Re: [Flexradio] Diversity Reception for Flex 5000 owners
radio...@frontiernet.net wrote: Bob, how would this work with the SDR-1000 and Flex3000 considering they only have one RX? Are you using the Multi-Rx capability in PowerSDR and them applying the ESPRIT algorithms from the paper you referenced in this email?? 73, Dennis Petrich Amateur Radio Station K0EOO Lakeville Minnesota USA k0...@arrl.net 952-898-1082 Yes, but it will not be to do diversity combing on the same transmitted signal from independent receive paths. It will be do other enhancements that can be made by understanding the ENVIRONMENT AROUND the signal of interest. Also the SDR-1000 and the Flex 3000 are BOTH capable of supporting frequency diversity reception and frequency diversity path transmission BECAUSE of their wider IF paths that sustain large dynamic range as are other SDR offerings in the ham community now. Bob -- (Co)Author: DttSP, Quiktrak, PowerSDR, GnuRadio Member: ARRL, AMSAT, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. "You don't need to see the whole staircase, just take the first step.", MLK. Twitter:rwmcgwier Active: Facebook,Myspace,LinkedIn ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
Bob, how would this work with the SDR-1000 and Flex3000 considering they only have one RX? Are you using the Multi-Rx capability in PowerSDR and them applying the ESPRIT algorithms from the paper you referenced in this email?? 73, Dennis Petrich Amateur Radio Station K0EOO Lakeville Minnesota USA k0...@arrl.net 952-898-1082 - Original Message - From: "Bob McGwier" To: audio...@charter.net Cc: "FLEX USERS" Sent: Tuesday, May 5, 2009 7:39:01 PM GMT -06:00 US/Canada Central Subject: Re: [Flexradio] Diversity Reception for Flex 5000 owners Jim: We can do this right now with a software receiver. We need to make the oscillators coherent in the same way we have done (in software). So this will be usable by SDR-1000 and Flex3000 owners. Good idea. I do not agree that the algorithm you suggest is the correct one but it will be the first one because it is easy. It will be applicable to HF broadcast very quickly. The algorithms based on MUSIC and ESPRIT are better suited, especially to the typical amateur installation where the elements are not identical and not spaced the correct distance apart. http://eprints.eemcs.utwente.nl/15144/01/final_report_Jasper_Vrielink.pdf http://www.springerlink.com/content/y8001q047g520398/ These algorithms allow for much more than two elements and are pretty efficient when only two elements are involved. My work partners and I are running a phased array with SDR design contract with a well known (not Flex) SDR hardware manufacturer and these algorithms will be part of the adaptive phased array work that must be done. Again, open source will benefit all. Happy Cinco de Mayo to all! http://twitpic.com/4mqnv We are about to embark on some SERIOUS adaptive algorithm development with DttSP, Flex, Gnuradio, etc. all involved. All of us will benefit. Jim Barber wrote: > Not being familiar with the architecture or sources, would there be > any value in developing a 2-input, LMS-style noise reduction scheme > using the same antenna for both receivers and a small frequency > offset? (RX2 would be tuned to an unoccupied "noise" frequency as > close as possible to the "active" RX1 operating frequency) > > That technique has been successfully used elsewhere and has the > advantage of adaptively canceling any static or long-term difference > in "phase" between the signals. (primarily group delay in this case?). > The obvious disadvantage is having to choose a suitable noise > frequency on a busy band, assuming one is available. > > Thoughts? > > Thanks, > Jim Barber, N7CXI > -- (Co)Author: DttSP, Quiktrak, PowerSDR, GnuRadio Member: ARRL, AMSAT, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. "You don't need to see the whole staircase, just take the first step.", MLK. Twitter:rwmcgwier Active: Facebook,Myspace,LinkedIn ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/ ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
Back when I was in the Navy we would setup three different types of diversity reception for news broadcasts. Phase (spacing between antennas) diversity, frequency diversity and polarization diversity... Usually one or the other would give us the best SNR. And thats all I remember 73's Dennis Petrich Amateur Radio Station K0EOO Lakeville Minnesota USA k0...@arrl.net 952-898-1082 - Original Message - From: "Lee A Crocker" To: p...@pharman.org, "Bob McGwier" Cc: "Flexradio" Sent: Tuesday, May 5, 2009 8:32:59 PM GMT -06:00 US/Canada Central Subject: Re: [Flexradio] Diversity Reception for Flex 5000 owners My impression is you need more than a single pair of antenna choices. I spent a lot of time trying to seperate WWVH and WWVB from FL using 2 verticals that were endfire to the E/W. I think something like a triangle feeding 2 els against one, or 3 x 2el pairs may be a better topology 73 W9OY From: Phil Harman To: Bob McGwier Cc: Lee A Crocker ; Flexradio Sent: Tuesday, May 5, 2009 9:02:44 PM Subject: Re: [Flexradio] Diversity Reception for Flex 5000 owners > > Frank mentioned one person who had done some phasing experiments. I > would also like to mention Alex Shovkoplyas, VE3NEA who has done a > really neat version. I intend to steal his user interface idea > completely. It makes both mathematical and user sense. > > Bob > I had the good fortune to do some Beta testing of Alex's diversity software. I built a pair of 40m Softrocks and ran then off the same local oscillator. As Bob says, Alex's user interface is just teriffic and I'm pleased that Bob is going down the same UI path. My results of using the system was inconclusive. What I found was that strong local signals could be nulled completely. However, on DX stations it was very difficult to get any form of null or enhancement. When you looked at the direction the signals where coming from on the UI it was quite common to see massive, and rapid, angular changes. This may have been a quirk of the 40m band at night but it will be very interesting to see how others find the effectiveness of diversity reception on 40m. 73's PhilVK6APH ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/ ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
My impression is you need more than a single pair of antenna choices. I spent a lot of time trying to seperate WWVH and WWVB from FL using 2 verticals that were endfire to the E/W. I think something like a triangle feeding 2 els against one, or 3 x 2el pairs may be a better topology 73 W9OY From: Phil Harman To: Bob McGwier Cc: Lee A Crocker ; Flexradio Sent: Tuesday, May 5, 2009 9:02:44 PM Subject: Re: [Flexradio] Diversity Reception for Flex 5000 owners > > Frank mentioned one person who had done some phasing experiments. I > would also like to mention Alex Shovkoplyas, VE3NEA who has done a > really neat version. I intend to steal his user interface idea > completely. It makes both mathematical and user sense. > > Bob > I had the good fortune to do some Beta testing of Alex's diversity software. I built a pair of 40m Softrocks and ran then off the same local oscillator. As Bob says, Alex's user interface is just teriffic and I'm pleased that Bob is going down the same UI path. My results of using the system was inconclusive. What I found was that strong local signals could be nulled completely. However, on DX stations it was very difficult to get any form of null or enhancement. When you looked at the direction the signals where coming from on the UI it was quite common to see massive, and rapid, angular changes. This may have been a quirk of the 40m band at night but it will be very interesting to see how others find the effectiveness of diversity reception on 40m. 73's PhilVK6APH ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
Perhaps what we need is adaptive diversity reception. :) Phil Harman wrote: My results of using the system was inconclusive. What I found was that strong local signals could be nulled completely. However, on DX stations it was very difficult to get any form of null or enhancement. When you looked at the direction the signals where coming from on the UI it was quite common to see massive, and rapid, angular changes. This may have been a quirk of the 40m band at night but it will be very interesting to see how others find the effectiveness of diversity reception on 40m. 73's PhilVK6APH ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
> > Frank mentioned one person who had done some phasing experiments. I > would also like to mention Alex Shovkoplyas, VE3NEA who has done a > really neat version. I intend to steal his user interface idea > completely. It makes both mathematical and user sense. > > Bob > I had the good fortune to do some Beta testing of Alex's diversity software. I built a pair of 40m Softrocks and ran then off the same local oscillator. As Bob says, Alex's user interface is just teriffic and I'm pleased that Bob is going down the same UI path. My results of using the system was inconclusive. What I found was that strong local signals could be nulled completely. However, on DX stations it was very difficult to get any form of null or enhancement. When you looked at the direction the signals where coming from on the UI it was quite common to see massive, and rapid, angular changes. This may have been a quirk of the 40m band at night but it will be very interesting to see how others find the effectiveness of diversity reception on 40m. 73's PhilVK6APH ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
You idea is a good one. Period. That is all you should take away from my remarks. I had not even begun to think of doing coherent processing with the software receivers except to suck off interfering sidebands from other signals in our passband. Thank you. John lovingly calls it the Bob Sucker. DUMB. ;-). Bob Jim Barber wrote: Thanks for the reply, Bob. I have no axe to grind with regard to any particular algorithm, but I did want to make sure what I thought would be the simplest/most common case would be covered; IE one antenna available and the desire for the most effective noise reduction/cancellation. Having done that, I'll retract my nose and let you guys get back to your (excellent) work. Thanks & 73, Jim Barber, N7CXI Bob McGwier wrote: Jim: We can do this right now with a software receiver. We need to make the oscillators coherent in the same way we have done (in software). So this will be usable by SDR-1000 and Flex3000 owners. Good idea. I do not agree that the algorithm you suggest is the correct one but it will be the first one because it is easy. It will be applicable to HF broadcast very quickly. The algorithms based on MUSIC and ESPRIT are better suited, especially to the typical amateur installation where the elements are not identical and not spaced the correct distance apart. http://eprints.eemcs.utwente.nl/15144/01/final_report_Jasper_Vrielink.pdf http://www.springerlink.com/content/y8001q047g520398/ These algorithms allow for much more than two elements and are pretty efficient when only two elements are involved. My work partners and I are running a phased array with SDR design contract with a well known (not Flex) SDR hardware manufacturer and these algorithms will be part of the adaptive phased array work that must be done. Again, open source will benefit all. Happy Cinco de Mayo to all! http://twitpic.com/4mqnv We are about to embark on some SERIOUS adaptive algorithm development with DttSP, Flex, Gnuradio, etc. all involved. All of us will benefit. Jim Barber wrote: Not being familiar with the architecture or sources, would there be any value in developing a 2-input, LMS-style noise reduction scheme using the same antenna for both receivers and a small frequency offset? (RX2 would be tuned to an unoccupied "noise" frequency as close as possible to the "active" RX1 operating frequency) That technique has been successfully used elsewhere and has the advantage of adaptively canceling any static or long-term difference in "phase" between the signals. (primarily group delay in this case?). The obvious disadvantage is having to choose a suitable noise frequency on a busy band, assuming one is available. Thoughts? Thanks, Jim Barber, N7CXI -- (Co)Author: DttSP, Quiktrak, PowerSDR, GnuRadio Member: ARRL, AMSAT, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. "You don't need to see the whole staircase, just take the first step.", MLK. Twitter:rwmcgwier Active: Facebook,Myspace,LinkedIn ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
Thanks for the reply, Bob. I have no axe to grind with regard to any particular algorithm, but I did want to make sure what I thought would be the simplest/most common case would be covered; IE one antenna available and the desire for the most effective noise reduction/cancellation. Having done that, I'll retract my nose and let you guys get back to your (excellent) work. Thanks & 73, Jim Barber, N7CXI Bob McGwier wrote: Jim: We can do this right now with a software receiver. We need to make the oscillators coherent in the same way we have done (in software). So this will be usable by SDR-1000 and Flex3000 owners. Good idea. I do not agree that the algorithm you suggest is the correct one but it will be the first one because it is easy. It will be applicable to HF broadcast very quickly. The algorithms based on MUSIC and ESPRIT are better suited, especially to the typical amateur installation where the elements are not identical and not spaced the correct distance apart. http://eprints.eemcs.utwente.nl/15144/01/final_report_Jasper_Vrielink.pdf http://www.springerlink.com/content/y8001q047g520398/ These algorithms allow for much more than two elements and are pretty efficient when only two elements are involved. My work partners and I are running a phased array with SDR design contract with a well known (not Flex) SDR hardware manufacturer and these algorithms will be part of the adaptive phased array work that must be done. Again, open source will benefit all. Happy Cinco de Mayo to all! http://twitpic.com/4mqnv We are about to embark on some SERIOUS adaptive algorithm development with DttSP, Flex, Gnuradio, etc. all involved. All of us will benefit. Jim Barber wrote: Not being familiar with the architecture or sources, would there be any value in developing a 2-input, LMS-style noise reduction scheme using the same antenna for both receivers and a small frequency offset? (RX2 would be tuned to an unoccupied "noise" frequency as close as possible to the "active" RX1 operating frequency) That technique has been successfully used elsewhere and has the advantage of adaptively canceling any static or long-term difference in "phase" between the signals. (primarily group delay in this case?). The obvious disadvantage is having to choose a suitable noise frequency on a busy band, assuming one is available. Thoughts? Thanks, Jim Barber, N7CXI ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
Jim: We can do this right now with a software receiver. We need to make the oscillators coherent in the same way we have done (in software). So this will be usable by SDR-1000 and Flex3000 owners. Good idea. I do not agree that the algorithm you suggest is the correct one but it will be the first one because it is easy. It will be applicable to HF broadcast very quickly. The algorithms based on MUSIC and ESPRIT are better suited, especially to the typical amateur installation where the elements are not identical and not spaced the correct distance apart. http://eprints.eemcs.utwente.nl/15144/01/final_report_Jasper_Vrielink.pdf http://www.springerlink.com/content/y8001q047g520398/ These algorithms allow for much more than two elements and are pretty efficient when only two elements are involved. My work partners and I are running a phased array with SDR design contract with a well known (not Flex) SDR hardware manufacturer and these algorithms will be part of the adaptive phased array work that must be done. Again, open source will benefit all. Happy Cinco de Mayo to all! http://twitpic.com/4mqnv We are about to embark on some SERIOUS adaptive algorithm development with DttSP, Flex, Gnuradio, etc. all involved. All of us will benefit. Jim Barber wrote: Not being familiar with the architecture or sources, would there be any value in developing a 2-input, LMS-style noise reduction scheme using the same antenna for both receivers and a small frequency offset? (RX2 would be tuned to an unoccupied "noise" frequency as close as possible to the "active" RX1 operating frequency) That technique has been successfully used elsewhere and has the advantage of adaptively canceling any static or long-term difference in "phase" between the signals. (primarily group delay in this case?). The obvious disadvantage is having to choose a suitable noise frequency on a busy band, assuming one is available. Thoughts? Thanks, Jim Barber, N7CXI -- (Co)Author: DttSP, Quiktrak, PowerSDR, GnuRadio Member: ARRL, AMSAT, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. "You don't need to see the whole staircase, just take the first step.", MLK. Twitter:rwmcgwier Active: Facebook,Myspace,LinkedIn ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
I would upgrade to a Flex5000 just to get Diversity Keep up the great work guys. 73, Dennis, k0eoo - Original Message - From: "Bob McGwier" To: "Lee A Crocker" Cc: "Flexradio" Sent: Tuesday, May 05, 2009 6:58 PM Subject: Re: [Flexradio] Diversity Reception for Flex 5000 owners Wow is right. It is hard to understand just how impressive 40F really is. 40G sounds the most impressive but to the trained ear and tools, 40 F is amazing. The Flex 5000 is utterly coherent through the oscillators. It is two different DDS's that are synchronized by a built in system which Gerald made sure was supported. As soon as we made the software oscillators coherent (identical in fact) and then applied a phase and amplitude modification (scalar) to one of them for phasing, we get a phase stable system. I was expecting it to work but I had no idea it would be this impressive. More things like this are to follow. Frank mentioned one person who had done some phasing experiments. I would also like to mention Alex Shovkoplyas, VE3NEA who has done a really neat version. I intend to steal his user interface idea completely. It makes both mathematical and user sense. Bob Lee A Crocker wrote: I made a few more clips. The effect can be spectactular or very subtle. In 40-E I found on static the source is sort of from a quadrant and so the notching is very broad. None the less I could get about 3dB of noise reduction. In 40-F the SWBC is dramatic. The station was very weak. If this had been a CW station it would have been Q5. Finally in 40-G the AM BC station is about 4 miles north of my house and extremely strong. The effect is amazing!! (and the tuning is critical) As to the static canceling question, you have no real need of using the second receiver, just make another watch receiver and use the in-band noise you already have contained in the 192khz base band. I expect this test by Bob is the first step toward that goal. Once that is accomplished it will be the gorilla of "next killer apps!!!" 73 W9OY w9oy-sdr.blogspot.com ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/ -- (Co)Author: DttSP, Quiktrak, PowerSDR, GnuRadio Member: ARRL, AMSAT, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. "You don't need to see the whole staircase, just take the first step.", MLK. Twitter:rwmcgwier Active: Facebook,Myspace,LinkedIn ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/ __ Information from ESET NOD32 Antivirus, version of virus signature database 4054 (20090505) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __ Information from ESET NOD32 Antivirus, version of virus signature database 4054 (20090505) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
Wow is right. It is hard to understand just how impressive 40F really is. 40G sounds the most impressive but to the trained ear and tools, 40 F is amazing. The Flex 5000 is utterly coherent through the oscillators. It is two different DDS's that are synchronized by a built in system which Gerald made sure was supported. As soon as we made the software oscillators coherent (identical in fact) and then applied a phase and amplitude modification (scalar) to one of them for phasing, we get a phase stable system. I was expecting it to work but I had no idea it would be this impressive. More things like this are to follow. Frank mentioned one person who had done some phasing experiments. I would also like to mention Alex Shovkoplyas, VE3NEA who has done a really neat version. I intend to steal his user interface idea completely. It makes both mathematical and user sense. Bob Lee A Crocker wrote: I made a few more clips. The effect can be spectactular or very subtle. In 40-E I found on static the source is sort of from a quadrant and so the notching is very broad. None the less I could get about 3dB of noise reduction. In 40-F the SWBC is dramatic. The station was very weak. If this had been a CW station it would have been Q5. Finally in 40-G the AM BC station is about 4 miles north of my house and extremely strong. The effect is amazing!! (and the tuning is critical) As to the static canceling question, you have no real need of using the second receiver, just make another watch receiver and use the in-band noise you already have contained in the 192khz base band. I expect this test by Bob is the first step toward that goal. Once that is accomplished it will be the gorilla of "next killer apps!!!" 73 W9OY w9oy-sdr.blogspot.com ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/ -- (Co)Author: DttSP, Quiktrak, PowerSDR, GnuRadio Member: ARRL, AMSAT, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. "You don't need to see the whole staircase, just take the first step.", MLK. Twitter:rwmcgwier Active: Facebook,Myspace,LinkedIn ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
Lee A Crocker wrote: I made a few more clips. The effect can be spectactular or very subtle. In 40-E I found on static the source is sort of from a quadrant and so the notching is very broad. None the less I could get about 3dB of noise reduction. In 40-F the SWBC is dramatic. The station was very weak. If this had been a CW station it would have been Q5. Finally in 40-G the AM BC station is about 4 miles north of my house and extremely strong. The effect is amazing!! (and the tuning is critical) As to the static canceling question, you have no real need of using the second receiver, just make another watch receiver and use the in-band noise you already have contained in the 192khz base band. I expect this test by Bob is the first step toward that goal. Once that is accomplished it will be the gorilla of "next killer apps!!!" 73 W9OY w9oy-sdr.blogspot.com ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/ Thanks for all of the work and the feedback from all including Jim Barber, N7CXI . We made the steps in the controls too large. On point sources that are narrowband for real, it will be fairly sensitive control. Now that this technique is included in the code, and after we start doing multirate sampling techniques this week, a pretty thorough cleaning and optimization will need to be done with all of your inputs. A raft of adaptive signal processing things are on Eric's board for both the receiver and the transmitter. Each and everyone of them will be a significant improvement in radio for us and separate these offerings as SDR's from traditional radios even more. This will be crystallized/finalized in DttSP 3 in cgran as Frank makes it fit the overall architecture. Bob -- (Co)Author: DttSP, Quiktrak, PowerSDR, GnuRadio Member: ARRL, AMSAT, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. "You don't need to see the whole staircase, just take the first step.", MLK. Twitter:rwmcgwier Active: Facebook,Myspace,LinkedIn ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
I made a few more clips. The effect can be spectactular or very subtle. In 40-E I found on static the source is sort of from a quadrant and so the notching is very broad. None the less I could get about 3dB of noise reduction. In 40-F the SWBC is dramatic. The station was very weak. If this had been a CW station it would have been Q5. Finally in 40-G the AM BC station is about 4 miles north of my house and extremely strong. The effect is amazing!! (and the tuning is critical) As to the static canceling question, you have no real need of using the second receiver, just make another watch receiver and use the in-band noise you already have contained in the 192khz base band. I expect this test by Bob is the first step toward that goal. Once that is accomplished it will be the gorilla of "next killer apps!!!" 73 W9OY w9oy-sdr.blogspot.com ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
Not being familiar with the architecture or sources, would there be any value in developing a 2-input, LMS-style noise reduction scheme using the same antenna for both receivers and a small frequency offset? (RX2 would be tuned to an unoccupied "noise" frequency as close as possible to the "active" RX1 operating frequency) That technique has been successfully used elsewhere and has the advantage of adaptively canceling any static or long-term difference in "phase" between the signals. (primarily group delay in this case?). The obvious disadvantage is having to choose a suitable noise frequency on a busy band, assuming one is available. Thoughts? Thanks, Jim Barber, N7CXI Bob McGwier wrote: Eric and I have begun adding the diversity reception capability to the Flex 5000. It will work for those 5000's which have the RX2 installed. In my diversity branch, one can find the enabled code. It is VERY rough but as you can tell from Lee's blog: http://w9oy-sdr.blogspot.com/ the software antenna diversity can be used for signal enhancement by increased gain or by noise source nulling. It is rough to use and must be done manually for now. If you start running the code svn co svn://206.216.146.154/svn/repos_sdr_windows/PowerSDR/branches/n4hy/diversity/bin/Release you will be able to type ctrl-alt-D and bring up the form that you can see on Lee's blog. With RX1 and RX2 hooked to separate antennas, you "tune the array" using the right hand side of the DSP form. When you bring it up, and you have set RX1 and RX2 to the same mode and filter size, you click "sync" and then enable. This does several things. It locks the two VFO's together in hardware and then enable does it in software as well. You then play with mag, angle, and gain to optimize the signal you are wishing to listen to. This is pretty rough, but it does work. This will be automated for HF Shortwave folks in SAM-Diversity as soon as possible to do automated signal combining and as we learn from that, we will add additional capabilities. After this is completely vetted and made easier to use, it will be added to the main stream. THANK YOU to Lee for doing this blog entry and adding the mp3's showing the effects. Bob ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
Frank Brickle wrote: FWIW there is an article by Victor K1LT for QEX about work with this same technique, using multiple SoftRocks and Linux DttSP. Victor has been developing his own software for phased combining of multiple antenna inputs for a couple of years now, with considerable success, as related in the article. 73 Frank AB2KT On Mon, May 4, 2009 at 11:28 PM, Bob McGwier wrote: Eric and I have begun adding the diversity reception capability to the Flex 5000... I saw that work written up in QEX. I don't know what he did with Linux DttSP but to do it right several things need synchronization. In the current code implementation I needed to barrier across threads 1) to get the software oscillators to line up and shared across the receivers 2) to do the processing down to just before the agc and finally 3) to have the combined output appear before the threads are released to wait on new samples. I will do what is necessary in my branches and you can then help me do it the way you want it done from there. Bob -- (Co)Author: DttSP, Quiktrak, PowerSDR, GnuRadio Member: ARRL, AMSAT, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. "You don't need to see the whole staircase, just take the first step.", MLK. Twitter:rwmcgwier Active: Facebook,Myspace,LinkedIn ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Diversity Reception for Flex 5000 owners
FWIW there is an article by Victor K1LT for QEX about work with this same technique, using multiple SoftRocks and Linux DttSP. Victor has been developing his own software for phased combining of multiple antenna inputs for a couple of years now, with considerable success, as related in the article. 73 Frank AB2KT On Mon, May 4, 2009 at 11:28 PM, Bob McGwier wrote: > Eric and I have begun adding the diversity reception capability to the Flex > 5000... -- Poets don't seem to have fun anymore. -- Blaise Cendrars ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
