Loading ...
Sorry, an error occurred while loading the content.

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

Expand Messages
  • Alan
    ... Subject: [softrock40] Re: Sound System Tests. Especially Concerning EMU and Xonar D2X at 192KHz. ... Lee, Thanks for your input. I am wondering if the two
    Message 1 of 16 , Aug 1, 2011
    • 0 Attachment
       
      ----- Original Message -----
      Subject: [softrock40] Re: Sound System Tests. Especially Concerning EMU and Xonar D2X at 192KHz.

      >
      > I am using the EMU0202 with MME drivers and
      192kHz sample rate with HPSDR and get really excellent results across the whole 192kHz with the RX/TX Ensemble.
      >
      > However, with the RX Ensemble I
      find that beyond about 70kHz or 80kHz from the centre frequency (in both directions), the waterfall shows some noise on 40, 80 and 160m.
      >
      Lee,
       
      Thanks for your input.
      I am wondering if the two test programs I used are accurate or over-critical. <http://g4zfq.host-ed.net/RightMarkTests/E-MUTrackerPre%20_%20USB192.htm> BUT
       
      I have just done a crude test with my newly completed 2m VHF Softrock.
      It is just on the bench, unscreened, I hope it will not have so much spurious pickup when properly boxed.
       
      I attach two HDSDR screenshots using the EMU at 192KHz receiving the GB3VHF beacon on my discone.
      One near the centre, the other near the edge. I think the shots speak for themselves. The first one was when it was modulated, varying tones, I'll have to see what that is. The second just carrier, just about visible... Mine is not much good at the edges.
       
      My Xonar D2X looks similar, also that drops off sharply at over 30KHz TX output.
       
       
       
       
       
       
      73 Alan G4ZFQ
    • Alan
      I ll send this again with the pictures attached.. ... Subject: [softrock40] Re: Sound System Tests. Especially Concerning EMU and Xonar D2X at 192KHz. ... Lee,
      Message 2 of 16 , Aug 1, 2011
      I'll send this again with the pictures attached..


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


      >
      > I am using the EMU0202 with MME drivers and 192kHz sample rate with HPSDR
      > and get really excellent results across the whole 192kHz with the RX/TX
      > Ensemble.
      >
      > However, with the RX Ensemble I find that beyond about 70kHz or 80kHz from
      > the centre frequency (in both directions), the waterfall shows some noise
      > on 40, 80 and 160m.
      >

      Lee,

      Thanks for your input.
      I am wondering if the two test programs I used are accurate or
      over-critical.
      <http://g4zfq.host-ed.net/RightMarkTests/E-MUTrackerPre%20_%20USB192.htm>
      BUT

      I have just done a crude test with my newly completed 2m VHF Softrock.
      It is just on the bench, unscreened, I hope it will not have so much
      spurious pickup when properly boxed.

      I attach two HDSDR screenshots using the EMU at 192KHz receiving the GB3VHF
      beacon on my discone.
      One near the centre, the other near the edge. I think the shots speak for
      themselves. The first one was when it was modulated, varying tones, I'll
      have to see what that is. The second just carrier, just about visible...
      Mine is not much good at the edges.

      My Xonar D2X looks similar, also that drops off sharply at over 30KHz TX
      output.


      73 Alan G4ZFQ
    • Alan
      Just posted on the Genesis group. Look at and the pdf linked just below SDR-Widget: What is it? This
      Message 3 of 16 , Aug 2, 2011
      • 0 Attachment
        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 4 of 16 , Aug 2, 2011
        • 0 Attachment
          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 5 of 16 , Aug 2, 2011
          • 0 Attachment
            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 6 of 16 , Aug 2, 2011
            • 0 Attachment
              ----- 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 7 of 16 , Aug 2, 2011
              • 0 Attachment
                ----- 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 8 of 16 , Aug 2, 2011
                • 0 Attachment
                  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 9 of 16 , Aug 2, 2011
                  • 0 Attachment
                    ----- 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 10 of 16 , Aug 2, 2011
                    • 0 Attachment
                      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 11 of 16 , Aug 2, 2011
                      • 0 Attachment
                        ----- 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 12 of 16 , Aug 11, 2011
                        • 0 Attachment
                          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 13 of 16 , Aug 11, 2011
                          • 0 Attachment
                            ----- 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
                          Your message has been successfully submitted and would be delivered to recipients shortly.