Re: [Flexradio] DSP windows
Steve Kallal wrote: I've been playing with the Window selection on the DSP setup screen. I really can't tell any on the air difference between them in receive. There are very slight differences in the display. From past searches, I've noticed comments about differences in reception. In laymen's terms, what do these Window settings do? 73, Steve N6VL -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20071129/e5c6adb3/attachment.html ___ 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/ Hi Steve, Try this with the SDR1000 running: 1) Go to SETUP -- TESTS. 2) Select NOISE and INPUTon the SIGNAL GENERATOR. 3) Set DISPLAY MODE to SPECTRUM and AVG. 4) Let it run for a few seconds. 5) Go to STANDBY. 6) Set DISPLAY MODE back to PANADAPTER. 7) Go to SETUP -- DISPLAY and adjust the scale so the noise floor shows. Try this for the various display windowing functions and notice the difference while measuring amplitude and frequency. 73 Tom W0IVJ ___ 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/
Re: [Flexradio] DSP windows
On page 80 of the current FLEX-5000 Owner's Manual, Joe has added an excellent description of the effect Bob described below with graphs showing the shape of different window options. -Tim -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Robert McGwier Sent: Friday, November 30, 2007 12:52 AM To: Steve Kallal Cc: flexradio@flex-radio.biz Subject: Re: [Flexradio] DSP windows Steve Kallal wrote: I've been playing with the Window selection on the DSP setup screen. I really can't tell any on the air difference between them in receive. There are very slight differences in the display. From past searches, I've noticed comments about differences in reception. In laymen's terms, what do these Window settings do? 73, Steve N6VL Change the display windowing so that you minimize adjacent channel leakage in the display. Some will result in more sensitivity to the peaks but will have more leakage to adjacent channels in the display. They have no impact on the receiver. Bob -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair An optimist may see a light where there is none, but why must the pessimist always run to blow it out? Descartes ___ 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/
[Flexradio] DSP windows
I've been playing with the Window selection on the DSP setup screen. I really can't tell any on the air difference between them in receive. There are very slight differences in the display. From past searches, I've noticed comments about differences in reception. In laymen's terms, what do these Window settings do? 73, Steve N6VL -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20071129/e5c6adb3/attachment.html ___ 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/
Re: [Flexradio] DSP windows
Steve, Take a look at svn://206.216.146.154/svn/repos_sdr_windows/PowerSDR/trunk/Documentation/Fle x-5000_Owners_Manual_v1-10-3.pdf. The last section of the manual has an excellent tutorial on the windows. 73, Bob K5KDN -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Steve Kallal Sent: Thursday, November 29, 2007 10:42 AM To: flexradio@flex-radio.biz Subject: [Flexradio] DSP windows I've been playing with the Window selection on the DSP setup screen. I really can't tell any on the air difference between them in receive. There are very slight differences in the display. From past searches, I've noticed comments about differences in reception. In laymen's terms, what do these Window settings do? 73, Steve N6VL -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20 071129/e5c6adb3/attachment.html ___ 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/
Re: [Flexradio] DSP windows
Steve Kallal wrote: I've been playing with the Window selection on the DSP setup screen. I really can't tell any on the air difference between them in receive. There are very slight differences in the display. From past searches, I've noticed comments about differences in reception. In laymen's terms, what do these Window settings do? 73, Steve N6VL Change the display windowing so that you minimize adjacent channel leakage in the display. Some will result in more sensitivity to the peaks but will have more leakage to adjacent channels in the display. They have no impact on the receiver. Bob -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair “An optimist may see a light where there is none, but why must the pessimist always run to blow it out?” Descartes ___ 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] DSP Windows?
Eric and the whole Software Team, Thank you for the great v. 1.8.0. Nothing to complain - and that's something that I usually don't do. Just a question this time: I followed the recommendation of Eric and Bob and let the PowerSDR build the mdb-file instead of transferring my previous one. I noticed that the default DSP window was Hanning instead of Blackman-Harris that I have been using earlier. Wouldn't Blackman-Harris give a better skirt selectivity? What is the other side of the coin? My warmest Season's Greetings, Ahti OH2RZ ___ 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 Homepage: http://www.flex-radio.com
Re: [Flexradio] DSP Windows?
Ahti: I do not know how this changed happened or when. Blackman Harris is now the default (svn 795). Blackman Harris window when used in the FIR design does indeed give the best out of band rejection BUT AT A COST. The Q goes down slightly (shape factor slightly worsens). There is no such thing as free lunch. The transition band from full response (gain 1) to first zero response widens to accommodate much better sidelobe rejection in the final filter design. It is my opinion that the Blackman-Harris filter design is optimal for our needs. 73's Bob N4HY Ahti Aintila wrote: Eric and the whole Software Team, Thank you for the great v. 1.8.0. Nothing to complain - and that's something that I usually don't do. Just a question this time: I followed the recommendation of Eric and Bob and let the PowerSDR build the mdb-file instead of transferring my previous one. I noticed that the default DSP window was Hanning instead of Blackman-Harris that I have been using earlier. Wouldn't Blackman-Harris give a better skirt selectivity? What is the other side of the coin? My warmest Season's Greetings, Ahti OH2RZ -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair If you board the wrong train, it is no use running along the corridor in the other direction. - Dietrich Bonhoffer ___ 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 Homepage: http://www.flex-radio.com
Re: [Flexradio] DSP Windows?
On 23/12/06, Robert McGwier [EMAIL PROTECTED] wrote: final filter design. It is my opinion that the Blackman-Harris filter design is optimal for our needs. Bob, Thank you. I have the same opinion, but wanted to be sure. I will change back to Blackman-Harris. Xmas! Ahti OH2RZ ___ 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 Homepage: http://www.flex-radio.com
