Re: [Flexradio] Interesting artifact
I too see this and it whistles as it passes through the selected filter bandwidth. In fact I see this in all my SDRs (4) as I use them for IF radios for VHF+. The artifact shows up on fairly strong on 28 MHz and travels up and down the band in a random fashion. Like Tim indicated, they do not decrease in intensity, but seem to stabilze, but start moving around when using the radio. These are not covered up by band noise for me except when the gain from my trasverters pushes the pan adapter base level up a bit. I have often wondered what they are and if there is anything I can do to get rid of them. I am assuming it is being generated inside the SDR-1000 radio. The hardware versions of my SDRs vary over the last 2+ years, with the latest one about 6 months old. When I got my first SDR those few years back, I really dont remember seeing this, but now it is, might be an oversight however. However I was using the Turtle beach and Soundblaster cards. I now use all Delta 44s, I wonder if that might be a clue? Any more clues to eliminate would be appreciated! 73 Mike - KM0T www.km0t.com - Original Message - From: Ahti Aintila [EMAIL PROTECTED] To: Tim Ellison [EMAIL PROTECTED] Cc: FlexRadio@flex-radio.biz Sent: Thursday, May 11, 2006 10:53 PM Subject: Re: [Flexradio] Interesting artifact Tim, This sounds like interference coming from the 12 V to +/-15 V DC to DC converter (NMA1215S) on the PIO board. I have added some extra filtering, but still sometimes can see and hear it wandering across the panadapter window at a level -155 dBm. Naturally, that low level can be seen only without antenna connected to the SDR-1000. In the normal listening it disappears under the noise coming from the antenna. 73, Ahti OH2RZ On 12/05/06, Tim Ellison [EMAIL PROTECTED] wrote: I observed an interesting phenomenon this evening and I wonder if my assumption is on track. When I started up my SDR1K this evening, I had it connected to a dummy load to do a little audio testing. On the Panadapter, I noticed a signal 500 Hz wide that was about -100dBm in intensity that sounded like a whistle. I could really hear it because the noise floor was about -138dBm. The signal never changed in intensity, but was rapidly increasing in frequency. I checked on another radio and the signal was definitely in the SDR1K. I started tracking it at around 14.190 KHz and followed it up the band. As it crawled up the band, the rate of frequency change decreased, but the intensity never did. I tracked it to all the way to 14.290 KHz where it finally stabilized its frequency change. This whole process took about 20 minutes to complete. At this point I started transmitting and the peak jumped to 14.335 KHz. Once I quit transmitting it started to drop again to stabilize around 14.328 KHz. So it looks like this phenomenon is very likely temperature dependent. Am I correct to assume that this phenomenon is related to DDS thermally instability?? If it is DDS related, shouldn't the intensity of this signal decreased in intensity as it stabilized or should this S5 signal always be here? Should this DDS noise be this strong in intensity? I am just trying to figure out if this is normal operation of do I have some other problem. Any comments and opinions are welcome. -Tim --- Tim Ellison mailto:[EMAIL PROTECTED] ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Interesting artifact
Hi, I don´t have the radio here to measure frequencies, but I think I also saw this phenomenon several times. I usually do SW listening in non ham bands, and with the SDR1000 connected to a signal generator to de tests, I saw some strange signal sweeping the band and going slower as the radio warms up. I suspect the cause is relkated to harmonics from the +/- 12 v voltage converters in the IO board, not DDS spurs. Just a feeling, not properly tested. 73 de Ignacio, EB4APL Tim Ellison escribió wrote: I observed an interesting phenomenon this evening and I wonder if my assumption is on track. When I started up my SDR1K this evening, I had it connected to a dummy load to do a little audio testing. On the Panadapter, I noticed a signal 500 Hz wide that was about -100dBm in intensity that sounded like a whistle. I could really hear it because the noise floor was about -138dBm. The signal never changed in intensity, but was rapidly increasing in frequency. I checked on another radio and the signal was definitely in the SDR1K. I started tracking it at around 14.190 KHz and followed it up the band. As it crawled up the band, the rate of frequency change decreased, but the intensity never did. I tracked it to all the way to 14.290 KHz where it finally stabilized its frequency change. This whole process took about 20 minutes to complete. At this point I started transmitting and the peak jumped to 14.335 KHz. Once I quit transmitting it started to drop again to stabilize around 14.328 KHz. So it looks like this phenomenon is very likely temperature dependent. Am I correct to assume that this phenomenon is related to DDS thermally instability?? If it is DDS related, shouldn't the intensity of this signal decreased in intensity as it stabilized or should this S5 signal always be here? Should this DDS noise be this strong in intensity? I am just trying to figure out if this is normal operation of do I have some other problem. Any comments and opinions are welcome. -Tim --- Tim Ellison mailto:[EMAIL PROTECTED] Integrated Technical Services http://www.itsco.com/ Apex, NC USA 919.674.0044 Ext. 25 / 919.674.0045 (FAX) 919.215.6375 - cell PGP public key available at all public KeyServers Skype: kg4rzy -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20060512/4f963d5f/attachment.html ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Interesting artifact
Tim, After start-up I can see and hear what you describe on longwave between 300 and 400 kHz as well. I observed that said signal increases slowly and steady in frequency and it creates a diagonal line on the waterfall display. An educated guess is that this sig-nal originates from the DC converter chip NMA1215S on the PIO board. Best 73 es gl de SM6OMH Willi - Original Message - From: Tim Ellison [EMAIL PROTECTED] To: FlexRadio@flex-radio.biz Sent: Friday, May 12, 2006 4:16 AM Subject: [Flexradio] Interesting artifact I observed an interesting phenomenon this evening and I wonder if my assumption is on track. When I started up my SDR1K this evening, I had it connected to a dummy load to do a little audio testing. On the Panadapter, I noticed a signal 500 Hz wide that was about -100dBm in intensity that sounded like a whistle. I could really hear it because the noise floor was about -138dBm. The signal never changed in intensity, but was rapidly increasing in frequency. I checked on another radio and the signal was definitely in the SDR1K. I started tracking it at around 14.190 KHz and followed it up the band. As it crawled up the band, the rate of frequency change decreased, but the intensity never did. I tracked it to all the way to 14.290 KHz where it finally stabilized its frequency change. This whole process took about 20 minutes to complete. At this point I started transmitting and the peak jumped to 14.335 KHz. Once I quit transmitting it started to drop again to stabilize around 14.328 KHz. So it looks like this phenomenon is very likely temperature dependent. Am I correct to assume that this phenomenon is related to DDS thermally instability?? If it is DDS related, shouldn't the intensity of this signal decreased in intensity as it stabilized or should this S5 signal always be here? Should this DDS noise be this strong in intensity? I am just trying to figure out if this is normal operation of do I have some other problem. Any comments and opinions are welcome. -Tim --- Tim Ellison mailto:[EMAIL PROTECTED] Integrated Technical Services http://www.itsco.com/ Apex, NC USA 919.674.0044 Ext. 25 / 919.674.0045 (FAX) 919.215.6375 - cell PGP public key available at all public KeyServers Skype: kg4rzy ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ 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://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Interesting artifact
Tim, I've noticed the drifting whistler many times. At first I thought it was external, then I found it was internal. I'll try to follow it next time. Mike - AA8K Tim Ellison wrote: I observed an interesting phenomenon this evening and I wonder if my assumption is on track. When I started up my SDR1K this evening, I had it connected to a dummy load to do a little audio testing. On the Panadapter, I noticed a signal 500 Hz wide that was about -100dBm in intensity that sounded like a whistle. I could really hear it because the noise floor was about -138dBm. The signal never changed in intensity, but was rapidly increasing in frequency. I checked on another radio and the signal was definitely in the SDR1K. ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
[Flexradio] Interesting artifact
I observed an interesting phenomenon this evening and I wonder if my assumption is on track. When I started up my SDR1K this evening, I had it connected to a dummy load to do a little audio testing. On the Panadapter, I noticed a signal 500 Hz wide that was about -100dBm in intensity that sounded like a whistle. I could really hear it because the noise floor was about -138dBm. The signal never changed in intensity, but was rapidly increasing in frequency. I checked on another radio and the signal was definitely in the SDR1K. I started tracking it at around 14.190 KHz and followed it up the band. As it crawled up the band, the rate of frequency change decreased, but the intensity never did. I tracked it to all the way to 14.290 KHz where it finally stabilized its frequency change. This whole process took about 20 minutes to complete. At this point I started transmitting and the peak jumped to 14.335 KHz. Once I quit transmitting it started to drop again to stabilize around 14.328 KHz. So it looks like this phenomenon is very likely temperature dependent. Am I correct to assume that this phenomenon is related to DDS thermally instability?? If it is DDS related, shouldn't the intensity of this signal decreased in intensity as it stabilized or should this S5 signal always be here? Should this DDS noise be this strong in intensity? I am just trying to figure out if this is normal operation of do I have some other problem. Any comments and opinions are welcome. -Tim --- Tim Ellison mailto:[EMAIL PROTECTED] Integrated Technical Services http://www.itsco.com/ Apex, NC USA 919.674.0044 Ext. 25 / 919.674.0045 (FAX) 919.215.6375 - cell PGP public key available at all public KeyServers Skype: kg4rzy ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Interesting artifact
I'm sorry, I believe your SDR-1000 is processed by an evil Mongolian demon. Send it to me for about a year or two and I will exorcise the demons out. Let me know when you need my shipping address. On Thu, 2006-05-11 at 22:16 -0400, Tim Ellison wrote: I observed an interesting phenomenon this evening and I wonder if my assumption is on track. When I started up my SDR1K this evening, I had it connected to a dummy load to do a little audio testing. On the Panadapter, I noticed a signal 500 Hz wide that was about -100dBm in intensity that sounded like a whistle. I could really hear it because the noise floor was about -138dBm. The signal never changed in intensity, but was rapidly increasing in frequency. I checked on another radio and the signal was definitely in the SDR1K. I started tracking it at around 14.190 KHz and followed it up the band. As it crawled up the band, the rate of frequency change decreased, but the intensity never did. I tracked it to all the way to 14.290 KHz where it finally stabilized its frequency change. This whole process took about 20 minutes to complete. At this point I started transmitting and the peak jumped to 14.335 KHz. Once I quit transmitting it started to drop again to stabilize around 14.328 KHz. So it looks like this phenomenon is very likely temperature dependent. Am I correct to assume that this phenomenon is related to DDS thermally instability?? If it is DDS related, shouldn't the intensity of this signal decreased in intensity as it stabilized or should this S5 signal always be here? Should this DDS noise be this strong in intensity? I am just trying to figure out if this is normal operation of do I have some other problem. Any comments and opinions are welcome. -Tim --- Tim Ellison mailto:[EMAIL PROTECTED] Integrated Technical Services http://www.itsco.com/ Apex, NC USA 919.674.0044 Ext. 25 / 919.674.0045 (FAX) 919.215.6375 - cell PGP public key available at all public KeyServers Skype: kg4rzy ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ 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://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Interesting artifact
Tim, This sounds like interference coming from the 12 V to +/-15 V DC to DC converter (NMA1215S) on the PIO board. I have added some extra filtering, but still sometimes can see and hear it wandering across the panadapter window at a level -155 dBm. Naturally, that low level can be seen only without antenna connected to the SDR-1000. In the normal listening it disappears under the noise coming from the antenna. 73, Ahti OH2RZ On 12/05/06, Tim Ellison [EMAIL PROTECTED] wrote: I observed an interesting phenomenon this evening and I wonder if my assumption is on track. When I started up my SDR1K this evening, I had it connected to a dummy load to do a little audio testing. On the Panadapter, I noticed a signal 500 Hz wide that was about -100dBm in intensity that sounded like a whistle. I could really hear it because the noise floor was about -138dBm. The signal never changed in intensity, but was rapidly increasing in frequency. I checked on another radio and the signal was definitely in the SDR1K. I started tracking it at around 14.190 KHz and followed it up the band. As it crawled up the band, the rate of frequency change decreased, but the intensity never did. I tracked it to all the way to 14.290 KHz where it finally stabilized its frequency change. This whole process took about 20 minutes to complete. At this point I started transmitting and the peak jumped to 14.335 KHz. Once I quit transmitting it started to drop again to stabilize around 14.328 KHz. So it looks like this phenomenon is very likely temperature dependent. Am I correct to assume that this phenomenon is related to DDS thermally instability?? If it is DDS related, shouldn't the intensity of this signal decreased in intensity as it stabilized or should this S5 signal always be here? Should this DDS noise be this strong in intensity? I am just trying to figure out if this is normal operation of do I have some other problem. Any comments and opinions are welcome. -Tim --- Tim Ellison mailto:[EMAIL PROTECTED] Integrated Technical Services http://www.itsco.com/ Apex, NC USA 919.674.0044 Ext. 25 / 919.674.0045 (FAX) 919.215.6375 - cell PGP public key available at all public KeyServers Skype: kg4rzy ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ 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://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
