Re: [time-nuts] Why 9,192,631,770 ??
Le 11/05/2012 07:14, Peter Monta a écrit : Are there better estimates of the ET second nowadays (relative to the SI second)? It would be interesting to know what the cesium frequency should have been if much better estimates of the ephemeris-time second were available at the time. One would think that with all the solar-system data JPL and others have had at their disposal since the 1970s, a very good ET-second number could be cooked up; better than 1950s Moon cameras at any rate. There are various refs in the pedia to later estimates. Markowitz (1988) calculated an agreement to 1x10-10. but looking at the article I see there were still some uncertainty in terms used to calculate ET and depending on what was chosen gave 2x10-11 . Accordingly he concludes conservatively that ET has been equal to Si within 1x10-9. The uncertainties will have been reduced since then but not eliminated and so should have been is a moving target but it would appear from the above that the chosen SI value would still be preferred if the decision was to be reappraised. ___ 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.
Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?
I don't know what firmware version is in the units fluke.l is selling but after reading a technical bulletin regarding the Resolution T, I wonder if the SMT version is susceptible to the same signal tracking outage every 12.5 minutes bug that the Resolution T firmware previous to 1.17 (21/01/2010) suffered as they both use the same receiver architecture. Sam ___ 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.
Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?
OK, I see that indeed there are different views: in my opinion, for example, it is good that the unit doesn't talk by itself. I prefer to prepare the environment then command the unit to start talk or poll the unit on a cyclic base. I found a Trimble monitor here: http://f4ewz.free.fr/gps_trimble/TrimbleMon_V1-06-0.exe not the 1.5 but maybe useful. I haven't tried it. On Fri, May 11, 2012 at 1:23 AM, saidj...@aol.com wrote: There is the problem: I used the Trimble GPS Studio application that was posted here yesterday, that does not support the TEP protocol.. Will try with GPS Monitor.. Is the TrimbleMon available somewhere safe on the web? Can't seem to find it with Google. I got it working with Oncore12, and I am capturing 1PPS raw data already. Already noticed that while the signal strengths look good, there are way less Sats being seen than on the 50 channel receivers, and none of the WAAS ones are being decoded. thanks, Said In a message dated 5/10/2012 14:07:38 Pacific Daylight Time, hol...@hotmail.com writes: The receivers from fluke.l are the TEP version that emulates Motorola protocols by default. I used Trimble GPS Monitor V1.05 to set it for TSIP. Select the Initialize Menu, Detect Receiver, click TEP protocol button. It then found the receiver and offered to enable it for TSIP. Then clicked SAVE CONFIG (so some such). I set it up for 9600,8,N,1 to make it easier to use with Lady Heather (default is 9600,8,Odd,1) using the Recever Configuration menu. ___ 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.
Re: [time-nuts] Clocks for Audio gear
Ashihara's tests were with music/voice, taking into account psychoacoustics, for an average group of music savvy listeners, and even music professionals. As uncorrelated jitter is practically raising the noise floor, most of it was masked by the signal, making it more difficult to detect. Benjamin and Gannon used sinusoidal jitter, which isn't appearing normally in signal chains (badly designed ones excepted). In a real case, with higher probability (added) jitter would be correlated with the digital content transmitted over a path - S/PDIF, and AES/EBU are prone to jitter induced by the signal path characteristics, ISI - PSUs, and even external noise sources. A more realistic simulation would take those into account. OTOH there where tests on pure sine tones, with sine jitter, detectable by trained ears at even lower levels of jitter, which might indicate the lowest threshold of hearing, but using artificial conditions. Who would listen to pure sine tones? On 5/10/2012 8:25 PM, Heinzmann, Stefan (ALC NetworX GmbH) wrote: Chris Albertson wrote: If we are to believe the above paper,then those guys who claim to hear pS jitter are wrong. Note that the jitter spectrum matters for its audibility. Ashihara et.al. used random jitter, and it is not very suprising that the sensitivity for random jitter is lower than for jitter that has specially been shaped to improve detectability by human ears. Thus the results by Ashihara are credible, but they are not the lower limit on jitter audibility. Benjamin and Gannon, the first reference in Ashihara's paper, come to lower figures for sinusoidal jitter with carefully selected frequencies relative to the main signal, which is also sinusoidal. Their results reach down to the single figure nanosecond range, and that can be regarded as the real limit of audibility. Of course, that still leaves those who claim to hear jitter in the picoseconds range out in fairy-tale land. And jitter of just a few nanoseconds is still quite easy to achieve with crystal oscillators. No need for special and expensive parts, then. Normal developer diligence is enough. Cheers Stefan ___ 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.
Re: [time-nuts] Clocks for Audio gear
MailLists wrote: Ashihara's tests were with music/voice, taking into account psychoacoustics, for an average group of music savvy listeners, and even music professionals. As uncorrelated jitter is practically raising the noise floor, most of it was masked by the signal, making it more difficult to detect. Benjamin and Gannon used sinusoidal jitter, which isn't appearing normally in signal chains (badly designed ones excepted). In a real case, with higher probability (added) jitter would be correlated with the digital content transmitted over a path - S/PDIF, and AES/EBU are prone to jitter induced by the signal path characteristics, ISI - PSUs, and even external noise sources. A more realistic simulation would take those into account. OTOH there where tests on pure sine tones, with sine jitter, detectable by trained ears at even lower levels of jitter, which might indicate the lowest threshold of hearing, but using artificial conditions. Who would listen to pure sine tones? Ashihara et.al. wanted to find out what level of jitter was likely to be audible under real-world conditions. Those conditions would likely include music as the main signal, and random jitter. Benjamin/Gannon wanted to find out what levels of jitter could be detected if the conditions were as favorable as possible for detecting jitter. That is not the real-world situation, of course, but it can establish a baseline where you may legitimately say that if you stay below this line with jitter of whatever type, the effects are very unlikely to be audible. And, to add a comment towards Attila, one of the results by Benjamin/Gannon was that training matters a lot, and the best sensitivity was by trained listeners. Your comment is therefore warranted, but already accounted for. Hence, even though their results appear to be very different, they are both valid, because it depends on the exact question asked. I would dare to say, that no matter how you set up your realistic simulation, the results are likely to be somewhere between the values by Benjamin/Gannon and by Ashihara et.al. So, for the purpose of this group, I'd say the psychoacoustic stuff would lead too far, but it might be helpful to know at which jitter levels one can assume to be on the safe side in an audio system, regarding audibility of jitter effects. Judging from the mentioned studies, I concluded (for myself at least), that this boundary is somewhere in the single figure nanoseconds, until someone comes forth with hard evidence that it needs to be set lower. Cheers Stefan ___ 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] Calculating phase jitter from phase noise - appnote by silabs
Moin, I just stumbled over a nice little summary how to calculate the jitter of a signal from its phase noise plot by silicon labs: http://www.silabs.com/Support%20Documents/TechnicalDocs/AN256.pdf Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___ 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.
Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?
Why in the hell would anybody build a 50 channel receiver? At most you MIGHT see 12 usable GPS sats... I don't think that I've seen over 10. WAAS should be fairly useless for a timing receiver. I can think of a couple of reasons. I'm sure there are more. One would be marketing type bragging rights. I can scan more channels than you. Another area would be cold-start time. If you have to search N slots, more searchers runing in parallel is likely to speed things up. -- These are my opinions. I hate spam. ___ 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.
Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?
Zyfer produced a paper on WAAS for timing. http://support.fei-zyfer.com/downloads.aspx You will need to create a log-in and password to download their stuff. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Mark Sims Sent: 11 May 2012 05:02 To: time-nuts@febo.com Subject: [time-nuts] Trimble Resolution SMT - good/bad/indifferent? Why in the hell would anybody build a 50 channel receiver? At most you MIGHT see 12 usable GPS sats... I don't think that I've seen over 10. WAAS should be fairly useless for a timing receiver. Supposedly the Nortel NTGS50AA docs and support info (including GPSMONITOR were uploaded to the KO4BB site). ___ 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.
Re: [time-nuts] Clocks for Audio gear
The brain uses phase at low frequency and amplitude at higher frequencies to find the direction a signal is coming from. It works better for low frequencies than high when you have a steady tone, but high frequency positioning is better when the signal is pulsed. It is almost impossible to locate the source of a continuous high pitch tone in a confined space because of standing waves. My boat has a piezo buzzer to indicate low oil level. It was completely impossible for me to tell if it was located in the engine compartment or under the dash, or anywhere else, even though the cockpit is wide open. It turns out it was in the engine controller, to the right of the driving position. Someone had to tell me. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Dan Kemppainen d...@irtelemetrics.com Sender: time-nuts-boun...@febo.com Date: Thu, 10 May 2012 16:16:44 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Clocks for Audio gear Don't forget the human mind can compensate for a lot of things. Think of how we can triangulate a sound source in realtime even with the included echos in a small room. The only thing that I can think of that messes with that system is a single tone setting up standing waves. It's impressive if you think about it. So, it's probably not much of a stretch to imagine the mind compensating for a little movement here and there (since we have controls and feedback to monitor that). It may just take a few thousand years for us to evolve to deal with distortion due to jitter in our digital recordings :) All fun aside. This has been a worth while thread in my opinion. I'm learning more this week, than others watching this list! On 5/10/2012 1:49 PM, time-nuts-requ...@febo.com wrote: I've alway have thought that if nanosecond level jitter is bad then breathing while listening must be really bad. If you inhale the path length from your ear to the speaker changes at the microsecond level. You'd think the resulting doppler shift would drive these audiophiles nuts. All that pitch shifting. ___ 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] (no subject)
I like Less than $20... Not for Sale Sounds like vaporcrap to me... - Or 216 channels (GPS L1/L2/L2C/L5; GLONASS L1/L2; Galileo E1/E5A): http://www.javad.com/jgnss/products/triumph.html ___ 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] Trimble Resolution SMT - good/bad/indifferent?
I like Less than $20... Not for Sale Sounds like vaporcrap to me... - Or 216 channels (GPS L1/L2/L2C/L5; GLONASS L1/L2; Galileo E1/E5A): http://www.javad.com/jgnss/products/triumph.html ___ 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.
Re: [time-nuts] (no subject)
I like Less than $20... Not for Sale Sounds like vaporcrap to me... - Or 216 channels (GPS L1/L2/L2C/L5; GLONASS L1/L2; Galileo E1/E5A): http://www.javad.com/jgnss/products/triumph.html Have used Delta receivers in production at a former employment. They are very capable receivers. http://www.javad.com/jgnss/products/receivers/delta.html -- Björn ___ 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.
Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?
Wasn't this the company that was championing Lightspeed? :-) Rob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Mark Sims Sent: 11 May 2012 12:20 To: time-nuts@febo.com Subject: [time-nuts] Trimble Resolution SMT - good/bad/indifferent? I like Less than $20... Not for Sale Sounds like vaporcrap to me... - Or 216 channels (GPS L1/L2/L2C/L5; GLONASS L1/L2; Galileo E1/E5A): http://www.javad.com/jgnss/products/triumph.html ___ 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.
Re: [time-nuts] Clocks for Audio gear
Breathing and heart beat are filtered out and corrected for by the brain, otherwise we would have difficulties to hear a lot of things. Interestingly, that works well in our natural environment, but not as well when you are somewhere else. When free diving (when there is no noisy scuba gear and breathing), you can hear your own heartbeat and so can the fish, sometimes at significant distances as it propagates well under water. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Attila Kinali att...@kinali.ch Sender: time-nuts-boun...@febo.com Date: Thu, 10 May 2012 23:25:50 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Clocks for Audio gear On Thu, 10 May 2012 11:36:40 -0700 Hal Murray hmur...@megapathdsl.net wrote: Heartbeats may be more interesting than breathing. Does anybody know of spectrum domain data? It should be possible to collect position info while also monitoring heartbeat and chest diameter and then crunch some numbers do see how much of the position correlates with heartbeat vs breathing and then plot each part in the frequency domain. Please do not forget that there is a quite sofisticated error correction system attached to the hear, which we usually refere to as the brain. Breathing and heart beat are filtered out and corrected for by the brain, otherwise we would have difficulties to hear a lot of things. For more infos, please have a look at perceptual psychology. A not too bad introduction to that field is Sensation and Perception by E. B. Goldstein. But please do not expect mathematical rigor in that field. It's still a subfield of psychology. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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.
Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?
Yes, I moved them yesterday Didier KO4BB --Original Message-- From: Mark Sims Sender: time-nuts-boun...@febo.com To: Time-Nuts ReplyTo: Time-Nuts Subject: [time-nuts] Trimble Resolution SMT - good/bad/indifferent? Sent: May 10, 2012 11:02 PM Why in the hell would anybody build a 50 channel receiver? At most you MIGHT see 12 usable GPS sats... I don't think that I've seen over 10. WAAS should be fairly useless for a timing receiver. Supposedly the Nortel NTGS50AA docs and support info (including GPSMONITOR were uploaded to the KO4BB site). ___ 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. Sent from my BlackBerry Wireless thingy while I do other things... ___ 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.
Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?
And why would one not want to have 0.7m horizontal accuracy while moving at 100s of knots? You probably need a lot better than that when you fly a SAR on a jet like the GlobalHawk. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Said Jackson saidj...@aol.com Sender: time-nuts-boun...@febo.com Date: Thu, 10 May 2012 22:00:19 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Cc: time-nuts@febo.comtime-nuts@febo.com Subject: Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent? Think Galileo, Waas, Glonass, and gps could give you more than 38 sats, over determination will give better results and much faster cold starts without almanac and assist. Waas helps a lot when you run on a Uav chasing bad guys, think timing under motion without position hold mode, so there are four parameters to find every second and waas does improve timing in that scenario. And why would one not want to have 0.7m horizontal accuracy while moving at 100s of knots? Why not offer 50 Sats? Silicon doesn't cost anything anymore. Companies in china pay less than $8 for these parts in large quantity. I think the quality of the results speak for themselves.. CNS verified the ublox timing is almost as good as the M12+ but with everything else vastly improved. Trimble soarly seems lacking so far. We would love to use a US made or at least US designed GPS but alas there are none so far. Waiting to be proved wrong.. Sent From iPhone On May 10, 2012, at 21:02, Mark Sims hol...@hotmail.com wrote: Why in the hell would anybody build a 50 channel receiver? At most you MIGHT see 12 usable GPS sats... I don't think that I've seen over 10. WAAS should be fairly useless for a timing receiver. Supposedly the Nortel NTGS50AA docs and support info (including GPSMONITOR were uploaded to the KO4BB site). ___ 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] hey
you should definitely check this thing out http://www.four15news.net/biz/?read=8780772 ___ 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.
Re: [time-nuts] Clocks for Audio gear
Hi, That jitter value, was that one period jitter? Or was it jitter over a large number of periods, thus close by the carrier? Henk MailLists wrote: Ashihara's tests were with music/voice, taking into account psychoacoustics, for an average group of music savvy listeners, and even music professionals. As uncorrelated jitter is practically raising the noise floor, most of it was masked by the signal, making it more difficult to detect. Benjamin and Gannon used sinusoidal jitter, which isn't appearing normally in signal chains (badly designed ones excepted). In a real case, with higher probability (added) jitter would be correlated with the digital content transmitted over a path - S/PDIF, and AES/EBU are prone to jitter induced by the signal path characteristics, ISI - PSUs, and even external noise sources. A more realistic simulation would take those into account. OTOH there where tests on pure sine tones, with sine jitter, detectable by trained ears at even lower levels of jitter, which might indicate the lowest threshold of hearing, but using artificial conditions. Who would listen to pure sine tones? Ashihara et.al. wanted to find out what level of jitter was likely to be audible under real-world conditions. Those conditions would likely include music as the main signal, and random jitter. Benjamin/Gannon wanted to find out what levels of jitter could be detected if the conditions were as favorable as possible for detecting jitter. That is not the real-world situation, of course, but it can establish a baseline where you may legitimately say that if you stay below this line with jitter of whatever type, the effects are very unlikely to be audible. And, to add a comment towards Attila, one of the results by Benjamin/Gannon was that training matters a lot, and the best sensitivity was by trained listeners. Your comment is therefore warranted, but already accounted for. Hence, even though their results appear to be very different, they are both valid, because it depends on the exact question asked. I would dare to say, that no matter how you set up your realistic simulation, the results are likely to be somewhere between the values by Benjamin/Gannon and by Ashihara et.al. So, for the purpose of this group, I'd say the psychoacoustic stuff would lead too far, but it might be helpful to know at which jitter levels one can assume to be on the safe side in an audio system, regarding audibility of jitter effects. Judging from the mentioned studies, I concluded (for myself at least), that this boundary is somewhere in the single figure nanoseconds, until someone comes forth with hard evidence that it needs to be set lower. Cheers Stefan ___ 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.
Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?
I uploaded the FEI-Zyfer WAAS papers to zippyshare if anyone is interested. http://www32.zippyshare.com/v/66696070/file.html Sam. Zyfer produced a paper on WAAS for timing. http://support.fei-zyfer.com/downloads.aspx You will need to create a log-in and password to download their stuff. Rob Kimberley ___ 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.
Re: [time-nuts] question about Thunderbolt geo acuracy
On 11/05/2012 00:44, b...@lysator.liu.se wrote: Hi Tim, The answer is NO. Even though decent accuracy can be had with long averaging. It was discussed a few years ago on this list. -- Björn Hi all, Hope this isn't too chat roomy, however, I have need of a survey precise geolocation type gps. I was wondering if the precise timing abilities extend to its precision in position output? I have a thunderbolt and one of those conical white aerials from china and would like to know if this combination will give me accurate height data. Thanks Tim ___ 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. Well that's disappointing! I need to measure the height of my house floor to be above the flood plane contour. I might have a look at some dted from work. Might have to pay a real surveyor to measure the height datum. Thanks for all the info though guys Tim ___ 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.
Re: [time-nuts] question about Thunderbolt geo acuracy
Go to your local building and planning commission, and get yourself a copy of the topographical map for your address. They are cheap, and are the standard by which everyone (insurance, zoning, ...) determines your flood plane exposure. -Chuck Harris ... Well that's disappointing! I need to measure the height of my house floor to be above the flood plane contour. I might have a look at some dted from work. Might have to pay a real surveyor to measure the height datum. Thanks for all the info though guys Tim ___ 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.
Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?
On 5/11/12 4:34 AM, shali...@gmail.com wrote: Yes, I moved them yesterday Didier KO4BB --Original Message-- From: Mark Sims Sender: time-nuts-boun...@febo.com To: Time-Nuts ReplyTo: Time-Nuts Subject: [time-nuts] Trimble Resolution SMT - good/bad/indifferent? Sent: May 10, 2012 11:02 PM Why in the hell would anybody build a 50 channel receiver? At most you MIGHT see 12 usable GPS sats... I don't think that I've seen over 10. WAAS should be fairly useless for a timing receiver. Supposedly the Nortel NTGS50AA docs and support info (including GPSMONITOR were uploaded to the KO4BB site). ___ channel in GPS receiver speak is more than a single satellite.. L1 + L2 + L5 would be three channels. Sometimes the P/Y code is considered a separate channel. And when you start adding in other constellations and S/Vs (QZSS, Galileo, GLONASS), you add channels. ANd here's another reason to claim X channels where YX is the most you're likely to use. It gives an indication of processor/FPGA resources consumed, and can be used to estimate margin in a utilization review. For instance, if I've demonstrated acquiring and tracking 100 channels in the lab, and I know I'm never going to see more than, say, 12, in the field, then it is unlikely that there's some obscure timing/processor loading bug that's going to cause a problem. ___ 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.
Re: [time-nuts] Clocks for Audio gear
On 5/11/12 12:48 AM, MailLists wrote: Who would listen to pure sine tones? As a youth, I listened to WWV, which is a pure sine tone, in between the ticks. Drove my parents batty. ___ 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.
Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?
On 5/11/12 2:38 AM, Hal Murray wrote: Why in the hell would anybody build a 50 channel receiver? At most you MIGHT see 12 usable GPS sats... I don't think that I've seen over 10. WAAS should be fairly useless for a timing receiver. I can think of a couple of reasons. I'm sure there are more. One would be marketing type bragging rights. I can scan more channels than you. Another area would be cold-start time. If you have to search N slots, more searchers runing in parallel is likely to speed things up. Searchers and trackers are often different logic, these days.. Searching is very efficiently done with a FFT correlator, because you can search all lags simultaneously with NlogN effort as opposed to O(N/2) effort with a sequential search. Same for Doppler. But once you've acquired, you track with a conventional Early/Prompt/Late scheme. When you get into full-up implementations, where there is coupling between the tracking loops (think of a 2 frequency receiver.. L1 and L5 will have related doppler), there are other economies of scale possible. ___ 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.
Re: [time-nuts] Why 9,192,631,770 ??
OK I have learned a lot and absolutely fantastic news. No matter what my aged CS says I can claim its accurate now. Its simply the world has not caught up to or slowed down to it. Regards Paul On Fri, May 11, 2012 at 2:30 AM, mike cook michael.c...@sfr.fr wrote: Le 11/05/2012 07:14, Peter Monta a écrit : Are there better estimates of the ET second nowadays (relative to the SI second)? It would be interesting to know what the cesium frequency should have been if much better estimates of the ephemeris-time second were available at the time. One would think that with all the solar-system data JPL and others have had at their disposal since the 1970s, a very good ET-second number could be cooked up; better than 1950s Moon cameras at any rate. There are various refs in the pedia to later estimates. Markowitz (1988) calculated an agreement to 1x10-10. but looking at the article I see there were still some uncertainty in terms used to calculate ET and depending on what was chosen gave 2x10-11 . Accordingly he concludes conservatively that ET has been equal to Si within 1x10-9. The uncertainties will have been reduced since then but not eliminated and so should have been is a moving target but it would appear from the above that the chosen SI value would still be preferred if the decision was to be reappraised. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://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.
Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?
On 5/11/12 2:38 AM, Hal Murray wrote: Why in the hell would anybody build a 50 channel receiver? At most you MIGHT see 12 usable GPS sats... I don't think that I've seen over 10. WAAS should be fairly useless for a timing receiver. I can think of a couple of reasons. I'm sure there are more. One would be marketing type bragging rights. I can scan more channels than you. Another area would be cold-start time. If you have to search N slots, more searchers runing in parallel is likely to speed things up. Searchers and trackers are often different logic, these days.. Searching is very efficiently done with a FFT correlator, because you can search all lags simultaneously with NlogN effort as opposed to O(N/2) effort with a sequential search. Same for Doppler. But once you've acquired, you track with a conventional Early/Prompt/Late scheme. When you get into full-up implementations, where there is coupling between the tracking loops (think of a 2 frequency receiver.. L1 and L5 will have related doppler), there are other economies of scale possible. Here is an example of tracking loops coupled even more. http://www.javad.com/downloads/jns/papers/coop_tracking.pdf -- Björn ___ 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.
Re: [time-nuts] question about Thunderbolt geo acuracy
On 5/11/12 5:23 AM, swingbyte wrote: s disappointing! I need to measure the height of my house floor to be above the flood plane contour. I might have a look at some dted from work. Might have to pay a real surveyor to measure the height datum. Thanks for all the info though guys for that, you need a real surveyor who can provide a legally accepted measurement. Someone who can a) know from the flood level definition what vertical datum they are using (probably NOT something normal in the geodesy world) b) knows the legalities of establishing the difference The mechanics of surveying (leveling in this case) are straightforward to learn. The legalities and local practices in documentation are not. This is what getting a Land Surveyor's license is all about. There's also a question of what the legal height of your house is, relative to the property (from a flood insurance standpoint). They might have some arbitrary offset in the rules. Sort of like how baseline electrical power consumption is actually about 2/3 of the expected minimum consumption in the area for a given size house and appliances (e.g. nobody is likely to consume less than baseline) There are some mortgage servicers, by the way, who take property addresses that have been geolocated and FEMA flood plain definition maps to determine whether you definitely don't, definitely do, or just might need flood insurance. The maps change (as does the geolocation). From what I understand, about 3-5% of the properties scanned require some sort of manual intervention (maybe the address doesn't geolocate, or it's right on the line, or) ___ 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.
Re: [time-nuts] question about Thunderbolt geo acuracy
On 5/11/12 5:54 AM, Chuck Harris wrote: Go to your local building and planning commission, and get yourself a copy of the topographical map for your address. They are cheap, and are the standard by which everyone (insurance, zoning, ...) determines your flood plane exposure. I have been informed (in the last 5 minutes) that whether you are in a flood plain, these days, are determined almost entirely by the geographic position of your property on the FEMA flood plain map. (at least as far as lenders and HO insurance goes) FEMAs maps may or may not align with USGS maps. They almost certainly do NOT align with the county recorder's maps. If you're in an area where FEMA doesn't issue maps then it's something else, and USGS or local maps may determine. But I notice from the FEMA Flood Map server that they cover even things up in the mountains (e.g. Alpine county in California) ___ 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.
Re: [time-nuts] Calculating phase jitter from phase noise - appnote by silabs
On 5/11/12 1:51 AM, Attila Kinali wrote: Moin, I just stumbled over a nice little summary how to calculate the jitter of a signal from its phase noise plot by silicon labs: http://www.silabs.com/Support%20Documents/TechnicalDocs/AN256.pdf Attila Kinali and one from Wenzel http://www.wenzel.com/documents/spread1.htm ___ 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] TU-60 Instruction to set NMEA output
Hi, I am new to timenuts. Is anyone able to give me the binary command sentence/code to send to my Jupiter TU-60 to change it's output from Binary to NMEA please? I assume it has to be a binary command starting with @@ but I am unable to find a suitable command using Tac32 control software. Merv VK6BMT ___ 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.
Re: [time-nuts] question about Thunderbolt geo acuracy
The FEMA maps didn't exist the last time I did this. I would think it likely that the building and planning commission office for his area would have the appropriate maps, as establishing that the proposed house's location is outside of the the 100 year flood plane, is a necessary check mark in getting a building permit. -Chuck Harris Jim Lux wrote: On 5/11/12 5:54 AM, Chuck Harris wrote: Go to your local building and planning commission, and get yourself a copy of the topographical map for your address. They are cheap, and are the standard by which everyone (insurance, zoning, ...) determines your flood plane exposure. I have been informed (in the last 5 minutes) that whether you are in a flood plain, these days, are determined almost entirely by the geographic position of your property on the FEMA flood plain map. (at least as far as lenders and HO insurance goes) FEMAs maps may or may not align with USGS maps. They almost certainly do NOT align with the county recorder's maps. If you're in an area where FEMA doesn't issue maps then it's something else, and USGS or local maps may determine. But I notice from the FEMA Flood Map server that they cover even things up in the mountains (e.g. Alpine county in California) ___ 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.
Re: [time-nuts] Clocks for Audio gear
- Original Message - From: Jim Lux jim...@earthlink.net To: time-nuts@febo.com Sent: Friday, May 11, 2012 8:10 AM Subject: Re: [time-nuts] Clocks for Audio gear On 5/11/12 12:48 AM, MailLists wrote: Who would listen to pure sine tones? As a youth, I listened to WWV, which is a pure sine tone, in between the ticks. Drove my parents batty. me too, I think replaying this in my head is a better way to measure time than the 1 thousand, 2 ... trick, having low music skills would wonder what the limit of human time keeping is ? Director , Drummer ... how would we collect data to produce a Allan variance graph ? Does a timing savant exist ? http://discovermagazine.com/2002/feb/featsavant Stanley ___ 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.
Re: [time-nuts] Calculating phase jitter from phase noise - appnote by silabs
And one from HP/Agilent (taking into account the colored noise too: http://cp.literature.agilent.com/litweb/pdf/5990-3108EN.pdf And one from Fordahl, with the random zero cross consideration: http://www.metatech.com.tw/doc/appnote-fordahl/e-AN-02-3.pdf On Fri, May 11, 2012 at 4:00 PM, Jim Lux jim...@earthlink.net wrote: On 5/11/12 1:51 AM, Attila Kinali wrote: Moin, I just stumbled over a nice little summary how to calculate the jitter of a signal from its phase noise plot by silicon labs: http://www.silabs.com/Support%**20Documents/TechnicalDocs/**AN256.pdfhttp://www.silabs.com/Support%20Documents/TechnicalDocs/AN256.pdf Attila Kinali and one from Wenzel http://www.wenzel.com/**documents/spread1.htmhttp://www.wenzel.com/documents/spread1.htm __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://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.
Re: [time-nuts] Calculating phase jitter from phase noise - appnote by silabs
Hi Be very careful with all these phase noise to jitter conversions. They make some assumptions about the noise that are likely true, but may not be. The gotcha is that a normal noise measurement does not take phase data. Without the phase data you really can't properly do the reconstruction. You have to assume that it's random in the phase domain. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Friday, May 11, 2012 11:28 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Calculating phase jitter from phase noise - appnote by silabs And one from HP/Agilent (taking into account the colored noise too: http://cp.literature.agilent.com/litweb/pdf/5990-3108EN.pdf And one from Fordahl, with the random zero cross consideration: http://www.metatech.com.tw/doc/appnote-fordahl/e-AN-02-3.pdf On Fri, May 11, 2012 at 4:00 PM, Jim Lux jim...@earthlink.net wrote: On 5/11/12 1:51 AM, Attila Kinali wrote: Moin, I just stumbled over a nice little summary how to calculate the jitter of a signal from its phase noise plot by silicon labs: http://www.silabs.com/Support%**20Documents/TechnicalDocs/**AN256.pdfhttp:/ /www.silabs.com/Support%20Documents/TechnicalDocs/AN256.pdf Attila Kinali and one from Wenzel http://www.wenzel.com/**documents/spread1.htmhttp://www.wenzel.com/document s/spread1.htm __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/tim e-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.
Re: [time-nuts] Tbolt failure modes
The -12V is only used to support the RS-232 driver. The CPU should be running and you should have discipline even without the -12V Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: J. L. Trantham jlt...@att.net Sender: time-nuts-boun...@febo.com Date: Tue, 8 May 2012 21:29:06 To: 'Discussion of precise time and frequency measurement'time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Tbolt failure modes I had a failure of my -12 V supply that interrupted communications that was resolved by fixing the -12 V supply. You might want to make sure you are getting the -12 V supply in the unit. I suspect your 24 V supply provides power to an internal supply that generates +12, +5 and -12 V. Might want to check if that is the case for your unit and if the -12 V is present. Hope this helps. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of b...@lysator.liu.se Sent: Tuesday, May 08, 2012 4:52 PM To: time-nuts@febo.com Subject: [time-nuts] Tbolt failure modes Hi group! Just got a few Thunderbolts. It is a few PN 39448-61 and one PN 38223-61. Date codes from 9932 to 0025. This is the normal version with a 24VDC power board and Tbolt board integrated in a small AL box with red markings. One of the receivers is having a problem. Measuring from the outside there is: 1) Takes the same amount of power as the working units.(to the resolution measured) 2) Has 10MHz output. 3) Has 4.9VDC on antenna center pin. 4) -8.9VDC stable on rs232 Tx pin (pin2 in DB9) 5) 10MHz is 0.7Hz off after many power on hours with known good antenna 6) TP9 TP10 (close to the GPS board power connector) has 4.9VDC 7) Tboltmon will not talk to the board. 8) There is no serial output at all from the Tbolt. Differences compared to a good Tbolt 1) Tboltmon will ofcause communicate. 2) After locking 10MHz will be very close to nominal 3) TP9 and TP10 shows a square wave (ca 7V pp, 9.795625000kHz) I have looked at Tom's page at http://www.leapsecond.com/tbolt-faq.htm Brooke's at http://www.prc68.com/I/ThunderBolt.shtml#IC and John's at http://www.ke5fx.com/tbolt.htm Are there other good Thunderbolt sites? Has anyone done debugging of faulty Tbolts? Comments on what might be wrong with my faulty unit? (I am not that experienced in hardware debugging...) -- Björn ___ 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] Tbolt failure modes
It also makes the negative DAC voltage rail. The Tbolt DAC swings from -5V to +5V. Lose the -12V and you can lose oscillator control. - The -12V is only used to support the RS-232 driver. The CPU should be running and you should have discipline even without the -12V ___ 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.
Re: [time-nuts] question about Thunderbolt geo acuracy
On 5/11/2012 6:46 AM, Jim Lux wrote: On 5/11/12 5:23 AM, swingbyte wrote: s disappointing! I need to measure the height of my house floor to be above the flood plane contour. I might have a look at some dted from work. Might have to pay a real surveyor to measure the height datum. Thanks for all the info though guys for that, you need a real surveyor who can provide a legally accepted measurement. Someone who can a) know from the flood level definition what vertical datum they are using (probably NOT something normal in the geodesy world) b) knows the legalities of establishing the difference The mechanics of surveying (leveling in this case) are straightforward to learn. The legalities and local practices in documentation are not. This is what getting a Land Surveyor's license is all about. There's also a question of what the legal height of your house is, relative to the property (from a flood insurance standpoint). They might have some arbitrary offset in the rules. Sort of like how baseline electrical power consumption is actually about 2/3 of the expected minimum consumption in the area for a given size house and appliances (e.g. nobody is likely to consume less than baseline) There are some mortgage servicers, by the way, who take property addresses that have been geolocated and FEMA flood plain definition maps to determine whether you definitely don't, definitely do, or just might need flood insurance. The maps change (as does the geolocation). From what I understand, about 3-5% of the properties scanned require some sort of manual intervention (maybe the address doesn't geolocate, or it's right on the line, or) ___ 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. Actually, The percentage can be higher. The scale of the FEMA flood panels are usually around 1=2000. Some of the older panels were 1=4000. The newest panels can be around 1=1000 (approx 5 to the section). Horizontal scale is not the problem, it's the vertical scale. Also how the stream bed profile was established (surveyed). There can be a lot of change in the real world compared to was gets plotted on the panel and in the profile. When there is an obvious discrepancy between the two (mapped profile and real world) a registered surveyor or engineer must be called in to reconcile the difference. The cost for doing this might seem high, but when compared to the cost of flood insurance paid over the life of a mortgage, it's very cheep. Just my 2 cents worth. . . Randy Hunt, retired Engineering Technician, Flood Plain Administrator (32years) ___ 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.
Re: [time-nuts] Tbolt failure modes
Are there multiple hardware versions of the Tbolt (other than the Tbolt-E)? My Tbolt has an Intersil 232IBE dual TTL to RS232 converter - similar to MAX232. It generates it's own -12V. This is the version shown on Brooke Clarke's Thunderbolt page: http://www.prc68.com/I/ThunderBolt.shtml Ed On 5/11/2012 10:56 AM, shali...@gmail.com wrote: The -12V is only used to support the RS-232 driver. The CPU should be running and you should have discipline even without the -12V Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: J. L. Tranthamjlt...@att.net Sender: time-nuts-boun...@febo.com Date: Tue, 8 May 2012 21:29:06 To: 'Discussion of precise time and frequency measurement'time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Tbolt failure modes I had a failure of my -12 V supply that interrupted communications that was resolved by fixing the -12 V supply. You might want to make sure you are getting the -12 V supply in the unit. I suspect your 24 V supply provides power to an internal supply that generates +12, +5 and -12 V. Might want to check if that is the case for your unit and if the -12 V is present. Hope this helps. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of b...@lysator.liu.se Sent: Tuesday, May 08, 2012 4:52 PM To: time-nuts@febo.com Subject: [time-nuts] Tbolt failure modes Hi group! Just got a few Thunderbolts. It is a few PN 39448-61 and one PN 38223-61. Date codes from 9932 to 0025. This is the normal version with a 24VDC power board and Tbolt board integrated in a small AL box with red markings. One of the receivers is having a problem. Measuring from the outside there is: 1) Takes the same amount of power as the working units.(to the resolution measured) 2) Has 10MHz output. 3) Has 4.9VDC on antenna center pin. 4) -8.9VDC stable on rs232 Tx pin (pin2 in DB9) 5) 10MHz is 0.7Hz off after many power on hours with known good antenna 6) TP9 TP10 (close to the GPS board power connector) has 4.9VDC 7) Tboltmon will not talk to the board. 8) There is no serial output at all from the Tbolt. Differences compared to a good Tbolt 1) Tboltmon will ofcause communicate. 2) After locking 10MHz will be very close to nominal 3) TP9 and TP10 shows a square wave (ca 7V pp, 9.795625000kHz) I have looked at Tom's page at http://www.leapsecond.com/tbolt-faq.htm Brooke's at http://www.prc68.com/I/ThunderBolt.shtml#IC and John's at http://www.ke5fx.com/tbolt.htm Are there other good Thunderbolt sites? Has anyone done debugging of faulty Tbolts? Comments on what might be wrong with my faulty unit? (I am not that experienced in hardware debugging...) -- Björn ___ 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.
Re: [time-nuts] Clocks for Audio gear
Two things 1) - people in anechoic chambers will really notice the sound of their heartbeats as well as the s-sh-s-sh sound of the blood flowing through their heads. http://en.wikipedia.org/wiki/Anechoic_chamber They are designed to have complete sound absorption and are dead quiet. Very spooky to be in -- used to live in Boston and Harvard University had one that I was able to visit for an hour. 2) - an interesting experiment in brain filtering is to stand near a broadband noise source (fan or air conditioner or radio with someone talking) and talk with someone. Have a recorder going and record your conversation. You can understand the other person perfectly while face to face but listening to the recorded conversation, it will be hard to hear them over all that noise. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of shali...@gmail.com Sent: Friday, May 11, 2012 04:27 To: Time-Nuts Subject: Re: [time-nuts] Clocks for Audio gear Breathing and heart beat are filtered out and corrected for by the brain, otherwise we would have difficulties to hear a lot of things. Interestingly, that works well in our natural environment, but not as well when you are somewhere else. When free diving (when there is no noisy scuba gear and breathing), you can hear your own heartbeat and so can the fish, sometimes at significant distances as it propagates well under water. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Attila Kinali att...@kinali.ch Sender: time-nuts-boun...@febo.com Date: Thu, 10 May 2012 23:25:50 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Clocks for Audio gear On Thu, 10 May 2012 11:36:40 -0700 Hal Murray hmur...@megapathdsl.net wrote: Heartbeats may be more interesting than breathing. Does anybody know of spectrum domain data? It should be possible to collect position info while also monitoring heartbeat and chest diameter and then crunch some numbers do see how much of the position correlates with heartbeat vs breathing and then plot each part in the frequency domain. Please do not forget that there is a quite sofisticated error correction system attached to the hear, which we usually refere to as the brain. Breathing and heart beat are filtered out and corrected for by the brain, otherwise we would have difficulties to hear a lot of things. For more infos, please have a look at perceptual psychology. A not too bad introduction to that field is Sensation and Perception by E. B. Goldstein. But please do not expect mathematical rigor in that field. It's still a subfield of psychology. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ 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.
Re: [time-nuts] Why 9,192,631,770 ??
Are there better estimates of the ET second nowadays (relative to the SI second)? It would be interesting to know what the cesium frequency should have been if much better estimates of the ephemeris-time second were available at the time. Hi Peter, Everyone should take ten seconds and look at this animated GIF: http://leapsecond.com/pages/ut/ut-ani-v2.gif It shows what would have happened to earth time vs. atomic time if the cesium frequency had been defined to be other than 9192.631770 MHz. As you can see a slightly higher number would have meant less deviation between the two timescales. However it should also be clear, even with this short 40-year plot, that no number is the best or correct or right choice. It all depends on which year(s) you choose to base your earth rotation rate calibration on (the astronomers doing the calibration in the 1950's selected the year 1900 as their baseline). To see each page at your own pace here is it as a multi-page PDF file: http://leapsecond.com/pages/ut/ut-ani-v2.pdf If you wanted a near perfect match between atomic time and the rotation of the earth during the 1970's hindsight tells you the frequency should have been 9192.632080 MHz. Similarly if your crystal ball said to use 9192.632010 you would have been very close for three decades. If you wanted the best time accuracy from the year 1972 to present you should have picked 9192.631950. /tvb ___ 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.
Re: [time-nuts] Why 9,192,631,770 ??
So what you are saying is every 30 years select a new leap CS reference. Dispense with everything in between. On Fri, May 11, 2012 at 2:21 PM, Tom Van Baak t...@leapsecond.com wrote: Are there better estimates of the ET second nowadays (relative to the SI second)? It would be interesting to know what the cesium frequency should have been if much better estimates of the ephemeris-time second were available at the time. Hi Peter, Everyone should take ten seconds and look at this animated GIF: http://leapsecond.com/pages/ut/ut-ani-v2.gif It shows what would have happened to earth time vs. atomic time if the cesium frequency had been defined to be other than 9192.631770 MHz. As you can see a slightly higher number would have meant less deviation between the two timescales. However it should also be clear, even with this short 40-year plot, that no number is the best or correct or right choice. It all depends on which year(s) you choose to base your earth rotation rate calibration on (the astronomers doing the calibration in the 1950's selected the year 1900 as their baseline). To see each page at your own pace here is it as a multi-page PDF file: http://leapsecond.com/pages/ut/ut-ani-v2.pdf If you wanted a near perfect match between atomic time and the rotation of the earth during the 1970's hindsight tells you the frequency should have been 9192.632080 MHz. Similarly if your crystal ball said to use 9192.632010 you would have been very close for three decades. If you wanted the best time accuracy from the year 1972 to present you should have picked 9192.631950. /tvb ___ 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.
Re: [time-nuts] Why 9,192,631,770 ??
IMO, that would be a disaster for all areas of physics and engineering, except for possibly some aspects of astronomy. When they 'redefined' the Volt some years ago it was a goat rodeo. -John === So what you are saying is every 30 years select a new leap CS reference. Dispense with everything in between. On Fri, May 11, 2012 at 2:21 PM, Tom Van Baak t...@leapsecond.com wrote: Are there better estimates of the ET second nowadays (relative to the SI second)? It would be interesting to know what the cesium frequency should have been if much better estimates of the ephemeris-time second were available at the time. Hi Peter, Everyone should take ten seconds and look at this animated GIF: http://leapsecond.com/pages/ut/ut-ani-v2.gif It shows what would have happened to earth time vs. atomic time if the cesium frequency had been defined to be other than 9192.631770 MHz. As you can see a slightly higher number would have meant less deviation between the two timescales. However it should also be clear, even with this short 40-year plot, that no number is the best or correct or right choice. It all depends on which year(s) you choose to base your earth rotation rate calibration on (the astronomers doing the calibration in the 1950's selected the year 1900 as their baseline). To see each page at your own pace here is it as a multi-page PDF file: http://leapsecond.com/pages/ut/ut-ani-v2.pdf If you wanted a near perfect match between atomic time and the rotation of the earth during the 1970's hindsight tells you the frequency should have been 9192.632080 MHz. Similarly if your crystal ball said to use 9192.632010 you would have been very close for three decades. If you wanted the best time accuracy from the year 1972 to present you should have picked 9192.631950. /tvb ___ 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.
Re: [time-nuts] Calculating phase jitter from phase noise - appnote by silabs
Hi, here is a very nice and easy to use online calculator for doing exactly this: _http://jittertime.com/resources/pncalc.shtml_ (http://jittertime.com/resources/pncalc.shtml) bye, Said In a message dated 5/11/2012 09:17:30 Pacific Daylight Time, li...@rtty.us writes: Hi Be very careful with all these phase noise to jitter conversions. They make some assumptions about the noise that are likely true, but may not be. The gotcha is that a normal noise measurement does not take phase data. Without the phase data you really can't properly do the reconstruction. You have to assume that it's random in the phase domain. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Friday, May 11, 2012 11:28 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Calculating phase jitter from phase noise - appnote by silabs And one from HP/Agilent (taking into account the colored noise too: http://cp.literature.agilent.com/litweb/pdf/5990-3108EN.pdf And one from Fordahl, with the random zero cross consideration: http://www.metatech.com.tw/doc/appnote-fordahl/e-AN-02-3.pdf On Fri, May 11, 2012 at 4:00 PM, Jim Lux jim...@earthlink.net wrote: ___ 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.
Re: [time-nuts] TU-60 Instruction to set NMEA output
Hi Merv, I found the Navman Jupiter designers guide which has the message formats. What you need is message 1331. Tac32 supports this receiver, so there should be a possibility at setup to specify NMEA protocol. Else stuff it a 1331 . The guide is at http://gpsd.berlios.de/vendor-docs/jupiter/MN002000A_JupiterReceiver_DesignerGuide_print.pdf It tells you how messages are constructed. You should be able to work out the @@ format. Good hunting. Mike Le 11/05/2012 16:13, Merv Thomas a écrit : Hi, I am new to timenuts. Is anyone able to give me the binary command sentence/code to send to my Jupiter TU-60 to change it's output from Binary to NMEA please? I assume it has to be a binary command starting with @@ but I am unable to find a suitable command using Tac32 control software. Merv VK6BMT ___ 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.
Re: [time-nuts] TU-60 Instruction to set NMEA output
Hi Merv, Hi, I am new to timenuts. Is anyone able to give me the binary command sentence/code to send to my Jupiter TU-60 to change it's output from Binary to NMEA please? I assume it has to be a binary command starting with @@ but I am unable to find a suitable command using Tac32 control software. Merv VK6BMT I used to have an older Jupiter receiver. Does your receiver have the same 2x10 pin interface as shown in table 4 of the linked datasheet? http://gpskit.nl/documents/rockwell/jupiter-gps-board.pdf On that receiver, you could chose power up mode (NMEA or Jupiter binary) with a hardware jumper. Se below schematic (SW2) how the adapter board I used implemented the NMEA/binary choise. http://gpskit.nl/images/thekit-schematics-large.gif -- Björn ___ 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.
Re: [time-nuts] Why 9,192,631,770 ??
Everyone should take ten seconds and look at this animated GIF: http://leapsecond.com/pages/ut/ut-ani-v2.gif Very nice. I guess a comparable plot with ephemeris time would be a lot noisier and sparser, something like the graphs in the Markowitz 1988 paper. I wonder if there's some sort of IERS-like official repository for ephemeris-time data (or, for that matter, other non-Earth-rotation timescales like the pulsars). Probably not much call for it, being mostly of academic interest. Cheers, Peter ___ 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.
Re: [time-nuts] Why 9,192,631,770 ??
Hi BIH Bob On May 11, 2012, at 5:49 PM, Peter Monta wrote: Everyone should take ten seconds and look at this animated GIF: http://leapsecond.com/pages/ut/ut-ani-v2.gif Very nice. I guess a comparable plot with ephemeris time would be a lot noisier and sparser, something like the graphs in the Markowitz 1988 paper. I wonder if there's some sort of IERS-like official repository for ephemeris-time data (or, for that matter, other non-Earth-rotation timescales like the pulsars). Probably not much call for it, being mostly of academic interest. Cheers, Peter ___ 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] Improved timing through simple dish
Hugo's idea of using a Sat dish to zoom in on a WAAS Sat as discussed in the below paper is quite brilliant I think, and it seems one should be able to make use of it by disabling the GPS sats (via mask angle for example) in receivers that support WAAS, and that are used in position hold mode. According to their plots the WAAS-only setup gave them a huge improvement in timing accuracy. One should be able to make a much smaller dish, as all that gain is useful but probably not needed. bye, Said From: Sam _li...@digitalelectric.com.au_ (mailto:li...@digitalelectric.com.au) Date: May 11, 2012 5:14:24 PDT To: Discussion of precise time and frequency measurement _time-nuts@febo.com_ (mailto:time-nuts@febo.com) Subject: Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent? Reply-To: Discussion of precise time and frequency measurement _time-nuts@febo.com_ (mailto:time-nuts@febo.com) I uploaded the FEI-Zyfer WAAS papers to zippyshare if anyone is interested. _http://www32.zippyshare.com/v/66696070/file.html_ (http://www32.zippyshare.com/v/66696070/file.html) Sam. ___ 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.
Re: [time-nuts] helibowl GPS antennas
So, I've looked at several dozen helibowls and talked to makers of said items.. Thanks for posting this; maybe a homemade helibowl is a good way to get a low-cost GPS antenna with full frequency coverage down to L5. In my search for survey-grade antennas at hobbyist prices, I ran across this, as posted on Michele Bavaro's blog: http://www.onetalent-gnss.com/announcements/anovelpowerfulantennanavxperience3gc http://docs.google.com/viewer?a=vpid=sitessrcid=b25ldGFsZW50LWduc3MuY29tfHd3d3xneDo1NTdmMzQzMDljOGZmODJh http://www.navxperience.com/download/3G_C_english.pdf Most of the complexity seems to be in the combiner network, which, being a planar circuit, can be well modeled. Cheers, Peter ___ 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] Trimble Resolution SMT - good/bad/indifferent?
One nasty thing about these receivers is that they seem to be useless as a general purpose GPS receiver. Once they have a saved position (even if you erase the old one) it does not update the lat/lon/alt values (even if you put the receiver into 3D mode). It does not even update lat/lot/alt values when doing a survey. Perhaps I'm missing something? Anybody know how to get updated lat/lon/alts out of these things? ___ 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.
Re: [time-nuts] Tbolt failure modes
Well, this prompted a short experiment to test my observations in the past. I have a TBolt that requires +5, +12, and -12 VDC as separate inputs along with the antenna. A year or more ago, another list member posted a question about a failure of his TBolt, the specifics I do not remember, other than it included a 'failure to communicate'. I paid little attention to his issue at that time other than the fact that I had had another TBolt die in years past while connected to a switching power supply (computer type) in my shop which had a habit of having frequent power failures as a result of how a GCFI outlet had been wired. I still suspect one of these power failures triggered a 'spike' on the power supply that did my TBolt in. However, a couple of days after his post, I noted my current TBolt had exactly the same failure the list member had posted, interrupting communication via the serial connection to TBoltMon. I then noted that my -12 V supply had died. I changed power supplies and my TBolt came back to life. I posted the observation and the other list member found a poor connection at the connector to his TBolt on the -12 V pin. He repaired the connection and his problem was resolved. Tonight, I turned on a CS unit and compared the 10 MHz from the TBolt to the 5 MHz from the CS (5061A) after the TBolt had been up and operational for a couple of weeks and the CS up and 'Continuous' for about 30 minutes. I noted that the two were 'locked', as shown by triggering my scope with the TBolt 10 MHz and with the CS 5 MHz connected to the vertical. I then disconnected the -12 V supply and immediately connected it to ground. This left TBoltMon showing 'red' for 'Power Supply' and everything else 'as it was'. Even the SV indications were 'green' and AMU indications were normal. In addition, the outputs of the TBolt and the CS were still 'locked'. I then disconnected the -12 V supply from ground and let it 'float' in air, simulating the failure I had before. This immediately resulted in 'yellow' for 'Satellite Tracking', all the SV indications went 'white', and the TBolt frequency dropped about 24.6 Hz thus proving loss of 'lock'. 'COM 1' on TBoltMon remained 'green' for both situations. I then reconnected the -12 V lead to 'ground' and all observations reverted to the prior observations with the -12 V input grounded with the frequencies, again, 'locked'. So, I conclude that the observations are based on exactly what the failure of the -12 V is, open or short. Both my prior power supply failure and the other list member who had posted the question were 'open' failures. Hope this helps. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Ed Palmer Sent: Friday, May 11, 2012 12:39 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Tbolt failure modes Are there multiple hardware versions of the Tbolt (other than the Tbolt-E)? My Tbolt has an Intersil 232IBE dual TTL to RS232 converter - similar to MAX232. It generates it's own -12V. This is the version shown on Brooke Clarke's Thunderbolt page: http://www.prc68.com/I/ThunderBolt.shtml Ed On 5/11/2012 10:56 AM, shali...@gmail.com wrote: The -12V is only used to support the RS-232 driver. The CPU should be running and you should have discipline even without the -12V Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: J. L. Tranthamjlt...@att.net Sender: time-nuts-boun...@febo.com Date: Tue, 8 May 2012 21:29:06 To: 'Discussion of precise time and frequency measurement'time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Tbolt failure modes I had a failure of my -12 V supply that interrupted communications that was resolved by fixing the -12 V supply. You might want to make sure you are getting the -12 V supply in the unit. I suspect your 24 V supply provides power to an internal supply that generates +12, +5 and -12 V. Might want to check if that is the case for your unit and if the -12 V is present. Hope this helps. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of b...@lysator.liu.se Sent: Tuesday, May 08, 2012 4:52 PM To: time-nuts@febo.com Subject: [time-nuts] Tbolt failure modes Hi group! Just got a few Thunderbolts. It is a few PN 39448-61 and one PN 38223-61. Date codes from 9932 to 0025. This is the normal version with a 24VDC power board and Tbolt board integrated in a small AL box with red markings. One of the receivers is having a problem. Measuring from the outside there is: 1) Takes the same amount of power as the working units.(to the resolution measured) 2) Has 10MHz output. 3) Has 4.9VDC on antenna center pin. 4) -8.9VDC stable on rs232 Tx pin (pin2 in DB9) 5)
Re: [time-nuts] TU-60 Instruction to set NMEA output
Hi All, Thanks for the 2 prompt replies. Tac32 does not have any facility to enter 1331 as an instruction. It has numerous @@ commands but the TU 60 datasheets only list a small fraction of these commands and none pertain to setting the protocol!! It is like it is a carefully guarded secret! I downloaded Labmon which is a Navman proprietary software for the TU's but there does not seem to be a Win XP compatible version even though the one website stated it was for Win 2000/XP. I installed it but it refuses to locate Comm 1 which is the port I have connected to its RS232 data output. It would handle the 1331 instruction if it would communicate with the port. It is a real problem when doing things with fairly old GPS receivers and projects( eg I've just built the Shera GPS unit)which works well but there is no way I can get access to the .asm or hex files to play around with the software in the PIC as the originator is virtually inaccessible - does not answer emails. Sorry for the mixed subjects in this. Merv VK6BMT ___ 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.
Re: [time-nuts] TU-60 Instruction to set NMEA output
Hi Bj?m and Mike, I have some older TU's like the 30 and these are easy to set for binary or NMEA but the TU 60 requires a specific command 1331 and I am not savvy enough to convert this into a meaningful @@ command if there is such a valid command. One would have thought the manufacturer would have provided such an @@ command - he is very quick to state how you get it back into binary from NMEA!! I tried just putting 1331 into the command and it responds that it is an unknown command Merv VK6BMT ___ 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.
