[time-nuts] EFTF 2014
Fellow time-nuts, A guy can't show up at a conference without being spotted and hands being shaken by fellow time-nuts. Interesting days of tutorials and ice-breaker meeting. Lunch with Enrico Rubiola was interesting and fun. Cheers, Magnus ___ 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] TU60-D120-041 power up
Hi Michael, Thank you for your suggestion. This is my first post to the group so I hope I am replying correctly. I have downloaded WinLabMon (for Windows XP?) and WinOncore12 but I have not been able to communicate with the GPS receiver yet. Yes, please send me the program you mentioned and I will try it out. Please email to the address shown on my message. Thank you, 73 Jerry WA0ACF ___ 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] TU60-D120-041 power up
Hi Jerry PM sent. I developed some years ago a GPSDO using the TU series GPS receivers, you can see the product on this link under the GPS: http://rudius.net/oz2m/ngnb/index.htm Regarding the TU-60 you need to convert from the Motorola format to Navmann format first and then from Navmann format to NMEA format, then you can read all the information on your sw programs. I use the program realterm to do this. When you turn off power it will not remember the NMEA setting not even with a backup battery and you need to do the procedure again, the TU-30 modules remember the settings. Regards Michael, OZ2ELA -Oprindelig meddelelse- Fra: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] På vegne af Jerry Sendt: 24. juni 2014 04:14 Til: time-nuts@febo.com Emne: Re: [time-nuts] TU60-D120-041 power up Hi Michael, Thank you for your suggestion. This is my first post to the group so I hope I am replying correctly. I have downloaded WinLabMon (for Windows XP?) and WinOncore12 but I have not been able to communicate with the GPS receiver yet. Yes, please send me the program you mentioned and I will try it out. Please email to the address shown on my message. Thank you, 73 Jerry WA0ACF ___ 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] microcontroller based IRIG generator
I remember a few discussions over the last few years about building a microcontroller (PIC, Arduino, MPS430, whatever floats your boat) based IRIG generator. Did anyone ever get one working? There is a C source code file in the NTP distribution to generate IRIG via a sound card IIRC... That might be a good stepping stone if nobody has already come up with something packaged already. ___ 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] Loran, GPS, Lightning, Timing
A friend pointed me to this site: US http://www.blitzortung.org/Webpages/index.php?lang=enpage_0=30 EU http://www.blitzortung.org/Webpages/index.php?lang=en This is a wonderful out-of-the-box project, with echoes of Loran-C and GPS triangulation. It's also a clever combination of home-brew receivers, UTC timestamping, the web, and global participation. You'll find technical details on the site; it makes good reading for any time nut. And adds new meaning to pulse per second... Two questions. 1) Is anyone on the list a participant in this effort? 2) Can you imagine applying this entire process in reverse. That is, instead of using GPS to timetag lightning strikes, use lightning strikes to synchronize a global network of local clocks. Ok, getting accurate time and disciplining clocks with GPS or NTP or WWVB is too easy so why bother. But it would be interesting to use this raw data to set, calibrate, and discipline local clocks, as an redundant method, independent of existing broadcast TF sources. Some crunching on the data would at least determine what level of precision could be obtained with a, what shall we call it, CLDO (Coordinated Lightning Disciplined Oscillator). /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] Loran, GPS, Lightning, Timing
Indeed, very interesting. I stumbled across this the other day. After a preliminary read of one of their documents: A World-Wide Low-Cost Community-Based Time-of-Arrival Lightning Detection and Lightning Location Network Found here: http://www.blitzortung.org/Webpages/index.php?lang=enpage=3 I am seriously considering involved as I am a bit of a weather nut too. There are other similar projects too, this is one: http://lightningradar.net/ At the moment it seems there are only a handful of participating stations in North America. Cheers, Graham ve3gtc -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Van Baak Sent: June-24-14 12:52 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Loran, GPS, Lightning, Timing A friend pointed me to this site: US http://www.blitzortung.org/Webpages/index.php?lang=enpage_0=30 EU http://www.blitzortung.org/Webpages/index.php?lang=en This is a wonderful out-of-the-box project, with echoes of Loran-C and GPS triangulation. It's also a clever combination of home-brew receivers, UTC timestamping, the web, and global participation. You'll find technical details on the site; it makes good reading for any time nut. And adds new meaning to pulse per second... Two questions. 1) Is anyone on the list a participant in this effort? 2) Can you imagine applying this entire process in reverse. That is, instead of using GPS to timetag lightning strikes, use lightning strikes to synchronize a global network of local clocks. Ok, getting accurate time and disciplining clocks with GPS or NTP or WWVB is too easy so why bother. But it would be interesting to use this raw data to set, calibrate, and discipline local clocks, as an redundant method, independent of existing broadcast TF sources. Some crunching on the data would at least determine what level of precision could be obtained with a, what shall we call it, CLDO (Coordinated Lightning Disciplined Oscillator). /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. This electronic message, as well as any transmitted files included in the electronic message, may contain privileged or confidential information and is intended solely for the use of the individual(s) or entity to which it is addressed. If you have received this electronic message in error please notify the sender immediately and delete the electronic message. Any unauthorized copying, disclosure or distribution of the electronic message is strictly forbidden. NAV CANADA accepts no liability for any damage caused by any virus and/or other malicious code transmitted by this electronic communication. Le présent message électronique et tout fichier qui peut y être joint peuvent contenir des renseignements privilégiés ou confidentiels destinés à l’usage exclusif des personnes ou des organismes à qui ils s’adressent. Si vous avez reçu ce message électronique par erreur, veuillez en informer l’expéditeur immédiatement et supprimez le. Toute reproduction, divulgation ou distribution du présent message électronique est strictement interdite. NAV CANADA n’assume aucune responsabilité en cas de dommage causé par tout virus ou autre programme malveillant transmis par ce message électronique. ___ 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] Loran, GPS, Lightning, Timing
In message 06013AA10880459380352E3FB29C4B5C@pc52, Tom Van Baak writes: 2) Can you imagine applying this entire process in reverse. That is, instead of using GPS to timetag lightning strikes, use lightning strikes to synchronize a global network of local clocks. The first input you need is the exact longitude/latitude of the lightning bolt. The easiest way to do that is with a set of GPS synchronized receivers, nd we're back to sqare one! The next issue is that lightnings are seldom vertical, they can trivially wiggle many hundred meters sideways, so at absolute best your jitter is going to be no better than the microsecond domain, and probably much worse, increasing with distance. But there's a workaround: if you have the right kind of pregnant thundercloud overhead, a plain firework rocket trailing a thin grounded wire will, on your command, get you a lightning strike. Not only are these lightnings almost always entirely vertical, they are also particular sharp and potent (for that very reason). So if you live in the right kind of place, you *could* implement a daily clock synchronization service much more spectacular than a mere ball-drop. I belive the US electrical grid industry runs a joint research center somewhere in northern Florida, using this method to test lightning protection of the power grid components. I suspect they ignite their rockets using remote control. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | 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 To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
The first input you need is the exact longitude/latitude of the lightning bolt. The easiest way to do that is with a set of GPS synchronized receivers, nd we're back to sqare one! That's true for ultimate accuracy. But notice how each strike is seen by dozens of observers and each observer knows their (fixed) position and has their own local (approximate) clock. So it seems to me it's not unlike how GPS works: with enough samples, it should be possible to solve for latitude, longitude, and time of each strike. Like running GPS in 3D mode rather than position hold (zero D) mode. Now the accuracy is clearly not going to be at the nanosecond level. Maybe not even microsecond level, since as you mentioned, there are biases and jitter and who know what propagation variations. But over time, you should be able to converge on differential local clock measurements. What I'd like to see is the TDEV of this as a common view time transfer method. A couple of hops and we could compare UTC(PHK) with UTC(TVB), for example. Perhaps another side effect of their lightning project is that it could create dynamic propagation maps using the residuals in their massive database. When I first owned WWVB gear I thought I had accurate time. After I got GPS, I realized that my WWVB receivers now became accurate Colorado-to-Seattle weather stations. As they say, one man's error is another man's signal. /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] Loran, GPS, Lightning, Timing
as, ahem, one of the early experimenters of lightning detection, gotta tell ya, the return stroke risetime is on the order of 1 us. Also, the very beginning of the waveform, that is the first part of the spike, is connected with the beginning of the breakdown, hence the location on the ground. Subsequent parts of the waveform are due to higher portions of the channel. Also, there are two polarities of discharge, and the positive discharge gives a waveform that looks like a cloud discharge that does not strike ground at all. Those seriously interested should get hold of a copy of Lightning by Martin Uman; this is bby now old, but is available inexpensively and will get you started. The original detectors used wideband crossed loops to get direction and no time of arrival; well before GPS timing. I hadn't looked into the amateur network! Vaisala corp has the best USA net, otherwise there is one in Boston and TOA enterprisesin Florida. U of Washington has a network as well. Enjoy! I can tell you after 50 years of dinking with it, Lightning is fun if ya ain't too close. Don Tom Van Baak The first input you need is the exact longitude/latitude of the lightning bolt. The easiest way to do that is with a set of GPS synchronized receivers, nd we're back to sqare one! That's true for ultimate accuracy. But notice how each strike is seen by dozens of observers and each observer knows their (fixed) position and has their own local (approximate) clock. So it seems to me it's not unlike how GPS works: with enough samples, it should be possible to solve for latitude, longitude, and time of each strike. Like running GPS in 3D mode rather than position hold (zero D) mode. Now the accuracy is clearly not going to be at the nanosecond level. Maybe not even microsecond level, since as you mentioned, there are biases and jitter and who know what propagation variations. But over time, you should be able to converge on differential local clock measurements. What I'd like to see is the TDEV of this as a common view time transfer method. A couple of hops and we could compare UTC(PHK) with UTC(TVB), for example. Perhaps another side effect of their lightning project is that it could create dynamic propagation maps using the residuals in their massive database. When I first owned WWVB gear I thought I had accurate time. After I got GPS, I realized that my WWVB receivers now became accurate Colorado-to-Seattle weather stations. As they say, one man's error is another man's signal. /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. -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] quartz oscillator injection locking
Hi all, what would be the best method to try injection locking a butler common base crystal oscillator (see figure in http://www.eska.dk/oscillator_data.htm for schematic)? Any comment about close-in phase noise performance when adding injection locking to such oscillators? Thanks in advance for any hint. Frank ___ 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] Loran, GPS, Lightning, Timing
I am seriously considering involved as I am a bit of a weather nut too. I suspect this is quite common. You don't have to get into precise time very deep before you realize that all your timing gear is just pile of environmental sensors in disguise. Before time-nuts began, the first timing guy I met was Doug Hogarth (www.niceties.com) and he was seriously into weather measurement. He later got into the world of ultra-precise weight (mass) measurement. So I guess time-nuts is just a subset of measurement nuts. A quartz oscillator makes a good thermometer and sometimes a hygrometer and barometer too. An OCXO is a sensitive anemometer (just ask anyone who uses a PWM fan for TBolt temperature control). Quartz also makes an excellent accelerometer, gravimeter, tiltmeter, or even seismometer. An OCXO with EFC is a good voltmeter. Atomic clocks are superb magnetometers. And as Einstein predicted, atomic clocks make good altimeters and speedometers too. So everything we play with is a sensor. It's no wonder we are preoccupied with environmental sensing. Maybe Time is just what's left over after you shield or attenuate or compensate for everything else. /tvb See also: Quartz Resonators vs Their Environment: Time Base or Sensor? http://dev.quartzdyne.com/pdfs/quartzresonators.pdf http://www.paroscientific.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
Oh man does this bring back memories of 12au7s and loop antennas pre internet 1970 as I recall. A QST magazine article. I built it and it used a crt for readout. There wasn't really a way back then to share the data. But will say this is quite a nice setup. Regards Paul WB8TSL On Tue, Jun 24, 2014 at 3:35 PM, Tom Van Baak t...@leapsecond.com wrote: I am seriously considering involved as I am a bit of a weather nut too. I suspect this is quite common. You don't have to get into precise time very deep before you realize that all your timing gear is just pile of environmental sensors in disguise. Before time-nuts began, the first timing guy I met was Doug Hogarth (www.niceties.com) and he was seriously into weather measurement. He later got into the world of ultra-precise weight (mass) measurement. So I guess time-nuts is just a subset of measurement nuts. A quartz oscillator makes a good thermometer and sometimes a hygrometer and barometer too. An OCXO is a sensitive anemometer (just ask anyone who uses a PWM fan for TBolt temperature control). Quartz also makes an excellent accelerometer, gravimeter, tiltmeter, or even seismometer. An OCXO with EFC is a good voltmeter. Atomic clocks are superb magnetometers. And as Einstein predicted, atomic clocks make good altimeters and speedometers too. So everything we play with is a sensor. It's no wonder we are preoccupied with environmental sensing. Maybe Time is just what's left over after you shield or attenuate or compensate for everything else. /tvb See also: Quartz Resonators vs Their Environment: Time Base or Sensor? http://dev.quartzdyne.com/pdfs/quartzresonators.pdf http://www.paroscientific.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] FE5680 GPS Disciplined Controller Update
The response has been very positive such that a $ 45 kit is doable. Working on getting at least two beta tests lined up. However it is disappointing that no one has stepped up to tackle the temperature problem. how many have looked at the temperature attachment and clicked on the N5TNL link. Let me make it clear that yes the GPSDO will work but there will be one or two orders of magnitude degradation without active fan temperature control unless the internal temperature compensation is disabled. I like to float an other idea I did attach a picture of the auxiliary board which we also use on other projects. That board along with inductors and two mini circuit transformers could be added to the kit for an extra $ 8.00. Other parts are readily available. Going forward it would make sense to have a temperature control board and a clean up loop board. We have them but they are express PCB. if members would be willing to do a Gerber version I will gladly work with them off list and than they could be added for an extra $ 4.00 to the kit. We do not have the time. Total kit would be $ 57.00 maybe $ 55.00 including four 5 X 5 cm. boards. Let me know what you think. Bert Kehren In a message dated 6/19/2014 2:56:52 P.M. Eastern Daylight Time, t...@leapsecond.com writes: - Original Message - From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, June 19, 2014 8:31 AM Subject: Re: [time-nuts] FE5680 GPS Disciplined Controller I've been working in the same thing BUT I don't want anyone who builds it to need a PCB. And I want the firmware to load over USB so there is no need to ship programmed chips or deal with external programmers. I think I can get the cost below $20. That said I doubt I'll get 1E-13 performance out of my Rb. My little Arduino based controller has been running now for a couple months and keeping a crystal in lock. The board has a pins left over for a serial port that I'll hook up to the Rb. The trick to getting the cost down is NOT to do a custom PCB. Take advantage of one of the uP development boards and then for under $5 you get the USB interface, D/A and A/D, serial ports, timers and quite a bit of logic all 1/3rd the size of a credit card. On Thu, Jun 19, 2014 at 12:57 AM, Jan Boutsen jan.bout...@telenet.be wrote: Count me in for an assembled and tested board. Great project. Jan - Original Message - From: ewkeh...@aol.com To: time-nuts@febo.com Sent: Wednesday, June 18, 2014 8:49 PM Subject: [time-nuts] FE5680 GPS Disciplined Controller FE5680 GPS Disciplined Controller With all the FE 5680 rubidium oscillators being used as door stops out there some of us decided to develop a GPSDO for it. The main question we have: Is there sufficient interest among time nuts for a discipline controller for the FE5680 to make it available? Looking at the postings over the last two years I am not so sure. The construction and preliminary testing of a Brooks Shera style GPS discipline controller for the later version (6.81e-13 resolution) of the FE5680 has been completed. We are trying to determine the number of people that would be interested in obtaining an FE5680 discipline controller (if there is sufficient interest about $45 a kit shipping included, $75 for an assembled and tested board, international orders for an additional $5) when it is released. We are also looking for three Beta testers that would be willing to purchase, assemble, and test our Beta release controller kit with their own FE5680A and GPS receiver or Tbolt and provide feedback. Please send an email to _EWKehren@aol.com_ (mailto:ewkeh...@aol.com) Subject Time-Nuts FE 5680A, if you would be interested in being one of the three Beta testers. A key requirement is the willingness to get to it right away, the board assembly takes about 30 minutes. Instrumentation to measure results is also a requirement. We obtained impressive results using a cheap ublox 6M receiver. The FE5680 GPS discipline controller is a small (2” x 2”) board using 8 DIP’s and 1 SOT23-5 package powered by +5v with 0.1” headers for all inputs and outputs. Our plan is to have the kit supplier solder in the only SMD device on the board. A GPS receiver 1PPS and 10 MHz sine from the FE5680 feed the board with two 9600 baud serial ports sending TTL level tuning commands to the FE5680 and receiving commands from and sending status data to a PC for data logging and system control via a simple terminal program. In the chip count are two opto couplers that allow the use of isolated TTL to USB conversion. These USB adapters are readily available and furnish the 5 V necessary for the secondary of the opto circuit. An option is to not use the
Re: [time-nuts] FE5680 GPS Disciplined Controller Update
However it is disappointing that no one has stepped up to tackle the temperature problem. how many have looked at the temperature attachment and clicked on the N5TNL link. Let me make it clear that yes the GPSDO will work but there will be one or two orders of magnitude degradation without active fan temperature control unless the internal temperature compensation is disabled. Can you clarify the two orders of magnitude claim? That's hard for me to believe, I think, without seeing the ADEV plots or actual lab report. I mean, even a cheap XO or TCXO or OCXO can be disciplined against GPS and achieve superb results. Temperature (or rather, temperature rate of change) has little effect short-term. Temperature also has little to zero effect long-term. So it's only in the, what, tau 100 to 1000 or maybe 1 second range that temperature even matters. As long as the LO is locked to GPS; I assume you're not talking about holdover. Obviously you'd want a slightly shorter loop time constant for a non-temperature-controlled Rb than a fancy temperature-controlled Rb. But does this really make a one or two *orders of magnitude* difference? /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] FE5680 GPS Disciplined Controller Update
Tom, airflow, or changes in airflow are typically much worse for ADEV than actual ambient temperature changes in still air. In still air for example a typical Eurocan DOCXO will have a case temp of about 55C to 60C at 25C ambient. Turn on any kind of significant airflow over that part and the air temperature will be nearly the same as before, but the case of the DOCXO is now very quickly cooled to 30C to 40C by the airflow. This affects mostly TCXO and single-oven units (including Rb's etc), it does very little to DOCXO units typically because the outer oven takes the brunt of the temp change and insulates the inner oven. There are other components on the PCB though next to the DOCXO that will be affected such as the DAC, DAC reference, EFC filters, current ground loops due to changing heater-current on the ground pin, etc. This even affects TCXO's because they are typically heated by themselves and other components on the PCB, and any kind of airflow change will cause an instant temp change on the TCXO due to cooling. So in my opinion a bang-bang controlled fan near any kind of oscillator is about the worst thing one can do for short term stability. bye, Said In a message dated 6/24/2014 13:35:21 Pacific Daylight Time, t...@leapsecond.com writes: However it is disappointing that no one has stepped up to tackle the temperature problem. how many have looked at the temperature attachment and clicked on the N5TNL link. Let me make it clear that yes the GPSDO will work but there will be one or two orders of magnitude degradation without active fan temperature control unless the internal temperature compensation is disabled. Can you clarify the two orders of magnitude claim? That's hard for me to believe, I think, without seeing the ADEV plots or actual lab report. I mean, even a cheap XO or TCXO or OCXO can be disciplined against GPS and achieve superb results. Temperature (or rather, temperature rate of change) has little effect short-term. Temperature also has little to zero effect long-term. So it's only in the, what, tau 100 to 1000 or maybe 1 second range that temperature even matters. As long as the LO is locked to GPS; I assume you're not talking about holdover. Obviously you'd want a slightly shorter loop time constant for a non-temperature-controlled Rb than a fancy temperature-controlled Rb. But does this really make a one or two *orders of magnitude* difference? /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] Sad news Ulrich Bangert
Thank you Bruce. Like others, I was saddened to hear of Ulrich's passing. His contributions and the good spirit under which he contributed were notable. He will be missed. Didier KO4BB On June 23, 2014 4:58:24 PM CDT, br...@ko4bb.com br...@ko4bb.com wrote: Sadly Ina was terminally ill and died in May 2012. Ulrich kept this to himself until about six months later in an email explaining why he had been out of touch. In respect for Ulrich's wishes I kept this news off the list. Ulrich's Obituary indicates that one parent, his in-laws and siblings as well as his nieces/nephews survive him. If requested I'll post the URL for his obituary which includes a contact address. Bruce On June 22, 2014 at 1:16 PM ewkeh...@aol.com wrote: It is a shock and a loss not just to time nuts but many others that where touched and benefited from him. Like in the case of Brooks I know what I will do and I urge those of you that knew him through any type of contact make the old fashioned proper thing by sending his wife a letter or card Frau Ina Bangert, Ortholzer Weg 1, 27243 Gross Ippener Germany Bert Kehren In a message dated 6/22/2014 12:36:22 P.M. Eastern Daylight Time, ail...@t-online.de writes: I am shocked to hear that. Urich was a very helpful friend, I've learned a lot from him. I'm so sorry to hear that. Please allow me to say some words in Ulrichs (and my) native language. Die Nachricht vom Tode Urich's hat mich sehr getroffen. Ich habe ihn als einen hilfsbereiten und offenen Menschen kennen gelernt, aber leider nie persönlich kennen lernen können. Bitte, lieber Hartmut, falls Du Kontakt hast, richte der Familie mein herzliches Beileid aus. Thank you very much. Volker - DF9PL Am 20.06.2014 22:52, schrieb Hartmut Paesler: Dear group, unfortunately I have to deliver the sad news that Ulrich Bangert, DF6JB passed away on 11/06, aged 59. Best regards, Hartmut DL1YDD ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Sent from my Motorola Droid Razr HD 4G LTE wireless tracker 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] FE5680 GPS Disciplined Controller Update
bang-bang servos do depend on inherent low-pass filtering by the controlled device. Don saidj...@aol.com Tom, airflow, or changes in airflow are typically much worse for ADEV than actual ambient temperature changes in still air. In still air for example a typical Eurocan DOCXO will have a case temp of about 55C to 60C at 25C ambient. Turn on any kind of significant airflow over that part and the air temperature will be nearly the same as before, but the case of the DOCXO is now very quickly cooled to 30C to 40C by the airflow. This affects mostly TCXO and single-oven units (including Rb's etc), it does very little to DOCXO units typically because the outer oven takes the brunt of the temp change and insulates the inner oven. There are other components on the PCB though next to the DOCXO that will be affected such as the DAC, DAC reference, EFC filters, current ground loops due to changing heater-current on the ground pin, etc. This even affects TCXO's because they are typically heated by themselves and other components on the PCB, and any kind of airflow change will cause an instant temp change on the TCXO due to cooling. So in my opinion a bang-bang controlled fan near any kind of oscillator is about the worst thing one can do for short term stability. bye, Said In a message dated 6/24/2014 13:35:21 Pacific Daylight Time, t...@leapsecond.com writes: However it is disappointing that no one has stepped up to tackle the temperature problem. how many have looked at the temperature attachment and clicked on the N5TNL link. Let me make it clear that yes the GPSDO will work but there will be one or two orders of magnitude degradation without active fan temperature control unless the internal temperature compensation is disabled. Can you clarify the two orders of magnitude claim? That's hard for me to believe, I think, without seeing the ADEV plots or actual lab report. I mean, even a cheap XO or TCXO or OCXO can be disciplined against GPS and achieve superb results. Temperature (or rather, temperature rate of change) has little effect short-term. Temperature also has little to zero effect long-term. So it's only in the, what, tau 100 to 1000 or maybe 1 second range that temperature even matters. As long as the LO is locked to GPS; I assume you're not talking about holdover. Obviously you'd want a slightly shorter loop time constant for a non-temperature-controlled Rb than a fancy temperature-controlled Rb. But does this really make a one or two *orders of magnitude* difference? /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. -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] FE5680 GPS Disciplined Controller Update
Check out the temperature control code in Lady Heather. It uses a nice PID controller algorithm (from Warren Sarkison) to PWM modulate a fan to stabilize the environment around the Tbolt. It can achieve millidegree range stability... I have seen long term RMS values of the temperature plot less than a few micro-degrees. The standard Tbolt oscillator has a rather horrible tempco... I'll post some recommendations/findings about various environmental sensors I tried while I was building my weather/envionmental sensor package. Hint: the MS5611 pressure sensor chip is very nice. Has 24 bit ADCs for the pressure and temperature readings and produces very stable readings with a 100 Hz update rate. -- However it is disappointing that no one has stepped up to tackle the temperature 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] FE5680 GPS Disciplined Controller Update
On Tue, Jun 24, 2014 at 3:24 PM, Mark Sims hol...@hotmail.com wrote: ... However it is disappointing that no one has stepped up to tackle the temperature problem. I can post what I have. It's a uP based PWM fan controller. It is a stand alone device that does not know anything about the FE5680 but it would be easy to add into any GPSDO using the GPSDO's existing uP provided there were enough extra analog pins available. It uses the Arduino software environment but I built it using a bare 8-pin DIP. The problem with it is I do not have a good temperature sensor, The ones I tried are noisy. SO I'm looking forward to your sensor info. My first controller used a comparator chip. Then I figured the uP was the same cost and same 8-pin package but could do things like PID, data logging, led status blinking and whatever. This is a start on the code that works just like the comparator and uses a pot for the user to adjust a set point. If you see a way to make this better post the changes. Some things I will do are (1) use better sensor, (2) use PID library, (3) measure ambient air temp. FanController.ino https://dl.dropboxusercontent.com/u/28915695/FanController.ino BTW is there any design info on the FE5680 controller. Schematics of source code? -- Chris Albertson Redondo Beach, 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] FE5680 GPS Disciplined Controller Update
Again we are talking past each other I am talking about temperature compensation with the DDS that ideally should be removed. Those steps upset any loop. Bert In a message dated 6/24/2014 6:38:48 P.M. Eastern Daylight Time, hol...@hotmail.com writes: Check out the temperature control code in Lady Heather. It uses a nice PID controller algorithm (from Warren Sarkison) to PWM modulate a fan to stabilize the environment around the Tbolt. It can achieve millidegree range stability... I have seen long term RMS values of the temperature plot less than a few micro-degrees. The standard Tbolt oscillator has a rather horrible tempco... I'll post some recommendations/findings about various environmental sensors I tried while I was building my weather/envionmental sensor package. Hint: the MS5611 pressure sensor chip is very nice. Has 24 bit ADCs for the pressure and temperature readings and produces very stable readings with a 100 Hz update rate. -- However it is disappointing that no one has stepped up to tackle the temperature 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. ___ 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] FE5680 GPS Disciplined Controller Update
Hi If: 1) You are after better than 1.0 x 10^-13 accuracy 2) You are getting 1 to 9x10^-9 at one second ADEV out of your GPS 3) You have a telecom Rb with 1 to 5x10^-10 temp coef over a 70C delta 4) Your Rb self heats 20 to 30C in still air Here’s some math: You will need at least 10,000 seconds to get a single frequency estimate and likely 100,000 seconds. You are likely to go through temp cycles in a room at a 30 to 90 minute rate. (1800 to 3600 sec). Your room temp swings are *way* outside your likely loop. The Rb will have to deal with them by it’s self. —— Your Rb is “sort of” compensated in the temcom units. It’s more like a TCXO than an OCXO. 1x10^-10 over 50C would give you 2x10^-12 per degree C. That may be better or worse than the sample you have. The “worse” really comes in when you have one that’s a parabola or third order temp curve. At least around here a room swing of 2 to 4 C is pretty normal with the heat or air-conditioning turned on. That gets you into the 4 to 8x10^-12 swing range. In a typical garage you are at 10C and 2x10^-11. If you want that to be *below* your 1x10^-13 goal, you have to knock it down by about 100X. —— Is the goal rational? Well this is Time Nuts …. It is roughly the sort of goal Bert has said they are after. Most of the lightweight Rb’s have a major ADEV hump when the temperature compensation cuts in. Without *good* temperature stabilization, you will not disable this correction. There’s no real way to know what the ADEV is without this hunting until you do it. Because of the self heating (and gradients), it’s not a real easy thing to do. If you are using an ensemble of parts to get the ADEV, temperature likely will correlate between them. You will not get the “group vote” to suppress it the way you some other sources of ADEV. —— Yes, I’m sure Bert can cross the T’s and dot the i’s better than I can, but that’s a pretty good outline of the problem. Bob On Jun 24, 2014, at 4:34 PM, Tom Van Baak t...@leapsecond.com wrote: However it is disappointing that no one has stepped up to tackle the temperature problem. how many have looked at the temperature attachment and clicked on the N5TNL link. Let me make it clear that yes the GPSDO will work but there will be one or two orders of magnitude degradation without active fan temperature control unless the internal temperature compensation is disabled. Can you clarify the two orders of magnitude claim? That's hard for me to believe, I think, without seeing the ADEV plots or actual lab report. I mean, even a cheap XO or TCXO or OCXO can be disciplined against GPS and achieve superb results. Temperature (or rather, temperature rate of change) has little effect short-term. Temperature also has little to zero effect long-term. So it's only in the, what, tau 100 to 1000 or maybe 1 second range that temperature even matters. As long as the LO is locked to GPS; I assume you're not talking about holdover. Obviously you'd want a slightly shorter loop time constant for a non-temperature-controlled Rb than a fancy temperature-controlled Rb. But does this really make a one or two *orders of magnitude* difference? /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] temperature sensor
After having tried just about every solution under the sun, my opinion is that within the ambient temperature range (up to at least 100°C) and homebrew budgets, nothing beats an NTC thermistor. They are inexpensive, have a large output and interface most easily with a microcontroller's ADC in ratiometric mode requiring a single precision resistor. Even cheap ones have a 1% tolerance which is more precision than you will ever need. My favorite is a 10k at 25°C with a B factor of 3380 at 25/85 that costs $1.25 at Digikey. The math to derive the temperature from the ADC reading is simple (you do need the log function) and a mundane 12 bit ADC gives you temperature with a fraction of a degree resolution and much better than a degree absolute precision if you actually needed it. With a 2.5V reference (like those in my favorite Silabs uC), self heating is negligible, even in open air (a fraction of a degree). This is implemented in my Thunderbolt Monitor kit software to measure ambient temperature. If you need better resolution than what you can get by directly measuring the voltage at the junction of the resistor and thermistor (due to limited resolution of the ADC), add one op-amp and three resistors, or use the PGA if your microcontroller has one. Didier KO4BB On June 24, 2014 6:43:07 PM CDT, Chris Albertson albertson.ch...@gmail.com wrote: On Tue, Jun 24, 2014 at 3:24 PM, Mark Sims hol...@hotmail.com wrote: ... However it is disappointing that no one has stepped up to tackle the temperature problem. I can post what I have. It's a uP based PWM fan controller. It is a stand alone device that does not know anything about the FE5680 but it would be easy to add into any GPSDO using the GPSDO's existing uP provided there were enough extra analog pins available. It uses the Arduino software environment but I built it using a bare 8-pin DIP. The problem with it is I do not have a good temperature sensor, The ones I tried are noisy. SO I'm looking forward to your sensor info. My first controller used a comparator chip. Then I figured the uP was the same cost and same 8-pin package but could do things like PID, data logging, led status blinking and whatever. This is a start on the code that works just like the comparator and uses a pot for the user to adjust a set point. If you see a way to make this better post the changes. Some things I will do are (1) use better sensor, (2) use PID library, (3) measure ambient air temp. FanController.ino https://dl.dropboxusercontent.com/u/28915695/FanController.ino BTW is there any design info on the FE5680 controller. Schematics of source code? -- Chris Albertson Redondo Beach, 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. -- Sent from my Motorola Droid Razr HD 4G LTE wireless tracker 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] FE5680 GPS Disciplined Controller Update
Lets be clear the 1 E-13 is a totally different project and does not relate to the FE 5680 A. Yes most likely we will use the same universal controller but with different code, same board. GPS crosses the 1 E-13 line at 10 seconds little more than a day. I whish it was just temperature as I mentioned we are able to hold the back plate of a FRK at 0.01 C. But that is the easy part. Bert Kehren In a message dated 6/24/2014 8:06:52 P.M. Eastern Daylight Time, kb...@n1k.org writes: Hi If: 1) You are after better than 1.0 x 10^-13 accuracy 2) You are getting 1 to 9x10^-9 at one second ADEV out of your GPS 3) You have a telecom Rb with 1 to 5x10^-10 temp coef over a 70C delta 4) Your Rb self heats 20 to 30C in still air Here’s some math: You will need at least 10,000 seconds to get a single frequency estimate and likely 100,000 seconds. You are likely to go through temp cycles in a room at a 30 to 90 minute rate. (1800 to 3600 sec). Your room temp swings are *way* outside your likely loop. The Rb will have to deal with them by it’s self. —— Your Rb is “sort of” compensated in the temcom units. It’s more like a TCXO than an OCXO. 1x10^-10 over 50C would give you 2x10^-12 per degree C. That may be better or worse than the sample you have. The “worse” really comes in when you have one that’s a parabola or third order temp curve. At least around here a room swing of 2 to 4 C is pretty normal with the heat or air-conditioning turned on. That gets you into the 4 to 8x10^-12 swing range. In a typical garage you are at 10C and 2x10^-11. If you want that to be *below* your 1x10^-13 goal, you have to knock it down by about 100X. —— Is the goal rational? Well this is Time Nuts …. It is roughly the sort of goal Bert has said they are after. Most of the lightweight Rb’s have a major ADEV hump when the temperature compensation cuts in. Without *good* temperature stabilization, you will not disable this correction. There’s no real way to know what the ADEV is without this hunting until you do it. Because of the self heating (and gradients), it’s not a real easy thing to do. If you are using an ensemble of parts to get the ADEV, temperature likely will correlate between them. You will not get the “group vote” to suppress it the way you some other sources of ADEV. —— Yes, I’m sure Bert can cross the T’s and dot the i’s better than I can, but that’s a pretty good outline of the problem. Bob On Jun 24, 2014, at 4:34 PM, Tom Van Baak t...@leapsecond.com wrote: However it is disappointing that no one has stepped up to tackle the temperature problem. how many have looked at the temperature attachment and clicked on the N5TNL link. Let me make it clear that yes the GPSDO will work but there will be one or two orders of magnitude degradation without active fan temperature control unless the internal temperature compensation is disabled. Can you clarify the two orders of magnitude claim? That's hard for me to believe, I think, without seeing the ADEV plots or actual lab report. I mean, even a cheap XO or TCXO or OCXO can be disciplined against GPS and achieve superb results. Temperature (or rather, temperature rate of change) has little effect short-term. Temperature also has little to zero effect long-term. So it's only in the, what, tau 100 to 1000 or maybe 1 second range that temperature even matters. As long as the LO is locked to GPS; I assume you're not talking about holdover. Obviously you'd want a slightly shorter loop time constant for a non-temperature-controlled Rb than a fancy temperature-controlled Rb. But does this really make a one or two *orders of magnitude* difference? /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] temperature sensor
We use NTC 10K with the FRK. Precision is not important.We have to play with the settings in order to have fan starting voltage over the full temp. range. Bert Kehren In a message dated 6/24/2014 8:12:45 P.M. Eastern Daylight Time, shali...@gmail.com writes: After having tried just about every solution under the sun, my opinion is that within the ambient temperature range (up to at least 100°C) and homebrew budgets, nothing beats an NTC thermistor. They are inexpensive, have a large output and interface most easily with a microcontroller's ADC in ratiometric mode requiring a single precision resistor. Even cheap ones have a 1% tolerance which is more precision than you will ever need. My favorite is a 10k at 25°C with a B factor of 3380 at 25/85 that costs $1.25 at Digikey. The math to derive the temperature from the ADC reading is simple (you do need the log function) and a mundane 12 bit ADC gives you temperature with a fraction of a degree resolution and much better than a degree absolute precision if you actually needed it. With a 2.5V reference (like those in my favorite Silabs uC), self heating is negligible, even in open air (a fraction of a degree). This is implemented in my Thunderbolt Monitor kit software to measure ambient temperature. If you need better resolution than what you can get by directly measuring the voltage at the junction of the resistor and thermistor (due to limited resolution of the ADC), add one op-amp and three resistors, or use the PGA if your microcontroller has one. Didier KO4BB On June 24, 2014 6:43:07 PM CDT, Chris Albertson albertson.ch...@gmail.com wrote: On Tue, Jun 24, 2014 at 3:24 PM, Mark Sims hol...@hotmail.com wrote: ... However it is disappointing that no one has stepped up to tackle the temperature problem. I can post what I have. It's a uP based PWM fan controller. It is a stand alone device that does not know anything about the FE5680 but it would be easy to add into any GPSDO using the GPSDO's existing uP provided there were enough extra analog pins available. It uses the Arduino software environment but I built it using a bare 8-pin DIP. The problem with it is I do not have a good temperature sensor, The ones I tried are noisy. SO I'm looking forward to your sensor info. My first controller used a comparator chip. Then I figured the uP was the same cost and same 8-pin package but could do things like PID, data logging, led status blinking and whatever. This is a start on the code that works just like the comparator and uses a pot for the user to adjust a set point. If you see a way to make this better post the changes. Some things I will do are (1) use better sensor, (2) use PID library, (3) measure ambient air temp. FanController.ino https://dl.dropboxusercontent.com/u/28915695/FanController.ino BTW is there any design info on the FE5680 controller. Schematics of source code? -- Chris Albertson Redondo Beach, 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. -- Sent from my Motorola Droid Razr HD 4G LTE wireless tracker 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. ___ 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.
