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Homebuilt quantum tunneling experiment

  1. Apr 5, 2007 #1

    The website www.altair.org describes how to create a homebuilt quantum tunneling experiment which I would like to try.

    It requires the use of a Gunnplexer. If I search for that term, all references to that term seem presuppose more knowledge that I have.

    Can someone get me started on the path to learning the prerequisites?

  2. jcsd
  3. Apr 5, 2007 #2
    This is an excellent experiment to do. A detailed explanation can be found in Feynman Lectrues on Physics Vol 2, full of mathematical computations.

    It's about total internal reflection of light in different mediums. It turns out, when light is reflected, there is still an electric field outside that medium that is dying off expenetially. If you bring a second medium close by a wavelength apart, the dying field can be pick up and re-transmitted by the other medium.

    For visible light, the wavelength of red is 650 nano-meters. That is too small to perform a hands on experiment, this effect still exists though. So it was thought up to check internal reflection by a longer wavelength light. It's common to use a 3 cm wavelength light, that corresponds to 10 GHz in frequency in a region of electromangetic spectrum called microwave.

    A gunn diode is a special diode invented by a guy name gunn that oscillates in microwave frequencies. It is a perfect device for a cheap microwave generator.

    However, gunn generators are becoming more obsolote in microwave, so it be hard to find one. You can pull out a gunn generator from old garage motion detector. Or try looking around on ebay.

    The detector is usually a waveguide usually WR-90 with attacked microwave diode you could connect to a voltmeter. You will get a voltage reading when subjected to a microwave source.

    Hope that gets you started.
  4. Apr 5, 2007 #3


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    Staff: Mentor

    I went to the ARRL.org website (the main HAM radio organization), and did a search on Gunnplexer. I got some great hits, but the best ones were in the ARRL members-only area, so I can't post links to them here. :blushing:

    But I cut out the "Resources and Links" section from the best article (I'm pretty sure it's okay for me to do that), and I'll post that here to get you some good pointers. Looks to be interesting stuff. I couldn't tell from a quick read if you need a HAM license to transmit on the X-band that keeps getting mentioned for these Gunnplexer transceivers, but I'm sure that's covered in the links below. Feel free to PM me if you have HAM related questions.

  5. Apr 10, 2007 #4
    nice website actionintegral...good luck with ur project
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