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[dxatlas] Re: CW Skimmer clicks

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  • Graham
    Hi Pete. Thanks for the reply. Well, I ve now used a KK7UQ interface with two different sound cards (the one on the motherboard and a Delta 44) as well as the
    Message 1 of 6 , Sep 26, 2008
      Hi Pete. Thanks for the reply.

      Well, I've now used a KK7UQ interface with two different sound cards
      (the one on the motherboard and a Delta 44) as well as the Signalink
      USB.

      I've tried lots of combinations and in my set up at least, processor
      power / availability / affinity doesn't appear to make any difference
      (I even had CW Skimmer running at real time priority for a short
      while without any crash but also without any improvment).

      The one thing that DOES make it go away is switching from "MME"
      to "WDM".

      This is a real shame - the Windows USB sound driver used by the
      Signalink USB doesn't provide "WDM" according to CW Skimmer :-(

      So, in other words I only got CW Skimmer to work really smoothly with
      the KK7UQ interface and the two sound cards.

      I didn't observe any lines in the waterfall or any splitting up of
      characters - I'm thinking that perhaps what you experienced is a
      slightly different issue.

      73 de Graham G3ZOD
      Fists #8385 GQRP #11976


      --- In dxatlas_group@yahoogroups.com, Pete Smith <n4zr@...> wrote:
      > A couple of things you can try. Experiment with both drivers for
      the sound
      > card - I found MME to be quieter. Also, try resetting the priority
      of the
      > CW Skimmer processes in Task Manager to high (not real time, it'll
      > crash). If that helps, use a free utility called PRIO to reset its
      > priority permanently. With a dual-core machine, which I don't
      have, I'm
      > told you can also set things up so that Skimmer runs alone on one
      virtual
      > CPU, with everything else on the other.
      >
      > I think that what is happening is that each of the clicks
      represents an
      > interruption in the data flow to Skimmer, caused by interference
      with other
      > programs running on the same PC. If you look really hard at the
      waterfall,
      > you'll see these as faint dark vertical lines running from the top
      to the
      > bottom of the screen. If you can catch one running across a CW
      signal, you
      > will see either a shortening of the code element (if the drop-out
      occurs at
      > the beginning or end) or as breaking into two (an N becomes an S,
      for
      > example). If you're really quick, you correlate between the
      waterfall
      > effects and errors made by the decoder, typically reflecting the
      same
      > pattern (N becoming S, in the example above, or A becoming T).
      >
      > In my setup, using an SDR-IQ, no sound card, and a 2.66 GHz Celeron
      with
      > 2GB of memory, I spent many hours stopping all background processes
      and
      > then restarting them one by one (using MSCONFIG). Stopping them
      all
      > definitely cleaned up the noise (only Skimmer running), but I was
      never
      > able conclusively to figure out which of them cvould be run without
      it
      > recurring. Ultimately, fixing the priority at High helped more
      than anything.
    • Pete Smith
      ... It may well be a different source, but Alex told me that the audio crackles mean blocks are being dropped. Sorry you can t get the right driver for your
      Message 2 of 6 , Sep 26, 2008
        At 04:44 PM 9/26/2008, you wrote:
        >I didn't observe any lines in the waterfall or any splitting up of
        >characters - I'm thinking that perhaps what you experienced is a
        >slightly different issue.

        It may well be a different source, but Alex told me that the audio crackles
        mean blocks are being dropped.

        Sorry you can't get the right driver for your interface.

        73, Pete
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