Re: [time-nuts] Re: Accuracy of a sound card
Alberto di Bene wrote: Alberto di Bene wrote: P.S. Let me please test how this reflector behaves when sending HTML messages... I have noticed a strange behavior in the past... it insists on reformatting the HTML message at its will... Here following there should be an image... let's see if it shows up Yes, the original formatting of the message has been completely changed... and the embedded picture has been changed into an attachment... is this done on purpose, or something is broken with the reflector ? 73 Alberto I2PHD Hi Alberto -- The list is set to convert HTML to plain text. That's what Mailman defaults to on setup, but I pretty strongly agree with that approach, so left it as is. Images should come through as attachments as long as they have a safe (non-executable) extension and don't exceed the maximum allowed size (I don't remember for sure, but I think its 100kb). John ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Re: Accuracy of a sound card
In message [EMAIL PROTECTED], John Ackermann N8UR writes: The list is set to convert HTML to plain text. That's what Mailman defaults to on setup, but I pretty strongly agree with that approach, so left it as is. Yes please, no HTML if we can avoid it. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Re: Accuracy of a sound card
Hi Alberto, My point in starting this whole controversy was that there are no adjustments on the sound cards, and the oscillators are just garden variety in quality. Typically, they are simply a miniature crystal that runs an oscillator on an ASIC. The accuracy your card gets is luck-of-the-draw. The temperature stability is only as good as the temperature stability of the insides of your PC, and your room. These boards work just fine in the audio/music arena, but when used as a spectrum analyzer, they have very questionable timing accuracy. No one has yet addressed the actual oscillator that is on board the sound card. What are they using on the Delta 44? ... the Aureon Sky? I would have much more confidence if they would at least use a cheap TCXO module. -Chuck Alberto di Bene wrote: Just for the sake of curiosity and to end this topic, I measured the accuracy of another sound card I have in my PC, a Terratec Aureon Sky. A good card, but not of the same class of the Delta 44. But it was more accurate... 40001.5 Hz which translates into an error of 37.5 +- 2.5 ppm 73 Alberto I2PHD ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Re: Accuracy of a sound card
In message [EMAIL PROTECTED], Chuck Harris writes: No one has yet addressed the actual oscillator that is on board the sound card. What are they using on the Delta 44? ... the Aureon Sky? I would have much more confidence if they would at least use a cheap TCXO module. Using a tcxo for a soundcard is the technical equivalent of using twelve handpolished and individually goldplated railroad tracks for loudspeaker cable: It would look impressive but be pointless. The A/D converters used and the heavyhanded analog anti-alias filtering means, that any sort term frequency change in the order of 1PMM/minute is not measurable or hearable by any current means: the phase difference only shows up as one nanosecond after 44 seconds of audio. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Re: Accuracy of a sound card
Hi Poul, I am quite aware that making a soundcard more accurate is gilding the lilly. But if you return to the middle of this thread, where I offered powerline noise up as a reasonably accurate, ubiquitious timing reference, and had my suggestion refuted by a gentleman with a soundcard based spectrum analyzer, you would understand my point. If you are going to use a soundcard as the basis for a spectrum analyzer, and you are going to let your software readout 5 or 6 significant digits, you are going to have to also realize that the oscillator in the sound card is not very good, and your data is suspicious. In an effort to illustrate this point, TVB made a graph of the characteristics of his high quality sound card, and low and behold, it behaves just like it has an uncompensated crystal oscillator...imagine! There are no adjustments of any kind on these boards, let alone any for frequency. There is no reason to believe that they will be any more accurate than musicality requires. -Chuck Poul-Henning Kamp wrote: In message [EMAIL PROTECTED], Chuck Harris writes: No one has yet addressed the actual oscillator that is on board the sound card. What are they using on the Delta 44? ... the Aureon Sky? I would have much more confidence if they would at least use a cheap TCXO module. Using a tcxo for a soundcard is the technical equivalent of using twelve handpolished and individually goldplated railroad tracks for loudspeaker cable: It would look impressive but be pointless. The A/D converters used and the heavyhanded analog anti-alias filtering means, that any sort term frequency change in the order of 1PMM/minute is not measurable or hearable by any current means: the phase difference only shows up as one nanosecond after 44 seconds of audio. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Re: Accuracy of a sound card
From: Chuck Harris [EMAIL PROTECTED] Subject: Re: [time-nuts] Re: Accuracy of a sound card Date: Tue, 23 Aug 2005 15:43:54 -0400 Message-ID: [EMAIL PROTECTED] Hi Poul, Hi Chuck, I am quite aware that making a soundcard more accurate is gilding the lilly. But if you return to the middle of this thread, where I offered powerline noise up as a reasonably accurate, ubiquitious timing reference, and had my suggestion refuted by a gentleman with a soundcard based spectrum analyzer, you would understand my point. If you are going to use a soundcard as the basis for a spectrum analyzer, and you are going to let your software readout 5 or 6 significant digits, you are going to have to also realize that the oscillator in the sound card is not very good, and your data is suspicious. In an effort to illustrate this point, TVB made a graph of the characteristics of his high quality sound card, and low and behold, it behaves just like it has an uncompensated crystal oscillator...imagine! Like expected, indeed. Frequency accuracy and stability does not magically apear from thin air (but you can get a fair sense of it from space with magicless GPS for instance) in an el-cheapo solution. There are no adjustments of any kind on these boards, let alone any for frequency. There is no reason to believe that they will be any more accurate than musicality requires. If you don't have a sampling clock input of any kind, modding one in should be considered unless a audio-card upgrade is over the horizon. Having it lock to a 10 MHz (or other similar frequency) source of sufficient longterm stability and frequency accuracy should be of interest. Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Re: Accuracy of a sound card
Alberto di Bene wrote: Tom Van Baak wrote: I measured the phase, frequency and Allan deviation of the sound card on my cheap PC. You'll enjoy the results: http://www.leapsecond.com/pages/sound-1pps/ If any of you with a high-end sound card want to repeat the experiment let me know. Unfortunately, while my 5328B has the HPIB interface, my PC doesn't, so I cannot collect data automatically, otherwise it would have been a very interesting experiment... 73 Alberto I2PHD If your PC has an ISA slot, or you have an older PC with an ISA slot, then a GPIB board is not that expensive on eBay. Just save yourself a lot of hassle and get one from National Instruments, as they are better supported than other makes. PCI GPIB cards are current, and so are *much* more expensive. I guess a modern sound card will not fit in an old PC with an ISA slot, but there is nothing to stop you using a modern PC with the high-end sound card, and an old PC with a cheap ISA card for the data collection. There are free drivers for FreeBSD, linux and possibly Windoze, but I am not sure about the latter. -- David Kirkby, G8WRB Please check out http://www.g8wrb.org/ of if you live in Essex http://www.southminster-branch-line.org.uk/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Re: Accuracy of a sound card
From: David Kirkby [EMAIL PROTECTED] Subject: Re: [time-nuts] Re: Accuracy of a sound card Date: Mon, 22 Aug 2005 23:06:49 +0100 Message-ID: [EMAIL PROTECTED] David, Unfortunately, while my 5328B has the HPIB interface, my PC doesn't, so I cannot collect data automatically, otherwise it would have been a very interesting experiment... If you have the money, Tektronix have a nice little Ethernet/IP - GPIB adapter. Stick it between your GPIB chain and LAN, surf into the webserver to configure it and then use the VXI-11 RPC-based interface and access your GPIB chain. Works really well. Can also be configured to work as a printer for at least Tektronix-compatible devices (HP and Tek did things differently because they could). If your PC has an ISA slot, or you have an older PC with an ISA slot, then a GPIB board is not that expensive on eBay. Just save yourself a lot of hassle and get one from National Instruments, as they are better supported than other makes. PCI GPIB cards are current, and so are *much* more expensive. Yes, but I was fortunate enought to get one for reasnoble money. I use the Linux GPIB drivers and my problems is more that I am a bad GPIB-programmer and have yeat to learn all the quirks. (Maybe my HP3457As isn't the best to use as a test-case, better bring up the HP5372A which I have done several projects on succsefully over the years). I guess a modern sound card will not fit in an old PC with an ISA slot, but there is nothing to stop you using a modern PC with the high-end sound card, and an old PC with a cheap ISA card for the data collection. There are free drivers for FreeBSD, linux and possibly Windoze, but I am not sure about the latter. You can download the drivers for Windoze from NI if you need to. They actually have quite good documentation online. Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
RE: [time-nuts] Re: Accuracy of a sound card
National Instruments sells (or at one time, sold) GPIB adapters that will connect to any port on your PC, including USB, parallel, RS-232, the drain in your bathtub, you name it. They are definitely the way to go. There are certain OS limitations; for instance, NT-based versions of Windows including 2K and XP don't support the ISA cards, so you'll have to use Win9x or Me with those if you want to use Windows. Most of the drivers are free at www.ni.com, but not all; I'm not sure, for instance, if the USB drivers are. Make sure you can get the drivers, and that they will work with your OS, before you buy. PCI-GPIB cards aren't really all that pricy -- I see several completed auctions that closed at less than $150. That's about what I paid for mine. -- john, KE5FX -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Alberto di Bene Sent: Monday, August 22, 2005 3:46 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Re: Accuracy of a sound card David Kirkby wrote: ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Re: Accuracy of a sound card
From: Alberto di Bene [EMAIL PROTECTED] Subject: [time-nuts] Re: Accuracy of a sound card Date: Tue, 23 Aug 2005 00:45:59 +0200 Message-ID: [EMAIL PROTECTED] David Kirkby wrote: If your PC has an ISA slot, or you have an older PC with an ISA slot, then a GPIB board is not that expensive on eBay. Just save yourself a lot of hassle and get one from National Instruments, as they are better supported than other makes. I have an ISA GPIB card collecting dust on a shelf... I just don't have a PC with an ISA slot... probably I should find one at a ham swap fest... PCI GPIB cards are current, and so are *much* more expensive. I know :-( I checked the NI prices and for such a card they want a couple hundreds Euros or more... I am wondering... I know of the existence of USB = RS232 adaptors. May be someone sells also USB = GPIB converters ? Nobody knows ? Hmm... I once had a project in which I grab junk from the lab-bench and started designing a GPIB module which sat of the parallel port. It would probably have worked if I was getting the parallel port drivers of the ground, which I wasn't at that time. It was built around a Z80 PIO and a pair of TTLs for clock etc. Another project was to use my FPGA development board, again the parallel port driver stuff ate me up and now the FPGA chip is toast. :P I do have the GPIB code in VHDL at least, and my plan was to use the EPP style of parallel port control, which is *really* handy for DIY hardware/firmware haning of a parallel port. I have the parallel port driver stuff under sufficient control these days, so I could bring back those efforts when my backlog of other projects have ceased to hog my free time, which if no other project comes around would but it 5-10 years away. ;O) If one gets a GPIB chip, hooking it up and fiddle a little with driver should not be eternally difficult these days. Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Re: Accuracy of a sound card
Alberto di Bene wrote: David Kirkby wrote: If your PC has an ISA slot, or you have an older PC with an ISA slot, then a GPIB board is not that expensive on eBay. Just save yourself a lot of hassle and get one from National Instruments, as they are better supported than other makes. I have an ISA GPIB card collecting dust on a shelf... I just don't have a PC with an ISA slot... probably I should find one at a ham swap fest... PCI GPIB cards are current, and so are *much* more expensive. I know :-( I checked the NI prices and for such a card they want a couple hundreds Euros or more... Yes. For Solaris drivers, they want more than the cost of the card!! I think the drivers were 10 UKP more than the card last time I looked. But the cards have gone up quite a bit since then, so perhaps not any more. But I got my Solaris drivers in a copy of Labview for Solaris. I am wondering... I know of the existence of USB = RS232 adaptors. May be someone sells also USB = GPIB converters ? Nobody knows ? You can get a USB based GPIB adapter that is less than a PCI based one. But they are still not cheap. An old PC is probably your best bet. 73 Alberto I2PHD -- David Kirkby, G8WRB Please check out http://www.g8wrb.org/ of if you live in Essex http://www.southminster-branch-line.org.uk/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Re: Accuracy of a sound card
Alberto di Bene wrote: An old PC is probably your best bet. Before I start hunting for an old PC with an ISA slot, does anybody know if Capital Equipment Corporation (the maker of my ISA GPIB card) is still in business ? I am fearing that finding drivers for this card won't be that easy... 73 Alberto I2PHD No idea, but National Instruments ISA cards are selling as little as $9.99, so buying a NI one will not break the bank and will I am sure be a lot less hassle. For some unknown reason, this ISA GPIB card made Waters (who??) http://cgi.ebay.com/WATERS-HPLC-ISA-GPIB-CARD-FULL-SIZE-LAC-E-EC_W0QQitemZ7537580605QQcategoryZ78217QQssPageNameZWDVWQQrdZ1QQcmdZViewItem starting at $179 never got a single bid. I really can't understand why nobody took such a wonderful oppotunity to own a card. -- David Kirkby, G8WRB Please check out http://www.g8wrb.org/ of if you live in Essex http://www.southminster-branch-line.org.uk/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Re: Accuracy of a sound card
I know :-( I checked the NI prices and for such a card they want a couple hundreds Euros or more... I am wondering... I know of the existence of USB = RS232 adaptors. May be someone sells also USB = GPIB converters ? Nobody knows ? 73 Alberto I2PHD Alberto, I do almost all my logging with RS-232. It has the advantage that it's OS-independent; i.e., it requires no device drivers (since almost any OS supports RS-232 out-of-the-box). You can find cheap, surplus RS232-GPIB converters which will work well on a HP 5328A. To get more serial ports on a PC I use 4- or 8-way USB-serial converters. Again these can be found surplus for next to nothing. My favorite are those by Edgeport. /tvb ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
RE: [time-nuts] Re: Accuracy of a sound card
Agilent also now has a USB to GPIB converter. Of course it's several hundred dollars also, and uses the Agilent I/O libraries. Not sure, but I think that it only supports Windoze. I'll check with some of my buddies that survived to see it that's the case. Daun -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Tom Van Baak Sent: Monday, August 22, 2005 10:43 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Re: Accuracy of a sound card I know :-( I checked the NI prices and for such a card they want a couple hundreds Euros or more... I am wondering... I know of the existence of USB = RS232 adaptors. May be someone sells also USB = GPIB converters ? Nobody knows ? 73 Alberto I2PHD Alberto, I do almost all my logging with RS-232. It has the advantage that it's OS-independent; i.e., it requires no device drivers (since almost any OS supports RS-232 out-of-the-box). You can find cheap, surplus RS232-GPIB converters which will work well on a HP 5328A. To get more serial ports on a PC I use 4- or 8-way USB-serial converters. Again these can be found surplus for next to nothing. My favorite are those by Edgeport. /tvb ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
RE: [time-nuts] Re: Accuracy of a sound card
I _strongly_ recommend National Instruments for anything GPIB-related. It is much cheaper on eBay than buying anything new from Agilent, and much better for your sanity than buying anything from an unheard-of GPIB manufacturer. I write a fair amount of homebrew TM software; most of it is available for free with full source code, and it all requires NI488.2 hardware, because that's what I have. (Not to thread-jack, but I just released a nifty new phase-noise utility that duplicates most of the functionality of the HP 85671A package, for instance -- see http://www.speakeasy.org/~jmiles1/ke5fx/pn.htm). I have a lot of respect for NI as a company due to their quality hardware, good documentation, and ongoing free support for older products. -- john, KE5FX -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Daun Yeagley Sent: Monday, August 22, 2005 7:50 PM To: Tom Van Baak; Discussion of precise time and frequency measurement Subject: RE: [time-nuts] Re: Accuracy of a sound card Agilent also now has a USB to GPIB converter. Of course it's several hundred dollars also, and uses the Agilent I/O libraries. Not sure, but I think that it only supports Windoze. I'll check with some of my buddies that survived to see it that's the case. Daun -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Tom Van Baak Sent: Monday, August 22, 2005 10:43 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Re: Accuracy of a sound card I know :-( I checked the NI prices and for such a card they want a couple hundreds Euros or more... I am wondering... I know of the existence of USB = RS232 adaptors. May be someone sells also USB = GPIB converters ? Nobody knows ? 73 Alberto I2PHD Alberto, I do almost all my logging with RS-232. It has the advantage that it's OS-independent; i.e., it requires no device drivers (since almost any OS supports RS-232 out-of-the-box). You can find cheap, surplus RS232-GPIB converters which will work well on a HP 5328A. To get more serial ports on a PC I use 4- or 8-way USB-serial converters. Again these can be found surplus for next to nothing. My favorite are those by Edgeport. /tvb ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
