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Homemade Capacitor

  1. Jan 22, 2005 #1
    I have to make a homemade AM radio receiver for a physics course I'm doing, and I'm looking for any suggestions on the best way to make a homemade variable capacitor. I'm not expecting anyone to do my work for me of course, but any suggestions that anyone could offer would be appreciated.
  2. jcsd
  3. Jan 22, 2005 #2


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    Do you know values required?
  4. Jan 22, 2005 #3
    I need to be able to receive two AM radio stations. I haven't figured out what values I need yet. I'm just looking for different suggestions about how to construct one.

    Edit: Maybe something around the 100 pf range.
    Last edited: Jan 22, 2005
  5. Jan 22, 2005 #4


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    You can make a reasonable parallel plate cap with one adjustable plate that is moved by a screw. But to get more than a couple of tens of pFs, may be tricky (unless you just make a big box).

    Easier still may be a (cylindrical or) coaxial cap (a rod inside a tube), with the position of the inside rod adjusted by means of a simple screw.
  6. Jan 23, 2005 #5
    Here is an article on building air variable capacitors.

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