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Re: Crystals & Oscllators [Maybe more than you wanted to know]

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  • Claudio Re
    My big compliment Jack ! Thanks . Claudio I1RFQ ... with ... methods ... 20Parameters.pdf ... with
    Message 1 of 7 , Sep 2, 2007
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      My big compliment Jack !
      Thanks .
      Claudio I1RFQ


      --- In softrock40@yahoogroups.com, Jack Smith <Jack.Smith@...> wrote:
      >
      >
      >
      > dick_faust wrote:
      > >
      > >
      > > <snip>
      >
      >
      > > It is quite simple to measure the two frequencies of a crystal
      with
      > > minimum equipment.
      > > K9IVB
      >
      >
      >
      > I have written a detailed comparison of a dozen or so different
      methods
      > of measuring the parameters of a crystal, available at
      > http://www.cliftonlaboratories.com/Documents/Crystal%20Motional%
      20Parameters.pdf
      >
      > The techniques are compared against a standard reference crystal
      with
      > certified motional parameters.
      >
      > Jack K8ZOA
      >
    • Claudio Re
      Thanks a lot Dick ! What a nice and huge docs to digest ....! Some documents are in frames and I was not able to download them totally . Any suggestions ?
      Message 2 of 7 , Sep 2, 2007
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        Thanks a lot Dick !
        What a nice and huge docs to digest ....!
        Some documents are in frames and I was not able to download them
        totally .
        Any suggestions ?
        CLaudio I1RFQ


        --- In softrock40@yahoogroups.com, "dick_faust" <dick_faust@...>
        wrote:
        >
        > I was going to write something, but the following references do a
        > much better job at teaching and answering many of the questions
        > recently posted.
        >
        > Quartz Crystal Resonators and Oscillators for Frequency Control
        and
        > Timing Applications - A Tutorial, by John R. Vig [3 formats]
        > http://www.ieee-uffc.org/freqcontrol/VigBallato/fcdevices.PDF
        >
        > http://www.ieee-
        > uffc.org/freqcontrol/tutorials/vig2/tutorial2_files/frame.htm
        >
        > http://www.ieee-uffc.org/freqcontrol/tutorials/vig3/vig3.ppt
        >
        > The Fundamental Theory of Low Noise Oscillators with Special
        > Reference to Some Detailed Designs, by J. Everard
        > http://www.ieee-uffc.org/freqcontrol/tutorials/FCS%20Tutorials%
        > 2000/everard.pdf
        >
        > Low Noise Oscillator Design and Performance, by Michael M. Driscoll
        > http://www.ieee-
        > uffc.org/freqcontrol/tutorials/2002_IEEE_Tutorial_files/frame.htm
        >
        > Clock Jitter, by R. Temple
        > http://www.ieee-uffc.org/freqcontrol/tutorials/FCS%20Tutorials%
        > 2000/Temple_files/frame.htm
        >
        > Now my addition is limited to some crystal specifications & notes
        as
        > apply to the 20/30M daughter board.
        >
        > The crystal should be specified as a fundamental series resonate
        > device at what ever make tolerance desired. Note: the Butler
        > oscillator operates on the fundamental frequency which is slightly
        > different than 3rd overtone. I have no idea what drive level is
        > present, but stay in HC-49 case, if at all possible, as this is
        the
        > largest quartz blank.
        >
        > The Butler oscillator uses the "tuned" tank circuit to extract the
        > third harmonic and provide the balance of the phase shift and gain
        > required to sustain oscillation. The "tuned" circuit needs to
        > resonate higher than the third harmonic to meet the operating
        > conditions and usually is not critical [often why swamped with a
        > resistor]. The circuit will also work with a fundamental crystal
        but
        > at a higher crystal drive current. In both cases the actual
        > operating frequency will be somewhat higher than the actual series
        > resonant frequency. So use a frequency counter [or radio] to
        > determine the exact frequency.
        >
        > The series resonant frequency of a crystal is always lower than
        the
        > parallel resonant frequency. Parallel resonant crystals are
        > correlated with an external parallel capacitor across the crystal,
        > usually 18pF, 20pF or 32pF. The higher the external cap, the
        lower
        > the anti-resonant [parallel resonant] frequency will be.
        Oscillators
        > always operate between the series and loaded anti-resonant
        > frequencies. [Exception: If there is an external inductor, it
        will
        > move the series resonant frequency lower]
        >
        > It is quite simple to measure the two frequencies of a crystal
        with
        > minimum equipment. A stable 50 ohm signal generator or DDS and a
        rf
        > meter [a receiver, RF Voltmeter or an rf probe if you have a large
        > enough signal]. Take 2 resistors from 1K to 10K and connect
        together
        > in series. Connect one end to the generator and the other to the
        > meter. Connect one lead of the crystal at the center and the
        other
        > to the shields [gnd] of the generator and meter. As you manually
        > sweep the generator through the series resonant frequency of the
        > crystal there will be an 80 to 100 db drop in amplitude about 5Hz
        > wide at the series resonant frequency - so go slow. If you put
        the
        > crystal in series with the resistors the same effect will be
        observed
        > at a somewhat higher frequency when the elements are parallel
        > resonant and block the signal. A 20pF cap in parallel with the
        > crystal will lower the frequency to the 20pF correlation
        frequency.
        > The resistors serve to isolate the external strays and give very
        > reliable readings. The anti-resonant null is much broader than
        the
        > series resonant due to the effects of circuit Q.
        >
        > A final reference that may be found in Amateur publications is :
        > DEMPHANO, A device for measuring phase noise, Communications
        > Quarterly, Spring, 1999, pp. 9-17 by J. Makhinson – cq199904.pdf
        >
        > Dick Faust
        > K9IVB
        >
      • dick_faust
        Might try contacting John Vig at the IEEE - UFFC and see if he would make the power point presentations available like he has done with his post. I would not
        Message 3 of 7 , Sep 2, 2007
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          Might try contacting John Vig at the IEEE - UFFC and see if he would
          make the power point presentations available like he has done with
          his post. I would not mind getting copies on ppt, but for now I
          think you will have to just copy each frame.

          Dick
          K9IVB
          --- In softrock40@yahoogroups.com, "Claudio Re" <ReClaudio@...> wrote:
          >
          > Thanks a lot Dick !
          > What a nice and huge docs to digest ....!
          > Some documents are in frames and I was not able to download them
          > totally .
          > Any suggestions ?
          > CLaudio I1RFQ
          >
          >
          > --- In softrock40@yahoogroups.com, "dick_faust" <dick_faust@>
          > wrote:
          > >
          > > I was going to write something, but the following references do a
          > > much better job at teaching and answering many of the questions
          > > recently posted.
          > >
          > > Quartz Crystal Resonators and Oscillators for Frequency Control
          > and
          > > Timing Applications - A Tutorial, by John R. Vig [3 formats]
          > > http://www.ieee-uffc.org/freqcontrol/VigBallato/fcdevices.PDF
          > >
          > > http://www.ieee-
          > > uffc.org/freqcontrol/tutorials/vig2/tutorial2_files/frame.htm
          > >
          > > http://www.ieee-uffc.org/freqcontrol/tutorials/vig3/vig3.ppt
          > >
          > > The Fundamental Theory of Low Noise Oscillators with Special
          > > Reference to Some Detailed Designs, by J. Everard
          > > http://www.ieee-uffc.org/freqcontrol/tutorials/FCS%20Tutorials%
          > > 2000/everard.pdf
          > >
          > > Low Noise Oscillator Design and Performance, by Michael M.
          Driscoll
          > > http://www.ieee-
          > > uffc.org/freqcontrol/tutorials/2002_IEEE_Tutorial_files/frame.htm
          > >
          > > Clock Jitter, by R. Temple
          > > http://www.ieee-uffc.org/freqcontrol/tutorials/FCS%20Tutorials%
          > > 2000/Temple_files/frame.htm
          > >
          > > Now my addition is limited to some crystal specifications & notes
          > as
          > > apply to the 20/30M daughter board.
          > >
          > > The crystal should be specified as a fundamental series resonate
          > > device at what ever make tolerance desired. Note: the Butler
          > > oscillator operates on the fundamental frequency which is
          slightly
          > > different than 3rd overtone. I have no idea what drive level is
          > > present, but stay in HC-49 case, if at all possible, as this is
          > the
          > > largest quartz blank.
          > >
          > > The Butler oscillator uses the "tuned" tank circuit to extract
          the
          > > third harmonic and provide the balance of the phase shift and
          gain
          > > required to sustain oscillation. The "tuned" circuit needs to
          > > resonate higher than the third harmonic to meet the operating
          > > conditions and usually is not critical [often why swamped with a
          > > resistor]. The circuit will also work with a fundamental crystal
          > but
          > > at a higher crystal drive current. In both cases the actual
          > > operating frequency will be somewhat higher than the actual
          series
          > > resonant frequency. So use a frequency counter [or radio] to
          > > determine the exact frequency.
          > >
          > > The series resonant frequency of a crystal is always lower than
          > the
          > > parallel resonant frequency. Parallel resonant crystals are
          > > correlated with an external parallel capacitor across the
          crystal,
          > > usually 18pF, 20pF or 32pF. The higher the external cap, the
          > lower
          > > the anti-resonant [parallel resonant] frequency will be.
          > Oscillators
          > > always operate between the series and loaded anti-resonant
          > > frequencies. [Exception: If there is an external inductor, it
          > will
          > > move the series resonant frequency lower]
          > >
          > > It is quite simple to measure the two frequencies of a crystal
          > with
          > > minimum equipment. A stable 50 ohm signal generator or DDS and a
          > rf
          > > meter [a receiver, RF Voltmeter or an rf probe if you have a
          large
          > > enough signal]. Take 2 resistors from 1K to 10K and connect
          > together
          > > in series. Connect one end to the generator and the other to the
          > > meter. Connect one lead of the crystal at the center and the
          > other
          > > to the shields [gnd] of the generator and meter. As you manually
          > > sweep the generator through the series resonant frequency of the
          > > crystal there will be an 80 to 100 db drop in amplitude about 5Hz
          > > wide at the series resonant frequency - so go slow. If you put
          > the
          > > crystal in series with the resistors the same effect will be
          > observed
          > > at a somewhat higher frequency when the elements are parallel
          > > resonant and block the signal. A 20pF cap in parallel with the
          > > crystal will lower the frequency to the 20pF correlation
          > frequency.
          > > The resistors serve to isolate the external strays and give very
          > > reliable readings. The anti-resonant null is much broader than
          > the
          > > series resonant due to the effects of circuit Q.
          > >
          > > A final reference that may be found in Amateur publications is :
          > > DEMPHANO, A device for measuring phase noise, Communications
          > > Quarterly, Spring, 1999, pp. 9-17 by J. Makhinson – cq199904.pdf
          > >
          > > Dick Faust
          > > K9IVB
          > >
          >
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