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Re: Editing Skimmer WAV Files?

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  • jmaass_moose
    Editing the CW Skimmer WAV files does not seem to work with an audio editing tool. I sliced off all but the first 10 minutes of the file, and played it back
    Message 1 of 6 , May 1, 2010
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      Editing the CW Skimmer WAV files does not seem to work with an audio editing tool. I sliced off all but the first 10 minutes of the file, and played it back using CW Skimmer. It decodes the callsigns, but the absolute frequency information is lost. It plots against an offset rather than the absolute frequencey captured.

      The unedited original ~1 hour file decodes as expected.

      Any guidance how I can slice off a ten minute period of a large captured WC Skimmer WAV file without losing any information?

      73, Jeff K8ND


      --- In dxatlas_group@yahoogroups.com, "jmaass_moose" <jmaass@...> wrote:
      >
      > Is it possible to edit/trim the size of a CW Skimmer WAV recording?
      >
      > Are simple audio file editing tools (e.g. GoldWave) appropriate for this?
      >
      > I have many 2 GB 1-hour recording segments, and would like to break out interesting 5- or 10-minute portions to make them easier to handle when uploading or downloading to others.
      >
      > 73, Jeff K8ND
      >
    • Alex, VE3NEA
      Hi Jeff, The center frequency, UTC date/time and other parameters of the recording are stored in the WAV headers. If you save a fragment of a recording in a
      Message 2 of 6 , May 1, 2010
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        Hi Jeff,

        The center frequency, UTC date/time and other parameters of the recording
        are stored in the WAV headers. If you save a fragment of a recording in a
        new file, you can add the missing headers manually using the WavInfo tool
        available at (www.dxatlas.com/cwskimmer/files/wavinfo.zip). You can run two
        instances of this tool, open the original file in the first instance and the
        new file in the second instance, and copy-and-paste the headers.

        I believe many general purpose wav editors also have commands for editing
        the info headers.

        73 Alex VE3NEA




        ----- Original Message -----

        Editing the CW Skimmer WAV files does not seem to work with an audio editing
        tool. I sliced off all but the first 10 minutes of the file, and played it
        back using CW Skimmer. It decodes the callsigns, but the absolute frequency
        information is lost. It plots against an offset rather than the absolute
        frequencey captured.

        The unedited original ~1 hour file decodes as expected.

        Any guidance how I can slice off a ten minute period of a large captured WC
        Skimmer WAV file without losing any information?

        73, Jeff K8ND
      • jmaass_moose
        Thanks, Alex! That s solved it. I m assembling a few download-friendly-length extracts from some PJ2T logs from the 2009 CQWW 160 CW Contest. It s pretty
        Message 3 of 6 , May 2, 2010
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          Thanks, Alex! That's solved it.

          I'm assembling a few download-friendly-length extracts from some PJ2T logs from the 2009 CQWW 160 CW Contest. It's pretty jaw-dropping to watch the callsigns decoding from the target-rich environment (~800 decoders, 230 callsigns spotted under "paranoid" filter in an hours time). That's even with the PJ2T transmitter mucking up the receiver while running a pileup!

          73, Jeff

          --- In dxatlas_group@yahoogroups.com, "Alex, VE3NEA" <alshovk@...> wrote:
          >
          > Hi Jeff,
          >
          > The center frequency, UTC date/time and other parameters of the recording
          > are stored in the WAV headers. If you save a fragment of a recording in a
          > new file, you can add the missing headers manually using the WavInfo tool
          > available at (www.dxatlas.com/cwskimmer/files/wavinfo.zip). You can run two
          > instances of this tool, open the original file in the first instance and the
          > new file in the second instance, and copy-and-paste the headers.
          >
          > I believe many general purpose wav editors also have commands for editing
          > the info headers.
          >
          > 73 Alex VE3NEA
          >
          >
          >
          >
          > ----- Original Message -----
          >
          > Editing the CW Skimmer WAV files does not seem to work with an audio editing
          > tool. I sliced off all but the first 10 minutes of the file, and played it
          > back using CW Skimmer. It decodes the callsigns, but the absolute frequency
          > information is lost. It plots against an offset rather than the absolute
          > frequencey captured.
          >
          > The unedited original ~1 hour file decodes as expected.
          >
          > Any guidance how I can slice off a ten minute period of a large captured WC
          > Skimmer WAV file without losing any information?
          >
          > 73, Jeff K8ND
          >
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