Crystal Radio Circuits - Alternative Concepts

Discussion in 'Wireless & RF Design' started by vu2nan, Nov 22, 2015.

  1. vu2nan

    Thread Starter Member

    Sep 11, 2014
    43
    10
    1. The well-known parallel-tuned, series-fed circuit.

    [​IMG]
    Parallel-tuned, series-fed Crystal Radio circuit

    2. Alternative series-tuned, shunt-fed circuit. Shunt-feeding ensures a path for the resonant current through the headphones.

    [​IMG]
    Series-tuned, shunt fed Crystal Radio circuit

    3. Not-so-well-known, series-tuned, shunt-fed variant.

    [​IMG]
    Series-tuned, shunt-fed Crystal Radio variant

    Updates available at

    http://nandusthoughts.blogspot.in/2015/01/crystal-radio-circuits-alternative.html

    Regards,

    Nandu.
     
  2. DickCappels

    Moderator

    Aug 21, 2008
    2,655
    632
    Does the series-tuned, shunt-fed crystal radio have any advantages over the other two shown?
     
  3. boatsman

    Senior Member

    Jan 17, 2008
    165
    383
    I remember building crystal sets, winding wire on bakelite tubes and poking a piece of some crystal with a thin wire until I could hear something in the headphones. I used the circuit in No 1. One of the biggest snags was that you needed a very long aerial and a good ground connection.
     
  4. vu2nan

    Thread Starter Member

    Sep 11, 2014
    43
    10
    Hi Dick,

    The series-tuned, shunt-fed versions excel when the detector is a germanium transistor with its base and emitter interconnected.

    Regards,

    Nandu.
     
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