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Re: [powersdr-iq] Re: Using two SDR radios with one iteration of PowerSDR-x

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  • Tom Gentry
    ... I am not very good at waiting on something to possibly happen. :( Perhaps I can study a diagram of the architecture of PowerSDR or IQ available for study.
    Message 1 of 17 , Aug 28, 2012
      On 8/28/2012 4:44 AM, sv1eia wrote:
       

      Lets wait and see.
      :-)

      73,
      Christos sV1EIA


      I am not very good at waiting on something to possibly happen.  :(  Perhaps I can study a diagram of the architecture of PowerSDR or IQ available for study.  I found source code but a better understanding of what the code is doing would be helpful. 

      In the meantime, I will go work on my mode 'B' station and perhaps find another 2510 and convert it to a mode 'J' station.    I can at least make the receiver an SDR and use the analog transmitter in the 2510 for uplink. 

      Hey! I just discovered an old ICOM 202S SSB transceiver in my antique collection.  Perhaps I can use the 202S and a small amp for the  transmitter section and PowerSDR-IQ + a SoftRock  Ensemble RX + 435MHz downconverter for the receive section.  That should keep me occupied until you decide whether to modify the PowerSDR-IQ code for this sort of application. 

      Thanks for your informative input.

      73s,

      Tom K5VOU

    • tomg3usa
      Any updates on when the software modification for full duplex might be available? Thanks. 73, Tom K5VOU
      Message 2 of 17 , Jun 21, 2013
        Any updates on when the software modification for full duplex might be available? Thanks.

        73,

        Tom K5VOU

        --- In powersdr-iq@yahoogroups.com, "sv1eia" <sv1eia@...> wrote:
        >
        >
        >
        > --- In powersdr-iq@yahoogroups.com, "tomg3usa" <t.gentry@> wrote:
        > >
        > >
        > >
        > > --- In powersdr-iq@yahoogroups.com, "sv1eia" <sv1eia@> wrote:
        > > >
        > > > Hi Tom,
        > > >
        > > > Yes, I understand the full duplex case that you mention.
        > > >
        > > > Since you are asking about USB2SDR on this, a single one can handle >full duplex already even today
        > >
        > > >but the s/w application is still pending to support it.
        > >
        > > Does this mean that PowerSDR-IQ is not suitable for this application?
        >
        > That means I just didnt modified PowerSDR-IQ yet for that case.
        >
        > PowerSDR itself is way more capable than this, its already being used on Flex's Flex5000 with two reparate (one TxRx and one Rx) and there are configurations and experiments having three receivers concurrently operating.
        >
        > >
        > >
        > > > That is of course pending on the rig used, eg stock EnsembleRxTx or >UHFSDR or similars are not designed to have full duplex, so you'll >need two rigs for that.
        > >
        > > Of course, that is why I specified two seperate EnsembleRxTx units in the example. But one will be in RX while the other is used for TX. I feel certain it the application needs an Si570 in each unit.
        > >
        > > > Also, USB2SDR can handle up to two additional independent >transceivers (the RxTx modules, -yes I know, they are also due to >come- ) connected on the on-board expansion connectors.
        > >
        > > I want to use the EnsembleRxTx units for the radios.
        > >
        > >
        > > > And all these are with a single USB connection.
        > >
        > > Best news yet> Thanks
        > >
        > > >
        > > > > How is that for dreaming?
        > > >
        > > > Dreaming is good, its the driving force behind our efforts
        > > > :-)
        > > >
        > > > 73,
        > > > Christos SV1EIa
        > > >
        > > >
        > > > --- In powersdr-iq@yahoogroups.com, "tomg3usa" <t.gentry@> wrote:
        > > > >
        > > > >
        > > > >
        > > > >
        > > > > Thanks Christos,
        > > > > That is a very interesting video and very encouraging.
        > > > >
        > > > > I actually want to transmit on one of the radios and listen on the other in full duplex mode (like a 5000). Does this require two of the usb2sdr units or can it be handled by one?
        > > > >
        > > > > example of sat operation;
        > > > > The 29MHz frequency of the #1-RX/TX radio will drive/listen to the 2-meter transverter and the #2-RX/TX radio will drive/listen to the 435 MHz transverter. In mode 'J' the 2-meter unit will be in TX and the UHF in RX while in Mode 'B' the UHF unit will be in TX and the VHF in receive. I want to use only one computer (multiple USB connections is OK, multi-channel soundcard is OK) and one iteration of PowerSDR-IQ set up for displaying 2-meter frequency on VFO-A, and UHF frequency on VFO-B.
        > > > >
        > > > > OH, and the whole rig is to be CAT controlled by SatPC32 for tx and rx freqs.
        > > > >
        > > > > How is that for dreaming?
        > > > >
        > > > > 73,
        > > > >
        > > > > Tom K5VOU
        > > > >
        > > > > --- In powersdr-iq@yahoogroups.com, "sv1eia" <sv1eia@> wrote:
        > > > > >
        > > > > > Hi,
        > > > > >
        > > > > > A two receiver option for In-Band signals is already in place on PowerSDR-IQ
        > > > > > -> http://www.youtube.com/watch?v=fUJ6olyfFwU
        > > > > >
        > > > > > Its not the complete two independent receivers but good enough to monitor two
        > > > > > frequencies, very handy on split operation where you want to listen both the Dx
        > > > > > station and also the place you transmit.
        > > > > >
        > > > > > 73,
        > > > > > Christos SV1EIA
        > > > > >
        > > > > >
        > > > > > --- In powersdr-iq@yahoogroups.com, "Yannick" <yannick.devos@> wrote:
        > > > > > >
        > > > > > > That's a nice project Tom. Keep us updated about it.
        > > > > > >
        > > > > > > Good luck.
        > > > > > > 73,
        > > > > > > Yan.
        > > > > > > ---
        > > > > > > Yannick DEVOS - XV4Y
        > > > > > > http://xv4y.radioclub.asia/
        > > > > > > http://varc.radioclub.asia/
        > > > > > >
        > > > > > > --- In powersdr-iq@yahoogroups.com, "tomg3usa" <t.gentry@> wrote:
        > > > > > > >
        > > > > > > > I want to run two SDR radios from one iteration of PowerSDR. Only one radio will be in transmit at a time. Each SDR will run a transverter for satellite operation.
        > > > > > > >
        > > > > > > > 73,
        > > > > > > >
        > > > > > > > Tom K5VOU
        > > > > > > >
        > > > > > >
        > > > > >
        > > > >
        > > >
        > >
        >
      • tom
        Christos, I am using PSDR V12.X with RXTX V6.3 and Mobo. I have a 1db difference between left and right audio channels. My image rejection appears to be around
        Message 3 of 17 , Jun 21, 2013
          Christos,

          I am using PSDR V12.X with RXTX V6.3 and Mobo. I have a 1db difference
          between left and right audio channels. My image rejection appears to be
          around 28DB. Does the 1db difference account for the poor image
          rejection? I assume there is no way for me to adjust the software for
          the difference in db.

          Thanks,

          Tom
        • sv1eia
          Tom, Just some thoughts on your setup there. 1 dB is within the range but after all why not try to find the cause of imbalance and make it equal? Also bear in
          Message 4 of 17 , Jun 22, 2013
            Tom,

            Just some thoughts on your setup there.

            1 dB is within the range but after all why not try to find the cause of imbalance and make it equal?
            Also bear in mind that your rig might introduce some phase imbalance between I and Q which is not measured from ADCL/R (an o-scope is needed for that).
            Try very short length cables between rig and audio card.

            If you use the quite old v1.12 then there is a "EIA" button which stands for "Effective Image Adjustment" that enables the image rejection algo, yet it takes some time to see results. There is a coefficient number besides the button that also needs tweaking, it goes from 0.00 to 1.00 and the larger numbers are giving faster results with lower image rejection, whereas smaller numbers give slower results with higher image rejection.

            73,
            Christos SV1EIA


            --- In powersdr-iq@yahoogroups.com, tom <loeblt@...> wrote:
            >
            > Christos,
            >
            > I am using PSDR V12.X with RXTX V6.3 and Mobo. I have a 1db difference
            > between left and right audio channels. My image rejection appears to be
            > around 28DB. Does the 1db difference account for the poor image
            > rejection? I assume there is no way for me to adjust the software for
            > the difference in db.
            >
            > Thanks,
            >
            > Tom
            >
          • applewiz2000
            Hi Tom, A 1dB difference on some band or other (you don t say which you measured) is not unexpected. The amplitude difference varies across the 1 - 30MHz
            Message 5 of 17 , Jun 22, 2013
              Hi Tom,

              A 1dB difference on some band or other (you don't say which you measured) is not unexpected. The amplitude difference varies across the 1 - 30MHz range.

              What you need to do is put in a pot to adjust your gain. Then use a sig gen at a mid HF (e.g. 15MHz) frequency to balance. You will find that above and below the balance drifts off though. While you are about it, reduce your overall gain on the SR V6.3 board. The stock gain is too high for modern sound cards.

              As to the image rejection of PSDR, the V2.5.x algorithm is better than the old V2 beta. But there is still the recurring bug where the rejection fails altogether after switching from Rx to Tx and back a few times.

              ~/Rob
              www.m0rzf.co.uk
            • tom
              Thanks Christos....EIA works great. Meanwhile I will look into why I have the difference between L and R... Tom
              Message 6 of 17 , Jun 22, 2013
                Thanks Christos....EIA works great. Meanwhile I will look into why I
                have the difference between L and R...

                Tom

                On 6/22/2013 3:33 AM, sv1eia wrote:
                > Tom,
                >
                > Just some thoughts on your setup there.
                >
                > 1 dB is within the range but after all why not try to find the cause of imbalance and make it equal?
                > Also bear in mind that your rig might introduce some phase imbalance between I and Q which is not measured from ADCL/R (an o-scope is needed for that).
                > Try very short length cables between rig and audio card.
                >
                > If you use the quite old v1.12 then there is a "EIA" button which stands for "Effective Image Adjustment" that enables the image rejection algo, yet it takes some time to see results. There is a coefficient number besides the button that also needs tweaking, it goes from 0.00 to 1.00 and the larger numbers are giving faster results with lower image rejection, whereas smaller numbers give slower results with higher image rejection.
                >
                > 73,
                > Christos SV1EIA
                >
                >
                > --- In powersdr-iq@yahoogroups.com, tom <loeblt@...> wrote:
                >>
                >> Christos,
                >>
                >> I am using PSDR V12.X with RXTX V6.3 and Mobo. I have a 1db difference
                >> between left and right audio channels. My image rejection appears to be
                >> around 28DB. Does the 1db difference account for the poor image
                >> rejection? I assume there is no way for me to adjust the software for
                >> the difference in db.
                >>
                >> Thanks,
                >>
                >> Tom
                >>
                >
                >
                >
                >
                > ------------------------------------
                >
                > Yahoo! Groups Links
                >
                >
                >
                >
              • tom
                Hi Rob, Your amp is still humming away here and the 20 watts drives my SB220 to about 300 watts out. I saw some numbers on an old posting from Bob, g8voi, that
                Message 7 of 17 , Jun 22, 2013
                  Hi Rob,

                  Your amp is still humming away here and the 20 watts drives my SB220 to
                  about 300 watts out.

                  I saw some numbers on an old posting from Bob, g8voi, that stated that
                  even a .4 db difference in the channels can degrade the image rejection
                  to the low 30 db range, so I was a bit concerned. I am somewhere around
                  25 db rejection at the moment.

                  I thought perhaps I could insert a small pad in one channel to equalize
                  the audio between the SR and the PC audio card rather than tearing into
                  the Softrock but that may wind up being the only option.

                  As Christos suggested, the PSDR V12.20 EIA button seems to work very
                  well for me at the moment.

                  Tom

                  On 6/22/2013 10:04 AM, applewiz2000 wrote:
                  > Hi Tom,
                  >
                  > A 1dB difference on some band or other (you don't say which you measured) is not unexpected. The amplitude difference varies across the 1 - 30MHz range.
                  >
                  > What you need to do is put in a pot to adjust your gain. Then use a sig gen at a mid HF (e.g. 15MHz) frequency to balance. You will find that above and below the balance drifts off though. While you are about it, reduce your overall gain on the SR V6.3 board. The stock gain is too high for modern sound cards.
                  >
                  > As to the image rejection of PSDR, the V2.5.x algorithm is better than the old V2 beta. But there is still the recurring bug where the rejection fails altogether after switching from Rx to Tx and back a few times.
                  >
                  > ~/Rob
                  > www.m0rzf.co.uk
                  >
                  >
                  >
                  >
                  > ------------------------------------
                  >
                  > Yahoo! Groups Links
                  >
                  >
                  >
                  >
                • applewiz2000
                  Hi Tom,, I don t think 0.4dB will make any difference. The algorithm (not that I have detailed knowledge of it) should be able to cope with small amounts of
                  Message 8 of 17 , Jun 23, 2013
                    Hi Tom,,

                    I don't think 0.4dB will make any difference. The algorithm (not that I have detailed knowledge of it) should be able to cope with small amounts of imbalance as one of it's major "raisons de etre".

                    It's a fair bet that the Flexradios do not always have <0.3dB amplitude match between I/Q channels across all HF bands.

                    I have not used PSDR-IQ V1.12 for years. The V2.5.2 version gets >40dB most of the time. Only Christos can really answer how good relatively the 1.12 rejection algorithm is compared to V2.5.x.

                    Excellent to see a product I designed in good use. Time will tell if the Mitsubishi RD16HHF FETs outlast the Heathkit SB220 !!

                    73s, Rob.


                    --- In powersdr-iq@yahoogroups.com, tom <loeblt@...> wrote:
                    > Hi Rob,
                    >
                    > Your amp is still humming away here and the 20 watts drives my SB220 to
                    > about 300 watts out.
                    >
                    > I saw some numbers on an old posting from Bob, g8voi, that stated that
                    > even a .4 db difference in the channels can degrade the image rejection
                    > to the low 30 db range, so I was a bit concerned. I am somewhere around
                    > 25 db rejection at the moment.
                    >
                    > I thought perhaps I could insert a small pad in one channel to equalize
                    > the audio between the SR and the PC audio card rather than tearing into
                    > the Softrock but that may wind up being the only option.
                    >
                    > As Christos suggested, the PSDR V12.20 EIA button seems to work very
                    > well for me at the moment.
                    >
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