How to Make a Metal Detector (Homemade DIY Approach)

Have you ever wondered if there is any hidden treasure buried in your backyard? Metal detecting can be an enjoyable hobby that can help remove trash from the surroundings while instilling in you a thrill of discovery.

A metal detector is a helpful tool that can help you discover metal objects. The tool is helpful when you need to find hidden metal objects underground.

The detector usually comes in a handheld form with a sensor coil placed on one end. The best and simple way to use an instrument that has a magnet on it to make a metal detector.

Keep reading to learn how to make a metal detector and find what surprising discoveries you could make!

Method 1: Using a Radio & Calculator

What you need:

You might get things in your home itself, but if you don’t find them, you can buy them in supermarkets or specialty stores that don’t cost much at all.

  • A calculator
  • A radio
  • Duct Tape
  • Shafts such as hockey stick or broomstick

Make sure that your radio and calculator have working batteries in them and overall work fine. Your old school calculator and your old tune-in radio are more than enough to make a metal detector.

Read on the steps to make your own fantastic metal detector.

Step 1:

Turn your radio on and set it to the highest AM band and ensure that you did not select any station. There should be no audio being received from radio stations.If everything is right, you should hear static only.

Step 2:

After that, you will set the sensor part of the metal detector. Once your radio is set, place the back of your calculator against the back of the radio.

You may have to try different positions and distances between the devices to get the right pitch. Use a glue stick, adhesive strip, or tape to fix the two.

Make sure that the two-part are correctly attached, and there is no chance of them slipping away.

Step 3:

After securing both the radio and calculator, make sure that the calculator and radio are emitting the correct buzzing or constant tone.

If you hear a crisp and clear sound, you can go ahead and mount it on a rod and then secure it using duct tape or use rubber bands to keep them together.

Step 4:

For your comfort, mounting can be done on anything that you find convenient, a broomstick or hockey stick, a ruler, pole, or anything that is kept above the ground.

Apply tape or glue and fix the metal detector to the shaft. Zip ties can also help if you don’t want to use tapes or adhesive.

Method 2: Transform Your Smartphone into a Metal Detector

You’d be surprised to know that your smartphone can actually turn into a metal detector! Mobile phones are electrical gadgets and produce a magnetic field.

All you need to do is download a metal detector app which will help you utilize the phone’s magnetic field to discover metals.

Usually, the app will show a color change with a beep once the metal has been detected. However, it is not as efficient as other methods and they can fail to perceive some metals. But this method is the simplest of them all and is fun to try.


Test your metal detector on different metallic household objects such as coins, silver spoons, gold rings, watches, cups, and jewelry items, etc.

This is a straightforward way of testing if the metal detector is working. If it does, then you just made an incredible metal detector.

If the instrument quickly detects the objects, it will work better outside in your backyard. When the tool senses metal, it produces a constant clear sound. Once you learn the range of your metal detector, you may take it outside and put it to good use.

Working of radio and Calculator Metal Detector

The detectable radio-frequency is emitted from a circuit board of the battery-powered calculator. The radio waves reflect from metal objects and this motion lets the AM receiver catch the waves to amplify them.

This is the sound that is heard when the tool is close to any metal object. The faint radio signal is interrupted if the music on the radio is played.


Figuring on how to make a metal detector is a great learning experience. Developing metal detectors and using them is fun and straightforward to use.

Building a metal detector is absolutely a fun activity and education for your family. However, you can experience some interferences that not even high-end brand detectors can avoid. If you are serious in metal detecting or treasure hunting, it is far better to purchase a high-end metal detector.