27.12mHz Crystal Oscillator Project.

Discussion in 'The Projects Forum' started by TJD, Dec 6, 2015.

  1. TJD

    Thread Starter New Member

    Dec 6, 2015
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    Hi all, I'm trying to make a 27.12mHz Oscillator circuit and, for stability would like to use a crystal. Looking on various component websites I see that such a crystal comes in a VERY small surface mount package. Does anyone know of a larger component size package for Breadboard Prototype/Project PCB type mounting?
     
  2. recklessrog

    Member

    May 23, 2013
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    Have a look for 27Mhz radio control transmitter crystals. Amazon list a lot, 27.125Mhz is a standard frequency, and if you put a small value trimmer capacitor in your circuit, you should be able to "pull" the xtal frequency to your 27.12.
     
  3. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    Those packages aren´t SO small, with a bit of patience you should be able to easilly connect wires to it.
    And also I think you mean 27.12 MHz, not mHz.
     
  4. bertus

    Administrator

    Apr 5, 2008
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  5. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    That frequency is between Chan 13 (27.115) MHz) and Chan 14 (27.125 MHz) in the standard CB band.

    I find old CBs, some crystal-controlled, most synthesized, at garage sales for cheap....
     
  6. TJD

    Thread Starter New Member

    Dec 6, 2015
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    Thanks for all the help. Short of just following an oscillator circuit from a book, does anyone know of any good oscillator tutorials to get me started. I'd rather understand how the circuit works than just build it. And if you haven't worked it out, yes I'm very new at this!
     
  7. BR-549

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    Sep 22, 2013
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  8. BR-549

    Well-Known Member

    Sep 22, 2013
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    If you want to understand how the oscillator works, I would recommend those military courses.......NEETS I think they call it. There’s a few here real familiar with it. They’ll chime in shortly. Hopefully.

    That’s as good a study as any.
     
  9. bertus

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    BR-549 likes this.
  10. TJD

    Thread Starter New Member

    Dec 6, 2015
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    Thanks for this, sounds ideal. The 27.12mHz is (apparently) used for RF Welding of PVC, which is what I need it for. I don't know if a few Hz either way would make too much difference.
     
  11. recklessrog

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    May 23, 2013
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    Dielectric loss pre heating of plastic pellets for extrusion moulding was done with a very powerful R.F generator at a company I used to work for, I am pretty sure it was not a critical frequency as it was not stabilised. As far as I can recall, it was anywhere from 25-30MHz. All I can remember is that It weighed about 200Lbs and had an enormous Valve that lit up like a light bulb!
     
  12. TJD

    Thread Starter New Member

    Dec 6, 2015
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    Great - Will keep you posted!!
     
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