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Modulation again

  1. Oct 24, 2009 #1
    why it is disaster if asignal exists in am at frequency of 455 khz , i mean asignal is at the IF frequency.

    also why IF not greater or smaller than 455khz i need to know
  2. jcsd
  3. Oct 25, 2009 #2


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    Staff: Mentor

    Your question is not clear. Please try again with more details and more context. Thanks.
  4. Oct 25, 2009 #3
    This should be obvious. If the signal is strong enough to enter the IF amplifiers then it will cause interference by coexisting with the signal you are trying to receive.

    455khz is not the only IF frequency. Other frequencies are used depending on the receiver design, desired receiving band, and number of conversions. For example, 10.7mhz is a common IF for the FM broadcast band receiver.
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