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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoPlainText>With Mercury (and PowerSDR) there are a few magic frequencies where the NCO hits the frequency exactly. But, on most frequencies, you will see what looks like a random error of +/- up to 30 milli-Hertz. But it is not a bug. Knowing the exact way that Mercury works, you can calculate a correction to tell you what frequency the radio is actually tuned to. I used these corrections in an FMT a few years ago and did quite well. I had the Mercury LO locked to a GPSDO.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Regards<o:p></o:p></p><p class=MsoPlainText>Ken<o:p></o:p></p><p class=MsoPlainText>KE2N<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>> On 12/9/2012 5:09 AM, Graham / KE9H wrote:<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>>> /PowerSDR itself, as used with Flex radios, and as it was used with <o:p></o:p></p><p class=MsoPlainText>>> Mercury/Ozy, does not contribute to frequency error. It gets a packet <o:p></o:p></p><p class=MsoPlainText>>> of data, and returns a packet of processed data. As long as the <o:p></o:p></p><p class=MsoPlainText>>> packets are sent and received in time with the clock domain in the <o:p></o:p></p><p class=MsoPlainText>>> radio, and you are getting your receive audio through the speaker/headphone jack on the radio, you should not see any errors from PowerSDR.<o:p></o:p></p><p class=MsoPlainText>>> /<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> I suppose that in PowerSDR there is, as in any other SDR program, an <o:p></o:p></p><p class=MsoPlainText>> NCO used to bring to zero IF the frequency of interest. So, at least <o:p></o:p></p><p class=MsoPlainText>> theoretically, an error in the computations of that NCO could cause a <o:p></o:p></p><p class=MsoPlainText>> tuning error.<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> Just a speculation. I don't have PowerSDR and I am not speaking from <o:p></o:p></p><p class=MsoPlainText>> experience on it.<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> --<o:p></o:p></p><p class=MsoPlainText>> /*73 Alberto I2PHD*/<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>Yes, all things are possible when software "bugs" are present.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>:-)<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>--- Graham<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>