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Homework Help: Best Radio Frequency AM/FM radio

  1. Mar 7, 2010 #1
    1. The problem statement, all variables and given/known data

    Build an AM/FM radio. Determine the frequency and wavelength of the radio wave for best reception.


    2. The attempt at a solution

    I have built a AM/FM radio. My only problem is how do I determine the optimum frequency for best reception? I have only one solution and that is going through the spectrum of radio waves that my radio picks up and judging whether they are good or bad by how much static is in the background and how clear the sound is. Is this the optimum solution to finding the best way to determining the best frequency and wavelength for best reception? Or is there another way?
     
  2. jcsd
  3. Mar 8, 2010 #2
    It does seem a strange/vague problem. The term "best" can be terribly subjective.

    One idea that cam to mind, however was if you had a transmitter as well, you could take the output of the receiver, and subtract the input of the transmitter (use a differential amp). Then you could make a case that the frequency with the least amount of noise had the best reception. (This assumes that the transmitter broadcasts equally well across all frequencies/modes.) You probably want to minimize 1. distortion and 2. noise.

    But with a vague term like "best" you could easily claim that everything on the airwaves is rubbish nowdays, and the best reception is the frequency where your radio fails to operate, producing wonderful golden silence. Or claim to be a fan of white noise, and choose the frequency with the most static.

    Your method doesn't sound too bad either.
     
    Last edited: Mar 8, 2010
  4. Mar 9, 2010 #3

    berkeman

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    Staff: Mentor

    Maybe they're just asking about the antenna and its frequency range. What kind of antenna did you mate with this radio that you "built"?
     
  5. Mar 10, 2010 #4
    I just attached a simple vertical antenna to the radio. Its a type of antenna that you would usually find on radios. I hope that is what you were asking.
     
  6. Mar 10, 2010 #5

    berkeman

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    Staff: Mentor

    And how would the length of that antenna be related to what frequencies the radio can pick up most efficiently?
     
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