What Factors Affect Am and Fm Radio Reception

What Factors Affect AM And FM Radio Reception? Background Information Communications are carried by waves. One type of communication is AM and FM radio. AM and FM radio’s use radio waves. A radio wave is an electromagnetic wave propagated by an antenna at various frequencies. In AM (amplitude modulated) radio waves, the audio signal changes the amplitude of the carrier wave. In FM (frequency modulated) radio waves, the audio signal changes the frequency of the carrier wave. Australia’s broadcast bandwidth for AM radio is 500-1500 KHz and for FM radio it is 80-108 MHz.AM radio waves can be affected by electrical interference (such as household appliances) and devices oscillating in the same frequency band. FM radio waves aren’t subject to electrical interference but are affected by devices oscillating in the same frequency band. Aim To test if – a TV; a microwave oven in use; a mobile phone making a phone call; a TV remote control; water surrounding the aerial; a thin-metal box; an incandescent light bulb; a fluorescent light bulb – causes interference with AM and FM radio reception. HypothesisI think that a TV will affect AM reception, but not FM reception, because TV’s will give off electrical pulses which will interfere with AM radio, but not FM. I think that a microwave oven being used next to a radio will affect AM and FM radio reception, because microwave ovens are believed to give off a little amount of radiation, which would probably interfere with the AM and FM reception. I think that a mobile phone making a call will affect both AM and FM radio reception, because when a mobile makes a call it is sending out radio signals. This should interfere with AM and FM radio.I don’t think a remote control will interfere with AM reception because it wouldn’t cause much electrical interference, but I think it will interfere with FM reception because remote controls use similar frequencies to FM radio stations. I don’t think water surrounding the radio antenna will affect the reception of AM and FM radio because water isn’t dense enough to block out the signal. I think a thin-metal box will affect AM reception if the radio is inside it because the signal is blocked out by the metal, but I don’t think it will affect the FM reception because the signal is strong enough to ake it through the thin-metal. I don’t think an incandescent light bulb and a fluorescent light bulb will affect the reception of AM and FM radio because I don’t think it gives out and any frequencies that would interfere. Method TV test I tuned the portable radio into the FM radio station 98. 1 MHz I recorded how good the quality of the reception is on a scale of 1-10 (1 being poor, 10 being good) I placed the radio in front of the TV screen and turned the TV on I recorded how good the quality of the reception is on a scale of 1-10 I repeated steps 1-4 three times for reliable resultsI repeated steps 1-5 but tuned into the AM radio station 1431 KHz Microwave Oven test I tuned the portable radio into the FM radio station 98. 1 MHz I recorded how good the quality of the reception is on a scale of 1-10 (1 being poor, 10 being good) I placed the radio in front of the microwave oven and turned on the microwave I recorded how good the quality of the reception is on a scale of 1-10 I repeated steps 1-4 three times for reliable results I repeated steps 1-5 but tuned into the AM radio station 1431 KHz Mobile Phone Call test I tuned the portable radio into the FM radio station 98. MHz I recorded how good the quality of the reception is on a scale of 1-10 (1 being poor, 10 being good) I placed the radio next to the mobile phone and made a call I recorded how good the quality of the reception is on a scale of 1-10 I repeated steps 1-4 three times for reliable results I repeated steps 1-5 but tuned into the AM radio station 1431 KHz TV Remote Control test I tuned the portable radio into the FM radio station 98. 1 MHz I recorded how good the quality of the reception is on a scale of 1-10 (1 being poor, 10 being good) I brought the TV remote control next to the radio antennaI recorded how good the quality of the reception is on a scale of 1-10 I repeated steps 1-4 three times for reliable results I repeated steps 1-5 but tuned into the AM radio station 1431 KHz Water test I tuned the portable radio into the FM radio station 98. 1 MHz I recorded how good the quality of the reception is on a scale of 1-10 (1 being poor, 10 being good) I submerged the radio antenna completely under water inside a glass I recorded how good the quality of the reception is on a scale of 1-10 I repeated steps 1-4 three times for reliable resultsI repeated steps 1-5 but tuned into the AM radio station 1431 KHz Metal Box test I tuned the portable radio into the FM radio station 98. 1 MHz I recorded how good the quality of the reception is on a scale of 1-10 (1 being poor, 10 being good) I placed the radio inside the metal box and closed the lid I recorded how good the quality of the reception is on a scale of 1-10 I repeated steps 1-4 three times for reliable results I repeated steps 1-5 but tuned into the AM radio station 1431 KHz Incandescent Light Bulb testI tuned the portable radio into the FM radio station 98. 1 MHz I recorded how good the quality of the reception is on a scale of 1-10 (1 being poor, 10 being good) I placed the radio right next to the light bulb I recorded how good the quality of the reception is on a scale of 1-10 I repeated steps 1-4 three times for reliable results I repeated steps 1-5 but tuned into the AM radio station 1431 KHz Fluorescent Light Bulb test I tuned the portable radio into the FM radio station 98. 1 MHz I recorded how ood the quality of the reception is on a scale of 1-10 (1 being poor, 10 being good) I placed the radio right next to the light bulb I recorded how good the quality of the reception is on a scale of 1-10 I repeated steps 1-4 three times for reliable results I repeated steps 1-5 but tuned into the AM radio station 1431 KHz *FOR ALL THE TESTS I USED THE SAME RADIO AND I TUNED INTO THE SAME AM AND FM RADIO STATIONS Results FM Radio Reception results Factors Tested Test 1 Reception Before Test In scale 1-10 Test1 Reception During TestIn scale 1-10 Repeat 1 Reception Before test In scale 1-10 Repeat 1 Reception During Test In scale 1-10 Repeat 2 Reception Before test In scale 1-10 Repeat 2 Reception During Test In scale 1-10 Repeat 3 Reception Before test In scale 1-10 Repeat 3 Reception During Test In scale 1-10 TV 9 9 9 9 9 9 9 9 Microwave Oven 8 2 8 1 8 1 8 1 Mobile Phone Call 8 1 8 1 8 1 8 1 TV Remote Control 8 1 8 2 8 1 8 1 Water 8 8 8 8 8 8 8 8 Metal Box 8 8 8 8 8 8 8 8 Incandescent Light Bulb 8 8 8 8 8 8 8 8 Fluorescent Blub 8 0* 8 0* 8 0* 8 0*AM Radio Reception results Factors Tested Test 1 Reception Before Test In scale 1-10 Test1 Reception During Test In scale 1-10 Repeat 1 Reception Before test In scale 1-10 Repeat 1 Reception During Test In scale 1-10 Repeat 2 Reception Before test In scale 1-10 Repeat 2 Reception During Test In scale 1-10 Repeat 3 Reception Before test In scale 1-10 Repeat 3 Reception During Test In scale 1-10 TV 9 1 9 1 9 1 9 1 Microwave Oven 8 4 8 4 8 4 8 4 Mobile Phone Call 9 4 9 5 9 4 9 5 TV Remote Control 7 7 7 7 7 7 7 7 Water 8 8 8 8 8 8 8 8 Metal Box 0* 9 0* 9 0* 9 0* Incandescent Light Bulb 8 7 8 7 8 7 8 7 Fluorescent Blub 8 4 8 4 8 4 8 4 0* no reception at all, not even a sound Analysis of results From looking at the results of this experiment, you can see the relationship between the factors (TV, microwave oven, mobile phone call etc) and how it affects the reception the radio gets. With the FM reception results you can see that the microwave oven, the mobile phone call, the TV remote control and the fluorescent light bulb affects the FM radio reception by degrading it heavily.You can also see that the TV, the water, the thin-metal box and the incandescent light bulb does not affect the FM radio reception at all. With the AM reception results you can see that the TV, the microwave oven, the mobile phone call, the thin-metal box and the fluorescent bulb affects the AM radio reception by degrading it pretty heavily. You can also see that the incandescent bulb degrades the reception of AM radio slightly and that the TV remote control and the water has no affect on the reception of AM radio at all.Conclusion As you can see from the results, FM radio reception can be affected by a microwave oven being used next to the radio, a mobile phone call being made next to the radio, a TV remote control being held next to the radio and the radio being held next to a fluorescent bulb. Because FM radio is frequency modulated and the audio signal changes the frequency of the wave, these factors will affect FM radio reception because they are all devices that oscillate frequencies that interfere with the FM bandwidth.You can also see from the results that AM radio reception can be affected by a TV being on next to the radio, a microwave oven being used next to the radio, a mobile phone call being made next to the radio, the radio being held next to a fluorescent and incandescent bulb and when you put the radio inside a thin-metal box. Because AM radio is amplitude modulated and the audio signal changes the amplitude of the wave, these factors will affect AM radio reception because they either electrically interfere with the AM reception, they block out the AM signal or they oscillate at a frequency hat interferes with the AM bandwidth. Therefore my earlier hypothesis was mostly right except that incandescent and fluorescent light bulbs DO affect AM reception and fluorescent light bulbs DO affect FM reception. Errors/Improvements My experiment could be improved if I had access to a device that digitally reads how good the radio reception is, so it is not me judging how good the reception is because you will not get 100% accurate results because humans aren’t computers and they make mistakes.My experiment could be improved if I carried it out in an empty room so there would be no chance of other things interfering. One error that I made was that I only used one type of TV remote control, because different types of remote controls use different frequencies. Another error I made was by only submerging the antenna in a glass of water that isn’t that deep, if you took the radio to the bottom of a swimming pool or deep in the ocean you could get different results.Bibliography School Physics Textbook www. howstuffworks. com www. cybercollege. com www. geocities. com