Junk science or truth?

Discussion in 'Electrical Forum discussion & Blog' started by Cookie, Feb 21, 2009.

  1. Cookie

    Cookie .

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    Remote Car Key
    Suppose your remote car door opener does not have the range to reach your car across the parking lot. Hold the metal key part of your key fob against your chin, then push the unlock button. The trick turns your head into an antenna, says Tim Pozar, a Silicon Valley radio engineer.
    Mr. Pozar explains, “You are capacitively coupling the fob to your head. With all the fluids in your head it ends up being a nice conductor. Not a great one, but it works.†Using your head can extend the key’s wireless range by a few car lengths. :D

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  2. hj

    hj Moderator & Master Plumber Staff Member

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    busted

    About the same as calling someone on your cellphone and having them push their unlock button while you hold your phone against your chin.
  3. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Yes, it does work...try it yourself.
  4. jimbo

    jimbo Plumber

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    Everyone has seen the or noticed the effect of touching rabbit ear television antenna can change the reception. If you are listening to a weak radio station on a little table radio, placing your hand on the radio can help.

    Haven't tried the key trick yet, but it has some logic. Bring on the mythbusters!
  5. gdog

    gdog write diagnostic firmware for embedded industrial

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    It is true that your body will capacitively couple to just about any RF (radio frequency) device (you should see what hoops RF engineers have to jump through to make sure cell phone antennas work in various environments..) but as far as extending it's range, couldn't say for sure; depends on lots of various parameters (carrier frequency used by remote, physical size/shape of your anatomy, how much salt you put on breakfast, etc.)... but yeah, it might work; i will have to try it next time...
  6. jimbo

    jimbo Plumber

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    I would opine that your body would often function well in a "receive" situation. Transmit might be different, as the impedance match of the xmtr to the antenna is more important. Once again.....bring on the myth busters!
  7. beekerc

    beekerc IT Consultant / Network Engineer

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    94
    Location:
    Seattle
    key fob extender

    yes, it works, not exactly sure of the science, but it does the trick. it's especially effective when i use the panic button as a car-finder in a big parking lot.

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