Help on Resonant Circuits

Discussion in 'Homework Help' started by Corey Esson, Feb 8, 2015.

  1. Corey Esson

    Thread Starter Member

    Feb 8, 2015
    30
    1
    Hi all, new here and like the whole site.
    I'm having issues with some online electronics classes/homework.
    The quest I can't find in my lesson is: All receivers, regardless of what type, have at least one:
    A. Power supply
    B. Tuning fork
    C. Vacuum tube
    D. Resonant circuit

    I have it narrowed down to either A or D but not quite sure. Thanks in advance for any all all help.
    Corey
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,056
    3,245
    So which of those two are absolutely required for operation even if you know nothing else about he design of the receiver circuit.
     
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  3. Corey Esson

    Thread Starter Member

    Feb 8, 2015
    30
    1
    I found it finally! Its "D". Resonant circuit
     
  4. Corey Esson

    Thread Starter Member

    Feb 8, 2015
    30
    1
    I know now that the resonant circuit is but thought the power supply was but found it wasn't. Thank you very much!
    Corey
     
  5. crutschow

    Expert

    Mar 14, 2008
    13,056
    3,245
    How can a receiver work without power? :confused:

    And certainly you can make a receiver without a resonant circuit (although perhaps not easily) using all digital processing.
     
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  6. Corey Esson

    Thread Starter Member

    Feb 8, 2015
    30
    1
    Very true when you put it that way for sure. Thank you.
    Corey
     
  7. WBahn

    Moderator

    Mar 31, 2012
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    4,805
    Crystal radio....

    The power comes from the signal itself, and not a power "supply".

    But I agree that a receiver doesn't absolutely have to have a resonant circuit, either.

    So I think the answer depends on what the person writing it had in mind as far as the "fine print".
     
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  8. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    With a topic titled Resonant Circuits, the answer was sort of a gimme. The problem is the distractors should sound feasible, but not correct.

    Answer A is also correct, unless your going to discriminate between power supplies and batteries ... calling them a power source. Multiple Choice (guess) questions need good distractors to have some level of validity and a decent degree of difficulty.
     
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  9. WBahn

    Moderator

    Mar 31, 2012
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    Don't forget about the good ole fashioned crystal radio! No power supply. No battery. Just a long wire, an inductor (wire wound on a toilet paper tube), a capacitor (I used a two liter soda bottle with aluminum foil taped on each side), a germanium diode, and a high-impedance earphone.
     
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  10. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    Very true WBahn. The crystal is a resonant circuit.

    Even antenna can be a bad distractor.
     
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