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va7dgp SL sampling

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  • Don Poaps
    Sample Rate HZ: 11025 Input: 11025.30 Difference PPM 27 Output 11100.28 Difference PPM 6827 Sample Rate HZ: 44100
    Message 1 of 3 , Oct 29 10:11 AM
      Sample Rate HZ: 11025


      Input: 11025.30

      Difference PPM 27


      Output 11100.28

      Difference PPM 6827


      Sample Rate HZ: 44100

      Input: 44098.33

      Difference PPM -37

      Output 44098.51

      Difference PPM -33

      This is from the Stores Signalink and FT 920.

      73


      --
      Don Poaps
      New Westminster, BC
      VA7DGP
      Satern Member
      Vector Member
      Surrey Amateur Radio
      Metrotown Salvation Army Community Church Member
    • Rick Muething
      Don, These show what are unfortunately common errors with certain sound card chips. Note the big error (6827 ppm) in output at 11025 Sample Rate ....this is
      Message 2 of 3 , Oct 29 2:38 PM
        Don,
         
        These show what are unfortunately common errors with certain sound card chips. Note the big error (6827 ppm) in output at 11025 Sample Rate ....this is not that uncommon and a function of the chip set used to make the sound card. It is the reason that all the programs I write do not use these “non cardinal” values (8000, 11025, 44100) .  Usually 96000, 48000, 12000 are more accurate on virtually all chip sets used. 
         
        I think if you repeat the measurement with a sample rate of 12000 you will find that the SignaLink USB is fairly close on both Input and Output (Probably < 300 ppm ). It any case that is plenty good for the H4 DSP code.
         
        73,

        Rick KN6KB
         
         
        From: Don Poaps
        Sent: Tuesday, October 29, 2013 1:11 PM
        Subject: [V4Protocol] va7dgp SL sampling
         
         

        Sample Rate HZ: 11025

        Input: 11025.30

        Difference PPM 27

        Output 11100.28

        Difference PPM 6827

        Sample Rate HZ: 44100

        Input: 44098.33

        Difference PPM -37

        Output 44098.51

        Difference PPM -33

        This is from the Stores Signalink and FT 920.

        73

        --
        Don Poaps
        New Westminster, BC
        VA7DGP
        Satern Member
        Vector Member
        Surrey Amateur Radio
        Metrotown Salvation Army Community Church Member

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      • Don Poaps
        This is from this morning run on checksr from shop. Sample Rate HZ: 12000 Input 12000.07 Difference PPM 6 Output 12077.65 Difference PPM 6471 ...
        Message 3 of 3 , Oct 30 8:27 AM
          This is from this morning run on checksr from shop.




          Sample Rate HZ: 12000

          Input 12000.07


          Difference PPM 6

          Output 12077.65


          Difference PPM 6471








          On Tue, Oct 29, 2013 at 10:11 AM, Don Poaps <va7dgp@...> wrote:
          > Sample Rate HZ: 11025
          >
          >
          > Input: 11025.30
          >
          > Difference PPM 27
          >
          >
          > Output 11100.28
          >
          > Difference PPM 6827
          >
          >
          > Sample Rate HZ: 44100
          >
          > Input: 44098.33
          >
          > Difference PPM -37
          >
          > Output 44098.51
          >
          > Difference PPM -33
          >
          > This is from the Stores Signalink and FT 920.
          >
          > 73
          >
          >
          > --
          > Don Poaps
          > New Westminster, BC
          > VA7DGP
          > Satern Member
          > Vector Member
          > Surrey Amateur Radio
          > Metrotown Salvation Army Community Church Member



          --
          Don Poaps
          New Westminster, BC
          VA7DGP
          Satern Member
          Vector Member
          Surrey Amateur Radio
          Metrotown Salvation Army Community Church Member
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