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Re: [softrock40] PSK31 IMD Ensemble RxTx

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  • David Turnbull
    ... My sound card is a Creative Labs E-MU 0204 sample rate: 96Khz ... The E-MU 0204 easily overdrives the RXTX Ensemble past linearity. It is designed for
    Message 1 of 4 , May 22 11:06 AM
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      On Tue, May 21, 2013 at 10:55 PM, Mike Saeger <mike.saeger@...> wrote:
      I worked a station on 20m PSK31 and was told that I had a lot of IMD on my signal.
      My sound card is a Creative Labs E-MU 0204 sample rate: 96Khz

      The E-MU 0204 easily overdrives the RXTX Ensemble past linearity. It is designed for 4.0Vp-p. Here's some sound device output levels I measured.

      2.40V iMic
      4.00V MackBook Pro Built-In (Intel HDA)
      4.00V Peaberry SDR (PCM3060)
      5.76V E-MU 0204 stereo output jack

      Here's a nice page about PSK31 IMD: http://www.n7yg.com/files/IMD.htm

      73 David AE9RB


    • warrenallgyer
      Great article David and spot on. My post about PSK31 being a single tone mode was obviously way off base. I hate to admit it but I read it as WSPR instead of
      Message 2 of 4 , May 22 6:50 PM
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        Great article David and spot on.

        My post about PSK31 being a single tone mode was obviously way off base. I hate to admit it but I read it as WSPR instead of PSK31... probably because I was staring at a WSPR waveform at the time.

        Apologies to Mike.

        Warren Allgyer - 9V1TD

        --- In softrock40@yahoogroups.com, David Turnbull <dturnbull@...> wrote:
        >
        > On Tue, May 21, 2013 at 10:55 PM, Mike Saeger <mike.saeger@...> wrote:
        >
        > > I worked a station on 20m PSK31 and was told that I had a lot of IMD on my
        > > signal.
        >
        > My sound card is a Creative Labs E-MU 0204 sample rate: 96Khz
        > >
        >
        > The E-MU 0204 easily overdrives the RXTX Ensemble past linearity. It is
        > designed for 4.0Vp-p. Here's some sound device output levels I measured.
        >
        > 2.40V iMic
        > 4.00V MackBook Pro Built-In (Intel HDA)
        > 4.00V Peaberry SDR (PCM3060)
        > 5.76V E-MU 0204 stereo output jack
        >
        > Here's a nice page about PSK31 IMD: http://www.n7yg.com/files/IMD.htm
        >
        > 73 David AE9RB
        > http://AE9RB.com/
        >
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