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Re: [softrock40] Re: Sound System Tests. Especially Concerning EMU and Xonar D2X at 192KHz.

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  • Alan
    Just posted on the Genesis group. Look at and the pdf linked just below SDR-Widget: What is it? This
    Message 1 of 16 , Aug 2, 2011
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      Just posted on the Genesis group.

      "Look at <http://sites.google.com/site/lofturj/sdr_widget> and the pdf
      linked just below "SDR-Widget: What is it?" "
      This includes tests on the EMU 0202 that look a little like mine. (and look
      at the FA66)

      73 Alan G4ZFQ
    • sv1eia
      Hi Alan, Comparing audio cards is nothing but comparing Audio Cards whereas I hope you see the emphasis here. You need to understand that we use these as
      Message 2 of 16 , Aug 2, 2011
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        Hi Alan,

        Comparing audio cards is nothing but comparing 'Audio Cards' whereas I hope you see the emphasis here.

        You need to understand that we use these as substitutes for our need which actually puts them outside of their intended use.

        So comparing these cards that have 'audio' audible frequencies as their design, is definitively a game where you cannot win.

        Appart from that, the only and actually the most beneficial measurement that we have in Rx, IMHO is the two tone IMD DR test, the same as used in Sherwood Eng. Labs for sorting the receivers performance.
        I can bet with safety that there is no such test for these 'audio' cards.

        Two-tone IMD DR tests in 96KHz and 192KHz
        http://groups.yahoo.com/group/softrock40/files/SV1EIA/
        http://groups.yahoo.com/group/powersdr-iq/files/

        http://www.wb5rvz.com/usb2sdr/index.htm

        Just my 2c.

        73,
        Christos SV1EIA
        http://groups.yahoo.com/group/powersdr-iq/


        --- In softrock40@yahoogroups.com, "Alan" <alan4alan@...> wrote:
        >
        > Just posted on the Genesis group.
        >
        > "Look at <http://sites.google.com/site/lofturj/sdr_widget> and the pdf
        > linked just below "SDR-Widget: What is it?" "
        > This includes tests on the EMU 0202 that look a little like mine. (and look
        > at the FA66)
        >
        > 73 Alan G4ZFQ
        >
      • Tony Estep
        I promised to try the RightMark testing software but for whatever reason the installation file bombs when I try to install it. Sorry - road to hell paved with
        Message 3 of 16 , Aug 2, 2011
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          I promised to try the RightMark testing software but for whatever reason the installation file bombs when I try to install it. Sorry - road to hell paved with good intentions.

          Tony KT0NY

          On Tue, Aug 2, 2011 at 2:47 AM, Alan <alan4alan@...> wrote:
           

          .... includes tests on the EMU 0202...

          --
          http://www.isb.edu/faculty/facultydir.aspx?ddlFaculty=352
        • Alan
          ... Subject: Re: [softrock40] Re: Sound System Tests. Especially Concerning EMU and Xonar D2X at 192KHz. ... Tony, Thanks Tony, since then I ve found work by
          Message 4 of 16 , Aug 2, 2011
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            ----- Original Message -----
            Subject: Re: [softrock40] Re: Sound System Tests. Especially Concerning EMU
            and Xonar D2X at 192KHz.


            >I promised to try the RightMark testing software but for whatever reason
            >the
            > installation file bombs when I try to install it.

            Tony,

            Thanks Tony, since then I've found work by others that seems to confirm my
            remarks.
            Then Christos' comments tell me I was hoping for too much.

            73 Alan G4ZFQ
          • Alan
            ... From: sv1eia Subject: [softrock40] Re: Sound System Tests. Especially Concerning EMU and Xonar D2X at 192KHz. ... Christos, Thank you. I was under the
            Message 5 of 16 , Aug 2, 2011
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              ----- Original Message -----
              From: "sv1eia"
              Subject: [softrock40] Re: Sound System Tests. Especially Concerning EMU and
              Xonar D2X at 192KHz.


              >
              > So comparing these cards that have 'audio' audible frequencies as their
              > design, is definitively a game where you cannot win.
              >

              Christos,

              Thank you.
              I was under the impression that some cards were being used sucessfully at
              192 KHz so thought it might be useful with the VHF Softrock.
              I obtained two, neither are satisfactory.
              The VHF Softrock possibly shows up the problem to a greater extent, more
              noise on lower bands will help cover up this defect unless attempts are
              made to use the greater expected dynamic range.
              But these systems can only be used at lower sample rates. As you say audio
              frequencies, or, a LITTLE higher.

              73 Alan G4ZFQ


              > Appart from that, the only and actually the most beneficial measurement
              > that we have in Rx, IMHO is the two tone IMD DR test, the same as used in
              > Sherwood Eng. Labs for sorting the receivers performance.
              > I can bet with safety that there is no such test for these 'audio' cards.
              >
              > Two-tone IMD DR tests in 96KHz and 192KHz
              > http://groups.yahoo.com/group/softrock40/files/SV1EIA/
              > http://groups.yahoo.com/group/powersdr-iq/files/
              >
              > http://www.wb5rvz.com/usb2sdr/index.htm
              >
              > Just my 2c.
              >
              > 73,
              > Christos
            • g3sew
              Very interesting plots Alan. Doing further checks with the EMU0202 on 192kHz with the RX Ensemble, it looks as if the gain across the full bandwidth is pretty
              Message 6 of 16 , Aug 2, 2011
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                Very interesting plots Alan.

                Doing further checks with the EMU0202 on 192kHz with the RX Ensemble, it looks as if the gain across the full bandwidth is pretty constant. The degree of noise from the soundcard apparent in the waterfall (and the overall S/N ratio of the system) will in part depend on the signal level from the Softrock. I imagine that the output from the RX/TX Ensemble is a little higher than that from the RX Ensemble, which would explain why I do not see any extra noise at the extreme ends of the waterfall on the RX/TX, but do on 40, 80 and 160 on the RX.

                See linked screen grab of HDSDR (and EMU0202 at 192kHz) with the RX Ensemble on 20m, with very little degradation at the bandwidth extremes.

                http://groups.yahoo.com/group/softrock40/files/G3SEW/


                Lee G3SEW


                --- In softrock40@yahoogroups.com, "Alan" <alan4alan@...> wrote:
                >
                > Just posted on the Genesis group.
                >
                > "Look at <http://sites.google.com/site/lofturj/sdr_widget> and the pdf
                > linked just below "SDR-Widget: What is it?" "
                > This includes tests on the EMU 0202 that look a little like mine. (and look
                > at the FA66)
                >
                > 73 Alan G4ZFQ
                >
              • Alan
                ... Subject: [softrock40] Re: Sound System Tests. Especially Concerning EMU and Xonar D2X at 192KHz. ... Lee, Try running HDSDR without the audio plugged in.
                Message 7 of 16 , Aug 2, 2011
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                  ----- Original Message -----
                  Subject: [softrock40] Re: Sound System Tests. Especially Concerning EMU and
                  Xonar D2X at 192KHz.


                  >
                  > Doing further checks with the EMU0202 on 192kHz with the RX Ensemble, it
                  > looks as if the gain across the full bandwidth is pretty constant. The
                  > degree of noise from the soundcard apparent in the waterfall (and the
                  > overall S/N ratio of the system) will in part depend on the signal

                  Lee,

                  Try running HDSDR without the audio plugged in.
                  When I try that it gives a fair representation of the other curves I see.
                  Look at the attachments here
                  <http://groups.yahoo.com/group/softrock40/message/57113> You will see my
                  noise floor at the centre is about -115dB, yours is -85dB? I can make mine
                  look like yours by turning up the EMU input gain but I think I'll loose
                  about 30dB in dynamic range at the centre.
                  I don't know how closely we may compare different computer setups but we are
                  using the same software and much the same audio devices.
                  Looking at my current setup my noise at the centre is -125dB. If I remove my
                  antenna and put on a dummy load I see a small drop. Switching the Softrock
                  off, or removing the audio jack reduces the level to -130dB which shows I
                  see the actual noise from the Softrock, no more gain is needed. The EMU
                  Tracker Pre gain controls are at minimum. I have no idea how that compares
                  with the 0202.
                  Increasing the EMU input to increase the centre noise by 30dB then makes the
                  sensitivity the same all across the range but at the expense of 30dB
                  headroom.

                  73 Alan G4ZFQ

                  > See linked screen grab of HDSDR (and EMU0202 at 192kHz) with the RX
                  > Ensemble on 20m, with very little degradation at the bandwidth extremes.
                  >
                  > http://groups.yahoo.com/group/softrock40/files/G3SEW/
                  >
                • g3sew
                  Alan, Without the audio input the waterfall reflects the plots that you linked to (with considerable noise at the extreme ends of the band). But in practical
                  Message 8 of 16 , Aug 2, 2011
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                    Alan,

                    Without the audio input the waterfall reflects the plots that you linked to (with considerable noise at the extreme ends of the band). But in practical terms (once the Softrock is plugged in) the thing performs extremely well. I have my input gains set very low on the EMU, and I really don't notice the lack of headroom. Not even the strongest stations seem to overload the system.

                    So I am quite happy with the EMU at 192kHz, and really like seeing the massive chunk of RF real estate on the waterfall for each amateur band.


                    Lee G3SEW


                    --- In softrock40@yahoogroups.com, "Alan" <alan4alan@...> wrote:
                    >
                    >
                    > ----- Original Message -----
                    > Subject: [softrock40] Re: Sound System Tests. Especially Concerning EMU and
                    > Xonar D2X at 192KHz.
                    >
                    >
                    > >
                    > > Doing further checks with the EMU0202 on 192kHz with the RX Ensemble, it
                    > > looks as if the gain across the full bandwidth is pretty constant. The
                    > > degree of noise from the soundcard apparent in the waterfall (and the
                    > > overall S/N ratio of the system) will in part depend on the signal
                    >
                    > Lee,
                    >
                    > Try running HDSDR without the audio plugged in.
                    > When I try that it gives a fair representation of the other curves I see.
                    > Look at the attachments here
                    > <http://groups.yahoo.com/group/softrock40/message/57113> You will see my
                    > noise floor at the centre is about -115dB, yours is -85dB? I can make mine
                    > look like yours by turning up the EMU input gain but I think I'll loose
                    > about 30dB in dynamic range at the centre.
                    > I don't know how closely we may compare different computer setups but we are
                    > using the same software and much the same audio devices.
                    > Looking at my current setup my noise at the centre is -125dB. If I remove my
                    > antenna and put on a dummy load I see a small drop. Switching the Softrock
                    > off, or removing the audio jack reduces the level to -130dB which shows I
                    > see the actual noise from the Softrock, no more gain is needed. The EMU
                    > Tracker Pre gain controls are at minimum. I have no idea how that compares
                    > with the 0202.
                    > Increasing the EMU input to increase the centre noise by 30dB then makes the
                    > sensitivity the same all across the range but at the expense of 30dB
                    > headroom.
                    >
                    > 73 Alan G4ZFQ
                    >
                    > > See linked screen grab of HDSDR (and EMU0202 at 192kHz) with the RX
                    > > Ensemble on 20m, with very little degradation at the bandwidth extremes.
                    > >
                    > > http://groups.yahoo.com/group/softrock40/files/G3SEW/
                    > >
                    >
                  • Alan
                    ... Subject: [softrock40] Re: Sound System Tests. Especially Concerning EMU and Xonar D2X at 192KHz. ... Lee, Thanks for checking. At least it confirms what I
                    Message 9 of 16 , Aug 2, 2011
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                      ----- Original Message -----
                      Subject: [softrock40] Re: Sound System Tests. Especially Concerning EMU and
                      Xonar D2X at 192KHz.


                      >
                      > Without the audio input the waterfall reflects the plots that you linked
                      > to (with considerable noise at the extreme ends of the band). But in
                      > practical terms (once the Softrock is plugged in) the thing performs
                      > extremely well.


                      Lee,

                      Thanks for checking. At least it confirms what I found.
                      I know what you mean, in spite of the enormous advances in technical
                      specifications I still reckon that most amateur contacts could still be made
                      with a FT101.
                      But I think it shows that sound systems like the EMU do not produce
                      astounding performance figures especially when operated at 192KHz.
                      Quite a few have enthused about the EMU's low noise figure, about 15dB
                      better than a Delta44 but to use satisfactorily at 192KHz it has to be
                      effectively be made 15dB worse than the Delta44.
                      Like you I have not knowingly experienced overload of a soundcard but I've
                      never investigated the reason for all those strange signals and lines on the
                      waterfall. I don't know what to expect but I know the hardware has no AGC so
                      as much headroom as possible must be a good thing, even more so at VHF.

                      Nobody has yet commented on the Xonar D2X which when using a fixed LO like
                      HDSDR just cannot be used for TX at 192KHz. This also has the rising noise
                      characteristic on the inputs.

                      So, a proper "SDR IF" from Christos has to be the next step towards
                      perfection.

                      73 Alan G4ZFQ
                    • g3sew
                      Alan, Just want to say how useful this thread has been. I was originally unsure of the reason for the noise at the edges of the 192kHz with the EMU, and had
                      Message 10 of 16 , Aug 11, 2011
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                        Alan,

                        Just want to say how useful this thread has been. I was originally unsure of the reason for the noise at the edges of the 192kHz with the EMU, and had put it down to the Softrock itself. Also I have now taken to sliding a station nearer to the central area if it is suffering from the noise at the edges of the 192kHz - with considerable improvement in performance in some cases.


                        Lee G3SEW


                        --- In softrock40@yahoogroups.com, "Alan" <alan4alan@...> wrote:
                        >
                        >
                        > ----- Original Message -----
                        > Subject: [softrock40] Re: Sound System Tests. Especially Concerning EMU and
                        > Xonar D2X at 192KHz.
                        >
                        >
                        > >
                        > > Without the audio input the waterfall reflects the plots that you linked
                        > > to (with considerable noise at the extreme ends of the band). But in
                        > > practical terms (once the Softrock is plugged in) the thing performs
                        > > extremely well.
                        >
                        >
                        > Lee,
                        >
                        > Thanks for checking. At least it confirms what I found.
                        > I know what you mean, in spite of the enormous advances in technical
                        > specifications I still reckon that most amateur contacts could still be made
                        > with a FT101.
                        > But I think it shows that sound systems like the EMU do not produce
                        > astounding performance figures especially when operated at 192KHz.
                        > Quite a few have enthused about the EMU's low noise figure, about 15dB
                        > better than a Delta44 but to use satisfactorily at 192KHz it has to be
                        > effectively be made 15dB worse than the Delta44.
                        > Like you I have not knowingly experienced overload of a soundcard but I've
                        > never investigated the reason for all those strange signals and lines on the
                        > waterfall. I don't know what to expect but I know the hardware has no AGC so
                        > as much headroom as possible must be a good thing, even more so at VHF.
                        >
                        > Nobody has yet commented on the Xonar D2X which when using a fixed LO like
                        > HDSDR just cannot be used for TX at 192KHz. This also has the rising noise
                        > characteristic on the inputs.
                        >
                        > So, a proper "SDR IF" from Christos has to be the next step towards
                        > perfection.
                        >
                        > 73 Alan G4ZFQ
                        >
                      • Alan
                        ... Subject: [softrock40] Re: Sound System Tests. Especially Concerning EMU and Xonar D2X at 192KHz. ... Lee, Yes, I am just a beginner with these 192KHz
                        Message 11 of 16 , Aug 11, 2011
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                          ----- Original Message -----
                          Subject: [softrock40] Re: Sound System Tests. Especially Concerning EMU and
                          Xonar D2X at 192KHz.


                          >
                          > Just want to say how useful this thread has been. I was originally unsure
                          > of the reason for the noise at the edges of the 192kHz with the EMU, and
                          > had put it down to the Softrock itself. Also I have now taken to sliding a
                          > station nearer to the central area if it is suffering from the noise at
                          > the edges of the 192kHz - with considerable improvement in performance in
                          > some cases.
                          >


                          Lee,

                          Yes, I am just a beginner with these 192KHz cards, still learning.
                          No, it is not the Softrock, these are quiet and as far as I can tell the
                          noise level does not increase with frequency.
                          I was forgetting the big difference between using HDSDR with the MME drivers
                          and ASIO. HDSDR uses only 16 bits MME, the ASIO is 24 bits and shows a very
                          much lower noise floor.
                          I find using ASIO when I connect an antenna to my 2m Softrock raises this
                          floor by 10dB, already beginning to mask the 30dB noise at the edges.
                          An HF Softrock raises the floor by 20dB or more. Quite a bit of gain
                          reduction required here for getting ultimate performance from a low noise
                          sound device..

                          73 Alan G4ZFQ
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