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    Hi Derek,<br>
    <br>
    with the current versions of UHD, you can specify the path to the
    firmware and FPGA images you want to use when constructing your
    device object, so that's not really the problem here -- the real
    problem is that the B200's FPGA size doesn't really allow for a
    whole second RX chain without throwing out crucial TX functionality.<br>
    <br>
    Greetings,<br>
    Marcus<br>
    <br>
    <div class="moz-cite-prefix">On 04/05/2015 10:59 PM, Derek Murphy
      via USRP-users wrote:<br>
    </div>
    <blockquote
cite="mid:CAPM65Yi9+fzGNdqT9GB3OJHJ6a+tT5Zeqh-e5h_CjMwx8PSO=A@mail.gmail.com"
      type="cite">
      <div dir="ltr">Ian, again thanks for the great information. I'm
        sure I'm not the first the have this problem, do you think there
        is a possibility of getting this as an option for a normal fpga
        flash. That way anybody wanting to do this will just have to
        load the firmware and then they could use the UHD to select eh
        center LO and then specifically select the other 2 signals.
        <div><br>
        </div>
        <div>I might be the only one interested in that but I thought
          that someone else might be.</div>
      </div>
      <div class="gmail_extra"><br>
        <div class="gmail_quote">On Sat, Apr 4, 2015 at 5:52 PM, Ian
          Buckley <span dir="ltr"><<a moz-do-not-send="true"
              href="mailto:ianb@ionconcepts.com" target="_blank">ianb@ionconcepts.com</a>></span>
          wrote:<br>
          <blockquote class="gmail_quote" style="margin:0 0 0
            .8ex;border-left:1px #ccc solid;padding-left:1ex">
            <div style="word-wrap:break-word">B200 uses AD9364 not
              AD9361…essentially they are identical in  programming and
              performance but with only one radio channel.
              <div>The reason I raise the 30.72MHz limit for running in
                2 channel mode is that these radios only have a single
                LO (each) for RX and TX.</div>
              <div>So if you want to capture 2 narrow band signals
                separated by 45MHz you'll need to run in single channel
                mode regardless of which radio version is on your USRP
                because you'll need to center your LO roughly between
                your 2 signals so they both fall within the complex
                sampling bandwidth.
                <div>
                  <div class="h5"><br>
                    <div><br>
                      <div>
                        <div>On Apr 4, 2015, at 12:32 PM, Derek Murphy
                          <<a moz-do-not-send="true"
                            href="mailto:cyrus104@gmail.com"
                            target="_blank">cyrus104@gmail.com</a>>
                          wrote:</div>
                        <br>
                        <blockquote type="cite">
                          <p dir="ltr">Thanks, that's great information.
                            My millage right now on uhd and verilog is
                            very low. I will start to look into it. </p>
                          <p dir="ltr">I thought that since the ad9361
                            was the same then maybe the firmware could
                            be modified to use both the a:rx2 and
                            a:tx/rx could be used at the same time. The
                            30MHz limit is not a big deal because the
                            signal is super narrow.</p>
                          <div class="gmail_quote">On Apr 4, 2015 3:13
                            PM, "Ian Buckley" <<a
                              moz-do-not-send="true"
                              href="mailto:ianb@ionconcepts.com"
                              target="_blank">ianb@ionconcepts.com</a>>
                            wrote:<br type="attribution">
                            <blockquote class="gmail_quote"
                              style="margin:0 0 0 .8ex;border-left:1px
                              #ccc solid;padding-left:1ex">
                              <div style="word-wrap:break-word">Derek,
                                <div>(You are specifically talking about
                                  B200 right? Not B210?)</div>
                                <div>In theory this can be done, but the
                                  stock FPGA image won't do it. You
                                  would want to use to use the radio in
                                  a 1 RX mode because this would allow
                                  the use of (upto) a 61.44MHz sample
                                  clock between radio and FPGA, rather
                                  than the 30.72MHz max when in a 2 RX
                                  mode. (B200 doesn't have 2 RX mode
                                  anyhow)</div>
                                <div>You would then want to take the
                                  B210 FPGA design, strip out the TX
                                  DUC's and buffer RAM so that it would
                                  fit in the B200's smaller FPGA, and
                                  then make one small alteration so that
                                  both RX DDC's are fed from the same (1
                                  RX) sample bus. (At this point it
                                  would look very like the RX design of
                                  N210 with 2 RX DDC chains.).</div>
                                <div>From there you have a few details
                                  to deal with in UHD (2 DDC's
                                  operational, but AD9364 delivering a
                                  single RX stream). And finally a flow
                                  graph that uses offset LO tuning such
                                  that you position the LO at (for
                                  example) 22.5MHz between your
                                  frequencies of interest and tune the 2
                                  CORDICs to +/- 22.5MHz, then decimate
                                  both RX streams until they are the
                                  right rate to contain your tuned
                                  signals of interest but pass freely
                                  over USB2.0 bandwidth.</div>
                                <div><br>
                                </div>
                                <div>It would be at least a days work
                                  for me to get that working well I
                                  suspect, and I'm very familiar with
                                  the FPGA code. Extrapolate your own
                                  milage accordingly. You should need
                                  very little new code, just a lot of
                                  shuffling of existing code, but you'll
                                  want a decent understanding of the
                                  workings of UHD and some verilog
                                  skills.</div>
                                <div><br>
                                </div>
                                <div>-Ian</div>
                                <div><br>
                                  <div>
                                    <div>On Apr 4, 2015, at 7:49 AM,
                                      Derek Murphy via USRP-users <<a
                                        moz-do-not-send="true"
                                        href="mailto:usrp-users@lists.ettus.com"
                                        target="_blank">usrp-users@lists.ettus.com</a>>
                                      wrote:</div>
                                    <br>
                                    <blockquote type="cite">
                                      <div dir="ltr">
                                        <div
                                          style="font-size:12.8000001907349px">I've
                                          done a lot of google research
                                          and have not found a solution
                                          yet.</div>
                                        <div
                                          style="font-size:12.8000001907349px"><br>
                                        </div>
                                        <div
                                          style="font-size:12.8000001907349px">I
                                          wanted to check and see if
                                          there is any way to use the
                                          B200 in 2 RX mode. I
                                          understand that you would not
                                          be able to TX at that time and
                                          the bandwidth on each RX
                                          channel would be lower than
                                          the full 56MB.</div>
                                        <div
                                          style="font-size:12.8000001907349px"><br>
                                        </div>
                                        <div
                                          style="font-size:12.8000001907349px">The
                                          use case that I am trying to
                                          get working in GnuRadio to
                                          process two signals that are
                                          45Mhz a part which wouldn't be
                                          terrible except the systems
                                          that I must use only have USB
                                          2.0. If I could have the B200
                                          use 2 RX each at low bandwidth
                                          that seems like it would work,
                                          the other option could be to
                                          have the B200 set to receive
                                          the full span of 45Mhz but
                                          filter out the unwanted
                                          regions and send back the much
                                          smaller result.</div>
                                        <div
                                          style="font-size:12.8000001907349px"><br>
                                        </div>
                                        <div
                                          style="font-size:12.8000001907349px">Thanks</div>
                                      </div>
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