I confirmed this behaviour before but never heard any comments. Had not the time to make any investigations. I tried to reproduce this effect last night with svn1644 and could not hear it but it was just a quick test and maybe not representative.
Gerd DJ8AY -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of a.groff Sent: Thursday, October 11, 2007 6:47 PM To: [EMAIL PROTECTED]; flexradio@flex-radio.biz Subject: [Flexradio] Strange Janus effect On Aug 30 I posted to the HPSDR mailing list ------------------------------------------------------------------------- Subject: [hpsdr] Strange Janus effect... ***** High Performance Software Defined Radio Discussion List ***** I am noticing a strange cross-talk ( ?? ) effect with Janus (& OZY ? ) when used with SDR-1000 & PowerSDR (v1.9.1 svn 1354, v1.10.2 ) that I do not notice with the D44 sound card... I notice this effect in the receive audio when I start to decrease the AGC-T ( RF Gain ) control in Power SDR. As the received signal starts to disappear from audibility, it is replaced by very distorted replica at a reduced amplitude. The effect was first observed in SSB modes but is also present it AM mode ( maybe more so. ) Does you one else have this effect or do I have a problem with my Janus/Ozy/system ?? How would I start to isolate the problem? AL, K0VM ------------------------------------------------------------------------- I received a couple of affirmative response and no "don't see it here's". I have uploaded spectrum analyze screen shots of the speaker/head phone audio that further demonstrate the problem.. ( SDR-1000 w/PwrSRD 1.10.3) The first screen shot *http://www.hamsdr.com/dnld.aspx?id=676 *is with the D44 sound ( preamp off, antenna connected to dummy load AGC-T = 120). Note noise floor above 3khz. The second screen shot *http://www.hamsdr.com/dnld.aspx?id=677 *is with the Janus sound card and AGC-T=120. Note elevated noise floor above 3khz. The third screen shot *http://www.hamsdr.com/dnld.aspx?id=678* is Janus with AGC-T=100. Note again noise floor above 3khz compared to AGC-T=120. The fourth screen shot *http://www.hamsdr.com/dnld.aspx?id=679 *is Janus with AGC-T=70. Note noise floor through entire audio range. With the D44 sound card, the noise floor about 3khz is consistently flat with all AGC-T settings. My first guess was that this may be a Ozy/Janus hardware problem but to the best of my knowledge, AGC-T only operated on software, which suggests to me that some kind of cross talk problem in the software specific to Ozy/Janus. I would be happy to isolate this with further testing if someone can suggest what to look for ?? > filesize: 43,021 > Downloads: 0 > *http://www.hamsdr.com/dnld.aspx?id= > filesize: 43,021 > Downloads: 0 > http://www.hamsdr.com/dnld.aspx?id=672* > > filesize: 43,021 > Downloads: 0 > *http://www.hamsdr.com/dnld.aspx?id=672* > > *672* > _______________________________________________ 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/