<html>
  <head>
    <meta content="text/html; charset=ISO-8859-1"
      http-equiv="Content-Type">
  </head>
  <body text="#000000" bgcolor="#FFFFFF">
    <div class="moz-cite-prefix">On 09/02/2014 01:57 PM, Kemp, Elizabeth
      - 1008 - MITLL wrote:<br>
    </div>
    <blockquote
cite="mid:E1DF51E69517144FB7619DEA362DBDF002928F@LLE2K10-MBX01.mitll.ad.local"
      type="cite">
      <meta http-equiv="Content-Type" content="text/html;
        charset=ISO-8859-1">
      <meta name="Generator" content="Microsoft Word 12 (filtered
        medium)">
      <style><!--
/* Font Definitions */
@font-face
        {font-family:"Cambria Math";
        panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
        {font-family:Calibri;
        panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
        {font-family:Tahoma;
        panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
        {font-family:Consolas;
        panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
        {margin:0in;
        margin-bottom:.0001pt;
        font-size:12.0pt;
        font-family:"Times New Roman","serif";
        color:black;}
a:link, span.MsoHyperlink
        {mso-style-priority:99;
        color:blue;
        text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
        {mso-style-priority:99;
        color:purple;
        text-decoration:underline;}
pre
        {mso-style-priority:99;
        mso-style-link:"HTML Preformatted Char";
        margin:0in;
        margin-bottom:.0001pt;
        font-size:10.0pt;
        font-family:"Courier New";
        color:black;}
p.MsoAcetate, li.MsoAcetate, div.MsoAcetate
        {mso-style-priority:99;
        mso-style-link:"Balloon Text Char";
        margin:0in;
        margin-bottom:.0001pt;
        font-size:8.0pt;
        font-family:"Tahoma","sans-serif";
        color:black;}
p.MsoNoSpacing, li.MsoNoSpacing, div.MsoNoSpacing
        {mso-style-priority:1;
        margin:0in;
        margin-bottom:.0001pt;
        font-size:12.0pt;
        font-family:"Times New Roman","serif";
        color:black;}
span.HTMLPreformattedChar
        {mso-style-name:"HTML Preformatted Char";
        mso-style-priority:99;
        mso-style-link:"HTML Preformatted";
        font-family:Consolas;
        color:black;}
span.EmailStyle20
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:windowtext;}
span.EmailStyle21
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
span.EmailStyle22
        {mso-style-type:personal;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
span.BalloonTextChar
        {mso-style-name:"Balloon Text Char";
        mso-style-priority:99;
        mso-style-link:"Balloon Text";
        font-family:"Tahoma","sans-serif";
        color:black;}
span.EmailStyle25
        {mso-style-type:personal-reply;
        font-family:"Calibri","sans-serif";
        color:#1F497D;}
.MsoChpDefault
        {mso-style-type:export-only;
        font-size:10.0pt;}
@page WordSection1
        {size:8.5in 11.0in;
        margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
        {page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
      <div class="WordSection1">
        <p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Marcus
            – The two channels are on two different BASIC_RX boards. I
            can try updating to 3.7.2 and see if that changes anything.<o:p></o:p></span></p>
        <p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Ian
            – Thanks, unfortunately I am using a 0 degree splitter (it
            would be nice if that was the fix!). I also picked an
            example where they are almost 180 degrees out of phase, for
            some other frequencies they are actually pretty close. I am
            using a mini circuits ZX10-2-12-S+ splitter – according to
            the datasheet the phase unbalance should only be 0.01
            degrees at 50 MHz.</span></p>
      </div>
    </blockquote>
    Is the phase offset always the same for any given frequency, or does
    it change from run to run?<br>
    <br>
    <br>
    <blockquote
cite="mid:E1DF51E69517144FB7619DEA362DBDF002928F@LLE2K10-MBX01.mitll.ad.local"
      type="cite">
      <div class="WordSection1">
        <p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p></o:p></span></p>
        <p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
        <div>
          <div style="border:none;border-top:solid #B5C4DF
            1.0pt;padding:3.0pt 0in 0in 0in">
            <p class="MsoNormal"><b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">From:</span></b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">
                Ian Buckley [<a class="moz-txt-link-freetext" href="mailto:ianb@ionconcepts.com">mailto:ianb@ionconcepts.com</a>]
                <br>
                <b>Sent:</b> Tuesday, September 02, 2014 1:37 PM<br>
                <b>To:</b> Marcus D. Leech<br>
                <b>Cc:</b> Kemp, Elizabeth - 1008 - MITLL;
                <a class="moz-txt-link-abbreviated" href="mailto:usrp-users@lists.ettus.com">usrp-users@lists.ettus.com</a><br>
                <b>Subject:</b> Re: [USRP-users] X310, 2 channel sample
                time and phase alignment<o:p></o:p></span></p>
          </div>
        </div>
        <p class="MsoNormal"><o:p> </o:p></p>
        <p class="MsoNormal">Thats a giant delay…nothing I can think of
          internal to X310 could account for that. I don't suppose you
          accidentally used a 180 degree splitter instead of a 0 degree?
          I only ask because I ddi the same once and wasted a bunch of
          time…<o:p></o:p></p>
        <div>
          <p class="MsoNormal"><o:p> </o:p></p>
          <div>
            <div>
              <p class="MsoNormal">On Sep 2, 2014, at 10:28 AM, Marcus
                D. Leech via USRP-users <<a moz-do-not-send="true"
                  href="mailto:usrp-users@lists.ettus.com">usrp-users@lists.ettus.com</a>>
                wrote:<o:p></o:p></p>
            </div>
            <p class="MsoNormal"><br>
              <br>
              <o:p></o:p></p>
            <div>
              <div>
                <p class="MsoNormal">On 09/02/2014 01:25 PM, Kemp,
                  Elizabeth - 1008 - MITLL wrote:<o:p></o:p></p>
              </div>
              <blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
                <p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Thank
                    you for the reply Marcus!</span><o:p></o:p></p>
                <p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><o:p></o:p></p>
                <p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I
                    just plotted as a complex pair and it still doesn’t
                    have the proper phase alignment...  I’m using UHD
                    version 3.7.1.</span><o:p></o:p></p>
                <p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><o:p></o:p></p>
              </blockquote>
              <p class="MsoNormal"><span style="color:windowtext">Could
                  you update to 3.7.2?<br>
                  <br>
                  Also, how are you setting up the two channels?  Are
                  they on two different BASIC_RX?<br>
                  <br>
                  <br>
                  <br>
                  <o:p></o:p></span></p>
              <p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">-Liz</span><o:p></o:p></p>
              <p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><o:p></o:p></p>
              <p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><o:p></o:p></p>
              <div>
                <div style="border:none;border-top:solid #B5C4DF
                  1.0pt;padding:3.0pt 0in 0in 0in">
                  <p class="MsoNormal"><b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">From:</span></b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">
                      USRP-users [<a moz-do-not-send="true"
                        href="mailto:usrp-users-bounces@lists.ettus.com">mailto:usrp-users-bounces@lists.ettus.com</a>]
                      <b>On Behalf Of </b>Marcus D. Leech via
                      USRP-users<br>
                      <b>Sent:</b> Tuesday, September 02, 2014 11:49 AM<br>
                      <b>To:</b> <a moz-do-not-send="true"
                        href="mailto:usrp-users@lists.ettus.com">usrp-users@lists.ettus.com</a><br>
                      <b>Subject:</b> Re: [USRP-users] X310, 2 channel
                      sample time and phase alignment</span><o:p></o:p></p>
                </div>
              </div>
              <p class="MsoNormal"> <o:p></o:p></p>
              <div>
                <p class="MsoNormal">On 09/02/2014 11:23 AM, Kemp,
                  Elizabeth - 1008 - MITLL via USRP-users wrote:<o:p></o:p></p>
              </div>
              <blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
                <p class="MsoNoSpacing"><span
                    style="font-family:"Calibri","sans-serif"">Hi,</span><o:p></o:p></p>
                <p class="MsoNoSpacing"><span
                    style="font-family:"Calibri","sans-serif""> </span><o:p></o:p></p>
                <p class="MsoNoSpacing"><span
                    style="font-family:"Calibri","sans-serif"">I
                    have a test set up where I am recording on both
                    channels of an X310.  I have the output of a signal
                    generator connected to the channels through a
                    splitter (and equal length cables).  I am using the
                    BasicRX Daughterboards (1-250 MHz).</span><o:p></o:p></p>
                <p class="MsoNoSpacing"><span
                    style="font-family:"Calibri","sans-serif""> </span><o:p></o:p></p>
                <p class="MsoNoSpacing"><span
                    style="font-family:"Calibri","sans-serif"">I
                    have attached a screenshot from GRC of the WX GUI
                    that shows a plot of the real samples, and the
                    magnitude of the two channels.  As you can see in
                    the magnitude plot, the two channels seem to be
                    time-aligned, but there is a huge phase offset
                    between the two channels.  I’ve observed that the
                    phase offset varies across different frequencies.</span><o:p></o:p></p>
                <p class="MsoNoSpacing"><span
                    style="font-family:"Calibri","sans-serif""> </span><o:p></o:p></p>
                <p class="MsoNoSpacing"><span
                    style="font-family:"Calibri","sans-serif"">So
                    my question is – why is there a phase offset between
                    the 2 channels?  Is there anything that can be done
                    to correct it?</span><o:p></o:p></p>
                <p class="MsoNoSpacing"><span
                    style="font-family:"Calibri","sans-serif""> </span><o:p></o:p></p>
                <p class="MsoNoSpacing"><span
                    style="font-family:"Calibri","sans-serif"">Thanks
                    for your help,</span><o:p></o:p></p>
                <p class="MsoNoSpacing"><span
                    style="font-family:"Calibri","sans-serif"">Liz</span><o:p></o:p></p>
                <p class="MsoNormal"><br>
                  <br>
                  <br>
                  <br>
                  <o:p></o:p></p>
                <pre>_______________________________________________<o:p></o:p></pre>
                <pre>USRP-users mailing list<o:p></o:p></pre>
                <pre><a moz-do-not-send="true" href="mailto:USRP-users@lists.ettus.com">USRP-users@lists.ettus.com</a><o:p></o:p></pre>
                <pre><a moz-do-not-send="true" href="http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com">http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com</a><o:p></o:p></pre>
              </blockquote>
              <p class="MsoNormal" style="margin-bottom:12.0pt">There
                may not be.  In the past, the scope sink has had issues
                with proper phase display.  If you plot it as a complex
                pair instead, it maintains proper phase<br>
                  display.<br>
                <br>
                Also, what version of UHD are you using?<br>
                <br>
                <br>
                <o:p></o:p></p>
              <p class="MsoNormal"><span style="color:windowtext"><o:p> </o:p></span></p>
            </div>
            <p class="MsoNormal"><span style="color:windowtext">_______________________________________________<br>
                USRP-users mailing list<br>
                <a moz-do-not-send="true"
                  href="mailto:USRP-users@lists.ettus.com">USRP-users@lists.ettus.com</a><br>
                <a moz-do-not-send="true"
href="http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com">http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com</a><o:p></o:p></span></p>
          </div>
          <p class="MsoNormal"><span style="color:windowtext"><o:p> </o:p></span></p>
        </div>
      </div>
    </blockquote>
    <br>
  </body>
</html>