How to Make a Metal Detector


Last updated on March 7th, 2023

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Learn how to make a metal detector at home with these household objects in a few easy steps and discover this addictive hobby for yourself.

How to Make a Metal Detector_featured

Have you ever wondered if there is hidden treasure buried in your backyard? Perhaps you’ve found yourself at the beach wondering how much metal is buried in the sand you’re stepping on… shipwrecks, lost jewelry, Aztec gold… if you have, keep reading, you’ll find out how to make a homemade metal detector and learn what amazing discoveries you could make!

Metal detecting can be a fun pastime that helps to clean the environment while providing the thrill of discovery. From archaeological artifacts to be displayed in museums, sold at a profit to collectors or helping out a desperate husband who lost his wedding gold band at the beach, you can become a metal-detecting enthusiast without spending a fortune on a high-tech metal detector before deciding whether it is the best hobby for you.

Here’s a way you can build a homemade metal detector for yourself MacGyver style.

What you’ll need

You might find these things lying around the house but if you’re not that fortunate they’re not difficult to track down and don’t cost much at all.

  • A calculator
  • A radio
  • Duct tape
  • Some sort of shaft, such as a broomstick or hockey stick (optional)
  • Some patience
  • A thrill for discovery
How to Make a Metal Detector_searching on the beach

How to make a metal detector

Making a metal detector at home is not difficult, but requires some skill and patience. Gather your supplies and make sure both the radio and the calculator have working batteries in them and overall work fine.

There is no need for high-tech devices: grandpa’s old tune-in radio that hasn’t been used since he discovered the Netflix and your old school calculator should be more than enough.

Step One

Turn the radio on and set it to the AM band, but do not select any station.

If everything is right, you will hear the white noise radios make when stuck between stations.

How to Make a Metal Detector_analog radio

If you’re under 30, chances are you’ve never heard this sound before, so familiarize yourself with this buzzing as changes in it will inform you when metal is being detected once this homemade metal detector is put together.

Step Two

Once the radio is set, place the back of your calculator against the back of the radio.

When both radio and calculator are turned on, you should be able to hear a dull buzzing sound.

How to Make a Metal Detector_calculator

You may have to try different positions or distances between the devices to get the right pitch.

The antenna of the radio will be the input of the device through which the metals will be detected: make sure you don’t obstruct it with the tape and that it can be fully extended and retracted.

Recommended Article: Make sure to check out our awesome guide to the top pinpoint metal detectors next!

Step Three

Use the tape to fix both devices into position, making sure the calculator and radio are producing the correct buzzing tone in unison.

You may use a board or plank to pin your creation to and keep them in place with the duct tape or some other nifty way to keep them together, like some rubber bands.

Be creative, but make sure the materials you use do not interfere with the connection between the radio and the calculator.

Step Four

For comfort, you may wish to attach your home-made metal detector to an extendable arm – ideally it would be around 1-1.2m long. Some kind of altered hockey stick would be perfect. This will allow you to scan the floor without crouching like Igor in Young Frankenstein. Use duct tape at will but make sure not to interfere with the buzzing.

You may keep the radio and calculator on to make sure you don’t accidentally interfere with the conjoined sound they produce while you do this. Once everything is fixed in its place – it’s done! You just finished making a metal detector!

Articles like this: Don’t miss our list of the top discoveries ever made with a metal detector.


To check it works, test your rudimentary metal detector on some spoons, nails or coins by running it over them and listening for the detector to produce any different noise from the buzzing that is already permanently emitting. If it does, congratulations! You just detected a metallic spoon!

You should also check the distance from which it detects objects – this may vary depending on the radio and calculator you used, but should be no more than a few centimeters.

You may test how deep in the ground it detects objects by burying some old cutlery at different depths in your backyard. This would prove a great way to baffle the dog or make a fun game with the kids.

Remember other objects or ground between the metallic artifact you wish to the find and your homemade metal detector may interfere with its capabilities, but you will get the hang of it… Once you learn the range of your metal detector, you may take it outside and put it to good use!

The alternative method

How to Make a Metal Detector_iphone apps

If old school is not your style, you may also profit from new technology by turning your smartphone into a metal detector.

There are different apps for both Android and iPhone that can turn your phone into a metal detector. They work by measuring the magnetic field around the location of your phone – usually, they start with a baseline measurement and that goes up when it detects a metal.

These kinds of apps use your smartphone’s built-in sensor to measure a magnetic field’s value. By placing your phone near metallic objects, the app will show how the strength of the magnetic field around it increases.

This method may be defective and not detect certain metals due to the limitations of the sensor (which was not built with such applications in mind), but they do have some handy applications in sectors such as construction as an emergency tool to find copper wires or pipes in walls.

You may even use a selfie-stick as a pole to turn your phone into a makeshift extendable arm.

In any case, whether you decide to go analog or digital to build your homemade metal detector, its accuracy will depend on the magnetic field sensor used as well as on the environment: you may often get interferences that not even the top-brand detectors would be able to avoid!

Hope you learned how to make a metal detector and soon you’ll discover this wonderful hobby.

We’d love to know how you got on making a metal detector. Let us know down in the comments section!

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Thomas S.

With a background in government supply and a keen interest in emerging technologies, I have developed a passion for the realm of stealth technology. My expertise lies in analyzing the latest advancements in spy gadgets and high-tech products, with a particular focus on those available to the public that offer a modern-day James Bond experience. Through my work, I strive to uncover the most cutting-edge innovations in the field and provide valuable insights to fellow enthusiasts and industry professionals alike.

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