Understanding Metal Detector’s Coil

Understanding Metal Detector's Coil

Understanding the metal detector’s coil is essential for both seasoned treasure hunters and curious newbies.

Metal detecting is a fascinating hobby that draws enthusiasts from all walks of life. There’s a special kind of excitement that comes from unearthing items hidden beneath the earth’s surface.

But have you ever wondered how the magic happens? How does a metal detector, seemingly simple in design, manage to detect objects buried underground? The answer lies in one essential component: the coil.

In this guide, we’ll delve deep into the world of metal detector coils, shedding light on their function, variety, and how to use them effectively.

Importance of Coils in Metal Detection

Imagine your metal detector as a person, with its various parts serving different functions. 

In this analogy, the coil would be its heart this states the importance of the coil. Just as the heart pumps blood, giving life to the body, the coil is the driving force behind a metal detector’s ability to find hidden treasures. 

It truly is the “heartbeat” of the device.

The coil has a very special job. 

It works by sending out and picking up invisible waves called electromagnetic signals. 

These signals have the power to find and identify metals hidden deep below the surface.

  • Transmission: Think of the coil as a mini radio station.
    This station doesn’t play songs but instead sends out electromagnetic waves deep into the ground.
    These waves are like invisible fingers, reaching out, searching for anything metallic in their path.
  • Reception: Now, when these invisible fingers (waves) touch a piece of metal, something cool happens.
    The metal reacts and sends back its own set of waves. It’s like the metal is saying, “Hey, I’m here!”
    The coil, being super smart, feels this new set of waves and picks them up.
    It then tells the metal detector, which in turn beeps or gives a signal, letting you know that you’ve found something.

In simple words, the coil is like a conversation starter. It starts by saying “Hello?” into the ground, and when there’s metal there, it responds with its own “Hello!” back.
Without this amazing component, metal detecting would be impossible.
So, the next time you’re out with your metal detector, remember to thank its “heartbeat” – the coil!

Choosing the Right Size Coil for Your Metal Detectors

If you’ve ever looked at metal detectors, you might have noticed they don’t all look the same, especially the circular part at the bottom, known as the coil.
These coils come in different sizes, and it’s not just for show.
Just like we wear different shoes for running, hiking, or a fancy event, metal detectors have different coil sizes for different jobs. Let’s break it down in simple terms:

Small Coils (less than 8 inches):

Imagine these as your nimble and quick shoes, like slippers you’d wear around the house.

  • Precision Experts: Small coils are good at finding tiny things like small jewelry or coins.
  • Nimble Navigators: If you’re searching in a place with lots of trash or obstacles, these coils are perfect. They can easily move around obstacles, just like how you’d navigate through a cluttered room in your slippers.
  • Special Soil Masters: Some soils have lots of minerals, making them tricky to detect. But these small coils are great for such tricky terrains because they can tell apart, or “separate”, good targets from junk.

Medium Coils (8-11 inches):
Think of these as your every day sneakers. Good for a bit of everything.

  • Jack of All Trades: These are the go-to sizes for most treasure hunters. They’re like the shoes you wear when you’re not sure what the day might bring.
  • Balanced Buddies: They’re not too big and not too small, so they provide a good balance of depth (how deep they can find stuff) and ground coverage (how much ground they can search in one go).

Large Coils (more than 11 inches):
These are like your hiking boots. Built for specific tough tasks.

  • Wide Sweepers: If you’ve got a huge open area, like a beach, these coils will help you cover it fast. It’s like how hiking boots support you in long treks.
  • Deep Divers: Large coils can sense objects buried deep down, like old relics or big treasure chests.
  • Heavy Lifters: Just like hiking boots are heavier than slippers, these coils are heavier and might take some getting used to. But the treasures they can find? Worth it!

Types of Coils in Metal Detection

Imagine the different types of coil of a metal detector like the different types of nets used in fishing.
Just as each net is designed for a specific type of catch, coils are designed differently to make them suitable for certain detecting tasks.
Let’s delve into these designs using straightforward language.

Concentric Coils:
Think of these as a bullseye target with many circles inside each other.

  • Circular Layers: Their design is like having multiple rings inside rings. Picture a dartboard or the rings of a tree trunk.
  • Spot-On Seekers: If two objects say coins, are close to each other in the ground, these coils can tell them apart quite well. It’s like being able to tell apart two fish swimming close to each other in a pond.
  • Consistent Searchers: These coils have an even searching area, which means they are super precise. It’s like having a flashlight that shines a steady, even light, helping you find things more accurately.

Double-D Coils:
Visualize the capital letter D placed next to its mirror image.

  • Twin Design: They’re shaped like two letter Ds sitting side by side, almost like a pair of glasses.
  • Mineral Magicians: Some grounds have a lot of minerals, like tiny bits of iron, which can be confusing for some detectors. But these coils handle such grounds beautifully.
  • Wide Watchers: They cover large spaces efficiently. Imagine casting a wide net and capturing a lot of fish in one go.
  • Deep Seekers: They’re good at finding stuff that’s buried deep, especially in tough areas. It’s like having a net that can go deep into the water to catch bigger fish.

Mono Coils:

Picture a simple, single loop, much like a single hula hoop.

  • Solo Circle: Their design is just one loop, straightforward and no fuss.
  • Pulse Pros: These coils are often seen in detectors called pulse induction detectors. These are like fishermen who have a special technique for catching fish deep underwater.
  • Deep Divers, But Choosy: While they’re excellent at finding things deep down, they might sometimes struggle to tell the difference between a valuable old coin and a soda can tab. It’s a bit like catching everything in the net, both the fish you want and the ones you don’t.

How to Efficiently Use a Coil

Owning a metal detector is like having a secret key to hidden treasures. But, just like any key, you need to know how to use it right to unlock its full potential.

Think of the coil as the sharp edge of that key. Using it correctly can open up a world of discoveries. Here’s a simple guide on how to efficiently use a coil.

Ground Contact:
Imagine the coil as the bottom of your shoe.

  • Close But Not Too Close: Keep the coil near the ground, just like you’d keep your feet close to the floor when walking. But don’t let it touch or scrape. This way, it can sense things buried deeper in the earth.

Sweeping Technique:
Think of it like mopping a floor.

  • Slow and Steady: Move the coil gently across the ground, just like you’d move a mop over a dirty spot. If you go too fast, you might miss something.
  • Overlap-Like Tiles: Each time you sweep, make sure a bit of your last sweep is covered again. It’s like placing tiles where each one slightly overlaps the other. This ensures you don’t miss any spots.

Coil Angle:
Picture it as a book lying flat on a table.

  • Stay Level: Keep the coil flat against the ground, much like how you’d keep a book flat on a table. If you tilt it, you might get the wrong signals, just as words in a book might look confusing if viewed from a weird angle.
  • Remember the coil should be flat on the ground but your holding angle should be 45 degrees so that your detector coil may not end up detecting your control box’s metal.

Listening Carefully:
It’s like learning a new language.

  • Beep Talk: The coil “talks” with beeps and sounds. By paying close attention, you can learn what it’s saying. Different metals make it beep differently. Over time, you’ll learn to tell what might be under the ground just by listening!

Regular Maintenance:
Think of this as caring for a beloved pet.

  • Cleanliness Counts: After each adventure, clean off any dirt or mud from the coil, much like you’d clean your shoes after a muddy walk. This helps it work its best next time.
  • Health Checkups: Now and then, look over your coil for any damage, like cracks or cuts. It’s like checking your pet for any hurt. If the coil is damaged, it might not “beep-talk” correctly.


In wrapping up, the coil is more than just a part of your metal detector; it’s the heartbeat that drives your treasure-hunting adventures.

With the knowledge you’ve gained, you’re now better equipped to make informed decisions about your equipment and to use it to its fullest potential.
Always remember that while technology is crucial, your passion and curiosity are the real keys to discovering hidden wonders.

So, embrace the journey, let the coil be your guiding hand, and may you unearth treasures that tell tales of times gone by. Happy detecting!

Howard rockse

Hey there, I am Howard a deeply committed individual who likes to share my knowledge and insights in this field, having spent over ten years as a metal detectorist.

My experience with GoldXtra has allowed me to provide trustworthy and informative advice to both new and experienced metal-detecting enthusiasts. I’m committed to assisting others in exploring and enjoying the world of metal detecting with the same enthusiasm and dedication that I have.

Howard Rockse
Senior Content Writer at GoldXtra

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