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Re: [dxatlas] Re: CW Skimmer clicks

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  • Pete Smith
    ... 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
    Message 1 of 6 , Sep 22, 2008
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      At 02:14 PM 9/22/2008, rt_tclay wrote:
      >I assume you mean clicks in the receive audio? Yes, I have noticed
      >those for a while.
      >
      >My config is not very similar: K2+SoftRock, Core 2 Duo 3GHz, Win XP
      >Pro. Sound card is a Bgears b-Enspirer (PCI). I don't think they are
      >related to cpu load or the type of sound card.

      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.

      73, Pete N4ZR
    • Graham
      Hi Tor. Thanks for the reply. After a lot of experimenting, I agree with your conclusions! 73 de Graham G3ZOD Fists #8385 GQRP #11976
      Message 2 of 6 , Sep 26, 2008
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        Hi Tor. Thanks for the reply. After a lot of experimenting, I agree
        with your conclusions!

        73 de Graham G3ZOD
        Fists #8385 GQRP #11976


        --- In dxatlas_group@yahoogroups.com, "rt_tclay" <rt_clay@...> wrote:
        > I assume you mean clicks in the receive audio? Yes, I have noticed
        > those for a while.
        >
        > My config is not very similar: K2+SoftRock, Core 2 Duo 3GHz, Win XP
        > Pro. Sound card is a Bgears b-Enspirer (PCI). I don't think they are
        > related to cpu load or the type of sound card.
      • 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 3 of 6 , Sep 26, 2008
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          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 4 of 6 , Sep 26, 2008
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            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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