<div dir="ltr"><div>I see. Thanks for the information. It seems the temp sensor incorporated in the QR210 is also for the 'ambient temperature', similar to your suggestion, right?<br><a href="http://www.ettus.com/kb/detail/qr210-architecture-and-overview" target="_blank">http://www.ettus.com/kb/detail/qr210-architecture-and-overview</a><br><br></div>Khalid<br><div><br><br><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Dec 2, 2014 at 12:43 PM, Marcus D. Leech <span dir="ltr"><<a href="mailto:mleech@ripnet.com" target="_blank">mleech@ripnet.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><u></u>

  
    
  
  <div bgcolor="#ffffff" text="#000000"><span>
    On 12/02/2014 11:02 AM, khalid.el-darymli wrote:
    </span><span><blockquote type="cite">
      <div dir="ltr">
        <div>I am not sure if we are talking about the same thing. Since
          I need to track the internal electronic circuit variation in
          temperature, which pins on the USRP board/daughterboard are
          suitable for extracting information that correlates with the
          temperature variation?<br>
          <br>
        </div>
        <div>Thanks,<br>
        </div>
        Khalid<br>
        <br>
      </div>
    </blockquote></span>
    With the exception of the TVRRX2, there are no internal temperature
    sensors in USRP hardware.  That's why I suggested a separate device,
    placed<br>
      inside the N210 cabinet to be used as a proxy.  There are very few
    electronic components that provide an "internal temperature" output
    as<br>
      a kind of monitoring thing.  Particularly in the analog RF space. 
    Some computer motherboards have this, but it's not an inherent
    property of<br>
      electronics to provide a temperature output as a side effect or
    anything.<div><div><br>
    <br>
    <br>
    <blockquote type="cite">
      <div dir="ltr">
        <div>
          <div>
            <div class="gmail_extra"><br>
              <div class="gmail_quote">On Tue, Dec 2, 2014 at 11:53 AM,
                Marcus D. Leech <span dir="ltr"><<a href="mailto:mleech@ripnet.com" target="_blank">mleech@ripnet.com</a>></span>
                wrote:<br>
                <blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
                  <div bgcolor="#ffffff" text="#000000"><span>
                      On 12/02/2014 10:21 AM, khalid.el-darymli wrote:
                      <blockquote type="cite">
                        <div dir="ltr">
                          <div>
                            <div>Thanks for the prompt reply. I need to
                              monitor the<b> internal temperature </b>(i.e.,
                              not the ambient temperature) of the N200
                              USRP board/ chip/etc., to compensate for
                              the temperature-based variations in the Rx
                              FMCW chirp. <br>
                              <br>
                            </div>
                            How the USB based sensor can do that?<br>
                            <br>
                          </div>
                          Khalid<br>
                          <br>
                        </div>
                      </blockquote>
                    </span> Plenty of room inside the enclosure, you'd
                    have to use some mechanical creativity.
                    <div>
                      <div><br>
                        <br>
                        <br>
                        <blockquote type="cite">
                          <div dir="ltr">
                            <div>
                              <div>
                                <div>
                                  <div>
                                    <div class="gmail_extra"><br>
                                      <div class="gmail_quote">On Tue,
                                        Dec 2, 2014 at 11:41 AM, Marcus
                                        D. Leech <span dir="ltr"><<a href="mailto:mleech@ripnet.com" target="_blank">mleech@ripnet.com</a>></span>
                                        wrote:<br>
                                        <blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
                                          <div bgcolor="#ffffff" text="#000000"><span> On
                                              12/02/2014 10:06 AM,
                                              khalid.el-darymli wrote:
                                              <blockquote type="cite">
                                                <div dir="ltr">
                                                  <div>
                                                    <div>
                                                      <div>Hi Marcus,<br>
                                                        <br>
                                                      </div>
                                                      Is there a
                                                      temperature sensor
                                                      on-board the N200
                                                      unit? If not, does
                                                      it support
                                                      installing any
                                                      such sensor?<br>
                                                      <br>
                                                    </div>
                                                    Thanks.<br>
                                                  </div>
                                                </div>
                                              </blockquote>
                                            </span> No, and no.<br>
                                            <br>
                                            But there are a tonne of
                                            USB-based temperature
                                            sensors out there.  Google
                                            is your friend, etc.
                                            <div>
                                              <div><br>
                                                <br>
                                                <br>
                                                <br>
                                                <blockquote type="cite">
                                                  <div dir="ltr">
                                                    <div><br>
                                                    </div>
                                                    Best regards,<br>
                                                    Khalid<br>
                                                    <br>
                                                    <div>
                                                      <div>
                                                        <div>
                                                          <div>
                                                          <div>
                                                          <div class="gmail_extra"><br>
                                                          <div class="gmail_quote">On

                                                          Fri, Nov 28,
                                                          2014 at 5:44
                                                          PM, Marcus D.
                                                          Leech <span dir="ltr"><<a href="mailto:mleech@ripnet.com" target="_blank">mleech@ripnet.com</a>></span>
                                                          wrote:<br>
                                                          <blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
                                                          <div bgcolor="#ffffff" text="#000000"><span>
                                                          On 11/28/2014
                                                          03:41 PM,
                                                          khalid.el-darymli
                                                          wrote:
                                                          <blockquote type="cite">
                                                          <div dir="ltr"><br>
                                                          <div><span style="color:rgb(0,0,255)"><br>
                                                          </span></div>
                                                          <div><span style="color:rgb(0,0,255)">Back to
                                                          my original
                                                          question, what
                                                          should I do to
                                                          correct for
                                                          this?<br>
                                                          <br>
                                                          </span></div>
                                                          <div><span style="color:rgb(0,0,255)">Thanks
                                                          in advance.<br>
                                                          <br>
                                                          </span></div>
                                                          <div><span style="color:rgb(0,0,255)">Best,<br>
                                                          Khalid</span><br>
                                                          <br>
                                                          </div>
                                                          <div>
                                                          <div>
                                                          <div>
                                                          <div>
                                                          <div><br>
                                                          </div>
                                                          </div>
                                                          </div>
                                                          </div>
                                                          </div>
                                                          </div>
                                                          </blockquote>
                                                          </span>
                                                          Khalid:<br>
                                                          <br>
                                                          Thanks very
                                                          much for the
                                                          very-extensive
                                                          data.  My main
                                                          concern, as
                                                          one of the
                                                          Ettus support
                                                          team, was that
                                                          there was
                                                          something
                                                          wrong with<br>
                                                            the
                                                          hardware, but
                                                          the magnitude
                                                          of both the
                                                          apparent phase
                                                          and magnitude
                                                          drift is
                                                          entirely
                                                          consistent
                                                          with
                                                          analog-hardware
                                                          temperature<br>
                                                            effects,
                                                          unrelated to
                                                          clock
                                                          stability,
                                                          etc.<br>
                                                          <br>
                                                          Coax cables,
                                                          for example,
                                                          will change
                                                          their loss
                                                          characteristics
                                                          and *effective
                                                          length* with
                                                          temperature,
                                                          so with
                                                          precise
                                                          hardware like
                                                          USRPs, it's<br>
                                                            easy to see
                                                          these effects.<br>
                                                          <br>
                                                          FMCW radar
                                                          isn't my area
                                                          of expertise,
                                                          so hopefully
                                                          others can
                                                          comment on
                                                          RX-processing
                                                          strategies to
                                                          deal with
                                                          this, as it
                                                          *must* also be
                                                          a problem<br>
                                                            with non-SDR
                                                          FMCW radar
                                                          implementations.<span><br>
                                                          <br>
                                                          <br>
                                                          <blockquote type="cite">
                                                          <div dir="ltr">
                                                          <div>
                                                          <div>
                                                          <div>
                                                          <div>
                                                          <div><br>
                                                          <br>
                                                          <br>
                                                          </div>
                                                          </div>
                                                          </div>
                                                          </div>
                                                          </div>
                                                          <div class="gmail_extra"><br>
                                                          <div class="gmail_quote">On

                                                          Fri, Nov 28,
                                                          2014 at 12:08
                                                          PM, <span dir="ltr"><<a href="mailto:mleech@ripnet.com" target="_blank">mleech@ripnet.com</a>></span>
                                                          wrote:<br>
                                                          <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
                                                          <div style="font-size:10pt;font-family:Verdana,Geneva,sans-serif">
                                                          <p>What is the
                                                          magnitude of
                                                          the frequency
                                                          drift?</p>
                                                          <p>What is the
                                                          magnitude of
                                                          the gain
                                                          drift?</p>
                                                          <p>What are
                                                          you measuring
                                                          backscatter
                                                          *from*?</p>
                                                          <div>
                                                          <div>
                                                          <p> </p>
                                                          <p> </p>
                                                          <div> </div>
                                                          <p>On
                                                          2014-11-28
                                                          10:14,
                                                          khalid.el-darymli
                                                          via USRP-users
                                                          wrote:</p>
                                                          </div>
                                                          </div>
                                                          <blockquote type="cite" style="padding-left:5px;border-left:2px solid rgb(16,16,255);margin-left:5px">
                                                          <div>
                                                          <div>
                                                          <div dir="ltr">
                                                          <div>
                                                          <div>Hi,<br>
                                                          <br>
                                                          </div>
                                                          Given a set of
                                                          synced <i>(i.e.,

                                                          using external
                                                          GPS REF/PPS)</i>,
                                                          time-commanded
                                                          and calibrated
                                                          <i>(i.e.,
                                                          through
                                                          compensating
                                                          for the
                                                          phase/mag
                                                          offset between
                                                          digital Tx
                                                          chirp prior to
                                                          transmission
                                                          and ADC'ed Rx
                                                          signals) </i>N200


                                                          devices with
                                                          LFTX/LFRX
                                                          daughterboards,
                                                          that work with
                                                          coherent LFMCW
                                                          chirps, I am
                                                          still seeing a
                                                          tiny drift
                                                          (both in the
                                                          magnitude and
                                                          frequency) of
                                                          the
                                                          calibrated 
                                                          back-scatter
                                                          Rx chirp
                                                          received at
                                                          time t1 when
                                                          compared to an
                                                          Rx chirp
                                                          received at an
                                                          earlier time
                                                          t0. <br>
                                                          <br>
                                                          </div>
                                                          <div>The more
                                                          the N200
                                                          device runs
                                                          (e.g., 5
                                                          hours), the
                                                          greater the
                                                          drift is.
                                                          Obviously,
                                                          this drift is
                                                          pertinent to
                                                          both the DAC
                                                          and ADCs and
                                                          the GPS
                                                          referenced
                                                          clocks of the
                                                          N200 devices.</div>
                                                          <div><br>
                                                          My questions
                                                          are:<br>
                                                          <br>
                                                          </div>
                                                          <div>1- Why I
                                                          still see such
                                                          drift although
                                                          my devices are
                                                          synced with an
                                                          external GPS?
                                                          and how do I
                                                          correct for
                                                          it?</div>
                                                          <div><br>
                                                          2- Can the <b>PLL


                                                          Carrier
                                                          Tracking </b>block



                                                          in GRC be used
                                                          to track and
                                                          correct for
                                                          such a drift?
                                                          If so, how do
                                                          I set the
                                                          max/min freq
                                                          inputs for
                                                          this block?<br>
                                                          <br>
                                                          </div>
                                                          <div>3- Can <b>AGC2</b>
                                                          or <b>AGC3 </b>block


                                                          be useful in
                                                          this regard?
                                                          If so, are
                                                          there any
                                                          examples to
                                                          explain how
                                                          the input
                                                          parameters of
                                                          these blocks
                                                          can be set up?<br>
                                                          <br>
                                                          <br>
                                                          </div>
                                                          <div>Thanks.<br>
                                                          <br>
                                                          </div>
                                                          <div>Best
                                                          regards,</div>
                                                          <div>Khalid<br>
                                                          <br>
                                                          </div>
                                                          </div>
                                                          <br>
                                                          </div>
                                                          </div>
                                                          <pre>_______________________________________________
USRP-users mailing list
<a href="mailto:USRP-users@lists.ettus.com" target="_blank">USRP-users@lists.ettus.com</a>
<a href="http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com" rel="noreferrer" target="_blank">http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com</a>
</pre>
                                                          </blockquote>
                                                          </div>
                                                          </blockquote>
                                                          </div>
                                                          <br>
                                                          <div><br>
                                                          <div> </div>
                                                          </div>
                                                          </div>
                                                          </div>
                                                          </blockquote>
                                                          <br>
                                                          <br>
                                                          </span><span><font color="#888888">
                                                          <pre cols="72">-- 
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
<a href="http://www.sbrac.org" target="_blank">http://www.sbrac.org</a>
</pre>
                                                          </font></span></div>
                                                          </blockquote>
                                                          </div>
                                                          <br>
                                                          <div><br>
                                                          <div> </div>
                                                          </div>
                                                          </div>
                                                          </div>
                                                          </div>
                                                        </div>
                                                      </div>
                                                    </div>
                                                  </div>
                                                </blockquote>
                                                <br>
                                                <br>
                                                <pre cols="72">-- 
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
<a href="http://www.sbrac.org" target="_blank">http://www.sbrac.org</a>
</pre>
                                              </div>
                                            </div>
                                          </div>
                                        </blockquote>
                                      </div>
                                      <br>
                                      <br clear="all">
                                      <br>
                                      -- 
                                      <div>
                                        <div> </div>
                                      </div>
                                    </div>
                                  </div>
                                </div>
                              </div>
                            </div>
                          </div>
                        </blockquote>
                        <br>
                        <br>
                        <pre cols="72">-- 
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
<a href="http://www.sbrac.org" target="_blank">http://www.sbrac.org</a>
</pre>
                      </div>
                    </div>
                  </div>
                </blockquote>
              </div>
              <br>
            </div>
          </div>
        </div>
      </div>
    </blockquote>
    <br>
    <br>
    <pre cols="72">-- 
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
<a href="http://www.sbrac.org" target="_blank">http://www.sbrac.org</a>
</pre>
  </div></div></div>

</blockquote></div><br><br clear="all"><br></div></div></div></div></div>