Hi Gerald, That's my first choice, but I didn't want to be presumptuous. I kinda figured that with SVN# 1819, us CW bigots who never key a mike or transmit a digit might be forced to calibrate our transmit mode.
Perhaps there ought to be a QST to SDR1K CW ops suggesting an transmit IQ Cal if using SVN# 1819 and beyond? Anyway I do have a Spectrum Analyzer so will post some data tomorrow or the next day. Thanks so much for the advice. Keep up the great work! vy 73's Rob AB7CF On Tue, 18 Dec 2007 18:11:54 -0600 "Gerald Youngblood \(FlexRadio Systems\)" <[EMAIL PROTECTED]> writes: > This sounds like you need to go through the transmitter image > rejection > calibration as defined in the SDR1k manual. The I/Q imbalance on > the SDR1k > will cause an image at 2X the CW pitch frequency away from the main > CW tone. > Gerald > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of > [EMAIL PROTECTED] > Sent: Monday, December 17, 2007 11:57 PM > To: [EMAIL PROTECTED] > Cc: flexradio@flex-radio.biz > Subject: Re: [Flexradio] Strange signal report > > > Hi Jim, > > Dave said: > > 1. My main signal sounded absolutely perfect > 2. There was a second "ghost" signal about 1Khz lower. > 3. On the "ghost" signal > a. He could not hear "ghost" dits > b. He could here like a click at the beginning and end of the > "ghost" dashes. > 4. Together the two signals made like a "clucking" noise. He'd > never > heard anything like it. > 5. The phenomena was very consistent > > My first thought was RF feed back through the line from the paddles > to > COM1 but using the keyboard via CWX the same phenomenon was present. > Of > course I could have still been getting feedback on 30 though I don't > on > any other band. My other thoughts are something to do with the > caution > in the notes on SVN 1829 or I haven't done a calibration since > before SVN > 1818 was released and I have now have an IQ imbalance on CW XMIT. > > Didn't have time to do any further on air testing today. But have > a > buddy about 6 miles away. So will try to get some reproducible > results > tomorrow. > > Hope this helps... > > vy 73's > Rob > AB7CF > > > On Mon, 17 Dec 2007 15:59:39 -0800 Jim Lux > <[EMAIL PROTECTED]> > writes: > > At 10:10 AM 12/17/2007, [EMAIL PROTECTED] wrote: > > >Hi all, > > > > > >Have been using Beta V1.10.4 SVN:1829 since it was released with > no > > known > > >problems. Just finished a Q with W0GMO on 30M. (Actually > first > > time > > >ever with the rig on 30.) > > > > > >Dave reports that the rig was actually transmitting two signals > 1 > > at S7 > > >on 10.12481 and 1 at about S1 on approximately 10.12381. > > > > > > So, exactly 100 kHz away and 36 dB down? Or might it be 96 kHz > > away? > > (which would be quite suspicious, since the sampling rate is > > probably > > either 48 or 96 kS/sec) > > > > What's your DDS IF (default is 9kHz.. in DDS box of setup form if > > "expert" is checked) > > > > > > > > What sort of receiver was Dave using? (and does it have a 50 kHz > > IF?) > > > > >He could only > > >hear the second signal as clicks at the beginning and end of the > > dashes. > > >Same was true whether using the paddles or the CWX keyboard. > > > > Hmm.. could it be a slight imbalance between I/Q for higher > (audio) > > > > frequencies? > > > > The sideband suppression can vary across the audio band. For > > instance, if one channel (L or R) had a bit more or less HF > rolloff > > > > (say, because the cable is slightly different, so different > > parasitic > > C) It's less likely across the RF band (the variation in > frequency > > is > > a smaller fraction of the center frequency. > > > > If you want to do some tests.. does it change as you change your > > frequency (in big or little steps)? > > > > Jim, W6RMK > > > > > > > > > > > _______________________________________________ > FlexRadio mailing list > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archive Link: > http://www.mail-archive.com/flexradio%40flex-radio.biz/ > FlexRadio Knowledge Base: http://kb.flex-radio.com/ > FlexRadio Homepage: http://www.flex-radio.com/ > > > > _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
