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USB2SDR & SoftRock/Lima-SDR Rx IMD Dynamic Range performance measurements

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  • sv1eia
    Hi, I ve seen and studied quite a few times the Sherwood Eng. receiver test data page - http://www.sherweng.com/table.html so I ve assembled a small lab setup
    Message 1 of 7 , Apr 20, 2011
      Hi,

      I've seen and studied quite a few times the Sherwood Eng. receiver test data page
      -> http://www.sherweng.com/table.html
      so I've assembled a small lab setup for this and performed the tests in my homebrew rigs that are combined now with the USB2SDR.

      I've uploaded two files that show the performance of IMD DR of USB2SDR with a SoftRock RxTx v6.2 and USB2SDR with a Lima-SDR.

      The results are 86 dB and 84 dB respectively and can be seen in these files

      USB2SDR & SoftRock v6.2
      -> http://groups.yahoo.com/group/powersdr-iq/message/1826

      USB2SDR & Lima-SDR
      -> http://groups.yahoo.com/group/powersdr-iq/message/1827

      I did my best to be accurate and tried to follow exactly the Rx IMD procedure so I hope I didnt miss anything important. Sometime in the future these need to be verified.
      The numbers are quite higher than what I expected to see so I'm a bit surprised. Specially since these are homebrew rigs.

      Any thoughts and comments are welcome.

      Best regards & 73,
      Christos SV1EIA
    • ericwd9
      Christos, The results you are getting are very much the same as I get from a SR6.3/MoBo with an Edirol FA-66 sound card at 192KHz the Edirol falls off at the
      Message 2 of 7 , Apr 21, 2011
        Christos,
        The results you are getting are very much the same as I
        get from a SR6.3/MoBo with an Edirol FA-66 "sound card"
        at 192KHz the Edirol falls off at the high end and has
        a couple of artifacts that are visible. The Edirol is
        a high priced professional card and it would appear that
        the USB2SDR will be at least as good and may well be better
        with the add on's proposed.
        Regards Eric VK5ZAG

        --- In powersdr-iq@yahoogroups.com, "sv1eia" <sv1eia@...> wrote:
        >
        > Hi,
        >
        > I've seen and studied quite a few times the Sherwood Eng. receiver test data page
        > -> http://www.sherweng.com/table.html
        > so I've assembled a small lab setup for this and performed the tests in my homebrew rigs that are combined now with the USB2SDR.
        >
        > I've uploaded two files that show the performance of IMD DR of USB2SDR with a SoftRock RxTx v6.2 and USB2SDR with a Lima-SDR.
        >
        > The results are 86 dB and 84 dB respectively and can be seen in these files
        >
        > USB2SDR & SoftRock v6.2
        > -> http://groups.yahoo.com/group/powersdr-iq/message/1826
        >
        > USB2SDR & Lima-SDR
        > -> http://groups.yahoo.com/group/powersdr-iq/message/1827
        >
        > I did my best to be accurate and tried to follow exactly the Rx IMD procedure so I hope I didnt miss anything important. Sometime in the future these need to be verified.
        > The numbers are quite higher than what I expected to see so I'm a bit surprised. Specially since these are homebrew rigs.
        >
        > Any thoughts and comments are welcome.
        >
        > Best regards & 73,
        > Christos SV1EIA
        >
      • sv1eia
        Hi Eric, I ve already send recordings and other data to local close friends that have the FA-66 in order to compare. One of them has the SDR1K/FA-66 and his
        Message 3 of 7 , Apr 22, 2011
          Hi Eric,

          I've already send recordings and other data to local close friends that have the FA-66 in order to compare.
          One of them has the SDR1K/FA-66 and his words were "the results are at least equal", the other has a G59/FA-66 and he said that the results and recordings I send him "are better" than his own setup.

          Based on these observations I got intrigued so I decided to assemble the IMD DR test here and the outcome is indeed a very nice surprise, it landed right there in the big league radios neighborhood.

          Now, I want to have an IMD DR direct comparison with the FA-66 so arranged to have it here for the test.
          If you already have performed the IMD DR test on this, I would realy be very interested to see any screenshot results and data.

          And of course we need to note that the USB2SDR is a true 4+4 USB2 streaming device at 192KHz/32bit so it has all the required Rx & Tx channels for proper configuration.
          Yes, the AK5394A optional module performance numbers are yet to come, nevertheless though even with the stock-basic configuration to be in a stone's throw distance from the big guys and that from just a homebrew rig, it definitively shows something.

          Best regards & 73,
          Christos SV1EIA


          --- In powersdr-iq@yahoogroups.com, "ericwd9" <ericwd9@...> wrote:
          >
          > Christos,
          > The results you are getting are very much the same as I
          > get from a SR6.3/MoBo with an Edirol FA-66 "sound card"
          > at 192KHz the Edirol falls off at the high end and has
          > a couple of artifacts that are visible. The Edirol is
          > a high priced professional card and it would appear that
          > the USB2SDR will be at least as good and may well be better
          > with the add on's proposed.
          > Regards Eric VK5ZAG
          >
          > --- In powersdr-iq@yahoogroups.com, "sv1eia" <sv1eia@> wrote:
          > >
          > > Hi,
          > >
          > > I've seen and studied quite a few times the Sherwood Eng. receiver test data page
          > > -> http://www.sherweng.com/table.html
          > > so I've assembled a small lab setup for this and performed the tests in my homebrew rigs that are combined now with the USB2SDR.
          > >
          > > I've uploaded two files that show the performance of IMD DR of USB2SDR with a SoftRock RxTx v6.2 and USB2SDR with a Lima-SDR.
          > >
          > > The results are 86 dB and 84 dB respectively and can be seen in these files
          > >
          > > USB2SDR & SoftRock v6.2
          > > -> http://groups.yahoo.com/group/powersdr-iq/message/1826
          > >
          > > USB2SDR & Lima-SDR
          > > -> http://groups.yahoo.com/group/powersdr-iq/message/1827
          > >
          > > I did my best to be accurate and tried to follow exactly the Rx IMD procedure so I hope I didnt miss anything important. Sometime in the future these need to be verified.
          > > The numbers are quite higher than what I expected to see so I'm a bit surprised. Specially since these are homebrew rigs.
          > >
          > > Any thoughts and comments are welcome.
          > >
          > > Best regards & 73,
          > > Christos SV1EIA
          > >
          >
        • dan
          Christos happy easter. Is it possible to test the rig on 160m also? 73, w5xz, dan
          Message 4 of 7 , Apr 22, 2011
            Christos

            happy easter. Is it possible to test the rig on 160m also?

            73, w5xz, dan
          • sv1eia
            Hi Dan, You mean to check the IMD DR numbers if the used frequency is in the 160m band? Now I use the 10m band in the testing which is the most difficult of
            Message 5 of 7 , Apr 22, 2011
              Hi Dan,

              You mean to check the IMD DR numbers if the used frequency is in the 160m band? Now I use the 10m band in the testing which is the most difficult of all in the HF regarding the QSD timings and LO frequencies used.

              I guess you know that there is no external antenna connected during the lab tests, the antenna port is only connected to the lab instruments, in that specific case of IMD DR it is connected to the output of a hybrid combiner which combines the narrow spaced signals from two HF generators.

              As far as the USB2SDR ADC concern, there will be no difference since it always listens to a down-converted 192KHz bandwidth signal from the QSD in either of 10m or 160m band or whatever.
              The only thing that matters when another band is used, is the QSD receiver itself and how it behaves in the specific band.

              Is there any specific reason why you want such thing?

              73,
              Christos SV1EIA


              --- In powersdr-iq@yahoogroups.com, "dan" <w5xz@...> wrote:
              >
              > Christos
              >
              > happy easter. Is it possible to test the rig on 160m also?
              >
              > 73, w5xz, dan
              >
            • dan
              yes, I thought the results might be even better.... 73, w5xz, dan
              Message 6 of 7 , Apr 28, 2011
                yes, I thought the results might be even better.... 73, w5xz, dan
              • sv1eia
                Hi Dan, As you ve seen, I uploaded that test, yet the numbers are the same. The good performance is constant in all bands as expected. 73, Christos SV1EIA
                Message 7 of 7 , Apr 28, 2011
                  Hi Dan,

                  As you've seen, I uploaded that test, yet the numbers are the same.
                  The good performance is constant in all bands as expected.

                  73,
                  Christos SV1EIA


                  --- In powersdr-iq@yahoogroups.com, "dan" <w5xz@...> wrote:
                  >
                  > yes, I thought the results might be even better.... 73, w5xz, dan
                  >
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