Hi I've used Cool edit for audio mixing. Very nice program. I hadn't realized just how much Adobe had jacked up the price. Lots of features, but not the PSD (Hz normalization) or decimation I'm looking for. Maybe what I need is a program called "HP 3561A Dynamic Signal Analyzer on your Computer". Just pulled one of those out f the shed at work today. That's what got me back to thinking about the home version .... Bob On Feb 18, 2010, at 8:10 PM, Jean-Louis Oneto wrote: > Hello, > A long time ago (1996-2000...), there was a shareware program called CoolEdit (96 then 2k in case you didn't guess) that was really powerful, written by David Johnston. Unfortunately, (it was may be a little too smart ;-} ), Adobe took it over and it become the Audition product, and of course make it a commercial product. > If you're able to grab a copy of the old shareware, the trial version, even limited on the number of filters and/or transforms you can use together, should be worth a try. > Best regards, > Jean-Louis > ----- Original Message ----- From: "Bob Camp" <lists@cq.nu> > To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> > Sent: Friday, February 19, 2010 12:26 AM > Subject: Re: [time-nuts] Sound Card Spectrum Analyzer > > >> Hi >> >> Linrad is one that I have looked at. It was in a SDR adventure, but I've seen it. Lots of very neat RF stuff packed in there. Still missing the part that I'm after. >> >> I guess I need a program written by an audio guy who's never heard of RF ... >> >> Bob >> >> On Feb 18, 2010, at 7:08 PM, Stan, W1LE wrote: >> >>> Linrad should fill the bill. >>> >>> Do a search for the SM5BSZ website >>> >>> At his index page, http://www.sm5bsz.com/update.htm >>> >>> there is some recent work on phase noise. >>> >>> Usable in Linux or windows. Not for the faint of heart, very capable, >>> very experimental, very flexible. Grab your saddle and hang on..... >>> >>> If Spectrum Laboratory does not immediately satisfy the need, contact the author >>> >>> http://freenet-homepage.de/dl4yhf/spectra1.html >>> >>> Stan, W1LE >>> >>> >>> >>> Bob Camp wrote: >>>> Hi >>>> >>>> Assuming I have a decent sound card, and a computer, the next thing I need is software. If I want: >>>> >>>> Required: >>>> >>>> 1) non- commercial 2) 1 Hz normalization >>>> 3) good low frequency processing (decimation ahead of the fft) >>>> 4) low cost >>>> >>>> Much preferred: >>>> >>>> 5) a non-evil OS 6) Rational performance on a non-quad core system >>>> 7) free >>>> 8) rational calibration 9) scope view. >>>> 10) reasonable graphics >>>> 11) active support by the author >>>> >>>> The application is measuring phase noise. That what makes 2 & 3 pop up on the list. >>>> I've looked at a lot of programs and they all seem to be pretty slick. The ones I've looked at so far don't quite hit the mark for phase noise. I'm pretty sure that there are others on the list who have dug into this same issue already. >>>> >>>> Bob >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>>> >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. >

You could also consider whether Gnuradio (http://www.gnuradio.org) could do what you need. It has interfaces to the Linux sound system. John ---- Bob Camp said the following on 02/18/2010 08:10 PM: > Hi > > Ok, A bit more info: > > 1) Quadrature PLL using an RPD-1 DBM and a home brew lock box. > 2) Willingness to accept that I'm measuring a pair of oscillators > 3) Plenty of sources at the appropriate frequencies > 4) First took a shot at this in 1975 (I forget the Fluke app note number ...) been doing it ever since > 5) Appropriate preamp between the RPD and sound card is a work in progress > 6) Sound card is a 192 KHz / 24 bit / ~110 db snr class card > 7) Sound card will get butchered for the application. > 8) Should be able to hit -165 ish floor, -120 ish at 1 Hz > > Except for the 16 bit limitation, Baudline looks like it's got what I need. > > Bob > > > On Feb 18, 2010, at 7:53 PM, John Miles wrote: > >> Unfortunately there's no way to build a sound-card application that can >> measure phase noise in the general case without a lot of additional >> hardware. Baseband PN analysis with an FFT presupposes that you have some >> external means of downconverting the DUT signal to DC with a superior >> reference at the same frequency, tuned with a quadrature PLL. There must be >> a suitable high-pass filter and LNA to block any DC residuals and preamplify >> the remaining part of the noise sideband. >> >> Further, it's often the case that noise close to the carrier is strong >> enough to keep you from being able to use enough gain to see the broadband >> floor, so you actually need more than one high-pass filter ahead of the >> sound card in many cases. These switchable filters were mandatory with the >> old 13-bit signal analyzers like the 3561A, and may still be needed today if >> you want to look down to 1 Hz. If you restrict your offset range to (say) >> 100 Hz to 20 kHz and require a 24-bit sound card, you can probably get away >> without the switchable HPFs. >> >> It'd be helpful to know exactly what sorts of measurements you need to make, >> and on what devices. PN measurement is a *lot* of work, on both the >> software and hardware sides. Much of it goes into developing a suitable >> calibration process. Take a look at the 3048A manuals sometime, realizing >> that the 3048A hardware itself is not very complicated... >> >> -- john, KE5FX >> >>> -----Original Message----- >>> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On >>> Behalf Of Bob Camp >>> Sent: Thursday, February 18, 2010 4:18 PM >>> To: Discussion of precise time and frequency measurement >>> Subject: Re: [time-nuts] Sound Card Spectrum Analyzer >>> >>> >>> Hi >>> >>> Both are very cool programs. Both are full of all sorts of neat >>> features. As far as I can see, neither one has the features I'm after. >>> >>> More or less - I want it to run like a clunky HP audio analyzer >>> rather than a very cool tool for ham radio. >>> >>> Bob >>> >>> On Feb 18, 2010, at 6:33 PM, Don Latham wrote: >>> >>>> You have looked at: >>>> spectran and spectrum lab ? >>>> Don >>>> >>>> Bob Camp >>>>> Hi >>>>> >>>>> Assuming I have a decent sound card, and a computer, the next >>> thing I need >>>>> is software. If I want: >>>>> >>>>> Required: >>>>> >>>>> 1) non- commercial >>>>> 2) 1 Hz normalization >>>>> 3) good low frequency processing (decimation ahead of the fft) >>>>> 4) low cost >>>>> >>>>> Much preferred: >>>>> >>>>> 5) a non-evil OS >>>>> 6) Rational performance on a non-quad core system >>>>> 7) free >>>>> 8) rational calibration >>>>> 9) scope view. >>>>> 10) reasonable graphics >>>>> 11) active support by the author >>>>> >>>>> The application is measuring phase noise. That what makes 2 & >>> 3 pop up on >>>>> the list. >>>>> >>>>> I've looked at a lot of programs and they all seem to be >>> pretty slick. The >>>>> ones I've looked at so far don't quite hit the mark for phase >>> noise. I'm >>>>> pretty sure that there are others on the list who have dug >>> into this same >>>>> issue already. >>>>> >>>>> Bob >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> >>>> >>>> -- >>>> Dr. Don Latham AJ7LL >>>> Six Mile Systems LLP >>>> 17850 Six Mile Road >>>> POB 134 >>>> Huson, MT, 59846 >>>> VOX 406-626-4304 >>>> www.lightningforensics.com >>>> www.sixmilesystems.com >>>> >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

Got it. So you're planning to have a way to supply an offset frequency to generate a beatnote for calibration at some known reduced amplitude, correct? That, and an FFT program that understands how to normalize to 1 Hz BW (and correct the window's noise-equivalent bandwidth) should be all you need. Bonus if the FFT program allows the calibration factor to be added to whatever numbers it draws on the Y-axis. What brand/model sound card are you looking to use? With a white-noise source you might be able to add a calibration step that takes the effect of the input coupling capacitor out of the measurement, so you wouldn't need to modify the card itself. There was an article in QEX a year or so ago on the basic idea. Again, this all assumes you have some control over the software. There may also be some DC-coupled sound cards at that end of the market, too -- I haven't looked lately. -- john, KE5FX > -----Original Message----- > From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On > Behalf Of Bob Camp > Sent: Thursday, February 18, 2010 5:10 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Sound Card Spectrum Analyzer > > > Hi > > Ok, A bit more info: > > 1) Quadrature PLL using an RPD-1 DBM and a home brew lock box. > 2) Willingness to accept that I'm measuring a pair of oscillators > 3) Plenty of sources at the appropriate frequencies > 4) First took a shot at this in 1975 (I forget the Fluke app note > number ...) been doing it ever since > 5) Appropriate preamp between the RPD and sound card is a work in progress > 6) Sound card is a 192 KHz / 24 bit / ~110 db snr class card > 7) Sound card will get butchered for the application. > 8) Should be able to hit -165 ish floor, -120 ish at 1 Hz > > Except for the 16 bit limitation, Baudline looks like it's got > what I need. > > Bob > > > On Feb 18, 2010, at 7:53 PM, John Miles wrote: > > > Unfortunately there's no way to build a sound-card application that can > > measure phase noise in the general case without a lot of additional > > hardware. Baseband PN analysis with an FFT presupposes that > you have some > > external means of downconverting the DUT signal to DC with a superior > > reference at the same frequency, tuned with a quadrature PLL. > There must be > > a suitable high-pass filter and LNA to block any DC residuals > and preamplify > > the remaining part of the noise sideband. > > > > Further, it's often the case that noise close to the carrier is strong > > enough to keep you from being able to use enough gain to see > the broadband > > floor, so you actually need more than one high-pass filter ahead of the > > sound card in many cases. These switchable filters were > mandatory with the > > old 13-bit signal analyzers like the 3561A, and may still be > needed today if > > you want to look down to 1 Hz. If you restrict your offset > range to (say) > > 100 Hz to 20 kHz and require a 24-bit sound card, you can > probably get away > > without the switchable HPFs. > > > > It'd be helpful to know exactly what sorts of measurements you > need to make, > > and on what devices. PN measurement is a *lot* of work, on both the > > software and hardware sides. Much of it goes into developing a suitable > > calibration process. Take a look at the 3048A manuals > sometime, realizing > > that the 3048A hardware itself is not very complicated... > > > > -- john, KE5FX > > > >> -----Original Message----- > >> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On > >> Behalf Of Bob Camp > >> Sent: Thursday, February 18, 2010 4:18 PM > >> To: Discussion of precise time and frequency measurement > >> Subject: Re: [time-nuts] Sound Card Spectrum Analyzer > >> > >> > >> Hi > >> > >> Both are very cool programs. Both are full of all sorts of neat > >> features. As far as I can see, neither one has the features I'm after. > >> > >> More or less - I want it to run like a clunky HP audio analyzer > >> rather than a very cool tool for ham radio. > >> > >> Bob > >> > >> On Feb 18, 2010, at 6:33 PM, Don Latham wrote: > >> > >>> You have looked at: > >>> spectran and spectrum lab ? > >>> Don > >>> > >>> Bob Camp > >>>> Hi > >>>> > >>>> Assuming I have a decent sound card, and a computer, the next > >> thing I need > >>>> is software. If I want: > >>>> > >>>> Required: > >>>> > >>>> 1) non- commercial > >>>> 2) 1 Hz normalization > >>>> 3) good low frequency processing (decimation ahead of the fft) > >>>> 4) low cost > >>>> > >>>> Much preferred: > >>>> > >>>> 5) a non-evil OS > >>>> 6) Rational performance on a non-quad core system > >>>> 7) free > >>>> 8) rational calibration > >>>> 9) scope view. > >>>> 10) reasonable graphics > >>>> 11) active support by the author > >>>> > >>>> The application is measuring phase noise. That what makes 2 & > >> 3 pop up on > >>>> the list. > >>>> > >>>> I've looked at a lot of programs and they all seem to be > >> pretty slick. The > >>>> ones I've looked at so far don't quite hit the mark for phase > >> noise. I'm > >>>> pretty sure that there are others on the list who have dug > >> into this same > >>>> issue already. > >>>> > >>>> Bob > >>>> _______________________________________________ > >>>> time-nuts mailing list -- time-nuts@febo.com > >>>> To unsubscribe, go to > >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >>>> and follow the instructions there. > >>>> > >>> > >>> > >>> -- > >>> Dr. Don Latham AJ7LL > >>> Six Mile Systems LLP > >>> 17850 Six Mile Road > >>> POB 134 > >>> Huson, MT, 59846 > >>> VOX 406-626-4304 > >>> www.lightningforensics.com > >>> www.sixmilesystems.com > >>> > >>> > >>> _______________________________________________ > >>> time-nuts mailing list -- time-nuts@febo.com > >>> To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >> and follow the instructions there. > >> > > > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.

Hi It's certainly got all the blocks you would need to do the processing. Linking it to a decent interface looks like a bit of a chore. I plead "LAZY" when it comes to doing this from scratch. I keep thinking there's got to be something out there that does all this .... Bob On Feb 18, 2010, at 8:27 PM, John Ackermann N8UR wrote: > You could also consider whether Gnuradio (http://www.gnuradio.org) could do what you need. It has interfaces to the Linux sound system. > > John > ---- > > Bob Camp said the following on 02/18/2010 08:10 PM: >> Hi >> Ok, A bit more info: >> 1) Quadrature PLL using an RPD-1 DBM and a home brew lock box. 2) Willingness to accept that I'm measuring a pair of oscillators >> 3) Plenty of sources at the appropriate frequencies >> 4) First took a shot at this in 1975 (I forget the Fluke app note number ...) been doing it ever since >> 5) Appropriate preamp between the RPD and sound card is a work in progress >> 6) Sound card is a 192 KHz / 24 bit / ~110 db snr class card >> 7) Sound card will get butchered for the application. >> 8) Should be able to hit -165 ish floor, -120 ish at 1 Hz >> Except for the 16 bit limitation, Baudline looks like it's got what I need. >> Bob >> On Feb 18, 2010, at 7:53 PM, John Miles wrote: >>> Unfortunately there's no way to build a sound-card application that can >>> measure phase noise in the general case without a lot of additional >>> hardware. Baseband PN analysis with an FFT presupposes that you have some >>> external means of downconverting the DUT signal to DC with a superior >>> reference at the same frequency, tuned with a quadrature PLL. There must be >>> a suitable high-pass filter and LNA to block any DC residuals and preamplify >>> the remaining part of the noise sideband. >>> >>> Further, it's often the case that noise close to the carrier is strong >>> enough to keep you from being able to use enough gain to see the broadband >>> floor, so you actually need more than one high-pass filter ahead of the >>> sound card in many cases. These switchable filters were mandatory with the >>> old 13-bit signal analyzers like the 3561A, and may still be needed today if >>> you want to look down to 1 Hz. If you restrict your offset range to (say) >>> 100 Hz to 20 kHz and require a 24-bit sound card, you can probably get away >>> without the switchable HPFs. >>> >>> It'd be helpful to know exactly what sorts of measurements you need to make, >>> and on what devices. PN measurement is a *lot* of work, on both the >>> software and hardware sides. Much of it goes into developing a suitable >>> calibration process. Take a look at the 3048A manuals sometime, realizing >>> that the 3048A hardware itself is not very complicated... >>> >>> -- john, KE5FX >>> >>>> -----Original Message----- >>>> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On >>>> Behalf Of Bob Camp >>>> Sent: Thursday, February 18, 2010 4:18 PM >>>> To: Discussion of precise time and frequency measurement >>>> Subject: Re: [time-nuts] Sound Card Spectrum Analyzer >>>> >>>> >>>> Hi >>>> >>>> Both are very cool programs. Both are full of all sorts of neat >>>> features. As far as I can see, neither one has the features I'm after. >>>> >>>> More or less - I want it to run like a clunky HP audio analyzer >>>> rather than a very cool tool for ham radio. >>>> >>>> Bob >>>> >>>> On Feb 18, 2010, at 6:33 PM, Don Latham wrote: >>>> >>>>> You have looked at: >>>>> spectran and spectrum lab ? >>>>> Don >>>>> >>>>> Bob Camp >>>>>> Hi >>>>>> >>>>>> Assuming I have a decent sound card, and a computer, the next >>>> thing I need >>>>>> is software. If I want: >>>>>> >>>>>> Required: >>>>>> >>>>>> 1) non- commercial >>>>>> 2) 1 Hz normalization >>>>>> 3) good low frequency processing (decimation ahead of the fft) >>>>>> 4) low cost >>>>>> >>>>>> Much preferred: >>>>>> >>>>>> 5) a non-evil OS >>>>>> 6) Rational performance on a non-quad core system >>>>>> 7) free >>>>>> 8) rational calibration >>>>>> 9) scope view. >>>>>> 10) reasonable graphics >>>>>> 11) active support by the author >>>>>> >>>>>> The application is measuring phase noise. That what makes 2 & >>>> 3 pop up on >>>>>> the list. >>>>>> >>>>>> I've looked at a lot of programs and they all seem to be >>>> pretty slick. The >>>>>> ones I've looked at so far don't quite hit the mark for phase >>>> noise. I'm >>>>>> pretty sure that there are others on the list who have dug >>>> into this same >>>>>> issue already. >>>>>> >>>>>> Bob >>>>>> _______________________________________________ >>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>> To unsubscribe, go to >>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>> and follow the instructions there. >>>>>> >>>>> >>>>> -- >>>>> Dr. Don Latham AJ7LL >>>>> Six Mile Systems LLP >>>>> 17850 Six Mile Road >>>>> POB 134 >>>>> Huson, MT, 59846 >>>>> VOX 406-626-4304 >>>>> www.lightningforensics.com >>>>> www.sixmilesystems.com >>>>> >>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. >

> -----Original Message----- > From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On > Behalf Of Bob Camp > Sent: Thursday, February 18, 2010 5:26 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Sound Card Spectrum Analyzer > > > Hi > > I've used Cool edit for audio mixing. Very nice program. I hadn't > realized just how much Adobe had jacked up the price. Lots of > features, but not the PSD (Hz normalization) or decimation I'm > looking for. > > Maybe what I need is a program called "HP 3561A Dynamic Signal > Analyzer on your Computer". Just pulled one of those out f the > shed at work today. That's what got me back to thinking about the > home version .... If you don't mind using Windows I can certainly throw an FFT into my freeware phase-noise app for you. That's been on my list for awhile, and since you already have the hardware and know-how to test it, it wouldn't be hard to justify moving it up in my queue. -- john, KE5FX

Hi I did a search for *input* DC coupled sound cards and came up empty handed. There are *output* DC coupled cards out there. I have a pile of old Audigy 2's that are ripe for destruction. Essentially they are free at this point in their life. I've also got a E-MU 0202, an Xonar DX, a couple of Presonus firewire boxes running around. As the price goes up, the probability of destructive mods goes down pretty fast. The Xonar is probably the one that will be in the "final product". ----------- The lock box provides an easy way to bump one source off far enough for a beat note calibration. Having a DC coupled "scope" mode would be very nice for doing an accurate calibration. Sine wave approximations are one step to many. --------- You could model the input to the sound card. I'll certainly try that on some of the more expensive boxes. Also going to 1 Hz is not an every day need. Most of these cards should do just fine at 10 Hz with no mods. -------- Still looking for software. Bob On Feb 18, 2010, at 8:31 PM, John Miles wrote: > Got it. So you're planning to have a way to supply an offset frequency to > generate a beatnote for calibration at some known reduced amplitude, > correct? That, and an FFT program that understands how to normalize to 1 Hz > BW (and correct the window's noise-equivalent bandwidth) should be all you > need. Bonus if the FFT program allows the calibration factor to be added to > whatever numbers it draws on the Y-axis. > > What brand/model sound card are you looking to use? With a white-noise > source you might be able to add a calibration step that takes the effect of > the input coupling capacitor out of the measurement, so you wouldn't need to > modify the card itself. There was an article in QEX a year or so ago on the > basic idea. Again, this all assumes you have some control over the > software. > > There may also be some DC-coupled sound cards at that end of the market, > too -- I haven't looked lately. > > -- john, KE5FX > >> -----Original Message----- >> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On >> Behalf Of Bob Camp >> Sent: Thursday, February 18, 2010 5:10 PM >> To: Discussion of precise time and frequency measurement >> Subject: Re: [time-nuts] Sound Card Spectrum Analyzer >> >> >> Hi >> >> Ok, A bit more info: >> >> 1) Quadrature PLL using an RPD-1 DBM and a home brew lock box. >> 2) Willingness to accept that I'm measuring a pair of oscillators >> 3) Plenty of sources at the appropriate frequencies >> 4) First took a shot at this in 1975 (I forget the Fluke app note >> number ...) been doing it ever since >> 5) Appropriate preamp between the RPD and sound card is a work in progress >> 6) Sound card is a 192 KHz / 24 bit / ~110 db snr class card >> 7) Sound card will get butchered for the application. >> 8) Should be able to hit -165 ish floor, -120 ish at 1 Hz >> >> Except for the 16 bit limitation, Baudline looks like it's got >> what I need. >> >> Bob >> >> >> On Feb 18, 2010, at 7:53 PM, John Miles wrote: >> >>> Unfortunately there's no way to build a sound-card application that can >>> measure phase noise in the general case without a lot of additional >>> hardware. Baseband PN analysis with an FFT presupposes that >> you have some >>> external means of downconverting the DUT signal to DC with a superior >>> reference at the same frequency, tuned with a quadrature PLL. >> There must be >>> a suitable high-pass filter and LNA to block any DC residuals >> and preamplify >>> the remaining part of the noise sideband. >>> >>> Further, it's often the case that noise close to the carrier is strong >>> enough to keep you from being able to use enough gain to see >> the broadband >>> floor, so you actually need more than one high-pass filter ahead of the >>> sound card in many cases. These switchable filters were >> mandatory with the >>> old 13-bit signal analyzers like the 3561A, and may still be >> needed today if >>> you want to look down to 1 Hz. If you restrict your offset >> range to (say) >>> 100 Hz to 20 kHz and require a 24-bit sound card, you can >> probably get away >>> without the switchable HPFs. >>> >>> It'd be helpful to know exactly what sorts of measurements you >> need to make, >>> and on what devices. PN measurement is a *lot* of work, on both the >>> software and hardware sides. Much of it goes into developing a suitable >>> calibration process. Take a look at the 3048A manuals >> sometime, realizing >>> that the 3048A hardware itself is not very complicated... >>> >>> -- john, KE5FX >>> >>>> -----Original Message----- >>>> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On >>>> Behalf Of Bob Camp >>>> Sent: Thursday, February 18, 2010 4:18 PM >>>> To: Discussion of precise time and frequency measurement >>>> Subject: Re: [time-nuts] Sound Card Spectrum Analyzer >>>> >>>> >>>> Hi >>>> >>>> Both are very cool programs. Both are full of all sorts of neat >>>> features. As far as I can see, neither one has the features I'm after. >>>> >>>> More or less - I want it to run like a clunky HP audio analyzer >>>> rather than a very cool tool for ham radio. >>>> >>>> Bob >>>> >>>> On Feb 18, 2010, at 6:33 PM, Don Latham wrote: >>>> >>>>> You have looked at: >>>>> spectran and spectrum lab ? >>>>> Don >>>>> >>>>> Bob Camp >>>>>> Hi >>>>>> >>>>>> Assuming I have a decent sound card, and a computer, the next >>>> thing I need >>>>>> is software. If I want: >>>>>> >>>>>> Required: >>>>>> >>>>>> 1) non- commercial >>>>>> 2) 1 Hz normalization >>>>>> 3) good low frequency processing (decimation ahead of the fft) >>>>>> 4) low cost >>>>>> >>>>>> Much preferred: >>>>>> >>>>>> 5) a non-evil OS >>>>>> 6) Rational performance on a non-quad core system >>>>>> 7) free >>>>>> 8) rational calibration >>>>>> 9) scope view. >>>>>> 10) reasonable graphics >>>>>> 11) active support by the author >>>>>> >>>>>> The application is measuring phase noise. That what makes 2 & >>>> 3 pop up on >>>>>> the list. >>>>>> >>>>>> I've looked at a lot of programs and they all seem to be >>>> pretty slick. The >>>>>> ones I've looked at so far don't quite hit the mark for phase >>>> noise. I'm >>>>>> pretty sure that there are others on the list who have dug >>>> into this same >>>>>> issue already. >>>>>> >>>>>> Bob >>>>>> _______________________________________________ >>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>> To unsubscribe, go to >>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>> and follow the instructions there. >>>>>> >>>>> >>>>> >>>>> -- >>>>> Dr. Don Latham AJ7LL >>>>> Six Mile Systems LLP >>>>> 17850 Six Mile Road >>>>> POB 134 >>>>> Huson, MT, 59846 >>>>> VOX 406-626-4304 >>>>> www.lightningforensics.com >>>>> www.sixmilesystems.com >>>>> >>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. >

Hi Hey - that sounds like one I can't pass up. Sign me up !!!! Bob On Feb 18, 2010, at 8:36 PM, John Miles wrote: > > >> -----Original Message----- >> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On >> Behalf Of Bob Camp >> Sent: Thursday, February 18, 2010 5:26 PM >> To: Discussion of precise time and frequency measurement >> Subject: Re: [time-nuts] Sound Card Spectrum Analyzer >> >> >> Hi >> >> I've used Cool edit for audio mixing. Very nice program. I hadn't >> realized just how much Adobe had jacked up the price. Lots of >> features, but not the PSD (Hz normalization) or decimation I'm >> looking for. >> >> Maybe what I need is a program called "HP 3561A Dynamic Signal >> Analyzer on your Computer". Just pulled one of those out f the >> shed at work today. That's what got me back to thinking about the >> home version .... > > If you don't mind using Windows I can certainly throw an FFT into my > freeware phase-noise app for you. That's been on my list for awhile, and > since you already have the hardware and know-how to test it, it wouldn't be > hard to justify moving it up in my queue. > > -- john, KE5FX > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. >

A better calibration technique may be to add a known amount of RF noise (eg from an amplified noise diode or similar) to one of the mixer inputs. This allows calibration without switching the sound card preamp gain to a value different from that used to make measurements. The added RF noise only has to be white over the spectrum analyser bandwidth. This allows the frequency response of the entire measurement setup to be determined. Bruce Bob Camp wrote: > Hi > > I did a search for *input* DC coupled sound cards and came up empty handed. There are *output* DC coupled cards out there. > > I have a pile of old Audigy 2's that are ripe for destruction. Essentially they are free at this point in their life. I've also got a E-MU 0202, an Xonar DX, a couple of Presonus firewire boxes running around. As the price goes up, the probability of destructive mods goes down pretty fast. The Xonar is probably the one that will be in the "final product". > > ----------- > > The lock box provides an easy way to bump one source off far enough for a beat note calibration. Having a DC coupled "scope" mode would be very nice for doing an accurate calibration. Sine wave approximations are one step to many. > > --------- > > You could model the input to the sound card. I'll certainly try that on some of the more expensive boxes. Also going to 1 Hz is not an every day need. Most of these cards should do just fine at 10 Hz with no mods. > > -------- > > Still looking for software. > > Bob > > > On Feb 18, 2010, at 8:31 PM, John Miles wrote: > > >> Got it. So you're planning to have a way to supply an offset frequency to >> generate a beatnote for calibration at some known reduced amplitude, >> correct? That, and an FFT program that understands how to normalize to 1 Hz >> BW (and correct the window's noise-equivalent bandwidth) should be all you >> need. Bonus if the FFT program allows the calibration factor to be added to >> whatever numbers it draws on the Y-axis. >> >> What brand/model sound card are you looking to use? With a white-noise >> source you might be able to add a calibration step that takes the effect of >> the input coupling capacitor out of the measurement, so you wouldn't need to >> modify the card itself. There was an article in QEX a year or so ago on the >> basic idea. Again, this all assumes you have some control over the >> software. >> >> There may also be some DC-coupled sound cards at that end of the market, >> too -- I haven't looked lately. >> >> -- john, KE5FX >> >> >>> -----Original Message----- >>> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On >>> Behalf Of Bob Camp >>> Sent: Thursday, February 18, 2010 5:10 PM >>> To: Discussion of precise time and frequency measurement >>> Subject: Re: [time-nuts] Sound Card Spectrum Analyzer >>> >>> >>> Hi >>> >>> Ok, A bit more info: >>> >>> 1) Quadrature PLL using an RPD-1 DBM and a home brew lock box. >>> 2) Willingness to accept that I'm measuring a pair of oscillators >>> 3) Plenty of sources at the appropriate frequencies >>> 4) First took a shot at this in 1975 (I forget the Fluke app note >>> number ...) been doing it ever since >>> 5) Appropriate preamp between the RPD and sound card is a work in progress >>> 6) Sound card is a 192 KHz / 24 bit / ~110 db snr class card >>> 7) Sound card will get butchered for the application. >>> 8) Should be able to hit -165 ish floor, -120 ish at 1 Hz >>> >>> Except for the 16 bit limitation, Baudline looks like it's got >>> what I need. >>> >>> Bob >>> >>> >>> On Feb 18, 2010, at 7:53 PM, John Miles wrote: >>> >>> >>>> Unfortunately there's no way to build a sound-card application that can >>>> measure phase noise in the general case without a lot of additional >>>> hardware. Baseband PN analysis with an FFT presupposes that >>>> >>> you have some >>> >>>> external means of downconverting the DUT signal to DC with a superior >>>> reference at the same frequency, tuned with a quadrature PLL. >>>> >>> There must be >>> >>>> a suitable high-pass filter and LNA to block any DC residuals >>>> >>> and preamplify >>> >>>> the remaining part of the noise sideband. >>>> >>>> Further, it's often the case that noise close to the carrier is strong >>>> enough to keep you from being able to use enough gain to see >>>> >>> the broadband >>> >>>> floor, so you actually need more than one high-pass filter ahead of the >>>> sound card in many cases. These switchable filters were >>>> >>> mandatory with the >>> >>>> old 13-bit signal analyzers like the 3561A, and may still be >>>> >>> needed today if >>> >>>> you want to look down to 1 Hz. If you restrict your offset >>>> >>> range to (say) >>> >>>> 100 Hz to 20 kHz and require a 24-bit sound card, you can >>>> >>> probably get away >>> >>>> without the switchable HPFs. >>>> >>>> It'd be helpful to know exactly what sorts of measurements you >>>> >>> need to make, >>> >>>> and on what devices. PN measurement is a *lot* of work, on both the >>>> software and hardware sides. Much of it goes into developing a suitable >>>> calibration process. Take a look at the 3048A manuals >>>> >>> sometime, realizing >>> >>>> that the 3048A hardware itself is not very complicated... >>>> >>>> -- john, KE5FX >>>> >>>> >>>>> -----Original Message----- >>>>> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On >>>>> Behalf Of Bob Camp >>>>> Sent: Thursday, February 18, 2010 4:18 PM >>>>> To: Discussion of precise time and frequency measurement >>>>> Subject: Re: [time-nuts] Sound Card Spectrum Analyzer >>>>> >>>>> >>>>> Hi >>>>> >>>>> Both are very cool programs. Both are full of all sorts of neat >>>>> features. As far as I can see, neither one has the features I'm after. >>>>> >>>>> More or less - I want it to run like a clunky HP audio analyzer >>>>> rather than a very cool tool for ham radio. >>>>> >>>>> Bob >>>>> >>>>> On Feb 18, 2010, at 6:33 PM, Don Latham wrote: >>>>> >>>>> >>>>>> You have looked at: >>>>>> spectran and spectrum lab ? >>>>>> Don >>>>>> >>>>>> Bob Camp >>>>>> >>>>>>> Hi >>>>>>> >>>>>>> Assuming I have a decent sound card, and a computer, the next >>>>>>> >>>>> thing I need >>>>> >>>>>>> is software. If I want: >>>>>>> >>>>>>> Required: >>>>>>> >>>>>>> 1) non- commercial >>>>>>> 2) 1 Hz normalization >>>>>>> 3) good low frequency processing (decimation ahead of the fft) >>>>>>> 4) low cost >>>>>>> >>>>>>> Much preferred: >>>>>>> >>>>>>> 5) a non-evil OS >>>>>>> 6) Rational performance on a non-quad core system >>>>>>> 7) free >>>>>>> 8) rational calibration >>>>>>> 9) scope view. >>>>>>> 10) reasonable graphics >>>>>>> 11) active support by the author >>>>>>> >>>>>>> The application is measuring phase noise. That what makes 2& >>>>>>> >>>>> 3 pop up on >>>>> >>>>>>> the list. >>>>>>> >>>>>>> I've looked at a lot of programs and they all seem to be >>>>>>> >>>>> pretty slick. The >>>>> >>>>>>> ones I've looked at so far don't quite hit the mark for phase >>>>>>> >>>>> noise. I'm >>>>> >>>>>>> pretty sure that there are others on the list who have dug >>>>>>> >>>>> into this same >>>>> >>>>>>> issue already. >>>>>>> >>>>>>> Bob >>>>>>> _______________________________________________ >>>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>>> To unsubscribe, go to >>>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>>> and follow the instructions there. >>>>>>> >>>>>>> >>>>>> >>>>>> -- >>>>>> Dr. Don Latham AJ7LL >>>>>> Six Mile Systems LLP >>>>>> 17850 Six Mile Road >>>>>> POB 134 >>>>>> Huson, MT, 59846 >>>>>> VOX 406-626-4304 >>>>>> www.lightningforensics.com >>>>>> www.sixmilesystems.com >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>> To unsubscribe, go to >>>>>> >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> >>>>> and follow the instructions there. >>>>> >>>>> >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to >>>> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> >>> and follow the instructions there. >>> >>> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > >

Fellow time-nuts, Please forgive the tangential and blatantly commercial subject matter. I remember that a few of you expressed interest in my nixie tube wristwatch when I last mentioned it. I have finally gotten it back into production after a too-long hiatus brought on by obsolete parts. http://www.nixiewatch.com/ And no, it doesn't have a rubidium oscillator. But you can adjust the crystal oscillator frequency (test point provided) and obsess over its inadequacies as a precision time source. And the Woz wears one. -- --David Forbes, Tucson, AZ http://www.cathodecorner.com/

Will follow up off-list for now... -- john, KE5FX > -----Original Message----- > From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On > Behalf Of Bob Camp > Sent: Thursday, February 18, 2010 5:44 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Sound Card Spectrum Analyzer > > > Hi > > Hey - that sounds like one I can't pass up. > > Sign me up !!!! > > Bob > > > On Feb 18, 2010, at 8:36 PM, John Miles wrote: > > > > > > >> -----Original Message----- > >> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On > >> Behalf Of Bob Camp > >> Sent: Thursday, February 18, 2010 5:26 PM > >> To: Discussion of precise time and frequency measurement > >> Subject: Re: [time-nuts] Sound Card Spectrum Analyzer > >> > >> > >> Hi > >> > >> I've used Cool edit for audio mixing. Very nice program. I hadn't > >> realized just how much Adobe had jacked up the price. Lots of > >> features, but not the PSD (Hz normalization) or decimation I'm > >> looking for. > >> > >> Maybe what I need is a program called "HP 3561A Dynamic Signal > >> Analyzer on your Computer". Just pulled one of those out f the > >> shed at work today. That's what got me back to thinking about the > >> home version .... > > > > If you don't mind using Windows I can certainly throw an FFT into my > > freeware phase-noise app for you. That's been on my list for > awhile, and > > since you already have the hardware and know-how to test it, it > wouldn't be > > hard to justify moving it up in my queue. > > > > -- john, KE5FX > > > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.