<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12pt">Thanks for the quick response, Phil.<br><span><br>Easy two-line code change to the gnuradio HermesNB software module<br>to flip the I and Q symbols in the output stream.<br><br>Have p</span><span>osted the revised source compatible with Gnuradio 3.7 to the TAPR SVN.<br><br></span><span></span><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif; background-color: transparent; font-style: normal;"><span>http://svn.tapr.org/repos_sdr_hpsdr/trunk/N5EG/GRC3.7/gr-hpsdr</span></div><br><br><span></span>-- Tom, N5EG<div><br></div> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12pt;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial,
Lucida Grande, sans-serif; font-size: 12pt;"> <div dir="ltr"> <hr size="1"> <font size="2" face="Arial"> <b><span style="font-weight:bold;">From:</span></b> Phil Harman <phil@pharman.org><br> <b><span style="font-weight: bold;">To:</span></b> Tom McDermott <tom.mcdermott4@yahoo.com>; hpsdr@lists.openhpsdr.org <br> <b><span style="font-weight: bold;">Sent:</span></b> Thursday, March 13, 2014 4:27 AM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [hpsdr] Hermes transmit baseband frequency reversal ?<br> </font> </div> <div class="y_msg_container"><br><div id="yiv4621105368"><div dir="ltr">
<div dir="ltr">
<div style="FONT-SIZE:12pt;FONT-FAMILY:'Calibri';COLOR:#000000;">
<div>Hi Tom, </div>
<div> </div>
<div>It’s not a bug, its a feature. In order to get the correct sideband
out of the CORDIC used in Penelope many years ago I needed to swap the I&Q
inputs. I guess PowerSDR had them reversed since day one and its been
carried forward ever since. </div>
<div> </div>
<div>Not game to change at this late stage.....</div>
<div> </div>
<div>73 Phil....VK6PH </div>
<div style="FONT-SIZE:small;TEXT-DECORATION:none;">
<div style="FONT:10pt tahoma;">
<div> </div>
<div style="BACKGROUND:#f5f5f5;">
<div style=""><b>From:</b> <a rel="nofollow" shape="rect" title="tom.mcdermott4@yahoo.com" ymailto="mailto:tom.mcdermott4@yahoo.com" target="_blank" href="mailto:tom.mcdermott4@yahoo.com">Tom McDermott</a> </div>
<div><b>Sent:</b> Thursday, March 13, 2014 6:26 PM</div>
<div><b>To:</b> <a rel="nofollow" shape="rect" title="hpsdr@lists.openhpsdr.org" ymailto="mailto:hpsdr@lists.openhpsdr.org" target="_blank" href="mailto:hpsdr@lists.openhpsdr.org">hpsdr@lists.openhpsdr.org</a> </div>
<div><b>Subject:</b> [hpsdr] Hermes transmit baseband frequency reversal
?</div></div></div>
<div> </div></div>
<div style="FONT-SIZE:small;TEXT-DECORATION:none;">*****
High Performance Software Defined Radio Discussion List *****<br clear="none"><br clear="none">
<div>
</div><hr>
<div class="yiv4621105368yqt5755289833" id="yiv4621105368yqt94004"><div style="FONT-SIZE:12pt;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:#000;BACKGROUND-COLOR:#fff;">
<div> </div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;">HI,</div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;"> </div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;">In
playing with some gnuradio sources, I am getting a baseband frequency reversal
going through Hermes.</div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;">This
using the definitions for I and Q in the HPSDR USB protocol document (ver
1.43).<br clear="none"></div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;">That
is - a downward frequency chirping IQ baseband signal into transmit causes an
upward chirping</div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;">IQ
baseband signal at the receive output.</div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;"> </div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;">It
appears that the transmit I & Q side is doing the reversal, while the
receiver seems to be normal, by testing this with an external SSB receiver, and
by using various gnuradio instrumentation.<br clear="none"></div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;"> </div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;">In
looking through my own code that formats I & Q into the transmit frame, I
cannot seem to find any</div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;">deviation
from the protocol specification (rev 1.43). Do I have a bug in my code, or
is there a known </div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;">issue
with Hermes that causes the frequency sign inversion on transmit?</div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;"> </div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;">--
Tom, N5EG</div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;"> </div>
<div style="FONT-SIZE:16px;FONT-FAMILY:helveticaneue, helvetica neue, helvetica, arial, lucida grande, sans-serif;COLOR:rgb(0,0,0);FONT-STYLE:normal;BACKGROUND-COLOR:transparent;"></div></div></div>
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