How to Make a Parabolic Microphone With an Old TV Dish




About: I am a student and a electronic enthusiast. I just started instructables and need your support.

In this project I am going to show how to make a parabolic microphone.I think you have an old TV dish that is laying around your house because you no longer use it. It is time to take out your TV dish and re purpose it. I was Thinking what will be useful for someone like Mcgyver and can be made with stuff that is in your house. the parabolic microphone can even hear low voices from 25 meters away. This will be a perfect tool for Mcgyver.

Let's Start

Step 1: Gather Everything !

Materials Needed:

  • An Old Rusty TV Dish
  • Paint Brush
  • ESDEE Super Set AUTO FINISH (or any paint)
  • Earphones with Microphones
  • A Small piece of foam board
  • Tape

First you need your rusty dish which is our parabolic structure. This structure will collect sound from all around and reflect it to a certain point. You are also going to need a painting brush and a can of paint I am using a metallic finish you can use any paint or you can leave it as it is. The next thing you need is a earphone which have a microphone I took The earphone which came with a phone. You are also going to need some device to record everything I used a phone. You need a piece of foam board for later use. You are going to need some tape you can use any kind of tape I am using transparent tape because it is what I have. Gather these things and start working!.

Step 2: Cleaning the Rusty Dish

Start by taking a bucket of water and steel scrubber or something to brush of the dirt.Now you can pour some water and brush of the dirt. After a minute of cleaning look if it is clean and repeat this process until you are satisfied. Note that the rusty part may not go after cleaning and that is not a problem. Wipe of all water from the dish and let it dry.

Step 3: Painting the Dish

Make sure that the dish is dried and you can start painting. Open your can of paint and mix it very well and take your paint brush and start painting. You can make your dish any color you want I used an metallic finish because I only had that paint left. Let your paint dry it can take 1 or 2 days. Let's wait for it to dry. We need do some stuff with our receiver unit in the dish. So we can jump into our next step.

Step 4: Opening Up the Receiver Unit

Let's open up the receiver unit. Start by removing the screw from the stand that is holding the receiver unit. You may need a big screw driver because it is possibly a big screw. I had to put some effort on unscrewing this because the screw was so rusty. After you remove your receiver unit you need to open it. Open it up by using a flat screwdriver and pushing up like shown in the image. Be careful it maybe filled with insects luckily mine was clear. Take out the Metal thing inside. If you look close they are really covered with some kind of red glue or something. I think the companies do this to make it waterproof.

Step 5: Repurposing the Receiver Unit

Scratch out the covering in your receiver unit. Yours may not have the covering. There will be some screws unscrew them don't throw them away you need it later.Apply some force and take out the white membrane which is in top of the unit.After unscrewing you will see a circuit board take it out. don't throw anything everything is useful.

Step 6: Setting Up the Microphone

Take a 6mm drill bit and drill a hole. I used 6mm to drill because my microphone could go through it. You can use what suits you. Pass your microphone through the hole. If you look at the top of the casing you will see 2 things shaped like cone's inner side.After you have placed your microphone you can make some holes to the membrane with a screwdriver. I made holes in a pattern. Let's close it up

Step 7: Closing the Unit

Use a piece of foam board to hold the microphone.feed the microphone's audio cable through the hole in the bottom of the unit.If there is a nut then remove it. Take the membrane and place it where you got it. Tape the base and the membrane of the unit. After all of that it should look like the above images. Make sure everything is nice.

Step 8: Placing the Unit in the Dish

Place the unit in the dish and tighten the screw. Now the parabolic microphone is complete. This can hear the faintest noise from meters away. You can use this to spy on people or here bird songs. Now we can see how can you use this. You can use this to spy on anyone and the sound quality is not depleted.

Step 9: Record the Sound With Your Phone

Connect The earphone's pin to your phone . Use The app that came with your phone for recording sound. You can save it and here it. With this you can record what people are saying. Now go Outside and spy on someone!.

Step 10: Support

support this by sharing and voting this for the mcgyver and first time author challenge. I am new to instructables and need your support For making new instructables.



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    6 Discussions


    1 year ago

    Many years ago I did a similar project professionally using parabolic radar dishes. The principle is exactly the same.

    It can be difficult to pinpoint the exact place for the microphone so that it's positioned precisely at the focal point of the dish. I was using dynamic microphones ( which don't use batteries ) and one useful feature of them is that if you feed sound into them from a headphone jack, they replay that sound in a similar manner to a loudspeaker.

    I then fed the microphone with a series of fairly high frequency ( 5kHz ) beeps and listened from a distance of about twenty yards or more while an assistant adjusted the microphone position. I could walk a few steps from side to sideband easily listen for the sweet spot and try adjustments of the microphone position to improve the range. These days, I'd create the beeps on a computer and record them as an MP3 file and play them on an iPod or smartphone.

    You can also hold up your hand at the sweet spot so that the assistant can align a sight ( short length of 1/2" tube ) to point accurately at it, which makes setting it up on location much easier.

    Parabs are brilliant for recording birdsong and other high frequency sounds, but become less directional at lower frequencies. They work by magnifying the sound that you do want, whereas professional rifle microphones work by cancelling out the sound that you don't want. You get a higher sound level coming out of a parab and that magnification is clean amplification without introducing electronic noise or distortion.

    3 replies

    Reply 1 year ago

    What is done with the ear phones? And the Jack pin, is it used with the Smart phone, how do you record or hear from a distance?


    Reply 1 year ago

    The pin is connected to the smart phone for recording.


    1 year ago

    Very interesting project! Nice and clear as well, You'll get a vote from me :D

    1 reply