How to Build a 5th Grade Radio Science Project
Radio frequencies, referred to as "RF" in the electronics industry, are signals which oscillate at very high frequencies. Radio, TV and satellite RF signals are used to transmit sound, video and data through the air. Appliances such as TVs and computers, which contain circuitry that operate at high frequencies, radiate RF energy. A fifth-grade science project can build an RF detector to investigate the presence of RF radiation from common household appliances.
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Things You'll Need
- Portable AM radio
- Shoebox
- Aluminum foil
- TV that has a picture tube
- TV that has a flat screen
- Computer
- Tape measure
Instructions
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1
Remove the lid from a shoebox or tear off the flaps of a similar size cardboard box so that there is one opening to the box.
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2
Line the inside of the box with aluminum foil.
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3
Tune an AM radio to a spot on the dial where there are no local stations, and all you hear is silence or a soft hissing sound.
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4
Place the radio inside the box. The aluminum foil will act as an RF shield, so that when you point the open end of the box at an appliance, any RF radiation detected by the radio will be known to come only from the object you are pointing toward. Radiation is present when you hear a hum or buzz in the radio's speaker.
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5
Turn on a TV set that uses a glass CRT (cathode ray tube, or "picture tube") for its screen. Point the open end of your box toward the TV and slowly walk closer to the screen. When holding the box, keep it fairly level to prevent the radio from falling out. Listen for a hum or buzzing sound in the radio. This indicates the presence of electromagnetic radiation. Notice if the buzzing gets louder the closer you get to the TV.
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6
Turn on a TV that uses "flat screen" technology. Point your box toward the TV and listen for buzzing in the radio as you approach it.
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7
Measure the distance from each of the TVs where you can no longer detect the sound in your radio.
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8
Turn on a computer. Point your detector box at the computer, and again walk slowly toward the computer. Measure the distance from the computer where you first detect a sound in the radio.
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9
Compare the three distances and determine which appliance is radiating RF energy the farthest out from its source.
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Tips & Warnings
If you are entering this project in a science fair, you will first need to form a hypothesis. One suggestion is to hypothesize which appliance you believe will have the strongest detectable RF radiation, as indicated by the loudest sound heard in the radio. Another suggested hypothesis would be to state which of the three appliances you believe will have RF radiation detected the farthest away from it.
