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Re: [SpectrumLabUsers] Question about analyzing wav files

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  • wolf_dl4yhf
    Hello JSS, I m afraid no, since SL was designed for real-time operation. Of course you could let it run in wave-analysis mode (in which the input from the
    Message 1 of 13 , Jun 11, 2013
      Hello JSS,

      I'm afraid no, since SL was designed for real-time operation. Of course
      you could let it run in wave-analysis mode (in which the input from the
      soundcard is replaced by a wave file as 'source') and use the signal
      analysis functions, entered in a table to define the values which are to
      be measured:

      http://www.qsl.net/dl4yhf/speclab/textexpt.htm#def_contents

      But ...

      How do you define 'instantaneous peak' ? This would be the waveform
      itself, unless you define a measuring interval during which the peaks
      are to be measured. But then the peak isn't "instantaneous" anymore.
      The problem is that (almost) all of SL's signal analysis functions are
      based on the output of the spectrum analyser, which means they analyse
      the signal in the frequency domain, not (entirely) in the time domain.
      Strictly said, they operate on the short time fourier transforms which
      are calculated for the spectrum display. Thus, the measuring intervals
      are dictated by the FFT length, so they cannot measure instantaneous
      peaks in the time domain (waveform).

      The function which come closest to the what you are looking for are
      peak(), veff(), and avrg() .

      All the best,
      Wolf .
    • Bill Cromwell
      Hi, I m a Ham radio licensee (I know not everybody here is). I have Spectrum Lab, Spectran, fldigi, and some other digital mode, sound card packages. Spectran
      Message 2 of 13 , Jun 16, 2013
        Hi,

        I'm a Ham radio licensee (I know not everybody here is). I have Spectrum
        Lab, Spectran, fldigi, and some other digital mode, sound card packages.
        Spectran does some of the same tricks that Spectrum Lab does (not a
        comparison) but not nearly as many. Ergo, Spectran has a smaller
        learning curve and is dramatically quicker to get into action. Spectran
        can do more for me when I get it "mastered".

        I have been working my way into the goodies in Spectrum Lab and I am
        ready to try calibration for general "frequency measurements". I have
        used my dual loop PLL receiver to apply signals from WWV in AM mode (no
        BFO to consider and VFO only needs to be 'close enough') to several of
        my sound card programs and they all show me that the standard tones are
        within just about 100 millihertz on the displays. I do NOT have my sound
        card or computer timebase synced to anything like a rubidium or gps
        "standard".

        I can look at the manuals myself to see how Spec Lab wants me to adjust
        for the sound card clock error (and the other packages, too). What kind
        of overall accuracy can I expect from Spectrum Lab under the conditions
        I have outlined? I intend to use the information I can get from Spectrum
        Lab and Spectran to correct the alignment of my duall loop PLL and BFOs
        in that (and other receivers). For the most part, being within 100
        milliHertz is overkill in most ham radio operation (never mind about
        WSPR for now). But it's always good to know the limitations.

        Incidentally, when I bring in the BFO the actuall PLL "VFO" frequency
        and the BFO come into play and it's definitely "out of whack". Starting
        point is sound card calibration.

        73,

        Bill KU8H
      • Jurgen Bartels
        Hi Bill, ... I started similar by using Spectran. After a while I missed several things and looked around how to fix it. Eventually I found it is not possible
        Message 3 of 13 , Jun 16, 2013
          Hi Bill,

          > I'm a Ham radio licensee (I know not everybody here is). I have Spectrum
          > Lab, Spectran, fldigi, and some other digital mode, sound card packages.
          > Spectran does some of the same tricks that Spectrum Lab does (not a
          > comparison) but not nearly as many. Ergo, Spectran has a smaller
          > learning curve and is dramatically quicker to get into action. Spectran
          > can do more for me when I get it "mastered".

          I started similar by using Spectran. After a while I missed several things and
          looked around how to fix it. Eventually I found it is not possible and then
          came across SpecLab that allowed me to fullfill all my needs. In retrospect
          trying with something else than SpecLab was a complete loss of time, even when
          it initially looked easier. But you're are always smarter afterwards. :-)

          > in that (and other receivers). For the most part, being within 100
          > milliHertz is overkill in most ham radio operation (never mind about
          > WSPR for now). But it's always good to know the limitations.

          I can't answer your question. But I use SL with Winradio for TV carrier
          monitoring. I usually calibrate it on 14.996 MHz or 25 MHz (Finland) if
          propagation is right. Then I measure TV carrier in the 48-84 MHz range and I
          get 1Hz accruracy there. The deviation/drift of Winradio and SL is thus taken
          care of with a Winradio plugin that adjust SL scale to show the real frequency
          See http://dx.3sdesign.de/waterfalls.htm

          SL is fed by WR's virtual soundcard

          Jurgen Bartels Suellwarden, N. Germany
          Ant. hor: 29-45MHz 7-el, 45-87MHz 11-el, FM 15.11, Band-3:13-el, UHF:48-el
          TV: Winradio G305 / Fly2000 + video noise filter & variable IF BW
          FM: Downconverter + Perseus + Speclab as WFM demod.
          MW: 30 x 4m EWE 320° with JB-terminator, Winradio & Perseus
          http://zeiterfassung.3sdesign.de/station_list.htm
          http://dx.3sdesign.de/tv_offset_list.htm
        • wolf_dl4yhf
          Hello Bill, Without a means to monitor ( calibrate ) the soundcard s sampling rate against a reference signal, you can expect accuracies in the range of a few
          Message 4 of 13 , Jun 16, 2013
            Hello Bill,

            Without a means to monitor ("calibrate") the soundcard's sampling rate against a reference signal,
            you can expect accuracies in the range of a few ppm (parts per million). Of course this requires measuring the soundcard's sampling rate *once*, which can be done easily with an off-air standard like an audio tone received in AM (not SSB!).

            After that, the accuracy depends largely on the soundcard (no big surprise..).
            The manual contains two examples of a 'good' and a 'poor' soundcard, concering the stability of the clock source:

            http://www.qsl.net/dl4yhf/speclab/frqcalib.htm#soundcard_clock_drift_measurements

            As you can see, with the E-MU 0202 (used for the 2nd, "good" example) the sampling rate settles to less then 0.1 ppm after > 1 hour of warm-up. Thus, with a sufficiently large FFT (i.e. sufficient *resolution* of the measurement), a 1 kHz audio signal can be measured with an accuracy 0.1 milliHertz.

            Thus the accuracy of the entire system (with HF receiver / VFO+BFO + Soundcard) is limited by the stability of the radio, not by the soundcard.

            All the best,
               Wolf .

            Am 16.06.2013 15:39, schrieb Bill Cromwell:
             

            Hi,

            I'm a Ham radio licensee (I know not everybody here is). I have Spectrum
            Lab, Spectran, fldigi, and some other digital mode, sound card packages.
            Spectran does some of the same tricks that Spectrum Lab does (not a
            comparison) but not nearly as many. Ergo, Spectran has a smaller
            learning curve and is dramatically quicker to get into action. Spectran
            can do more for me when I get it "mastered".

            I have been working my way into the goodies in Spectrum Lab and I am
            ready to try calibration for general "frequency measurements". I have
            used my dual loop PLL receiver to apply signals from WWV in AM mode (no
            BFO to consider and VFO only needs to be 'close enough') to several of
            my sound card programs and they all show me that the standard tones are
            within just about 100 millihertz on the displays. I do NOT have my sound
            card or computer timebase synced to anything like a rubidium or gps
            "standard".

            I can look at the manuals myself to see how Spec Lab wants me to adjust
            for the sound card clock error (and the other packages, too). What kind
            of overall accuracy can I expect from Spectrum Lab under the conditions
            I have outlined? I intend to use the information I can get from Spectrum
            Lab and Spectran to correct the alignment of my duall loop PLL and BFOs
            in that (and other receivers). For the most part, being within 100
            milliHertz is overkill in most ham radio operation (never mind about
            WSPR for now). But it's always good to know the limitations.

            Incidentally, when I bring in the BFO the actuall PLL "VFO" frequency
            and the BFO come into play and it's definitely "out of whack". Starting
            point is sound card calibration.

            73,

            Bill KU8H


          • Bill Cromwell
            ... Thanks Wolf, I started wading into that information. I copied the entire web page to my hard drive for study offline and bookmarked it in my browser.
            Message 5 of 13 , Jun 16, 2013
              On 06/16/2013 02:58 PM, wolf_dl4yhf wrote:
              >
              > Hello Bill,
              >
              > Without a means to monitor ("calibrate") the soundcard's sampling rate
              > against a reference signal,
              > you can expect accuracies in the range of a few ppm (parts per
              > million). Of course this requires measuring the soundcard's sampling
              > rate *once*, which can be done easily with an off-air standard like an
              > audio tone received in AM (not SSB!).
              >
              > After that, the accuracy depends largely on the soundcard (no big
              > surprise..).
              > The manual contains two examples of a 'good' and a 'poor' soundcard,
              > concering the stability of the clock source:
              >
              > http://www.qsl.net/dl4yhf/speclab/frqcalib.htm#soundcard_clock_drift_measurements
              >
              > As you can see, with the E-MU 0202 (used for the 2nd, "good" example)
              > the sampling rate settles to less then 0.1 ppm after > 1 hour of
              > warm-up. Thus, with a sufficiently large FFT (i.e. sufficient
              > *resolution* of the measurement), a 1 kHz audio signal can be measured
              > with an accuracy 0.1 milliHertz.
              >
              > Thus the accuracy of the entire system (with HF receiver / VFO+BFO +
              > Soundcard) is limited by the stability of the radio, not by the soundcard.
              >
              > All the best,
              > Wolf .
              >

              Thanks Wolf,

              I started wading into that information. I copied the entire web page to
              my hard drive for study offline and bookmarked it in my browser.
              Whenever the internet is available to my computer the links to other
              material in the web document will work.

              Noting the 440, 500, 600, and 1000 Hz streams in the waterfall and on
              the SA window with the frequency readout that so closely matched what is
              supposed to be sent by WWV (yes - AM mode) I have more confidence in
              what I am seeing on my screen. I believe that both Spectran and Spectrum
              Lab along with my sound card are already close enough for much of the
              work here (all at the hobby level). Nobody's life or livelihood hangs in
              the balance (grin). I will soon begin to use the tools to tweak my
              radios into (hopefully) a little better performance. One way to become
              more familiar with the tools is to just "play" with them. My eyebrows
              are getting some exercise, too, with some "aha" moments (raise of the
              eyebrows).

              I have my first SDR kit from SoftRock and not yet assembled. I will
              probably start on that sometime near the end of this month. Meanwhile I
              have good candidates for inspection by Spectrum Lab and Spectran.
              Another list member pointed out that Spectran is nowhere near capable as
              Spectrum Lab but I already knew that. The things that Spectran does
              perform seem to be okay and I am using that as some kind of comparison
              to see if all the tools show the same kind of results - so far they do.

              73,

              Bill KU8H
            • sm5le
              Hello Wolf Is it better to use internal soundcard SoundMAX Digital Audio insted of external E-MU 0202 for best freq. accuracies and drift ? tnx /Sven
              Message 6 of 13 , Jun 18, 2013
                Hello Wolf
                Is it better to use internal soundcard "SoundMAX Digital Audio" insted of external "E-MU 0202" for best freq. accuracies and drift ?
                tnx /Sven

                --- In SpectrumLabUsers@yahoogroups.com, wolf_dl4yhf <dl4yhf@...> wrote:
                >
                > Hello Bill,
                >
                > Without a means to monitor ("calibrate") the soundcard's sampling rate
                > against a reference signal,
                > you can expect accuracies in the range of a few ppm (parts per million).
                > Of course this requires measuring the soundcard's sampling rate *once*,
                > which can be done easily with an off-air standard like an audio tone
                > received in AM (not SSB!).
                >
                > After that, the accuracy depends largely on the soundcard (no big
                > surprise..).
                > The manual contains two examples of a 'good' and a 'poor' soundcard,
                > concering the stability of the clock source:
                >
                > http://www.qsl.net/dl4yhf/speclab/frqcalib.htm#soundcard_clock_drift_measurements
                >
                > As you can see, with the E-MU 0202 (used for the 2nd, "good" example)
                > the sampling rate settles to less then 0.1 ppm after > 1 hour of
                > warm-up. Thus, with a sufficiently large FFT (i.e. sufficient
                > *resolution* of the measurement), a 1 kHz audio signal can be measured
                > with an accuracy 0.1 milliHertz.
                >
                > Thus the accuracy of the entire system (with HF receiver / VFO+BFO +
                > Soundcard) is limited by the stability of the radio, not by the soundcard.
                >
                > All the best,
                > Wolf .
                >
                > Am 16.06.2013 15:39, schrieb Bill Cromwell:
                > >
                > > Hi,
                > >
                > > I'm a Ham radio licensee (I know not everybody here is). I have Spectrum
                > > Lab, Spectran, fldigi, and some other digital mode, sound card packages.
                > > Spectran does some of the same tricks that Spectrum Lab does (not a
                > > comparison) but not nearly as many. Ergo, Spectran has a smaller
                > > learning curve and is dramatically quicker to get into action. Spectran
                > > can do more for me when I get it "mastered".
                > >
                > > I have been working my way into the goodies in Spectrum Lab and I am
                > > ready to try calibration for general "frequency measurements". I have
                > > used my dual loop PLL receiver to apply signals from WWV in AM mode (no
                > > BFO to consider and VFO only needs to be 'close enough') to several of
                > > my sound card programs and they all show me that the standard tones are
                > > within just about 100 millihertz on the displays. I do NOT have my sound
                > > card or computer timebase synced to anything like a rubidium or gps
                > > "standard".
                > >
                > > I can look at the manuals myself to see how Spec Lab wants me to adjust
                > > for the sound card clock error (and the other packages, too). What kind
                > > of overall accuracy can I expect from Spectrum Lab under the conditions
                > > I have outlined? I intend to use the information I can get from Spectrum
                > > Lab and Spectran to correct the alignment of my duall loop PLL and BFOs
                > > in that (and other receivers). For the most part, being within 100
                > > milliHertz is overkill in most ham radio operation (never mind about
                > > WSPR for now). But it's always good to know the limitations.
                > >
                > > Incidentally, when I bring in the BFO the actuall PLL "VFO" frequency
                > > and the BFO come into play and it's definitely "out of whack". Starting
                > > point is sound card calibration.
                > >
                > > 73,
                > >
                > > Bill KU8H
                > >
                > >
                >
              • Werner Karn
                Sven, from my experience, that will depend on where you can best control temperature stability. BR Werner 2013/6/18 sm5le
                Message 7 of 13 , Jun 18, 2013
                  Sven,
                   
                  from my experience, that will depend on where you can best control temperature stability.
                   
                  BR
                   
                  Werner


                  2013/6/18 sm5le <sm5le@...>
                   

                  Hello Wolf
                  Is it better to use internal soundcard "SoundMAX Digital Audio" insted of external "E-MU 0202" for best freq. accuracies and drift ?
                  tnx /Sven

                  --- In SpectrumLabUsers@yahoogroups.com, wolf_dl4yhf <dl4yhf@...> wrote:
                  >
                  > Hello Bill,
                  >
                  > Without a means to monitor ("calibrate") the soundcard's sampling rate
                  > against a reference signal,
                  > you can expect accuracies in the range of a few ppm (parts per million).
                  > Of course this requires measuring the soundcard's sampling rate *once*,
                  > which can be done easily with an off-air standard like an audio tone
                  > received in AM (not SSB!).
                  >
                  > After that, the accuracy depends largely on the soundcard (no big
                  > surprise..).
                  > The manual contains two examples of a 'good' and a 'poor' soundcard,
                  > concering the stability of the clock source:
                  >
                  > http://www.qsl.net/dl4yhf/speclab/frqcalib.htm#soundcard_clock_drift_measurements
                  >
                  > As you can see, with the E-MU 0202 (used for the 2nd, "good" example)
                  > the sampling rate settles to less then 0.1 ppm after > 1 hour of
                  > warm-up. Thus, with a sufficiently large FFT (i.e. sufficient
                  > *resolution* of the measurement), a 1 kHz audio signal can be measured
                  > with an accuracy 0.1 milliHertz.
                  >
                  > Thus the accuracy of the entire system (with HF receiver / VFO+BFO +
                  > Soundcard) is limited by the stability of the radio, not by the soundcard.
                  >
                  > All the best,
                  > Wolf .
                  >
                  > Am 16.06.2013 15:39, schrieb Bill Cromwell:
                  > >
                  > > Hi,
                  > >
                  > > I'm a Ham radio licensee (I know not everybody here is). I have Spectrum
                  > > Lab, Spectran, fldigi, and some other digital mode, sound card packages.
                  > > Spectran does some of the same tricks that Spectrum Lab does (not a
                  > > comparison) but not nearly as many. Ergo, Spectran has a smaller
                  > > learning curve and is dramatically quicker to get into action. Spectran
                  > > can do more for me when I get it "mastered".
                  > >
                  > > I have been working my way into the goodies in Spectrum Lab and I am
                  > > ready to try calibration for general "frequency measurements". I have
                  > > used my dual loop PLL receiver to apply signals from WWV in AM mode (no
                  > > BFO to consider and VFO only needs to be 'close enough') to several of
                  > > my sound card programs and they all show me that the standard tones are
                  > > within just about 100 millihertz on the displays. I do NOT have my sound
                  > > card or computer timebase synced to anything like a rubidium or gps
                  > > "standard".
                  > >
                  > > I can look at the manuals myself to see how Spec Lab wants me to adjust
                  > > for the sound card clock error (and the other packages, too). What kind
                  > > of overall accuracy can I expect from Spectrum Lab under the conditions
                  > > I have outlined? I intend to use the information I can get from Spectrum
                  > > Lab and Spectran to correct the alignment of my duall loop PLL and BFOs
                  > > in that (and other receivers). For the most part, being within 100
                  > > milliHertz is overkill in most ham radio operation (never mind about
                  > > WSPR for now). But it's always good to know the limitations.
                  > >
                  > > Incidentally, when I bring in the BFO the actuall PLL "VFO" frequency
                  > > and the BFO come into play and it's definitely "out of whack". Starting
                  > > point is sound card calibration.
                  > >
                  > > 73,
                  > >
                  > > Bill KU8H
                  > >
                  > >
                  >


                • Bill Cromwell
                  Hi, So I have been playing. I have a number of radios but the stars of the show here are a Kenwood R-599, the receiver in the Kenwood Twins lineup and a Ten
                  Message 8 of 13 , Jun 19, 2013
                    Hi,

                    So I have been playing. I have a number of radios but the stars of the
                    show here are a Kenwood R-599, the receiver in the Kenwood Twins lineup
                    and a Ten Tec RX-325 that I am planning some "hot rod" mods. The R-599
                    has xtal BFOs, xtal heterodyne oscillators, and a free running L-C VFO
                    that is adequately stable. It also has a xtal calibrator with front
                    panel switch for either 100 kHz or 25 kHz markers. I have always set
                    these to zero beat with WWV the best I could in AM mode as recommended.
                    I am aware that human hearing response does NOT extend to zero Hertz and
                    the audio in our receivers rolls off at some low, non-zero frequency as
                    well.

                    I examined the signal format from WWV and looked at it in AM mode as
                    well as in USB and LSB mode with the Kenwood. Sometimes there is
                    interference in the display...maybe from intermod products in the
                    receiver...but I was always able to identify the tones in AM mode and in
                    either sideband mode I was able to shift the carrier to 1 kHz on the
                    spectrum display and identify the tones. Then I turned on the calibrator
                    and found it to be almost 100 Hz off at 10 MHz! That is not a real
                    surprise. In the AM mode I cannot hear that and the pip is masked in the
                    junk that lives at zero on the display. By moving the control on the
                    calibrator I may be able to identify it in that mess and try to move it
                    zero. However, it looks like dialing the WWV carrier up to 1 kHz on the
                    spectrum display (for example) using SSB mode I should be able to adjust
                    the calibrator's pip directly on top of the incoming WWV carrier's pip
                    and end up with a much smaller error. I am planning to turn the R-599
                    over this evening and make the adjustment. And after that I will couple
                    my frequency counter clock into the R-599 and set THAT the same way.
                    When I get into the RX-325 I will set it's 10 MHz reference the same
                    way. The computer, both radios, and the counter run 24/7 except when
                    thunderstorms come into the area so warmup drift is eliminated. I'll let
                    the calibrator run for a while, too. Hopefully there won't be any
                    surprises from that.

                    Did I overlook anything?

                    73,

                    Bill KU8H
                  • wolf_dl4yhf
                    Hi Sven, During all tests, the external soundcard was always better - MUCH better - last not least because its temperature-dependent oscillator drift was alway
                    Message 9 of 13 , Jun 19, 2013
                      Hi Sven,

                      During all tests, the external soundcard was always better - MUCH better - last not least because its temperature-dependent oscillator drift was alway very predictable (decay function). All of the internal devices suffer from rapid temperature changes when the PC's internal fan goes on/off. Unless you have a fan-less PC, or a netbook which hardly ever turns on one of the internal fans (but when doing number crunching they usually have to turn on the fan sooner or later, even a netbook with an Atom CPU was no exception).

                      All the best,
                        Wolf .


                      Am 18.06.2013 16:39, schrieb Werner Karn:
                       
                      Sven,
                       
                      from my experience, that will depend on where you can best control temperature stability.
                       
                      BR
                       
                      Werner


                      2013/6/18 sm5le <sm5le@...>
                       

                      Hello Wolf
                      Is it better to use internal soundcard "SoundMAX Digital Audio" insted of external "E-MU 0202" for best freq. accuracies and drift ?
                      tnx /Sven

                      --- In SpectrumLabUsers@yahoogroups.com, wolf_dl4yhf <dl4yhf@...> wrote:
                      >
                      > Hello Bill,
                      >
                      > Without a means to monitor ("calibrate") the soundcard's sampling rate
                      > against a reference signal,
                      > you can expect accuracies in the range of a few ppm (parts per million).
                      > Of course this requires measuring the soundcard's sampling rate *once*,
                      > which can be done easily with an off-air standard like an audio tone
                      > received in AM (not SSB!).
                      >
                      > After that, the accuracy depends largely on the soundcard (no big
                      > surprise..).
                      > The manual contains two examples of a 'good' and a 'poor' soundcard,
                      > concering the stability of the clock source:
                      >
                      > http://www.qsl.net/dl4yhf/speclab/frqcalib.htm#soundcard_clock_drift_measurements
                      >
                      > As you can see, with the E-MU 0202 (used for the 2nd, "good" example)
                      > the sampling rate settles to less then 0.1 ppm after > 1 hour of
                      > warm-up. Thus, with a sufficiently large FFT (i.e. sufficient
                      > *resolution* of the measurement), a 1 kHz audio signal can be measured
                      > with an accuracy 0.1 milliHertz.
                      >
                      > Thus the accuracy of the entire system (with HF receiver / VFO+BFO +
                      > Soundcard) is limited by the stability of the radio, not by the soundcard.
                      >
                      > All the best,
                      > Wolf .
                      >
                      > Am 16.06.2013 15:39, schrieb Bill Cromwell:
                      > >
                      > > Hi,
                      > >
                      > > I'm a Ham radio licensee (I know not everybody here is). I have Spectrum
                      > > Lab, Spectran, fldigi, and some other digital mode, sound card packages.
                      > > Spectran does some of the same tricks that Spectrum Lab does (not a
                      > > comparison) but not nearly as many. Ergo, Spectran has a smaller
                      > > learning curve and is dramatically quicker to get into action. Spectran
                      > > can do more for me when I get it "mastered".
                      > >
                      > > I have been working my way into the goodies in Spectrum Lab and I am
                      > > ready to try calibration for general "frequency measurements". I have
                      > > used my dual loop PLL receiver to apply signals from WWV in AM mode (no
                      > > BFO to consider and VFO only needs to be 'close enough') to several of
                      > > my sound card programs and they all show me that the standard tones are
                      > > within just about 100 millihertz on the displays. I do NOT have my sound
                      > > card or computer timebase synced to anything like a rubidium or gps
                      > > "standard".
                      > >
                      > > I can look at the manuals myself to see how Spec Lab wants me to adjust
                      > > for the sound card clock error (and the other packages, too). What kind
                      > > of overall accuracy can I expect from Spectrum Lab under the conditions
                      > > I have outlined? I intend to use the information I can get from Spectrum
                      > > Lab and Spectran to correct the alignment of my duall loop PLL and BFOs
                      > > in that (and other receivers). For the most part, being within 100
                      > > milliHertz is overkill in most ham radio operation (never mind about
                      > > WSPR for now). But it's always good to know the limitations.
                      > >
                      > > Incidentally, when I bring in the BFO the actuall PLL "VFO" frequency
                      > > and the BFO come into play and it's definitely "out of whack". Starting
                      > > point is sound card calibration.
                      > >
                      > > 73,
                      > >
                      > > Bill KU8H
                      > >
                      > >
                      >



                    • wolf_dl4yhf
                      ... Not a good idea, because in SSB mode, the audio from the receiver depends on the radio s VFO/BFO. That s why I mentioned AM (because even when the AM
                      Message 10 of 13 , Jun 19, 2013
                        Am 19.06.2013 14:34, schrieb Bill Cromwell:
                        > Hi,
                        >
                        > So I have been playing. I have a number of radios but the stars of the
                        > show here are a Kenwood R-599, the receiver in the Kenwood Twins lineup
                        > and a Ten Tec RX-325 that I am planning some "hot rod" mods. The R-599
                        > has xtal BFOs, xtal heterodyne oscillators, and a free running L-C VFO
                        > that is adequately stable. It also has a xtal calibrator with front
                        > panel switch for either 100 kHz or 25 kHz markers. I have always set
                        > these to zero beat with WWV the best I could in AM mode as recommended.
                        > I am aware that human hearing response does NOT extend to zero Hertz and
                        > the audio in our receivers rolls off at some low, non-zero frequency as
                        > well.
                        >
                        > I examined the signal format from WWV and looked at it in AM mode as
                        > well as in USB and LSB mode with the Kenwood. Sometimes there is
                        > interference in the display...maybe from intermod products in the
                        > receiver...but I was always able to identify the tones in AM mode and in
                        > either sideband mode I was able to shift the carrier to 1 kHz on the
                        > spectrum display and identify the tones. Then I turned on the calibrator
                        > and found it to be almost 100 Hz off at 10 MHz! That is not a real
                        > surprise. In the AM mode I cannot hear that and the pip is masked in the
                        > junk that lives at zero on the display. By moving the control on the
                        > calibrator I may be able to identify it in that mess and try to move it
                        > zero. However, it looks like dialing the WWV carrier up to 1 kHz on the
                        > spectrum display (for example) using SSB mode I should be able to adjust
                        > the calibrator's pip directly on top of the incoming WWV carrier's pip
                        > and end up with a much smaller error.

                        Not a good idea, because in SSB mode, the audio from the receiver
                        depends on the radio's VFO/BFO.
                        That's why I mentioned AM (because even when the AM receiver is detuned,
                        the audio frequency of a 1000.000 Hz signal will still be at 1000.000 Hz
                        at the AF output).
                        Not sure about WWV / WWVB but afaik they have very stable, calibrated
                        audio tones similar to the 1000 Hz 'test tone' transmitted by TV
                        stations before going QRT at night. Oh, those were the days.. long gone.

                        Cheers,
                        Wolf .
                      • Bill Cromwell
                        ... Hi Wolf, WWV and WWVB are frequency standards. Yes, the carriers and the tones are all very accurate. When I use SSB (or CW) it moves the WWV carrier off
                        Message 11 of 13 , Jun 19, 2013
                          On 06/19/2013 01:28 PM, wolf_dl4yhf wrote:
                          >
                          > Not a good idea, because in SSB mode, the audio from the receiver
                          > depends on the radio's VFO/BFO.
                          > That's why I mentioned AM (because even when the AM receiver is detuned,
                          > the audio frequency of a 1000.000 Hz signal will still be at 1000.000 Hz
                          > at the AF output).
                          > Not sure about WWV / WWVB but afaik they have very stable, calibrated
                          > audio tones similar to the 1000 Hz 'test tone' transmitted by TV
                          > stations before going QRT at night. Oh, those were the days.. long gone.
                          >
                          > Cheers,
                          > Wolf .
                          >
                          >

                          Hi Wolf,

                          WWV and WWVB are frequency standards. Yes, the carriers and the tones
                          are all very accurate.

                          When I use SSB (or CW) it moves the WWV carrier off the zero end of the
                          spectrum display. It moves the calibrator (or other signal being
                          measured the same amount. So with WWV at an arbitrary 800 HZ on the
                          spectrum display the signal being examined - in this case my calbrator -
                          should be on 800 Hz, too. It's entirely so true that if my VFO changes
                          or my BFO changes or my heterodyne oscillator changes (yes, three
                          oscillators - one signal) then WWV moves on the display too. But the
                          device under test moves also the exact same amount. On the R-599 the
                          drift was very small and slow but observable. It was not enough to be
                          distracting. In fact, I opened the receiver and aligned my crystal
                          calibrator to display exactly on top of WWV's carrier. The error is now
                          less than on Hz. As I approached zero I could see the sidebands on the
                          WWV carrier that were created by the Crytsal calibrator diminish to the
                          point of small undulating bumps on the slopes of WWV's carrier and then
                          finally - completely disappear. As I watched over several hours the
                          bumps would return, undulate slowly on the slopes, and then again
                          disappear. There is nothing I can to about that with the present gear
                          but that is much better accuracy than is needed for day to day ham
                          operation.

                          I am pleased with the results. I fully intend to put the tools to work
                          daily here because they are more than adequate. And now that I can
                          actually see fine errors I will gradually make improvements to my gear
                          as I am able. I know that people who are using WSPR and techniques to
                          produce signals from vapor have to be concerned about those "miniscule"
                          errors. But those are not a part of my day to day operating - yet. If I
                          keep playing with the tools I am sure the improvements will come and
                          when I can make WSPR actually work I will certainly turn it on.

                          73,

                          Bill KU8H
                        • sm5le
                          RRR Tnx Wolf /Sven
                          Message 12 of 13 , Jun 20, 2013
                            RRR
                            Tnx Wolf

                            /Sven

                            --- In SpectrumLabUsers@yahoogroups.com, wolf_dl4yhf <dl4yhf@...> wrote:
                            >
                            > Hi Sven,
                            >
                            > During all tests, the external soundcard was always better - MUCH better
                            > - last not least because its temperature-dependent oscillator drift was
                            > alway very predictable (decay function). All of the internal devices
                            > suffer from rapid temperature changes when the PC's internal fan goes
                            > on/off. Unless you have a fan-less PC, or a netbook which hardly ever
                            > turns on one of the internal fans (but when doing number crunching they
                            > usually have to turn on the fan sooner or later, even a netbook with an
                            > Atom CPU was no exception).
                            >
                            > All the best,
                            > Wolf .
                            >
                            >
                            > Am 18.06.2013 16:39, schrieb Werner Karn:
                            > > Sven,
                            > > from my experience, that will depend on where you can best control
                            > > temperature stability.
                            > > BR
                            > > Werner
                            > >
                            > >
                            > > 2013/6/18 sm5le <sm5le@... <mailto:sm5le@...>>
                            > >
                            > > Hello Wolf
                            > > Is it better to use internal soundcard "SoundMAX Digital Audio"
                            > > insted of external "E-MU 0202" for best freq. accuracies and drift ?
                            > > tnx /Sven
                            > >
                            > > --- In SpectrumLabUsers@yahoogroups.com
                            > > <mailto:SpectrumLabUsers%40yahoogroups.com>, wolf_dl4yhf
                            > > <dl4yhf@> wrote:
                            > > >
                            > > > Hello Bill,
                            > > >
                            > > > Without a means to monitor ("calibrate") the soundcard's
                            > > sampling rate
                            > > > against a reference signal,
                            > > > you can expect accuracies in the range of a few ppm (parts per
                            > > million).
                            > > > Of course this requires measuring the soundcard's sampling rate
                            > > *once*,
                            > > > which can be done easily with an off-air standard like an audio
                            > > tone
                            > > > received in AM (not SSB!).
                            > > >
                            > > > After that, the accuracy depends largely on the soundcard (no big
                            > > > surprise..).
                            > > > The manual contains two examples of a 'good' and a 'poor'
                            > > soundcard,
                            > > > concering the stability of the clock source:
                            > > >
                            > > >
                            > > http://www.qsl.net/dl4yhf/speclab/frqcalib.htm#soundcard_clock_drift_measurements
                            > > >
                            > > > As you can see, with the E-MU 0202 (used for the 2nd, "good"
                            > > example)
                            > > > the sampling rate settles to less then 0.1 ppm after > 1 hour of
                            > > > warm-up. Thus, with a sufficiently large FFT (i.e. sufficient
                            > > > *resolution* of the measurement), a 1 kHz audio signal can be
                            > > measured
                            > > > with an accuracy 0.1 milliHertz.
                            > > >
                            > > > Thus the accuracy of the entire system (with HF receiver /
                            > > VFO+BFO +
                            > > > Soundcard) is limited by the stability of the radio, not by the
                            > > soundcard.
                            > > >
                            > > > All the best,
                            > > > Wolf .
                            > > >
                            > > > Am 16.06.2013 15:39, schrieb Bill Cromwell:
                            > > > >
                            > > > > Hi,
                            > > > >
                            > > > > I'm a Ham radio licensee (I know not everybody here is). I
                            > > have Spectrum
                            > > > > Lab, Spectran, fldigi, and some other digital mode, sound card
                            > > packages.
                            > > > > Spectran does some of the same tricks that Spectrum Lab does
                            > > (not a
                            > > > > comparison) but not nearly as many. Ergo, Spectran has a smaller
                            > > > > learning curve and is dramatically quicker to get into action.
                            > > Spectran
                            > > > > can do more for me when I get it "mastered".
                            > > > >
                            > > > > I have been working my way into the goodies in Spectrum Lab
                            > > and I am
                            > > > > ready to try calibration for general "frequency measurements".
                            > > I have
                            > > > > used my dual loop PLL receiver to apply signals from WWV in AM
                            > > mode (no
                            > > > > BFO to consider and VFO only needs to be 'close enough') to
                            > > several of
                            > > > > my sound card programs and they all show me that the standard
                            > > tones are
                            > > > > within just about 100 millihertz on the displays. I do NOT
                            > > have my sound
                            > > > > card or computer timebase synced to anything like a rubidium
                            > > or gps
                            > > > > "standard".
                            > > > >
                            > > > > I can look at the manuals myself to see how Spec Lab wants me
                            > > to adjust
                            > > > > for the sound card clock error (and the other packages, too).
                            > > What kind
                            > > > > of overall accuracy can I expect from Spectrum Lab under the
                            > > conditions
                            > > > > I have outlined? I intend to use the information I can get
                            > > from Spectrum
                            > > > > Lab and Spectran to correct the alignment of my duall loop PLL
                            > > and BFOs
                            > > > > in that (and other receivers). For the most part, being within 100
                            > > > > milliHertz is overkill in most ham radio operation (never mind
                            > > about
                            > > > > WSPR for now). But it's always good to know the limitations.
                            > > > >
                            > > > > Incidentally, when I bring in the BFO the actuall PLL "VFO"
                            > > frequency
                            > > > > and the BFO come into play and it's definitely "out of whack".
                            > > Starting
                            > > > > point is sound card calibration.
                            > > > >
                            > > > > 73,
                            > > > >
                            > > > > Bill KU8H
                            > > > >
                            > > > >
                            > > >
                            > >
                            > >
                            > >
                            >
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