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<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>
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style='FONT-SIZE: small; TEXT-DECORATION: none; FONT-FAMILY: "Calibri"; FONT-WEIGHT: normal; COLOR: #000000; FONT-STYLE: normal; DISPLAY: inline'>
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<DIV> </DIV>
<DIV style="BACKGROUND: #f5f5f5">
<DIV style="font-color: black"><B>From:</B> <A title=tom.mcdermott4@yahoo.com
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 title=hpsdr@lists.openhpsdr.org
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; FONT-FAMILY: "Calibri"; FONT-WEIGHT: normal; COLOR: #000000; FONT-STYLE: normal; DISPLAY: inline'>*****
High Performance Software Defined Radio Discussion List *****<BR><BR>
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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></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></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>
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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>
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