many metal detectorists will argue that bigger metal detecting coils are always better than smaller metal detecting coils. This is usually supported by the logic that a bigger metal detecting coil can cover more ground in a shorter amount of time, which means you’re more likely to find what you’re looking for faster.
While this is true to some extent, it’s important to understand that there are also benefits to using smaller metal detecting coils.
Small Coil Metal Detector
- Able to search any area
- Strong discrimination capabilities
- Smaller objects very easy to detect
- Ideal for small coins and shallow depths
- Depth range is limited
- Takes longer to cover a large area
- Requires more sweeping than a big coil
One of the main advantages of using a smaller metal detector coil is that it’s easier to maneuver and control.
This is especially true when metal detecting in tight spaces or areas with a lot of debris. Smaller metal detecting coils are also better at picking up smaller objects, which can be difficult to find with a bigger coil.
Big Coil Metal Detector
- Greater depth detection
- Cover more ground in less time
- Perfect for pulse induction metal detectors
- Ideal for hunting relics and coin-rich areas
- Struggles with discrimination
- Tough to maneuver in tight spaces
- Heavier after longer periods of hunting
- More difficult to pinpoint objects
Granted, searching a given area will take longer with a small coil metal detector, big coils will not only save you valuable time by covering more ground, but they can also be more reliable at metal detecting deeper targets.
Ultimately, the choice of metal detecting coil size depends entirely on your metal detecting needs, location, and preference. Some metal detectorists will swear by the capabilities of a small metal detector coil while others won’t go anywhere without their big double D coil.
What Size Coil Is Best for Metal Detecting?
The answer to this question largely depends on your metal detecting goals and the types of metal detecting you intend to do.
For example, if you’re metal detecting for coins or jewelry, a smaller coil metal detector might be preferable so that you can more easily navigate tight spaces and pick up small targets.
On the other hand, if you’re metal detecting for larger targets or want to cover more ground quickly, a bigger metal detecting coil might be a better option.
In the end, the best metal detector coil size is one that can help you achieve your metal detecting goals while also being comfortable and easy to use.
Whether you choose a small metal detector coil, a big metal detector coil, or something in between, the key is to find a metal detector that can deliver the results you need.
What Do Different Coils Do for Metal Detectors?
There are a number of different metal detector coils that metal detectorists might use depending on their metal detecting goals and preferences. Some of these we have already touched on, but other features offered by varying coils add an extra element to a treasure hunt.
Each type of metal detection coil serves a different metal detecting purpose, from imaging to discrimination and everything in between. Also, the size of the particular coil may alter the capabilities often found in a metal detector.
While it is ultimately dependent on the metal detector and what features are built into it, a carefully chosen search coil can take you to the next level.
Search coils will offer capabilities for those looking for treasure in deep waters, shallow water, on the beach, in the woods, and more.
One metal detector coil may beat out the competition when it comes to detecting large gold nuggets, while a different coil has no match when searching for tiny metal fragments. In short, the capabilities of your metal detector are greatly enhanced by choosing the right coil.
The most important factor in deciding which metal detecting coil is best for you is to know what you hope to find and where you will be searching. With that information, any metal detecting enthusiast can make an informed decision on which coil will help.
What Is Inside a Metal Detector Coil?
At its most basic level, metal detector coils are metal wires coiled around a metal or plastic core.
These metal wires create an electromagnetic field that is used to detect metal targets at varying depths.
Inside the metal detecting coil housing, the receiving coil is what detects changes in how the magnetic field reacts to metal objects and eventually sends that information to the control box.
Depending on the metal detector and metal detecting coil, other components may be added to this basic design in order to improve performance or provide additional features. For instance, if the coil is waterproof, it will likely have a waterproofing sealant and air-tight housing to prevent water damage.
While metal detectors are complex pieces of equipment with many different parts and configurations, the metal detecting coil is a fundamental component that determines what types of targets you can find and how deep you can find them.
The metal detecting coil is a fundamental component that determines what types of targets you can find and how deep you can find them. While metal detectors are complex pieces of equipment with many different parts and configurations, the metal detecting coil is a key part that should be carefully chosen to match your metal detecting goals.
Metal detector coils are interchangeable in some scenarios but to be sure, always read the specification sheet on any coil you intend to buy.
If you want to learn more about search coils and other metal detector facts, be sure to read our full breakdown before you go!
Until next time…