Re: [time-nuts] Have done some more cutting on the Cs beam tube
Is it possible that the higher temp keeps the tube "cooked off?" Bill Dailey > On Feb 19, 2017, at 12:54 PM, <cdel...@juno.com> <cdel...@juno.com> wrote: > > Hi, > > The tiny coil inside the beam path is the low frequency coil used for DC > testing of the tube. > > The tube shown is a standard performance tube and has no degaussing coil. > > The flat windings on top of the shield are the C-field winding. > > The high performance cavity is even "prettier". > > You can see one at http://www.leapsecond.com/pages/cesium-tube/ > > Towards the bottom you can see the C-field windings in slots around the > circumference of the cavity. > > BTW in 5071A tubes there is no internal difference between the STD and > High Performance tubes. > > They just run at different temperatures! Saves having to build two > different tubes! > > Some more interesting 5071A tube info will post in a couple weeks!!! > > (Hint: Run your 5071A HiPerf tube at the Std tube temperature to extend > life!!!???) > > Cheers, > > Corby > > ___ > 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] more teensies
It would be neat to drive one off a disciplined 16MHz synthesizer and compare. Bill Dailey > On Sep 25, 2015, at 1:40 PM, Jim Lux <jim...@earthlink.net> wrote: > > I ran 5 teensys in parallel, driven from the same Rb source for an hour.. > They track reasonably well. > The differences are probably due to where they are relative to their > neighbors, and where the AC is blowing in my office. They're all on a single > piece of perfboard side by side. I'll find a cardboard box and some foam to > put them in. (excuse me.. an isothermal atmospheric convection current > inhibition system) > > There's a pretty noticeable "turn on" transient, so I should probably wait a > few minutes before taking data.. > > They're actually run off a 16 MHz crystal, which is presumably multiplied up > by 4 internally. > <5teensyfreq.png> > <5teensyquadfreqremoved.png> > ___ > 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] beaglebones, time, web services
These are pricey but offer 5900 steps over 120 degrees. 0.02 degree per step. At least you could try a couple. If you have many of them it would get expensive quickly. http://www.horizonhobby.com/ds8231-ultra-precision-servo-jrps8231 Sent from mobile On Jul 5, 2015, at 7:46 AM, Jim Lux jim...@earthlink.net wrote: On 7/4/15 7:53 PM, Hal Murray wrote: jim...@earthlink.net said: Exactly... I've got an array of mirrors on az/el mounts (two servos stacked) and the reflection from the mirrors on the wall forms the display. How many pixels in that display? Or what is the unit of quality measurement? What sort of ADEV are you aiming for? If your goal is solar time rather than TAI or UTC, you should be able to get pretty good. Prototype is 6 pixels to demonstrate concept and work out the bugs. Long term, probably several dozen. Time Accuracy? better than a second Turns out, having done some experimenting, the real issue is angular accuracy. RC servos aren't all that great, and have significant jitter (probably not an issue in their design application which tends to have good mechanical low pass filtering). They're cheap and easy to use (as in, I had a bunch in the garage I could cannibalize out of another project). But if you have 3x3 inch mirrors (call it 7.5 cm), and want to create a picture on the wall that's, say, 10 meters away, you really need angular pointing of 0.007 radians.. that's about 1/2 degree. An RC servo has roughly 270 degree rotation corresponding to 256 steps of PWM (in the Arduino implementation). ___ 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] beaglebones, time, web services
Pysolar Sent from mobile On Jul 4, 2015, at 8:13 AM, Jim Lux jim...@earthlink.net wrote: I've got a project I'm working on to make a sophisticated sundial with moving mirrors. I've got a batch of Arduinos that move the mirrors to the appropriate places, given the current sun angle, etc. I've got a beaglebone that runs some python code to calculate sun angle based on time The beaglebone will have a GPS feeding it to get time. BUT now, I'd like to add a web interface, so that it can be manipulated by a mobile device using a browser. One way I can think of is to run some sort of limited web server. there are a couple that come with the beaglebone, including the python simplehttpserver. But I'm sort of stuck on the interface between the webserver and the other code running. I've done this kind of thing where the one task goes out and updates files in the tree that's being served by the web server, and that works fine for status display kinds of things that don't update very quickly. It's also nicely partitioned. but I want to be able to change the behavior of the system (e.g. by having the server respond to a PUT or something) Is the best scheme to go in and modify the webserver code to look for specific URLs requested, and then fire off some custom code to do what I want? I'm not particularly interested in javascript, and would prefer python. Or are there libraries that make this more cookbook? (the little getting started with beaglebone book talks about flask) There's quite a few websites out there where someone has done some sort of home automation, but they tend to be a bit light on the analysis of pros and cons of implementation architectures: I built X using Y and Z and it sort of works. Actually, along a similar line.. my solar position code isn't very pretty (it's sort of replicating some code I wrote in Basic a long time ago, with some changes from stuff I cribbed from ccmatlab). If someone knows of a python package that just does this, I'd love to hear about it. Either Az El, or X,Y,Z in ECI or ECF would do. ___ 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] Jackson labs fury gpsdo with docxo for sale
The double oven? Sent from mobile On Jun 25, 2015, at 4:25 PM, Rhys D heyr...@gmail.com wrote: According to the brochure, they are only $750 new. Or am I missing something here? R On 26 June 2015 at 03:30, Mark Spencer m...@alignedsolutions.com wrote: Hi I'm wondering if there is any interest in my Jackson labs fury (desktop version) with the docxo option. I purchased it new from Jackson Labs in 2012. It has sat on a shelf powered up for almost the entire time I have owned it. I've been very happy with the unit but I haven't made much use of it over the last year and don't foresee any future need for it. I'm not in a huge hurry to sell it but I would be looking for 1,250 USD plus insured shipping from Canada (also the buyer would need to pay any taxes or duties that are payable by the buyer.) I would include the power supply it shipped with from Jackson labs. I'm also looking at selling it via some other channels as well so it may be gone soon. Please contact me off list if you are interested in pursuing this. I'm happy to send photos and provide more details to an interested party. Thanks Mark Spencer m...@alignedsolutions.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 10MHz LTE-Lite - PPS accuracy?
Or use 1ns per foot of antenna cable. That will get you closer. Sent from mobile On Dec 8, 2014, at 8:16 AM, David J Taylor david-tay...@blueyonder.co.uk wrote: Hi On *most* GPSDO’s, the simple answer is “there is a cable delay adjustment to align it”. Without some sort of reliable representation of UTC (at the ns level) it’s tough to measure. If you happen to live at USNO or NIST, you can access that sort of timing. For the rest of us - not so easy. The NIST two way GPS “modem” setup is about the only practical method that I know of. The PPS out of any GPSDO will be much lower jitter than the pps from a normal GPS module. Bob == Bob, Thanks for your comments. The antenna location and cable lengths are very similar (either 0, 5m or 10m) so I was expecting somewhat less than 50 ns difference. 200+ ns is rather more than I expected for the LTE-Lite, so I did wonder whether anyone else had measured it. Although I've not checked it rigorously, most of the GPS/PPS units here of various brands are within under 100 ns of each other, hence my expectation. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ 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] eBay seller has Z3801A upgraded to 58503A
Get the Fury. Plug and play. Sent from mobile On Nov 27, 2014, at 4:55 PM, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk wrote: There's a seller on eBay selling what he says is Z3801A upgraded to 58503A. One or two things have made me a bit suspicious of that seller - nothing to do with his GPS things. Does anyone know what he does? He also have an 58503A, but that's a couple of hundred $'s more than an upgraded Z3801A. I've been thinking of buying one of the Jackson Labs devices, which is obviously a more modern design, but I'm giving some consideration to buying a used GPSDO with an OCXO, rather than a TCXO. By the time I purchase the TCXO based unit, stick it in a box, build a buffer, add a power supply etc etc, it is not going to work out a lot cheaper than buying a used OCXO device. My mind is not made up about this. There are advantages and disadvantages of both. Dr. David Kirkby Ph.D CEng MIET Kirkby Microwave Ltd Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT, UK. Registered in England and Wales, company number 08914892. http://www.kirkbymicrowave.co.uk/ Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please) ___ 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] Hydrogen Maser KIT! Update #1
Good god, be core full with that. Did you find any references to sputtering the coating. I would think this would give you a more even and more adhesive coating. Some chemical engineering labs at universities do that and would probably coat it for free. I know Dr. Viljoen at Nebraska-Lincoln has a setup for that. He usually sputters metal but I think a Teflon target would work the same. Sent from mobile On Nov 3, 2014, at 10:09 AM, cdel...@juno.com cdel...@juno.com wrote: Coating the bulb with Teflon involves coating the inside with a Teflon liquid aqueous dispersion, letting it dry, and then curing it in an oven at 380 to 400 degrees C for around 30 minutes while circulating dry air through the bulb. A little bit intricate but doable. Main concern is getting the bulb surface absolutely clean before coating. A hydrofluoric acid rinse is a must! Cheers, Corby ___ 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] If any of your USB devices have stopped working lately...
I read somewhere that you can pay FTDI and re-enable the devices but further in the article it said they would be permanently disabled in windows. Confusing. On Thu, Oct 23, 2014 at 10:47 PM, jim s jwsm...@jwsss.com wrote: Petty BS. If they want to disable the competitors, rev the device to have something that they can use to id their devices, and leave the other driver alone. USB supposed to put the widest support in the host end, and the secret sauce in the device. If they have a problem, they will not produce anyone with a dead device wanting to ever do business with them by disabling infringing devices. If they put out a message or such, but still worked with their driver fine. Else I will expect a generic unsigned driver to be out, which can be installed and will again work with all. That isn't desirable for anyone, but if that is what it takes to get going, most will install the unsigned driver, then mark FTDI devices forever off their list. They aren't the only ones with the secret sauce. I've seen several others, and had I known about them planning to do this would have gone with them, and not FTDI. There are only a few things that I have that have incorporated FTDI in, and I'm going to look at dumping that code and device now. Jim On 10/23/2014 8:01 PM, Paul Berger wrote: Unfortunately the issue that FTDI is trying to combat is counterfeiters, and I think you will find that the counterfeit devices will report the same product and vendor id as the genuine ones. The product and vendor ids are how the OS identifies a device and how they decide which device driver should be used. Apparently at least some of these counterfeit devices are not perfect copies or else a device driver would be unable distinguish them from genuine. It is like a number of years ago when cable TV companies where having a lot of trouble with counterfeit cable descramblers, they found a flaw in the code used in them and transmitted what became know as a magic bullet that caused them to fail. Paul. On 2014-10-23 11:30 PM, Chris Albertson wrote: On Thu, Oct 23, 2014 at 7:05 PM, paul swed paulsw...@gmail.com wrote: Umm I think its profoundly hard to know one way or another what chip you have in a widget. Before you buy it yes, you can't know. But it's trivial to find out after you own it. For example click the Apple logo then choose about this Mac and the data is there. For example it says this random USB thumb drive I have is Product ID: 0x3260 Vendor ID: 0x0aec (Neodio Technologies Corporation) Version: 1.00 Serial Number: 20040602032741578 This same exact information is logged every time the device is inserted to my Linux system too. I assume MS Windows will tell you all the vendor info as well. The vendor IDs are handed out to manufacturers by an outfit at usb.org . So, check your devices. It's not hard to find out about the ones you have. This is pretty insane actually. I buy products that I believe are legit no way to know just as if the cpu in my acer or emachines not legal. Heck I have no idea. Regards Paul WB8TSL On Thu, Oct 23, 2014 at 10:02 PM, Bill Dailey docdai...@gmail.com wrote: Well..if they didn't properly license the technology... They should be disabled. Sent from my iPad On Oct 23, 2014, at 8:45 PM, Mark Sims hol...@hotmail.com wrote: Happened to a friend of mine. All his Arduino stuff died. This could be the reason: http://www.eevblog.com/forum/reviews/ftdi-driver-kills- fake-ftdi-ft232 Short story: FTDI released a new version of their USB driver (via Windows automatic updates no less) that bricks other vendor's compatible versions of their interface chip. They also updated their license file to indicate that this may happen... except you never get a chance to decline the new license with automatic driver updates. I can just hear the class action lawyers drooling... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin
Re: [time-nuts] If any of your USB devices have stopped working lately...
Well..if they didn't properly license the technology... They should be disabled. Sent from my iPad On Oct 23, 2014, at 8:45 PM, Mark Sims hol...@hotmail.com wrote: Happened to a friend of mine. All his Arduino stuff died. This could be the reason: http://www.eevblog.com/forum/reviews/ftdi-driver-kills-fake-ftdi-ft232 Short story: FTDI released a new version of their USB driver (via Windows automatic updates no less) that bricks other vendor's compatible versions of their interface chip. They also updated their license file to indicate that this may happen... except you never get a chance to decline the new license with automatic driver updates. I can just hear the class action lawyers drooling... ___ 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] LTE-Lite module
Said, How tough would it be to mate the 10Mhz version up to a really good 10811? I have one that I acquired from Corby some time ago. I was going to spin my own but I wont realistically get to that with everything else I have going on. I was thinking of throwing the LTE-Lite and the 10811 in a box. I woudl then have a stock fury, An enhanced OEM fury (datum-c) and then this gadget with a 10-13 10811. Let me know if this doesnt make sense. I am an amateur. Bill On Sat, Oct 18, 2014 at 5:13 PM, S. Jackson via time-nuts time-nuts@febo.com wrote: Guys, one last email. The board will not fit into the Hammond enclosure without reworking the enclosure or removing the TCXO socket. We initially planned to ship the board without the socket, now all of them will have it. The board was designed to be used without the TCXO/Socket to fit into that enclosure. Caveat: please expect some rework to be necessary when using the suggested Hammond enclosure. bye, Said In a message dated 10/18/2014 12:56:06 Pacific Daylight Time, time-nuts@febo.com writes: Guys, we have been getting a good number of emails with questions that have already been addressed in the user manual or the FAQ, see the below link. We spent a lot of time putting the collateral together, may I please ask that you first look into these two documents to see if your question might already be addressed there? Paul, please search the LTE Lite user manual for Hammond and you will find it there: http://www.jackson-labs.com/index.php/products/lte_lite Thanks, Said _ Do you have a recommended Hammond chassis part number? -- Paul ___ 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. -- Doc Bill Dailey KXØO ___ 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] Any simple way to get 200 MHz from 10 MHz?
I use this for my qs1r (125MHz) and to discipline a sound card (24.576MHz). http://www.valontechnology.com/5007%20synthesizer.html http://www.valontechnology.com/3008%20divider.html I actually have one 5007 sandwiched between two 3008's within a Hammond enclosure I built. Has voltage in, 10MHz in and two frequency outputs. I don't have the setup to measure phase noise but seems to do a decent job for my purposes. Bill Sent from my iPad On Sep 28, 2014, at 5:24 AM, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk wrote: I am looking for a quick simple way to create a frequency of 200 MHz from 10 MHz. Actually 100, 200, 300 or 400 MHz would all work, but 200 MHz would be my preference. The input will be around 0 to +10 dBm and the output needs to be about +13 dBm. I did think of a x5 x4 frequency multipliers and amplifiers from Minicircuits, but I don't know if the increase in phase noise might be a problem. The truth is I don't know how good it needs to be! I am trying to find a way of building something that will allow my HP 8720D VNA (50 MHz-20 GHz) to work below 50 MHz. My idea was to generate a 200 MHz local oscillator to feed a mixer. I was thinking of making it so as the VNA sweeps from 200.01-250 MHz, itthi possible to analyse a DUT over the frequency range 0.01-50 MHz. Having the an integer multiple of 100 MHz is good, as it makes reading the VNA easier. It is simpler to use if the VNA display shows the frequency 200 MHz off than if its 212.5564 MHz wrong. I would rather not have to program anything to do it, but maybe a VCO and PLL is the only sensible approach. I can't seem to find an off the shelf solution which I can lock to a 10 MHz reference. There are plenty of 200 MHz oscillators around based on a TCXO, but I can't lock them to the 10 MHz oscillator the VNA uses. Maybe someone knows of a device I don't know of. Dave. ___ 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] Update on my Arduino GPSDO / NTP server - going atomic
Cool. I have an udoo quad but am using it as a small mysql server for a medical project that is ongoing. I could just try another sd card. My biggest problem is time. I have about 5 simultaneous official work project, a new company that I am coding on an embedded jetson tk1 (computer vision) and a huge all digital phased array project that is on the back burner until we move (nov1) and get settled. Crazy life here. Keep up the good work... I will let you know when I catch up. Bill Sent from mobile On Sep 10, 2014, at 7:48 PM, Andrew Rodland and...@cleverdomain.org wrote: Bill, Since I accidentally let the smoke out of my Due, and I just *happen* to have an UDOO Dual sitting around, I decided to play with it while I wait for a replacement board to come around. UDOO ships an ARM version of Arduino IDE 1.5.4, which is a little bit too old to compile my code properly (I built against 1.5.7), but compiling the project on another machine with 1.5.7 and shipping the .bin to the udoo to upload with bossac works just fine. I removed the call to ether_init() since of course there's no W5100 Ethernet on the udoo. On the i.MX side of the UDOO I have Debian installed (UDOObuntu would work just fine, but it comes with loads and loads of unnecessary crap). First I tested using http://vanheusden.com/time/rpi_gpio_ntp/ which is a user-space daemon that listens for events from a Linux /sys/class/gpio device (Due pin 13 maps to Linux gpio40) and writes to an SHM segment compatible with the ntpd/chrony SHM refclock. That worked just fine, with about 5us jitter most of the time, but you could see that it was occasionally quite a bit higher. Then I worked on getting PPSAPI working. This requires rebuilding the kernel, but turned out to be relatively easy: there's a pps-gpio driver in Linux 3.2 that was easily backported to 3.0 just by applying the patch from LKML, and then it was just a little bit of work to init the device in the UDOO-specific board init function. My changes can be found at https://github.com/arodland/Kernel_Unico/compare/ppsapi if you're interested. With that in place, and the Rb sufficiently warm (I think) I'm seeing between 600ns and 1200ns RMS jitter on the PPS refclock as reported by chrony on the UDOO (pretty good!) and between 3us and 7us RMS jitter on the UDOO as measured over NTP from my desktop with 64-second polling, which is 4 or 5 us better than what I could get with the Due+W5100 combination. I bet at this point half of that figure is coming from instability on the desktop machine itself and nondeterministic ethernet switching delay. I still like the appeal of the bare metal approach, and when I get my new board (Taijiuino, a Due-alike board that routes the SAM3X's Ethernet MAC pins) I'm going to keep going with that, but this is pretty good performance for Linux, I'd say. Andrew On Sat, Sep 6, 2014 at 12:06 PM, Bill Dailey docdai...@gmail.com wrote: Will add it to my list of projects. Will touch bases when I get close. Sent from my iPad On Sep 6, 2014, at 10:18 AM, Andrew Rodland and...@cleverdomain.org wrote: Yes, the source is at http://github.com/arodland/Due-GPS-NTP-Server . It should be able to run just fine on the Due part of an Udoo, but you'll have to come up with a different arrangement for the Ethernet. One way would be to use chip-to-chip SPI to make the i.MX side of the Udoo act more-or-less like the W5100, translating between serial and Ethernet and interrupting the SAM3X when it gets packets. Another way would be to run regular ntpd on Linux (or FreeBSD?) on the i.MX side but give it a custom refclock driver that syncs to the Due (either by locking onto the generated PPS, or by asking the Due to timestamp events and reading the timecode back). If this works well, it could outperform my setup, since the i.MX is clocked quite a bit faster and has its Ethernet MAC on-chip :) Andrew On Sat, Sep 6, 2014 at 12:08 AM, Bill Dailey docdai...@gmail.com wrote: I was wondering if a board like the udoo would help your ntp performance. I have one and would be willing to try this configuration. Have you posted your source? I think I got confused as to who was doing this. I don't have a rubidium but I have a 6T on a breakout and a couple of very good ocxo's (mid 10-13 at 1s) that I could use. I have about 100 projects going on but a project like this has been on the back burner for awhile. I have a couple of furies I could test it against also. Bill Sent from my iPad On Sep 5, 2014, at 2:07 PM, Andrew Rodland and...@cleverdomain.org wrote: After some productive work, and some frustrating weeks spent fighting weird flakiness and needlessly replacing components, only to find that the problems went away after I reseated my main power connector, IT WORKS! Here's where I am now: * Main board: Arduino Due (ATSAM3X ARM Cortex-M3 CPU @ 84MHz) * Oscillator
Re: [time-nuts] Update on my Arduino GPSDO / NTP server - going atomic
I apologize. I didn't mean for that last post to go through the list. Sent from my iPad On Sep 10, 2014, at 7:48 PM, Andrew Rodland and...@cleverdomain.org wrote: Bill, Since I accidentally let the smoke out of my Due, and I just *happen* to have an UDOO Dual sitting around, I decided to play with it while I wait for a replacement board to come around. UDOO ships an ARM version of Arduino IDE 1.5.4, which is a little bit too old to compile my code properly (I built against 1.5.7), but compiling the project on another machine with 1.5.7 and shipping the .bin to the udoo to upload with bossac works just fine. I removed the call to ether_init() since of course there's no W5100 Ethernet on the udoo. On the i.MX side of the UDOO I have Debian installed (UDOObuntu would work just fine, but it comes with loads and loads of unnecessary crap). First I tested using http://vanheusden.com/time/rpi_gpio_ntp/ which is a user-space daemon that listens for events from a Linux /sys/class/gpio device (Due pin 13 maps to Linux gpio40) and writes to an SHM segment compatible with the ntpd/chrony SHM refclock. That worked just fine, with about 5us jitter most of the time, but you could see that it was occasionally quite a bit higher. Then I worked on getting PPSAPI working. This requires rebuilding the kernel, but turned out to be relatively easy: there's a pps-gpio driver in Linux 3.2 that was easily backported to 3.0 just by applying the patch from LKML, and then it was just a little bit of work to init the device in the UDOO-specific board init function. My changes can be found at https://github.com/arodland/Kernel_Unico/compare/ppsapi if you're interested. With that in place, and the Rb sufficiently warm (I think) I'm seeing between 600ns and 1200ns RMS jitter on the PPS refclock as reported by chrony on the UDOO (pretty good!) and between 3us and 7us RMS jitter on the UDOO as measured over NTP from my desktop with 64-second polling, which is 4 or 5 us better than what I could get with the Due+W5100 combination. I bet at this point half of that figure is coming from instability on the desktop machine itself and nondeterministic ethernet switching delay. I still like the appeal of the bare metal approach, and when I get my new board (Taijiuino, a Due-alike board that routes the SAM3X's Ethernet MAC pins) I'm going to keep going with that, but this is pretty good performance for Linux, I'd say. Andrew On Sat, Sep 6, 2014 at 12:06 PM, Bill Dailey docdai...@gmail.com wrote: Will add it to my list of projects. Will touch bases when I get close. Sent from my iPad On Sep 6, 2014, at 10:18 AM, Andrew Rodland and...@cleverdomain.org wrote: Yes, the source is at http://github.com/arodland/Due-GPS-NTP-Server . It should be able to run just fine on the Due part of an Udoo, but you'll have to come up with a different arrangement for the Ethernet. One way would be to use chip-to-chip SPI to make the i.MX side of the Udoo act more-or-less like the W5100, translating between serial and Ethernet and interrupting the SAM3X when it gets packets. Another way would be to run regular ntpd on Linux (or FreeBSD?) on the i.MX side but give it a custom refclock driver that syncs to the Due (either by locking onto the generated PPS, or by asking the Due to timestamp events and reading the timecode back). If this works well, it could outperform my setup, since the i.MX is clocked quite a bit faster and has its Ethernet MAC on-chip :) Andrew On Sat, Sep 6, 2014 at 12:08 AM, Bill Dailey docdai...@gmail.com wrote: I was wondering if a board like the udoo would help your ntp performance. I have one and would be willing to try this configuration. Have you posted your source? I think I got confused as to who was doing this. I don't have a rubidium but I have a 6T on a breakout and a couple of very good ocxo's (mid 10-13 at 1s) that I could use. I have about 100 projects going on but a project like this has been on the back burner for awhile. I have a couple of furies I could test it against also. Bill Sent from my iPad On Sep 5, 2014, at 2:07 PM, Andrew Rodland and...@cleverdomain.org wrote: After some productive work, and some frustrating weeks spent fighting weird flakiness and needlessly replacing components, only to find that the problems went away after I reseated my main power connector, IT WORKS! Here's where I am now: * Main board: Arduino Due (ATSAM3X ARM Cortex-M3 CPU @ 84MHz) * Oscillator: Symmetricom X72. * GPS: Trimble Resolution T with a cheap Gilsson puck antenna. * Ethernet: Wiznet W5100. The X72 is used to externally clock one of the ARM's hardware timer/counters at 10MHz (I'm not multiplying it up and using it to clock the CPU). The same timer timestamps the rising edge of the PPS using capture mode, jitter free @ 100ns resolution. All the PLL is done digitally using these values
Re: [time-nuts] Update on my Arduino GPSDO / NTP server - going atomic
Will add it to my list of projects. Will touch bases when I get close. Sent from my iPad On Sep 6, 2014, at 10:18 AM, Andrew Rodland and...@cleverdomain.org wrote: Yes, the source is at http://github.com/arodland/Due-GPS-NTP-Server . It should be able to run just fine on the Due part of an Udoo, but you'll have to come up with a different arrangement for the Ethernet. One way would be to use chip-to-chip SPI to make the i.MX side of the Udoo act more-or-less like the W5100, translating between serial and Ethernet and interrupting the SAM3X when it gets packets. Another way would be to run regular ntpd on Linux (or FreeBSD?) on the i.MX side but give it a custom refclock driver that syncs to the Due (either by locking onto the generated PPS, or by asking the Due to timestamp events and reading the timecode back). If this works well, it could outperform my setup, since the i.MX is clocked quite a bit faster and has its Ethernet MAC on-chip :) Andrew On Sat, Sep 6, 2014 at 12:08 AM, Bill Dailey docdai...@gmail.com wrote: I was wondering if a board like the udoo would help your ntp performance. I have one and would be willing to try this configuration. Have you posted your source? I think I got confused as to who was doing this. I don't have a rubidium but I have a 6T on a breakout and a couple of very good ocxo's (mid 10-13 at 1s) that I could use. I have about 100 projects going on but a project like this has been on the back burner for awhile. I have a couple of furies I could test it against also. Bill Sent from my iPad On Sep 5, 2014, at 2:07 PM, Andrew Rodland and...@cleverdomain.org wrote: After some productive work, and some frustrating weeks spent fighting weird flakiness and needlessly replacing components, only to find that the problems went away after I reseated my main power connector, IT WORKS! Here's where I am now: * Main board: Arduino Due (ATSAM3X ARM Cortex-M3 CPU @ 84MHz) * Oscillator: Symmetricom X72. * GPS: Trimble Resolution T with a cheap Gilsson puck antenna. * Ethernet: Wiznet W5100. The X72 is used to externally clock one of the ARM's hardware timer/counters at 10MHz (I'm not multiplying it up and using it to clock the CPU). The same timer timestamps the rising edge of the PPS using capture mode, jitter free @ 100ns resolution. All the PLL is done digitally using these values and the adjustment is sent to the X72 over serial (DDS, 2 ppt resolution). After about a day's solid running, the PPS phase stays within +/- 100ns as measured on the board itself, even out to a PLL tau of 1 hour, and the frequency adjust stays within 1 ppt when 5-minute averaged. I'm collecting data against an outside reference now (PPS generated by the board against the PPS of a Spectracom NetClock with OCXO option). Too early for graphs, but it looks good. On the Ethernet end, things are less good, but still respectable -- about 10us RMS added jitter. I think a lot of this is introduced by the W5100, and I'm working on getting my hands on a board that uses the same chip but actually makes use of the onchip Ethernet MAC that the Arduino doesn't bother to route, which should help substantially. Already it's better than conventional wisdom says NTP gets :) Questions I still have: 1. Should I try using the analog EFC to zero out the amount of correction I ask the X72's DDS for? Could reduce jitter in the timebase, could just add noise. I suppose I can test this one easily enough. 2. Is there any point in decoding the sawtooth correction from the GPS, or in wiring up the PICTIC and using it to measure the GPS offset more accurately, when my clock granularity is 100ns anyway? I suppose at best I'd be improving my accuracy from +/- 1.5 ticks to +/- 0.5 ticks. 3. Anything else I should consider? If anyone is curious, code is at https://github.com/arodland/Due-GPS-NTP-Server . Thanks for following, Andrew On Tue, Jul 29, 2014 at 12:42 AM, Andrew Rodland and...@cleverdomain.org wrote: Hi all, After a couple years not doing anything except letting it sit in my den and provide time for my home network, I've decided to start hacking on my hobby project again. For reference, what I've got right now is a Freetronics EtherMega (ATMega2560-based Arduino clone with integrated W5100 ethernet), wired up to a USGlobalSat ET-318-02 (a pretty cheap consumer SiRF-III module). It runs totally custom timekeeping, PLL, and NTP protocol code. The timebase is the onboard crystal, which I have no way of influencing directly, so it basically does DDS, adding or duplicating the occasional tick to keep lock. For such a ramshackle collection of equipment it does a pretty good job, tracking within around 10us of a Spectracom NetClock (and showing less Ethernet-induced jitter than the NetClock itself) I've been thinking for years about building a next-gen version, and sketched a few designs
Re: [time-nuts] Update on my Arduino GPSDO / NTP server - going atomic
I was wondering if a board like the udoo would help your ntp performance. I have one and would be willing to try this configuration. Have you posted your source? I think I got confused as to who was doing this. I don't have a rubidium but I have a 6T on a breakout and a couple of very good ocxo's (mid 10-13 at 1s) that I could use. I have about 100 projects going on but a project like this has been on the back burner for awhile. I have a couple of furies I could test it against also. Bill Sent from my iPad On Sep 5, 2014, at 2:07 PM, Andrew Rodland and...@cleverdomain.org wrote: After some productive work, and some frustrating weeks spent fighting weird flakiness and needlessly replacing components, only to find that the problems went away after I reseated my main power connector, IT WORKS! Here's where I am now: * Main board: Arduino Due (ATSAM3X ARM Cortex-M3 CPU @ 84MHz) * Oscillator: Symmetricom X72. * GPS: Trimble Resolution T with a cheap Gilsson puck antenna. * Ethernet: Wiznet W5100. The X72 is used to externally clock one of the ARM's hardware timer/counters at 10MHz (I'm not multiplying it up and using it to clock the CPU). The same timer timestamps the rising edge of the PPS using capture mode, jitter free @ 100ns resolution. All the PLL is done digitally using these values and the adjustment is sent to the X72 over serial (DDS, 2 ppt resolution). After about a day's solid running, the PPS phase stays within +/- 100ns as measured on the board itself, even out to a PLL tau of 1 hour, and the frequency adjust stays within 1 ppt when 5-minute averaged. I'm collecting data against an outside reference now (PPS generated by the board against the PPS of a Spectracom NetClock with OCXO option). Too early for graphs, but it looks good. On the Ethernet end, things are less good, but still respectable -- about 10us RMS added jitter. I think a lot of this is introduced by the W5100, and I'm working on getting my hands on a board that uses the same chip but actually makes use of the onchip Ethernet MAC that the Arduino doesn't bother to route, which should help substantially. Already it's better than conventional wisdom says NTP gets :) Questions I still have: 1. Should I try using the analog EFC to zero out the amount of correction I ask the X72's DDS for? Could reduce jitter in the timebase, could just add noise. I suppose I can test this one easily enough. 2. Is there any point in decoding the sawtooth correction from the GPS, or in wiring up the PICTIC and using it to measure the GPS offset more accurately, when my clock granularity is 100ns anyway? I suppose at best I'd be improving my accuracy from +/- 1.5 ticks to +/- 0.5 ticks. 3. Anything else I should consider? If anyone is curious, code is at https://github.com/arodland/Due-GPS-NTP-Server . Thanks for following, Andrew On Tue, Jul 29, 2014 at 12:42 AM, Andrew Rodland and...@cleverdomain.org wrote: Hi all, After a couple years not doing anything except letting it sit in my den and provide time for my home network, I've decided to start hacking on my hobby project again. For reference, what I've got right now is a Freetronics EtherMega (ATMega2560-based Arduino clone with integrated W5100 ethernet), wired up to a USGlobalSat ET-318-02 (a pretty cheap consumer SiRF-III module). It runs totally custom timekeeping, PLL, and NTP protocol code. The timebase is the onboard crystal, which I have no way of influencing directly, so it basically does DDS, adding or duplicating the occasional tick to keep lock. For such a ramshackle collection of equipment it does a pretty good job, tracking within around 10us of a Spectracom NetClock (and showing less Ethernet-induced jitter than the NetClock itself) I've been thinking for years about building a next-gen version, and sketched a few designs, but I could never quite find a board that I wanted to use as the core of it. Well, Freetronics sent me a product announcement for their EtherDue board (built around the ATSAM3X, which is an ARM Cortex-M3 chip from AVR), I read some specs, and decided to dive in. I've got a working, tuned-up LPRO-101, and I always figured that my next build would desolder the clock crystal and use the Rb as the CPU timebase, like most builds I've seen do. But I realized that the ATSAM3X is happy to run its timer/counters off of an external clock as long as it's less than 1:2.5 the CPU clock. 10MHz fits that bill. I lose a little bit on granularity by not letting the CPU multiply that up 8x for me, but probably no real change in accuracy. Just feed the Rb to a pair of pins and get a register that counts up every 100ns, seems simple! For locking to the PPS I could do the usual thing and use input capture on the timer clocked by the Rb, which would handily timestamp the rising edge of the PPS. But I have a couple of PICTIC IIs laying around, and I'm a bit
Re: [time-nuts] How are iPhones' clocks set under LTE?
For informational purposes I will show what I use to compare with my stock Iphone. It is an app called emerald time. Screenshot at: https://www.dropbox.com/s/zt6tjrsylrrtrc3/2014-08-04%2008.06.02.png You can set it up to sync with you own ntp server. I think. You can just spot check it. I have never done a rigorous analysis but it appears to be within 1.5s or better most of the time. Doc Sent from mobile On Aug 4, 2014, at 7:38 AM, BIll Ezell w...@quackers.net wrote: LTE does support the long-standard NITZ (network information and time zone) service. It's an easy way to find out just where you are without having to change your TZ settings constantly. In fact, if you go to time settings on HTC Android phones, the 'automatic time update(NITZ)' setting turns on NITZ syncing. iPhones also use NITZ, as do most 3G or LTE phones. But, not necessarily for time. NITZ implementation is carrier-optional, although almost all do support it. I know that Vodafone-Austrailia and a handful of other carriers at least at one point didn't support it. Additionally, the standard doesn't specify how accurate the time has to be, and it varies widely across providers. It's usually within a few seconds, but this isn't a high-precision time reference and can be off by minutes. But, a phone can use the timezone information to then localize time from some other time service. An alternative to determine what your physical location location is uses lower-level information such as the ECGI (extended cell group identity) or location information from the MME (Mobile Management Entity). Don't you just love telecom? Everything's an acronym and frequently an acronym^2 or ^3. Anyway, the phone then looks up the physical location from whatever id it uses, then uses a time service to get the actual time, then localizes it based on the physical location. Clearly, just using something like NTP directly isn't all that useful because you have to know your physical location to know what timezone correction to apply. I work on cell infrastructure, mostly 3G and LTE (Ericsson), and it just amazes me that phones work at all. It is incredibly complicated and convoluted. Unlike CDMA (where time distribution was an automatic part of the low-level protocol) I suspect the time displayed on many modern phones is not set by the telephony synchronous protocol but rather by IP-over-Wifi packets. And the packets don't seem to do a very effective job keeping the clock ont he phone correct. My employer gave me a Nokia Lumia 630 Windows Phone and its clock has always been off by at least a minute. There was a few years ago, a very nice article about the effort to repair the clocks in clock towers in many cities. What rang most true to me was if you visit a town they can't even keep the clock correct, who else knows what else is wrong there?. Tim N3QE -- Bill Ezell -- The day Microsoft makes something that doesn't suck will be the day they make vacuum cleaners. ___ 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] How are iPhones' clocks set under LTE?
you would have to dig around and look. I am sure there is. I have played with it for a year or two. I put my own ntp server in there and was frequently disappinted that it would prefer remote servers quite often.. which cant be better than mine. I dont get that but otherwise I like it. Bill On Mon, Aug 4, 2014 at 5:32 PM, Shane Morris edgecombe...@gmail.com wrote: Bill, I just got Emerald Time for my iPad - quite a great app, considering I need accurate time for things. Is there a website for the app developer? Many thanks! Shane. On Tue, Aug 5, 2014 at 8:16 AM, Bob Camp kb...@n1k.org wrote: Hi I *think* it’s even more specific than that. I’ve watched it switch time driving down the road in Indiana. As we did zig zags over the time zone line, the iPhone quite happily changed displayed time. My guess was that it used GPS location info to decide which side of the line it was on. Bob On Aug 4, 2014, at 1:19 PM, Glen Hoag h...@hiwaay.net wrote: As someone who crosses time zone boundaries with relative frequency, I can tell you that the iPhone does indeed set it's time zone automatically, based on information the phone gets from the cellular network. Sent from my iPhone On Aug 4, 2014, at 11:49, Chris Albertson albertson.ch...@gmail.com wrote: On Mon, Aug 4, 2014 at 5:38 AM, BIll Ezell w...@quackers.net wrote: Clearly, just using something like NTP directly isn't all that useful because you have to know your physical location to know what timezone correction to appl I'm pretty sure you have to set the time zone that is displayed. It does not change based on location. Although one col writ an app that would do that. There are MANY clock apps some show multiple time zones. Interannly the phone uses GMT (offset zero) -- 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. ___ 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. -- Doc Bill Dailey KXØO ___ 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] How are iPhones' clocks set under LTE?
ahhh.. I wondered On Mon, Aug 4, 2014 at 7:27 PM, Paul tic-...@bodosom.net wrote: On Mon, Aug 4, 2014 at 6:32 PM, Shane Morris edgecombe...@gmail.com wrote: Bill, I just got Emerald Time for my iPad - quite a great app, considering I need accurate time for things. Is there a website for the app developer? http://www.emeraldsequoia.com/ On Mon, Aug 4, 2014 at 8:01 PM, Bill Dailey docdai...@gmail.com wrote: I put my own ntp server in there and was frequently disappinted This is an acknowledged design flaw on their part. It will only choose a user provided clock if the default pool is unavailable (short or long term). ___ 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. -- Doc Bill Dailey KXØO ___ 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
In a container, as steam condenses the pressure will drop. The steam will stay saturated. This is as long as the container contains steam only. Eventually, as the steam cools and condenses you will be left with a vacuum contains only minimal water vapor. Sent from mobile On Jul 22, 2014, at 2:11 PM, Attila Kinali att...@kinali.ch wrote: On Tue, 22 Jul 2014 01:17:03 +0100 Brian D gro...@planet3.freeuk.co.uk wrote: Saturated steam at standard pressure will be exactly 212F, or 100C. Stupid question: How to you ensure that the steam is saturated, while keeping a constant pressure? I think just buying some indium off ebay and use that as a melting/freezing reference is easier than the contraption needed to ensure fully saturated steam, with a low temperature gradient over the temperature sensor. That said. My investigations into stability of PT100 sensors reveal, that the quality ones can be less than 10mK/year, but hysteresis is in the same ball park (see [1]). Attila Kinali [1] Long term stability and hysteresis effects in Pt100 sensors used in industry, by Ljungblad, Holmstein, Josefson, Klevedal, 2013 -- I pity people who can't find laughter or at least some bit of amusement in the little doings of the day. I believe I could find something ridiculous even in the saddest moment, if necessary. It has nothing to do with being superficial. It's a matter of joy in life. -- Sophie Scholl ___ 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
Ice water and boiling water coupled with altitude will give you two points. Sent from mobile On Jul 21, 2014, at 10:12 AM, Attila Kinali att...@kinali.ch wrote: On Mon, 21 Jul 2014 04:39:51 -0700 Alexander Pummer alex...@ieee.org wrote: NTC are not that very stable, they are amorphous material winch could recrystallize slowly and therefore change it's electrical behavior , PT100 style is more reliable since it is pure metal How long is the time constant for NTCs? I guess, it wouldn't matter for most of the measurements we do, as NTCs need to be calibrated before precision measurements anyways. Unless one measures over several months, or years. But on this timescales, i wouldn't really trust an off the shelf PT100 either. Not unless i measure its stability For use in GPSDOs and OCXOs, i guess it doesn't really matter, as long as the NTC stays within spec. There an external loop corrects for the variation/drift of the measurement. While we are at it: what is a good way to calibrate/characterize temperature sensors that is available to hobbyists? Attila Kinali -- I pity people who can't find laughter or at least some bit of amusement in the little doings of the day. I believe I could find something ridiculous even in the saddest moment, if necessary. It has nothing to do with being superficial. It's a matter of joy in life. -- Sophie Scholl ___ 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
You don't use ice as a reference. With ice water, the same principles apply that apply to boiling water. This is why these are convenient calibration check points. Sent from mobile On Jul 21, 2014, at 3:51 PM, jim s jwsm...@jwsss.com wrote: On 7/21/2014 11:36 AM, Hal Murray wrote: docdai...@gmail.com said: Ice water and boiling water coupled with altitude will give you two points. Has anybody used a good thermometer to measure air pressure? How much does the measured temperature vary between just barely boiling and a good roiling boil? Or in various locations within a pot of boiling water? When you are dealing with water phase changes, you are dealing with both temperature and heat. When you get up to a point like boiling, you have a mass of water which is at the local boiling point and the only thing stopping the water from going to steam phase is the amount of heat in the water. Once a pot of water is at rolling boil all of the water in the pan should be at and stay at the boiling point till it is all gone. Once you remove the heat, the boiling will slow and stop, and the temperature will begin to fall as the water loses the heat. As long as you maintain a balance between having the sensor too close to the point you are applying heat, and keeping it immersed in boiling water, you should be able to assume the local boiling point. That boiling point has to be adjusted for pressure, which affects the temp the most. Also assuming only water, and no other contaminants as mentioned by another poster. The same sort of action occurs when water freezes, along with some other oddball issues with the crystalization. You can arrive at the freezing point, and you will dwell there for some time as the water loses its heat and becomes solid. The thing that is different between freezing and boiling is that as long as you have water and are boiling the temperature will remain at boiling, and no higher. With freezing, if you are measuring water as you cool it and remove heat, it will go thru freezing with a pause as it goes to ice, then it can continue to cool as cold as you like. so when you are measuring by using ice as a reference, you should have frozen the sensor or drilled it into the center of a block of ice, and let it come to equilibrium in the ice w/o any freezing apparatus being active. It should come to the freezing point till all of the ice melts. Jim ___ 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] BeagleBone Black NTP server
I have the adafruit and a ublox-6T each mated to raspberry pi's. With NTP they are essentially indistinguishable. I have something other than NTP in mind for the 6Tpi. Sent from my iPad On May 9, 2014, at 9:32 PM, Brian Lloyd br...@lloyd.com wrote: On Fri, May 9, 2014 at 8:49 PM, Chris Albertson albertson.ch...@gmail.comwrote: On Fri, May 9, 2014 at 1:55 PM, Brian Lloyd br...@lloyd.com wrote: Has anyone here made NTP run on BBB? My plan is to run NTP disciplined by my Trimble Thunderbolt on BBB. NTP is likely already installed on the BBB. It ships with the BBB. That may be the case for the Angstrom distro but it is not the case for the Debian distro, which seems to be the future direction of BBB. Some configuration is needed to enable the service. Do this first and verify you can run using Internet pool servers. Then after this is running you physically connect your GPS then add lines in NTP's config file telling NTP you have added another ref. clock. This link: http://the8thlayerof.net/2013/12/08/adafruit-ultimate-gps-cape-creating-custom-beaglebone-black-device-tree-overlay-file/ Seems to have the bulk of the requisite information including building a GPS cape using the Adafruit GPS module. See: https://www.adafruit.com/product/746 This isn't a timing receiver but would probably be adequate for NTP. But since I already have a T-bolt I figured I would use that as my timing source. -- Brian Lloyd, WB6RQN/J79BPL 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ 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] Rb vs.Crystal OCXO
I unplug the antenna from my fury boards. I hope this is an effective alternative. Sent from mobile On Apr 27, 2014, at 9:02 AM, Tom Van Baak t...@leapsecond.com wrote: The Pendulum GPS-88 and GPS-89 have a button on the front you push when you want to force it into hold-over to do your measurement, for this very reason. PPS steering and OCXO steering is the same thing once you forced the PPS into the right range. Some *really* depend on the synchronicity between 10 MHz and PPS, and you should not obscure it if possible. Cheers, Magnus When doing a sensitive measurement where stability is more important than accuracy I turn off GPS disciplining. The TBolt has commands to go into and out of holdover. But more effective are the 0x8E,0xA3,4 and 0x8E,0xA3,5 commands which simply disable and enable disciplining. /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] Measuring 1 PPS with an HP 5335A
No idea. That's what's sad. They all blend together. Sent from mobile On Feb 16, 2014, at 6:17 PM, Jimmy D. Burrell jimmydb...@gmail.com wrote: Bingo! It's working now!! Thanks to everyone on the thread. Paul, I have to give chops to Bob on this one, even though my experience is the same as yours with respect to the preset triggers. Actually, your comments/question about the trigger lights flashing in concert with the 1PPS signal got me looking/thinking and no, they weren't. BTW, my 0.01 number was meant to be Hz but I left off the units. Both Bobs (Camp and Albert) were pointing me at the 'input'. So, I drug out the HP5335A manual and re-read about all 4 trigger levels. Auto-adjustable mode allows adjusting the trigger according to the amplitude of the input signal... a sort of percentage trigger mode, i.e. turn the trigger control clockwise to 3/4 scale and you're triggering at 75% of the signal's amplitude. The above trigger changes combined with reconfiguring for 50ohms input signal did the trick. I'm now seeing readings like 0.999 999 983 +0. Thanks again, Jim... N5SPE On Feb 16, 2014, at 4:07 PM, Bob Camp li...@rtty.us wrote: Hi If you have a 50/50 duty cycle 1 pps, it’s going to work with a lot of settings. With a narrow (say 10us wide) pulse, most of the counters have auto trigger issues. If it’s already known to be reading nutty, trigger is a good place to start looking. Bob On Feb 16, 2014, at 4:29 PM, Paul tic-...@bodosom.net wrote: On Sun, Feb 16, 2014 at 2:33 PM, Bob Camp li...@rtty.us wrote: On all these counters, you need to switch to DC input for 1 pps signals. You also need to manualy set the trigger level to something like +1.5V. I can't believe I'm disagreeing with Bob Camp but this is not my experience. 99.9% of the time preset trigger works fine and I think you should start with that. AC coupling almost always works and is sometimes required (with the Rb I think). I have a 5335A (w/ opt 010+040) and have measured 1PPS on my PRS-10, Fury, Firefly and random GPS parts. If the trigger light is not flashing at 1 Hz the only thing I've ever had to do is toggle AC coupling or enable 1PPS output on the device (or plug it in). Sometimes increasing the gate time tidies up the display. ___ 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.
Re: [time-nuts] Measuring 1 PPS with an HP 5335A
Disregard that. Meant for someone else. I apologize. Sent from mobile On Feb 16, 2014, at 7:33 PM, Bill Dailey docdai...@gmail.com wrote: No idea. That's what's sad. They all blend together. Sent from mobile On Feb 16, 2014, at 6:17 PM, Jimmy D. Burrell jimmydb...@gmail.com wrote: Bingo! It's working now!! Thanks to everyone on the thread. Paul, I have to give chops to Bob on this one, even though my experience is the same as yours with respect to the preset triggers. Actually, your comments/question about the trigger lights flashing in concert with the 1PPS signal got me looking/thinking and no, they weren't. BTW, my 0.01 number was meant to be Hz but I left off the units. Both Bobs (Camp and Albert) were pointing me at the 'input'. So, I drug out the HP5335A manual and re-read about all 4 trigger levels. Auto-adjustable mode allows adjusting the trigger according to the amplitude of the input signal... a sort of percentage trigger mode, i.e. turn the trigger control clockwise to 3/4 scale and you're triggering at 75% of the signal's amplitude. The above trigger changes combined with reconfiguring for 50ohms input signal did the trick. I'm now seeing readings like 0.999 999 983 +0. Thanks again, Jim... N5SPE On Feb 16, 2014, at 4:07 PM, Bob Camp li...@rtty.us wrote: Hi If you have a 50/50 duty cycle 1 pps, it’s going to work with a lot of settings. With a narrow (say 10us wide) pulse, most of the counters have auto trigger issues. If it’s already known to be reading nutty, trigger is a good place to start looking. Bob On Feb 16, 2014, at 4:29 PM, Paul tic-...@bodosom.net wrote: On Sun, Feb 16, 2014 at 2:33 PM, Bob Camp li...@rtty.us wrote: On all these counters, you need to switch to DC input for 1 pps signals. You also need to manualy set the trigger level to something like +1.5V. I can't believe I'm disagreeing with Bob Camp but this is not my experience. 99.9% of the time preset trigger works fine and I think you should start with that. AC coupling almost always works and is sometimes required (with the Rb I think). I have a 5335A (w/ opt 010+040) and have measured 1PPS on my PRS-10, Fury, Firefly and random GPS parts. If the trigger light is not flashing at 1 Hz the only thing I've ever had to do is toggle AC coupling or enable 1PPS output on the device (or plug it in). Sometimes increasing the gate time tidies up the display. ___ 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.
Re: [time-nuts] Line Frequency
The PicPET is what I use. Input is from a 5v ac transformer. Seems simple to me. I bought a handful of these. Love em. http://www.leapsecond.com/pic/picpet.htm Doc Sent from mobile On Feb 9, 2014, at 7:53 AM, M. Simon msimon6...@yahoo.com wrote: This probably came up during the recent discussion of Line Frequency Monitoring but I may have missed it. Does any one have a circuit (tested - operational) for monitoring line frequency? I'd like something that checks zero crossing so that it is relatively insensitive to line voltage variations. Simon Engineering is the art of making what you want from what you can get at a profit. ___ 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] Local Solar Time Clock
http://www.precisionsundials.com The sawyer looks like it fits the bill. $8,000 Sent from mobile On Jan 18, 2014, at 4:25 PM, P Nielsen pniel...@tpg.com.au wrote: I am looking for a physical clock (not software) that will indicate local solar time. IOW when the sun is at its highest point, the clock would reliably read 12:00 throughout the year. Is there a commercial product or kit available for this? Thank you for any suggestions. P Nielsen ___ 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] Is this measurement for real?
Sounds about right. Sent from mobile On Dec 7, 2013, at 2:24 PM, quartz55 quart...@hughes.net wrote: I've been testing my soundcard measurement capability with Speclab, so I hooked my LPRO Rb to lock my Moto Service Monitor, fed the 1K audio out into the sound card and I measured the freq over about a half hour. I got a spread of about 107uHz. I've tried a few other things through my TS2000 using a 1500Hz tone from the USB and I can see when the fan goes on and off although I have the RX main osc locked to the GPSDO with the XRef from VK3HZ. I can only assume the drifting in the RX is due to the DSP processing crystal drifting with temp. I get about 13mh drift on that. Anyhow, here's a shot of the 1000Hz directly into the soundcard with Speclab. http://i251.photobucket.com/albums/gg287/DogTi/time/1k30m_zpsc4173981.jpg I almost don't believe it, does anyone else? Dave N3DT ___ 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] Man killed in quartz crystal accident
So throw caution to the wind because other things kill people? 100% of people die from something. So we shouldn't try to keep from killing bystanders because they are going to die anyway? Sounds a bit sociopathic to me. Doc Sent from mobile On Nov 26, 2013, at 7:34 AM, J. Forster j...@quikus.com wrote: Far more people are killed and injured every year by car crashes and smoking than by all civilian incidents, or even atomic warfare, in history. -John === This quartz crystal accident is a canary in the coal mine that demonstrates how poor safety and regulations often work in the real world. What I feel is a bigger concern is the similar risks we have with our aging Nuclear reactors. Many are over twenty-five years past their intended life. The problem is today they are paid for, and the government insures them, so they are very profitable. The question is do any of the safety officials and inspectors really have the authority to close them when they become inherently unsafe? I don't think so. I think they will run until one catastrophically fails. I think government oversight is far to often an illusion. Thomas Knox Date: Tue, 26 Nov 2013 00:51:49 -0500 From: n...@verizon.net To: time-nuts@febo.com Subject: Re: [time-nuts] Man killed in quartz crystal accident I oncecancelled my purchase of a home when I found a sign nearby indicating an underground high pressure gas transmission line. These days they're probably removing the signs. Let's hope the government doesn't decide that precise timekeeping is of strategic value and not permitted amongst ordinary people. On 11/25/2013 11:49 PM, Joe Leikhim wrote: If you really want to lose sleep, think about those old rusty 24 inch gas mains running under your neighborhood like in San Bruno California. The warning signs were present there as well. Now thanks to Homeland Security you can't find accurate gas transmission maps on-line unless you are cleared. So if you are buying a house in a particular neighborhood, do some walking around looking for signs of buried facilities. ___ 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.
Re: [time-nuts] Man killed in quartz crystal accident
I am a chemical engineer and am quite frankly appalled that this kind of high pressure process would be done in such proximity to innocents. On Sun, Nov 24, 2013 at 6:53 PM, Bob Camp li...@rtty.us wrote: Hi NDK has multiple plants growing quartz around the world. They also have a number of competitors in that business. There are better places than NDK to buy high end bars. Bob On Nov 24, 2013, at 7:00 PM, Bill Hawkins b...@iaxs.net wrote: This is not as far from time-nutty things as it might appear. NDK makes precision crystal oscillators from those crystals. One of them is an OCXO less than an inch (20 mm) square and half that high with stability of 3x10E-9 over the range of -40 to 85 C. Annual drift is typically 50x10E-9. The data sheet is at: http://www.ndk.com/en/news/2013/1190702_1616.pdf The CSB released an impressive video of the incident last month. It is in the final report at: http://www.csb.gov/ndk-crystal-inc-explosion-with-offsite-fatality-/ The financial forecast for NDK shows 50 to 60% drop in profits for the same sales in 2013. If that was also true in 2009, management was motivated to maximize production with what they had. The original consultant strongly recommended inspections for stress corrosion cracking, but strong recommendations do not have financial penalties. It has become obvious that money is the only thing that matters at the management level these days. Oh, and don't bother trying to Google for pure quartz crystals to find out whether the cost went up in 2010 after one of the two manufacturers in the US was shut down. The people whose magical thinking extends to crystals want purity, so all crystals are pure. Help prevent incomplete knowledge. Bill Hawkins -Original Message- From: Robert Atkinson Sent: Sunday, November 24, 2013 1:43 AM The US Chemical Safety Board have released their report into the 2009 accident at NDK's synthetic crystal growing facility in Belvidere IL http://www.csb.gov/assets/1/19/CSB_CaseStudy_NDK_1107_500PM.pdf It also describes the process. Basically a 50ft autoclave failed, killing a member of the public at a rest stop 650ft away. Looks like management decisions, probably based on cost, overriding engineering advice even following an earlier minor incident. The letters from a consulting engineer in the annex make interesting reading. It illustrates the importance of those professional engineers amongst us notifying and recording any safety issues we discover. The facility is still shut down and the insurance company won't settle as NDK were told of possible issues. Robert G8RPI. ___ 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. -- Doc Bill Dailey KXØO ___ 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] Man killed in quartz crystal accident
I have operated nuclear plants... I would rather sleep 40 feet from a nuclear plant rather than 1000 feet from a 30,000 pound pressure vessel. The pressure vessel has a much higher likelihood of releasing tremendous potential energy. I am not talking about wilderness... but less than 1000 feet from a truckstop and freeway.. really. Huge pressure vessels? Bill On Sun, Nov 24, 2013 at 8:15 PM, Bob Camp li...@rtty.us wrote: Hi Well, let’s see, nearest operational facility is about 6 miles away down in the middle of town over by the High School. It’s been there since the 1950’s. There used to be a few more around here, since shut down. Bob On Nov 24, 2013, at 8:10 PM, Bill Dailey docdai...@gmail.com wrote: I am a chemical engineer and am quite frankly appalled that this kind of high pressure process would be done in such proximity to innocents. On Sun, Nov 24, 2013 at 6:53 PM, Bob Camp li...@rtty.us wrote: Hi NDK has multiple plants growing quartz around the world. They also have a number of competitors in that business. There are better places than NDK to buy high end bars. Bob On Nov 24, 2013, at 7:00 PM, Bill Hawkins b...@iaxs.net wrote: This is not as far from time-nutty things as it might appear. NDK makes precision crystal oscillators from those crystals. One of them is an OCXO less than an inch (20 mm) square and half that high with stability of 3x10E-9 over the range of -40 to 85 C. Annual drift is typically 50x10E-9. The data sheet is at: http://www.ndk.com/en/news/2013/1190702_1616.pdf The CSB released an impressive video of the incident last month. It is in the final report at: http://www.csb.gov/ndk-crystal-inc-explosion-with-offsite-fatality-/ The financial forecast for NDK shows 50 to 60% drop in profits for the same sales in 2013. If that was also true in 2009, management was motivated to maximize production with what they had. The original consultant strongly recommended inspections for stress corrosion cracking, but strong recommendations do not have financial penalties. It has become obvious that money is the only thing that matters at the management level these days. Oh, and don't bother trying to Google for pure quartz crystals to find out whether the cost went up in 2010 after one of the two manufacturers in the US was shut down. The people whose magical thinking extends to crystals want purity, so all crystals are pure. Help prevent incomplete knowledge. Bill Hawkins -Original Message- From: Robert Atkinson Sent: Sunday, November 24, 2013 1:43 AM The US Chemical Safety Board have released their report into the 2009 accident at NDK's synthetic crystal growing facility in Belvidere IL http://www.csb.gov/assets/1/19/CSB_CaseStudy_NDK_1107_500PM.pdf It also describes the process. Basically a 50ft autoclave failed, killing a member of the public at a rest stop 650ft away. Looks like management decisions, probably based on cost, overriding engineering advice even following an earlier minor incident. The letters from a consulting engineer in the annex make interesting reading. It illustrates the importance of those professional engineers amongst us notifying and recording any safety issues we discover. The facility is still shut down and the insurance company won't settle as NDK were told of possible issues. Robert G8RPI. ___ 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. -- Doc Bill Dailey KXØO ___ 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. -- Doc Bill Dailey KXØO ___ 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] Mains frequency
tom, nice plots. how do you figure out what the contribution of variability vs noise? In other words there is a differential between the ideal and the actual a dev curves... is there a way to tease out how much nose contribute to that differential? It does seem to me that there should be far less short term variability ( 100s) than there appears to be. Clearly in the very short tau ( 0.1 s) the picPET can't tease that out but as the curves diverge, how much of that is noise? between say 0.1s and 100s? Being a power plant operator I would say quite a bit although I am rethinking that some due to the way the turbines push and pull each other. I can envision some fine whole grid oscillations due to that push and pull. bill On Mon, Nov 18, 2013 at 4:15 PM, Tom Van Baak t...@leapsecond.com wrote: Magnus, I'm going to push back a bit on your mains sampling claim. Mostly, I'd like to see the results of the professional I-Q demodulated gear that you mentioned. Can you post raw data, or a sample plot? I agree that looking at power line voltage with 16- or 24-bits at 1 Msps is going to reveal interesting amplitude and phase noise information. But see how well a $1 PIC can do. Attached is a plot made using TimeLab + picPET just now. The picPET is fast enough to capture the zero-crossing of every 60 Hz cycle with 400 ns resolution; the TimeLab plots have tau0 of 16.67 ms. -- The blue trace was simply plugging a 9 VAC wall-wart into the picPET though a 10k resistor. -- The pink trace was adding a 10 nF cap across the input. -- The green trace was unplugging my laptop switching power supply from the same outlet! -- The red trace is replacing the mains wall-wart with a hp 33120A set to 9VAC at 60 Hz, a tentative noise floor measurement of the picPET when used this way. My conclusions are that at least here in the US, or at least at my house, the short-term stability of mains hits about 5e-6, at about tau 0.2 seconds. The attached short-term plot is also not-inconsistent with the long-term plot at http://leapsecond.com/pages/mains/ My other conclusion is that the picPET (a simple PIC-based time-stamping counter) is doing a pretty good job measuring this. Note, no software or data filtering was used. This is just raw serial/USB data going into TimeLab. /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. -- Doc Bill Dailey KXØO ___ 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] Mains frequency
I meant ideal at the noise floor of the picPET (i.e in this case the generated 60Hz). On Mon, Nov 18, 2013 at 8:08 PM, Bob Camp li...@rtty.us wrote: Hi An “ideal” curve would go to the bottom of the scale as soon as the plot started. Anything that shows on the ADEV curve is by definition noise. The slope of the ADEV curve can help you determine what sort of noise it is. The slope(s) on an modified ADEV curve can do that slightly better. Bob On Nov 18, 2013, at 8:03 PM, Bill Dailey docdai...@gmail.com wrote: tom, nice plots. how do you figure out what the contribution of variability vs noise? In other words there is a differential between the ideal and the actual a dev curves... is there a way to tease out how much nose contribute to that differential? It does seem to me that there should be far less short term variability ( 100s) than there appears to be. Clearly in the very short tau ( 0.1 s) the picPET can't tease that out but as the curves diverge, how much of that is noise? between say 0.1s and 100s? Being a power plant operator I would say quite a bit although I am rethinking that some due to the way the turbines push and pull each other. I can envision some fine whole grid oscillations due to that push and pull. bill On Mon, Nov 18, 2013 at 4:15 PM, Tom Van Baak t...@leapsecond.com wrote: Magnus, I'm going to push back a bit on your mains sampling claim. Mostly, I'd like to see the results of the professional I-Q demodulated gear that you mentioned. Can you post raw data, or a sample plot? I agree that looking at power line voltage with 16- or 24-bits at 1 Msps is going to reveal interesting amplitude and phase noise information. But see how well a $1 PIC can do. Attached is a plot made using TimeLab + picPET just now. The picPET is fast enough to capture the zero-crossing of every 60 Hz cycle with 400 ns resolution; the TimeLab plots have tau0 of 16.67 ms. -- The blue trace was simply plugging a 9 VAC wall-wart into the picPET though a 10k resistor. -- The pink trace was adding a 10 nF cap across the input. -- The green trace was unplugging my laptop switching power supply from the same outlet! -- The red trace is replacing the mains wall-wart with a hp 33120A set to 9VAC at 60 Hz, a tentative noise floor measurement of the picPET when used this way. My conclusions are that at least here in the US, or at least at my house, the short-term stability of mains hits about 5e-6, at about tau 0.2 seconds. The attached short-term plot is also not-inconsistent with the long-term plot at http://leapsecond.com/pages/mains/ My other conclusion is that the picPET (a simple PIC-based time-stamping counter) is doing a pretty good job measuring this. Note, no software or data filtering was used. This is just raw serial/USB data going into TimeLab. /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. -- Doc Bill Dailey KXØO ___ 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. -- Doc Bill Dailey KXØO ___ 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] Mains frequency
ok Bob, Then how do you tease out the difference between the clean generated 60Hz and the mains 60Hz adev curves to determine what is noise and what is the variability in the 60Hz? That is the point of my question not semantics about ideal vs non-ideal. doc On Mon, Nov 18, 2013 at 8:36 PM, Bob Camp li...@rtty.us wrote: Hi There is no way to come up with the noise floor of the picPET from that plot. In fact coming up with the floor of a single channel device like the picPET is not all that easy. First you need an ideal noise free sine wave signal …. I’ve spent more than a few hours on that particular project with other list members involved as well. As always we kept it off list to keep from offending those who place a high value on their bandwidth. Bob On Nov 18, 2013, at 9:11 PM, Bill Dailey docdai...@gmail.com wrote: I meant ideal at the noise floor of the picPET (i.e in this case the generated 60Hz). On Mon, Nov 18, 2013 at 8:08 PM, Bob Camp li...@rtty.us wrote: Hi An “ideal” curve would go to the bottom of the scale as soon as the plot started. Anything that shows on the ADEV curve is by definition noise. The slope of the ADEV curve can help you determine what sort of noise it is. The slope(s) on an modified ADEV curve can do that slightly better. Bob On Nov 18, 2013, at 8:03 PM, Bill Dailey docdai...@gmail.com wrote: tom, nice plots. how do you figure out what the contribution of variability vs noise? In other words there is a differential between the ideal and the actual a dev curves... is there a way to tease out how much nose contribute to that differential? It does seem to me that there should be far less short term variability ( 100s) than there appears to be. Clearly in the very short tau ( 0.1 s) the picPET can't tease that out but as the curves diverge, how much of that is noise? between say 0.1s and 100s? Being a power plant operator I would say quite a bit although I am rethinking that some due to the way the turbines push and pull each other. I can envision some fine whole grid oscillations due to that push and pull. bill On Mon, Nov 18, 2013 at 4:15 PM, Tom Van Baak t...@leapsecond.com wrote: Magnus, I'm going to push back a bit on your mains sampling claim. Mostly, I'd like to see the results of the professional I-Q demodulated gear that you mentioned. Can you post raw data, or a sample plot? I agree that looking at power line voltage with 16- or 24-bits at 1 Msps is going to reveal interesting amplitude and phase noise information. But see how well a $1 PIC can do. Attached is a plot made using TimeLab + picPET just now. The picPET is fast enough to capture the zero-crossing of every 60 Hz cycle with 400 ns resolution; the TimeLab plots have tau0 of 16.67 ms. -- The blue trace was simply plugging a 9 VAC wall-wart into the picPET though a 10k resistor. -- The pink trace was adding a 10 nF cap across the input. -- The green trace was unplugging my laptop switching power supply from the same outlet! -- The red trace is replacing the mains wall-wart with a hp 33120A set to 9VAC at 60 Hz, a tentative noise floor measurement of the picPET when used this way. My conclusions are that at least here in the US, or at least at my house, the short-term stability of mains hits about 5e-6, at about tau 0.2 seconds. The attached short-term plot is also not-inconsistent with the long-term plot at http://leapsecond.com/pages/mains/ My other conclusion is that the picPET (a simple PIC-based time-stamping counter) is doing a pretty good job measuring this. Note, no software or data filtering was used. This is just raw serial/USB data going into TimeLab. /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. -- Doc Bill Dailey KXØO ___ 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. -- Doc Bill Dailey KXØO ___ 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. -- Doc
Re: [time-nuts] Mains frequency (Tom Van Baak)
Agree. Luckily, I am good at what I do for a living. If this type stuff was my job I suspect I would either be out of work or paid very poorly. Electronics and time are very taxing on my brain.. which is why I play with them. I specifically avoided these things as a career path because they were very foreign to me. Now, I am at a point where I want to attack those things because they challenge me. Also, they allow me to develop my skills at programming; which is my first technical love. bill On Sun, Nov 17, 2013 at 10:14 AM, Bob Stewart b...@evoria.net wrote: John says: However I would most humbly point out that the cost of software is not zero if the time-nutter places any value on his or her time. Might I point out that the needs and goals of the hobbyist and the professional are often at odds? The professional needs a solution. The hobbyist needs a hobby. It's not that the hobbyist's time is worth nothing. In fact, the hobbyist's time pursuing his endeavor is worth everything. It's the whole point of doing it in the first place. I suspect that that's where the OP is at in his project to measure mains frequency. Bob - AE6RV ___ 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. -- Doc Bill Dailey KXØO ___ 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] Mains frequency
Understood.. I have it every 6 cycles now to sync up with his synchrophaser. I wrote the script so I can specify the number of cycles I average. Right now it is at 6 because his measures are every 0.1s. On Sat, Nov 16, 2013 at 2:52 AM, Chris Albertson albertson.ch...@gmail.comwrote: Your method tosses out a lot of data. You can't see transients. Ideally rather then record a 1 second average you'd record the time of EVERY zero crossing. It sounds like a lot of data but not really. You only record 32 bits 60 times each second. That is 240 bytes per second. On Fri, Nov 15, 2013 at 6:51 PM, Bill Dailey docdai...@gmail.com wrote: 110vac--5vac--100ohm--picpet event--- python average 60 cycles-- log freq every second. -- 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. -- Doc Bill Dailey KXØO ___ 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] Mains frequency
rough comparison... I didnt have my interval right for this set. https://www.dropbox.com/s/1gi5tbf96yop5hz/stonercompare.JPG On Sat, Nov 16, 2013 at 3:02 AM, Bill Dailey docdai...@gmail.com wrote: Understood.. I have it every 6 cycles now to sync up with his synchrophaser. I wrote the script so I can specify the number of cycles I average. Right now it is at 6 because his measures are every 0.1s. On Sat, Nov 16, 2013 at 2:52 AM, Chris Albertson albertson.ch...@gmail.com wrote: Your method tosses out a lot of data. You can't see transients. Ideally rather then record a 1 second average you'd record the time of EVERY zero crossing. It sounds like a lot of data but not really. You only record 32 bits 60 times each second. That is 240 bytes per second. On Fri, Nov 15, 2013 at 6:51 PM, Bill Dailey docdai...@gmail.com wrote: 110vac--5vac--100ohm--picpet event--- python average 60 cycles-- log freq every second. -- 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. -- Doc Bill Dailey KXØO -- Doc Bill Dailey KXØO ___ 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] Mains frequency
would probably be an interesting comparison. I am working with a guy on the eastern grid part now. You arent using python for processing on the pc are you? If so, I would be interested in your script. I am trying to verify I am not a just a little off with mine. Bill On Sat, Nov 16, 2013 at 1:55 AM, Kevin M. Rosenberg ke...@rosenberg.netwrote: Not on the eastern grid, but I had hook my picpet ac mains logger back to the southwest grid if that would be of any help. On Nov 15, 2013, at 7:51 PM, Bill Dailey docdai...@gmail.com wrote: I have my picpet faithfully measuring grid frequency and was wondering if anyone else if the eastern grid has a live measure to compare to? 110vac--5vac--100ohm--picpet event--- python average 60 cycles-- log freq every second. Sent from mobile ___ 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. -- Doc Bill Dailey KXØO ___ 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] Mains frequency
My purpose is to do it with a picpet. That's it. So, that eliminates a bunch of the options. I can decouple the measurements from the pc clock that way. Doc Sent from mobile On Nov 16, 2013, at 11:26 AM, Chris Albertson albertson.ch...@gmail.com wrote: The signal is 120 volts. You hardly need to amplify it. Clip it with a diode to +- 9 volts so as not to blow up your serial port. But I'd use a transformer for safety. The zero crossing detectors are built into the RS232 interface.You take advantage of the RS232 spec which has a DCD pin input of about +-9 volts that is already set up to find a leading edge of a pulse and cause a very low latency interrupt. The system software already will capture the time all inside a kernel level interrupt handler. The jitter turns out to be on the order of a single digit microseconds. Good enough for measuring a 60Hz signal. I guess if you want to see transients depends on the purpose of the experiment. Are you looking at local AC power quality or wanting to measure the grid. The grid is well monitored, just use FNET and you get real-time data for all of North America. I think the reason for measuring it yourself is to see local power quality and things load switching inside your own building, that's transients. The other way to measure AC with zero added equipment is to treat it as an audio signal and after reducing it to 1 volt run it into an audio interface And then use FFT. This will let you see very small spikes and noise. It depends again on your purpose for doing this. On Sat, Nov 16, 2013 at 1:18 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 11/16/2013 09:52 AM, Chris Albertson wrote: Your method tosses out a lot of data. You can't see transients. Ideally rather then record a 1 second average you'd record the time of EVERY zero crossing. It sounds like a lot of data but not really. You only record 32 bits 60 times each second. That is 240 bytes per second. But you want it filtered to avoid the transients. Those are really not that interesting when you measure the grid. Also, if you use the event trigger method you probably want to use an amplifier to increase the slew-rate such that noise does not convert into time jitter. 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. -- 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. ___ 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] Mains frequency
No trouble. Easy. I love it. Keeping track of the rolling counters was a hack because I am so far removed from serious programming. Sent from mobile On Nov 16, 2013, at 1:53 PM, Tom Van Baak (lab) t...@leapsecond.com wrote: Doc, I measure mains time frequency with a picPET all the time. In fact that's one of the reasons I designed it. If you're having any trouble contact me by email. /tvb (i5s) On Nov 16, 2013, at 11:23 AM, Bill Dailey docdai...@gmail.com wrote: My purpose is to do it with a picpet. That's it. So, that eliminates a bunch of the options. I can decouple the measurements from the pc clock that way. Doc Sent from mobile On Nov 16, 2013, at 11:26 AM, Chris Albertson albertson.ch...@gmail.com wrote: The signal is 120 volts. You hardly need to amplify it. Clip it with a diode to +- 9 volts so as not to blow up your serial port. But I'd use a transformer for safety. The zero crossing detectors are built into the RS232 interface.You take advantage of the RS232 spec which has a DCD pin input of about +-9 volts that is already set up to find a leading edge of a pulse and cause a very low latency interrupt. The system software already will capture the time all inside a kernel level interrupt handler. The jitter turns out to be on the order of a single digit microseconds. Good enough for measuring a 60Hz signal. I guess if you want to see transients depends on the purpose of the experiment. Are you looking at local AC power quality or wanting to measure the grid. The grid is well monitored, just use FNET and you get real-time data for all of North America. I think the reason for measuring it yourself is to see local power quality and things load switching inside your own building, that's transients. The other way to measure AC with zero added equipment is to treat it as an audio signal and after reducing it to 1 volt run it into an audio interface And then use FFT. This will let you see very small spikes and noise. It depends again on your purpose for doing this. On Sat, Nov 16, 2013 at 1:18 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 11/16/2013 09:52 AM, Chris Albertson wrote: Your method tosses out a lot of data. You can't see transients. Ideally rather then record a 1 second average you'd record the time of EVERY zero crossing. It sounds like a lot of data but not really. You only record 32 bits 60 times each second. That is 240 bytes per second. But you want it filtered to avoid the transients. Those are really not that interesting when you measure the grid. Also, if you use the event trigger method you probably want to use an amplifier to increase the slew-rate such that noise does not convert into time jitter. 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. -- 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. ___ 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] Mains frequency
There is no higher purpose actually. I just fiddle. This is how I relax. On Sat, Nov 16, 2013 at 3:47 PM, Chris Albertson albertson.ch...@gmail.comwrote: No, I meant the purpose of the whole thing. Why are you measuring power frequency? Not why are you using a PIC.How will the data be used, what is the question driving the measurement? On Sat, Nov 16, 2013 at 11:23 AM, Bill Dailey docdai...@gmail.com wrote: My purpose is to do it with a picpet. That's it. So, that eliminates a bunch of the options. I can decouple the measurements from the pc clock that way. Doc Sent from mobile On Nov 16, 2013, at 11:26 AM, Chris Albertson albertson.ch...@gmail.com wrote: The signal is 120 volts. You hardly need to amplify it. Clip it with a diode to +- 9 volts so as not to blow up your serial port. But I'd use a transformer for safety. The zero crossing detectors are built into the RS232 interface.You take advantage of the RS232 spec which has a DCD pin input of about +-9 volts that is already set up to find a leading edge of a pulse and cause a very low latency interrupt. The system software already will capture the time all inside a kernel level interrupt handler. The jitter turns out to be on the order of a single digit microseconds. Good enough for measuring a 60Hz signal. I guess if you want to see transients depends on the purpose of the experiment. Are you looking at local AC power quality or wanting to measure the grid. The grid is well monitored, just use FNET and you get real-time data for all of North America. I think the reason for measuring it yourself is to see local power quality and things load switching inside your own building, that's transients. The other way to measure AC with zero added equipment is to treat it as an audio signal and after reducing it to 1 volt run it into an audio interface And then use FFT. This will let you see very small spikes and noise. It depends again on your purpose for doing this. On Sat, Nov 16, 2013 at 1:18 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 11/16/2013 09:52 AM, Chris Albertson wrote: Your method tosses out a lot of data. You can't see transients. Ideally rather then record a 1 second average you'd record the time of EVERY zero crossing. It sounds like a lot of data but not really. You only record 32 bits 60 times each second. That is 240 bytes per second. But you want it filtered to avoid the transients. Those are really not that interesting when you measure the grid. Also, if you use the event trigger method you probably want to use an amplifier to increase the slew-rate such that noise does not convert into time jitter. 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. -- 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. ___ 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. -- 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. -- Doc Bill Dailey KXØO ___ 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] Mains frequency
Does an ac transformer hurt me? I was looking for that dang megohm page when I started this. Couldn't find it so I used a transformer. Doc Sent from my iPad On Nov 16, 2013, at 9:17 PM, Tom Van Baak t...@leapsecond.com wrote: Again, why are you measuring the AC line? I'd think maybe to measure the noise that is on it. The fundamental freq. changes second by second. It's not a clean 60Hz my any means. The rate of frequency change is one thing you'd like to measure I was just watching a minute ago and can see a 0.01Hz/second drift. It is likely MUCH worse as what I was watching is filtered over second Chris, No, forget the noise (it's actually quite clean: look at it sometime). We measure mains because we can. We also measure it because millions of wall-clocks are based on mains frequency; it was the original GPSDO. We measure it because its phase plot, frequency histogram, and ADEV plot are really quite interesting. We measure it because Seattle, WA (tvb) and New Mexico (Kevin) are both on the same grid and mutually agree to 10 microseconds (!) over an hour even though they can both wander by many seconds relative to UTC. It's a textbook example of common view time transfer. See also: http://leapsecond.com/pages/mains/ http://leapsecond.com/pages/ac-detect/ You too can join the mains party. Measure it with your own method, or a fancy TrueTime time/frequency deviation meter (TFDM) or use something simple like a picPET (http://www.leapsecond.com/pic/picpet.htm) or Arduino or even a NTP/Linux/serial DCD pin hack. /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] Mains frequency
This resonates with me somewhat since I used to run nuclear power plants and operate the actual turbines. It does seem that the time interval measurements have much more jitter than I would expect. I suspect the thousands of turbines phase locked may introduce all kinds of very subtle variations. I do know when you put a submarine turbine on shore power (grid). You no longer have to control speed... The grid does that for you. Sent from my iPad On Nov 16, 2013, at 9:35 PM, Charles Steinmetz csteinm...@yandex.com wrote: tvb wrote: I think we agree. Just to clarify... I rely on no hardware and no software filters when I use a time-stamping counter such as a sub-nanosecond Pendulum CNT-9x or sub-microsecond picPET. An electrical zero-crossing happens when it happens. If you filter you're just trying to change history: spikes are spikes; noise is noise; history is history. Deal with it. Record it, don't filter it away. Well, it depends on what one wants to investigate. The naked history one captures with no filtering may not be the cleanest history available of the phenomenon under investigation. Except in unusual circumstances, mains voltage is generated by massive rotating machinery -- so anything fast that happens on your incoming mains voltage is not a reflection of the grid frequency. If what you want to know is the grid frequency over time (vector sum of the rotational velocity of the various generators on the grid, as seen from your location), a filtered and limited signal may (probably will) provide the best assessment. Note that local zero crossings are only a proxy for grid frequency to begin with -- and not a very good one, specifically because of the high noise level. Of course, you can always filter in software if you time-stamp each zero cross in all its naked glory, but removing the noise prior to time-stamping is often preferable to digitally processing a noisy capture. Put another way, the massive rotating machinery that generates the mains voltage can only change the zero cross of the grid by a tiny amount from one cycle to the next. If a data capture method shows cycle-to-cycle jitter that is significantly greater than this amount, the increase cannot be due to the generators, it can only be due to noise. If one's interest is the grid frequency, removing this noise prior to time-stamping can only help. Note that I'm not talking about a filter Q in the millions -- I'd probably be inclined to use a linear-phase filter with several Hz bandwidth, after a more rigorous analysis of the application. You can either focus on the signal, or the noise. That's two separate plots. Agreed. If you are investigating incidental noise on the mains rather than the grid frequency, then the signal you capture needs to be at least as broadband as the noise in which you are interested. Since I do not use the actual local mains zero crossings for anything (other than electronically switching loads on at zero voltage and off at zero current, where absolute timing is irrelevant), I'm not sure why one might be interested in characterizing them. OTOH, since I do have equipment that responds to the grid frequency, I can see practical utility in characterizing that. Hence my suggestion to filter. Best regards, Charles ___ 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] Mains frequency
I have my picpet faithfully measuring grid frequency and was wondering if anyone else if the eastern grid has a live measure to compare to? 110vac--5vac--100ohm--picpet event--- python average 60 cycles-- log freq every second. Sent from mobile ___ 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] Clock block
Does anyone have any spares? Or bom with pcb files so I can order and build? Doc Sent from my iPad ___ 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] Computing GPS Distance Error in Time
The pps on that unit is good. Compares favorably to the ublox6T. I can't say how favorably. I am working on quantifying its pps as compared to my 2 fury units and the ublox 6T. Awaiting a 8 antenna splitter, and dso. Have another trick up my sleeve but need a Linux kernel hacker. I don't want to go down another rabbit hole if I can avoid it. Bill Sent from mobile On Nov 4, 2013, at 11:07 AM, Chris Albertson albertson.ch...@gmail.com wrote: On Mon, Nov 4, 2013 at 3:51 AM, Bob Camp li...@rtty.us wrote: . I can guess it's a vector difference between each two successive points converted to ns, That vector difference has to include altitude. Then as you say, convert distance to time via the speed of light. But I think this is only the upper bound of the error, it could be much less because there are multiple satellites in view. That 3 ns per meter rule of thumb is very conservative. But on the other hand,... On your specific make and model of GPS they could have simply dropped precision on the time, thinking that 0.01 second is good enough and allowed some approximations. You can't assume the calculation is perfect. You'd have to measure. Is there a spec for timing error? -- 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. ___ 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] Computing GPS Distance Error in Time
will do... i dont think I have dgps turned on either. never bothered. On Mon, Nov 4, 2013 at 11:43 AM, Bob Stewart b...@evoria.net wrote: Hi Bill, Keep me informed of what you find, would you? As I noted in my other note, I don't have DGPS turned on, and I take it that's pretty important for timing applications. I'll try to get that done early after lunch today. Bob From: Bill Dailey docdai...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, November 4, 2013 11:30 AM Subject: Re: [time-nuts] Computing GPS Distance Error in Time The pps on that unit is good. Compares favorably to the ublox6T. I can't say how favorably. I am working on quantifying its pps as compared to my 2 fury units and the ublox 6T. Awaiting a 8 antenna splitter, and dso. Have another trick up my sleeve but need a Linux kernel hacker. I don't want to go down another rabbit hole if I can avoid it. Bill Sent from mobile ___ 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. -- Doc Bill Dailey KXØO ___ 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] time-nuts Digest, Vol 111, Issue 70
The fury already has a fat pps correct? Sent from mobile On Oct 26, 2013, at 7:31 PM, Frank Hughes hp_cisco...@yahoo.com wrote: Discretion being the better part of valor, and I need plug play for this piece, in order to save time for other things that need attention, so I ordered : Symmectricom 58535A After I got the Fury working, noted an interesting anomaly (that turned out to be my fault, but interesting) Connected the 10Mhz from the Fury to the HP 5087A distribution amp feeding 10Mhz to all the HP and Agilent equipment needing a stable reference. One of the ancient HP things ( 59309A) said it had no 10Mhz external oscillator! The 59309A worked w/ the Trimble, not the Fury. Did some troubleshooting, the Fury 10Mhz signal is about 2 or 3 db less than the Trimble. This attenuation was enough to prevent the 59309A from locking on to the signal. All the other HP and Agilent worked fine with either 10Mhz source. I remembered that I had been too lazy to actually set the no-load voltage on each of the 5087A output amplifiers the last time I had it apart. So I pulled the 5087A out of the rack, took the cover off and and set the levels correctly. 59309A happy. Anyway, when I finished all that, went to see how to get both the Trimble and Fury operating in parallel. - Trimble feeds 1PPS to the FreeBSD NTP server via the FAT PPS serial port circuit. - Fury feeds the HP 5087A distribution amp for all the HP/Agilent to sync to. The FAT PPS won't fit on the Fury, Fury=male null modem DB9, TB=Female straight DB9. So I will use both GPSDO boxes. Which led me to the splitter.. 73 and thank again for the great ideas! Frank KJ4OLL On Saturday, October 26, 2013 5:49 PM, time-nuts-requ...@febo.com time-nuts-requ...@febo.com wrote: Send time-nuts mailing list submissions to time-nuts@febo.com To subscribe or unsubscribe via the World Wide Web, visit https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts or, via email, send a message with subject or body 'help' to time-nuts-requ...@febo.com You can reach the person managing the list at time-nuts-ow...@febo.com When replying, please edit your Subject line so it is more specific than Re: Contents of time-nuts digest... Today's Topics: 1. Re: Splitter for GPS antenna suggestions? (Tom Knox) 2. Re: Splitter for GPS antenna suggestions? (Bob Camp) 3. Re: Splitter for GPS antenna suggestions? (Magnus Danielson) 4. Re: Splitter for GPS antenna suggestions? (Brooke Clarke) 5. Re: Time stamping with a PICPET (Chris Albertson) 6. Re: Time stamping with a PICPET (Hal Murray) 7. Re: Splitter for GPS antenna suggestions? (Charles Steinmetz) -- Message: 1 Date: Sat, 26 Oct 2013 10:54:40 -0600 From: Tom Knox act...@hotmail.com To: Time-Nuts time-nuts@febo.com Subject: Re: [time-nuts] Splitter for GPS antenna suggestions? Message-ID: col130-w31bae6e1605519eb154c97df...@phx.gbl Content-Type: text/plain; charset=iso-8859-1 I think this discussion could use some parity. Some many options have been presented. But to return to one of the first posts, I would buy a Symmetricom Splitter on eBay. They have really become the industry standard and can be had for a reasonable price. There are certainly products that could be selected to meet your needs for less money but it will have some compromises, and there are others that could meet or perhaps even exceed Symmetricoms performance but are usually more money and are much less common on the surplus market. I would buy one with more ports then you need in case you ever want to test or install an additional GPS receivers. Remember If you buy the best you only cry once Thomas Knox From: li...@rtty.us Date: Sat, 26 Oct 2013 08:00:32 -0400 To: time-nuts@febo.com Subject: Re: [time-nuts] Splitter for GPS antenna suggestions? Hi Pretty much all of the MiniCircuits splitters seem to happily pass DC. The same is true of all of the TV splitters I've tried. The standard circuits (as in the lowest cost) have a transformer or transmission line that has no DC path to ground. Bob On Oct 26, 2013, at 12:58 AM, David okdavid5...@cox.net wrote: Hello -- I'm not very knowledgeable electronically, but I am currently using a Minicircuits ZAPD-3DB-1575-3 splitter to connect one TrueTime 142-400 GPS antenna to a Spectracom 8183 and a Spectracom 8183-A. I use the Spectracoms only as precise digital clocks, and they seem to work just fine. I bought the Minicircuits splitter on eBay for $30, buy-it-now, as I recall, but it's been a while ago. Hope that's helpful. David in Oklahoma City -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Frank Hughes Sent: Friday, October 25, 2013 5:31 PM
Re: [time-nuts] NTP REFCLOCK for a Jackson Fury??
Interesting.. I see something completely different with my Fury. My hard-coded fudge factor is 0.077 yielding: Every 2.0s: ntpq -p Thu Oct 17 10:20:00 2013 remote refid st t when poll reach delay offset jitter == -four2.fairy.mat 64.250.177.145 2 u 12 64 377 72.493 17.784 0.524 -66-162-15-65.li 64.236.96.53 2 u 33 64 377 50.226 15.291 1.181 +barricade.rack9 209.51.161.238 2 u 10 64 377 22.9081.075 0.362 -ccadmin.cycores 130.207.244.240 2 u 38 64 377 39.2183.972 1.241 192.168.1.171 .INIT. 16 u- 102400.0000.000 0.000 +SHM(0) .FURY. 0 l6 16 3770.0000.526 0.034 *SHM(1) .PPSF. 0 l5 64 3770.0000.008 0.001 -europium.canoni 193.79.237.142 u 32 64 377 116.177 -1.573 0.992 So... i could fine tune my fudge some but the point is the jitter is fairly low. (fury is from the sentences and ppsf is pps from fury). My soekris (soekris is the .171) numbers were much better but it is inoperable for some reason. Doc On Thu, Oct 17, 2013 at 9:59 AM, Tim Shoppa tsho...@gmail.com wrote: Back in 2003 or so, in the Z3801A with hpgps ntpd refclock driver, I had to add a negative offset of -0.98 seconds to the driver's decoding of PTIME:TCODE? to get it to be right in combination with PPS refclock. The documentation in the Z3801A manual correctly described the actual behavior PTIME:TCODE? Provides timecode message 980 to 20 ms prior to 1 PPS of indicated time. On Thu, Oct 17, 2013 at 9:40 AM, Scott Mace sm...@intt.net wrote: I posted a patch for the Fury to work with ntpd in Oct 2008. It uses the GPGGA output. The PTIME:TCODE? command is not on-time with the 1-PPS output on the Fury, so the HPGPS driver does not work. http://www.febo.com/pipermail/**time-nuts/2008-October/033901.**html http://www.febo.com/pipermail/time-nuts/2008-October/033901.html the ntp-fury.diff: http://www.febo.com/pipermail/**time-nuts/attachments/** 20081020/846021fe/attachment-**0001.bin http://www.febo.com/pipermail/time-nuts/attachments/20081020/846021fe/attachment-0001.bin Scott On 10/16/2013 04:44 PM, Frank Hughes wrote: Hi, What NTP REFCLOCK can be used for a Jackson Fury? I know that the Jackson Fury docs suggest using: http://www.realhamradio.com/**gpscon-info.htm http://www.realhamradio.com/gpscon-info.htm But that means I would have to put up a windows server to replace the FreeBSD ntpd server I built for use w/ the Trimble TB. Looking for open source options, if possible. Thanks, Frank KJ4OLL __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nuts 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 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. -- Doc Bill Dailey KXØO ___ 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] NTP REFCLOCK for a Jackson Fury??
It looks like in this Ubuntu I am using 28 SHM with gpsd which is different that the soekris. Sent from mobile On Oct 17, 2013, at 1:00 PM, Scott Mace sm...@intt.net wrote: I think the Fury does not guarantee that the PTIME:TCODE will be near the 1-PPS leading edge. When I tried it with the HPGPS driver and a net4501, ntpd wasn't happy with it. I also needed leap second processing to work, holdover notification, and to collect other data from it. The GPGGA sentence is on-time even if you are asking the Fury to do other things with SCPI commands. Try setting your Fury hpgps driver fudge flag4 to 1 and I bet it will stop working well. This flag logs the system:print output. Scott On 10/17/2013 10:24 AM, Bill Dailey wrote: Interesting.. I see something completely different with my Fury. My hard-coded fudge factor is 0.077 yielding: Every 2.0s: ntpq -p Thu Oct 17 10:20:00 2013 remote refid st t when poll reach delay offset jitter == -four2.fairy.mat 64.250.177.145 2 u 12 64 377 72.493 17.784 0.524 -66-162-15-65.li 64.236.96.53 2 u 33 64 377 50.226 15.291 1.181 +barricade.rack9 209.51.161.238 2 u 10 64 377 22.9081.075 0.362 -ccadmin.cycores 130.207.244.240 2 u 38 64 377 39.2183.972 1.241 192.168.1.171 .INIT. 16 u- 102400.0000.000 0.000 +SHM(0) .FURY. 0 l6 16 3770.0000.526 0.034 *SHM(1) .PPSF. 0 l5 64 3770.0000.008 0.001 -europium.canoni 193.79.237.142 u 32 64 377 116.177 -1.573 0.992 So... i could fine tune my fudge some but the point is the jitter is fairly low. (fury is from the sentences and ppsf is pps from fury). My soekris (soekris is the .171) numbers were much better but it is inoperable for some reason. Doc On Thu, Oct 17, 2013 at 9:59 AM, Tim Shoppa tsho...@gmail.com wrote: Back in 2003 or so, in the Z3801A with hpgps ntpd refclock driver, I had to add a negative offset of -0.98 seconds to the driver's decoding of PTIME:TCODE? to get it to be right in combination with PPS refclock. The documentation in the Z3801A manual correctly described the actual behavior PTIME:TCODE? Provides timecode message 980 to 20 ms prior to 1 PPS of indicated time. On Thu, Oct 17, 2013 at 9:40 AM, Scott Mace sm...@intt.net wrote: I posted a patch for the Fury to work with ntpd in Oct 2008. It uses the GPGGA output. The PTIME:TCODE? command is not on-time with the 1-PPS output on the Fury, so the HPGPS driver does not work. http://www.febo.com/pipermail/**time-nuts/2008-October/033901.**html http://www.febo.com/pipermail/time-nuts/2008-October/033901.html the ntp-fury.diff: http://www.febo.com/pipermail/**time-nuts/attachments/** 20081020/846021fe/attachment-**0001.bin http://www.febo.com/pipermail/time-nuts/attachments/20081020/846021fe/attachment-0001.bin Scott On 10/16/2013 04:44 PM, Frank Hughes wrote: Hi, What NTP REFCLOCK can be used for a Jackson Fury? I know that the Jackson Fury docs suggest using: http://www.realhamradio.com/**gpscon-info.htm http://www.realhamradio.com/gpscon-info.htm But that means I would have to put up a windows server to replace the FreeBSD ntpd server I built for use w/ the Trimble TB. Looking for open source options, if possible. Thanks, Frank KJ4OLL __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nuts 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 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.
Re: [time-nuts] NTP REFCLOCK for a Jackson Fury??
Correct. And I can access my soekris right now. Sent from mobile On Oct 17, 2013, at 1:35 PM, Paul tic-...@bodosom.net wrote: On Thu, Oct 17, 2013 at 2:00 PM, Scott Mace sm...@intt.net wrote: Try setting your Fury hpgps driver fudge flag4 to 1 He said he thought he was using 20+22 (NMEA+PPS). Of course the ntpq output suggests GPSD or other shared memory driver. -- Paul ___ 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] NTP REFCLOCK for a Jackson Fury??
You can use FreeBSD. I will dig out the refclock I am using with my disciplined soekris. Sent from mobile On Oct 16, 2013, at 4:44 PM, Frank Hughes hp_cisco...@yahoo.com wrote: Hi, What NTP REFCLOCK can be used for a Jackson Fury? I know that the Jackson Fury docs suggest using: http://www.realhamradio.com/gpscon-info.htm But that means I would have to put up a windows server to replace the FreeBSD ntpd server I built for use w/ the Trimble TB. Looking for open source options, if possible. Thanks, Frank KJ4OLL ___ 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] NTP REFCLOCK for a Jackson Fury??
I think I used type 20 and 22 with bsd on my soekris. I have had it off for some time because it started to error on boot. Have it apart now trying to figure out what is going on. I suspect a problem with the clock block. Set the fury to output ggtts. Bill Sent from my iPad On Oct 16, 2013, at 4:44 PM, Frank Hughes hp_cisco...@yahoo.com wrote: Hi, What NTP REFCLOCK can be used for a Jackson Fury? I know that the Jackson Fury docs suggest using: http://www.realhamradio.com/gpscon-info.htm But that means I would have to put up a windows server to replace the FreeBSD ntpd server I built for use w/ the Trimble TB. Looking for open source options, if possible. Thanks, Frank KJ4OLL ___ 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] NTP REFCLOCK for a Jackson Fury??
Yes Sent from mobile On Oct 16, 2013, at 8:39 PM, Paul tic-...@bodosom.net wrote: On Wed, Oct 16, 2013 at 7:18 PM, Bill Dailey docdai...@gmail.com wrote: Set the fury to output ggtts Did you mean GPGGA? If the Fury is producing RMC sentences then NMEA+PPS (20+22) should work. Some folks recommend the NMEA PPS option (flag1) but in my experience it's less stable than the stand-alone PPS driver. ___ 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 replacement part-2
Gpscon work fine as long as you are using win xp. I had a hitch when I tried to use it with win7. They also work with Z38xx. Bill Sent from my iPad On Oct 13, 2013, at 4:21 PM, Jim Sanford wb4...@wb4gcs.org wrote: Someone earlier suggested a group buy of the Jackson Labs device. I would be interested. As for power supplies, my Nortel-TB is on an analog power supply, deliberately. I do intend to put a scope on it, and see if it may be contributing noise to the issues I see. (I'm wondering if it has sufficient high frequency bypassing, and sufficient bulk capacitance to deal with transients.) If it is, I will put it on battery, with the analog supply as a charger... More I think about it, the more I like the Jackson Labs devices. Especially that they work with the GPSCON software (I think). Jim wb4...@amsat.org On 10/13/2013 5:47 AM, Robert Atkinson wrote: Hi Frank, I would NOT put the spare TB on a PC powersupply. Check out both TB's on the bench using decent linear supplies. I don't like using PC supplies on critical equipment. They are typically designed for a specific (high) load on one output (5V on early ones 12V on more modern) to maintain regulation on the other outputs. They are designed down to a cost and are often not great in terms of suppressing spikes and surges. You are running a sub 15W TB on a 100-300W PSU. And then there is the phase noise issue. Whay put a $30 PSU on $1000 Frequency standard? A 3 line analog supply is easy to build at most 2 transformers two bridge rectifiers a few capacitors and 3 78xx series regulators. Surplus (or new) linear supplies are available, I use a HTAA-16W-AG by Power-One / Condor / SL Power, like ebay items 300956540240 300956540566 ($15 each). Even new from Mouser they are under $100. These high quality 100% duty cycle units are slightly underated for start-up current on the +12V rail, but with virtually no load on the -12V and low load on the +5V it works fine. I'm in the UK on 50Hz mains so its worse case, the PSU has 20% more capacity on 60Hz. Bin the switcher! Robert G8RPI. From: Frank Hughes hp_cisco...@yahoo.com To: time-nuts@febo.com time-nuts@febo.com Sent: Saturday, 12 October 2013, 22:49 Subject: [time-nuts] Trimble replacement part-2 Hi, Well, now I have determined that the TB is actually bad and/or the goofy PC power brick is no longer making correct volts. http://i180.photobucket.com/albums/x257/fish1_07/am/trimble_trouble_zps70b440a7.png I had one spare Trimble remaining to replace it with. Not sure what model the new one is, the enclosure is red and a different form factor than the smaller anodized Aluminum TB that failed. New one works fine: http://i180.photobucket.com/albums/x257/fish1_07/am/Trimble_replaced_10_12_2013_zps5042b487.png Funny thing, my HP 59309A Clock had stopped working, I thought it had a failure too, but when a stable 10Mhz signal appeared at the HP input, the ancient HP clock is back to abby-normal again! I should remember that the HP is also a miners canary for the TB... In a state of delusion, I sent an EM to Jackson Labs sales to see if they will sell a Fury to an individual..can't imagine what Quan-1 $$$ is going to be... 73 Frank KJ4OLL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble replacement part-2
I have a double oven and oem. Prices are reasonable. Inquire. Sent from mobile On Oct 12, 2013, at 5:37 PM, Paul tic-...@bodosom.net wrote: On Sat, Oct 12, 2013 at 5:49 PM, Frank Hughes hp_cisco...@yahoo.com wrote: I sent an EM to Jackson Labs sales to see if they will sell a Fury to an individual Of course they will. ..can't imagine what Quan-1 $$$ is going to be... $1,000 Retail box $2,000. The double oven is naturally more expensive. Presumably the OEM board is less but probably not the great deal from back in the day. -- Paul ___ 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] A readl atomic wristwatch
No but I bet he could build several with what he has laying around. Sent from mobile On Oct 1, 2013, at 12:23 PM, Joseph Gray jg...@zianet.com wrote: http://www.ablogtowatch.com/bathys-hawaii-cesium-133-atomic-wrist-watch-accurate-second-1000-years/ But will TVB buy one? :-) Joe Gray W5JG ___ 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] Racal-Dana 199x DIY High Stability DIY Timebase
I watched his rubidium build last night. Good stuff. Sent from my iPad On Sep 23, 2013, at 11:47 PM, Raj vu2...@gmail.com wrote: Found via Hack-a-day http://gerrysweeney.com/racal-dana-199x-diy-high-stability-diy-timebase-hack-for-under-25/ Chees -- Raj, VU2ZAP Bangalore, India. ___ 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] Doppler and FMT
You shouldn't be seeing a 2Hz spread. It can happen but in my experience that is big. Check gain control and make sure you aren't seeing artifacts. There is an fmt-nuts on yahoo which may be more appropriate for this. Doc Sent from mobile On Sep 19, 2013, at 10:32 AM, quartz55 quart...@hughes.net wrote: I knew it was not that easy. I didn't think about WWVB, and yes, I hear them quite often on 20. So it's just a matter of averaging what you can measure and assuming that the average will be close? I can imagine the shift can be all one way or the other for extended periods and how would anyone know which way? I'll have to check another signal that I know is not a double and see what I see. With SpecLab, it's easy to see mHz, but it's constantly changing so I guess one needs to log the data and use the spreadsheet to average it and hope it's close. The other thing is the 2000 wanders around especially when the fan goes on, so I've got a circuit to lock the MO to a GPS. XRef-VS, there are others for other radios too. We'll see what happens when I get the XRef installed and working. When I saw the WWV/B? signals I figured it was just how lucky you were. If I'm seeing 2 Hz spread how can anything be measured with precision? You can get close to anything once, it's doing it all the time that counts. Dave N3DT - Original Message - From: Dan Rae To: Discussion of precise time and frequency measurement Sent: Thursday, September 19, 2013 10:07 AM Subject: Re: [time-nuts] Doppler and FMT On 9/19/2013 6:48 AM, quartz55 wrote: I was playing with SpecLab and my TS-2000 just to see how accurately I could measure frequencies in the HF region. I notice when I set the rx on cw and listen to the 750 Hz output of WWV at 15 or 20 MHz with SL, I get like 2 and sometimes more tracks about 2 Hz apart constantly shifting around. I assume this is Doppler going in and out? If that's so, how can anyone reasonably expect to measure any ionospheric HF signal in the mHz range? Dave, it's not that easy. I did the ARRL FMTs a few years back when they were transmitting from the other side of the States and thought I was doing well to get within 0.1 Hz. The phase shifts on 7 and 14 MHz I was seeing due to Doppler were up to 360 degrees, and quite rapid. Mind you I was using non computer techniques [1], so averaging by eyeball was possible. Also if you are using WWV / WWVH, here at least, you often get both signals at similar strength, so you might well be seeing two different offsets. Dan ac6ao [1] looking at the 100 kHz IF output of the receiver on a scope, both scope trigger and Rx reference driven by homebrew GPS unit. ___ 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. - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1432 / Virus Database: 3222/6180 - Release Date: 09/19/13 ___ 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] display on sale
Do you have a contact? Sent from mobile On May 29, 2013, at 11:11 AM, Robert Darlington rdarling...@gmail.com wrote: Their local distributer (Vic Meyers Associates) just emailed me back with a quote. $99 a pop for the Symmetricom analog displays/clocks. They are out of digital time displays. I hear that Symmetricom is getting out of the time display business. The guy said they're still going to keep their time server products. I ordered two PoE clocks, one with the 12 hour face, one with the 24 hour face.Earlier this week I considered using the Vetenari Clock project circuit board to control a cheap analog clock movement and have it do my bididng -however I can't write the code in $99 of my free time! -Bob On Mon, May 20, 2013 at 10:26 PM, J.D. Schoedel jdschoe...@verizon.netwrote: Most of you like to DIY, but this might be of interest to some. http://www.symmetricom.com/lp/**gbu/email/time-display-promo-** landing-page/?emailid=GBU078_**NTD_Promo_ProdPglead_source=**Webhttp://www.symmetricom.com/lp/gbu/email/time-display-promo-landing-page/?emailid=GBU078_NTD_Promo_ProdPglead_source=Web J.D. __**_ 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. ___ 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] Net4501's cheap...
I got 2 Sent from mobile On May 19, 2013, at 6:07 PM, Didier Juges shali...@gmail.com wrote: I snatched one for $20 and they are now $59 or best offer. On Sun, May 19, 2013 at 11:18 AM, Bob Camp li...@rtty.us wrote: Hi There are a number of things that a Net4501 could be used for…. Bob On May 19, 2013, at 10:45 AM, Jason Rabel ja...@extremeoverclocking.com wrote: Just a heads up, there are some (8+ @ last count) used Soekris Net4501's for $29 on eBay (Search for: Soekris)... I submitted a bid for $20 each and it was instantly accepted... Don't know how low you can go, from the description the guy wants to get rid of them or they are going in the trash. Seems like a good deal if you are looking to make a little NTP server, especially compared to the retail price for a net4501... ;) I'm not affiliated with the seller in any way, I just love those little net4501's... I already have 5 of them, I don't know why I just bought 5 more... lol... Now I need more GPS modules! ___ 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.
Re: [time-nuts] u-blox -6T purchase
I thought there was someplace where you can get them for $35 or $60. Check the archives Sent from mobile On Mar 18, 2013, at 1:23 PM, Paul tic-...@bodosom.net wrote: On Mon, Mar 18, 2013 at 12:00 PM, Pieter ten Pierick wrote: The -T models are not that expensive. The problem is that you have to buy them in batches 30 Sounds like a time-nuts group buy? Just going by the u-blox shop for North America: NEO-6T u-blox 6 GPS Module Precision Timing 1 - 999 pcs $ 179.00 Which is a bit more than 30 pieces. This compared to: NEO-6M u-blox 6 GPS Module (crystal) 1 - 999 pcs $ 99.00 which seems readily available for about $20 (USD) shipped. I have not contacted u-blox so I don't know if a normal bulk purchase would have price breaks at other points but I haven't seen the -6T for say $50 (USD). ___ 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] Off topic project sort of heart rate monitor NEED BEATS PRE MINUTE TO ANALOG VOLTAGE
Another thing they do in the rate algorithms is make sure each beat falls in accordance with the previous 3 or 4 beats. Sent from mobile On Feb 20, 2013, at 6:02 AM, Bob Camp li...@rtty.us wrote: Hi Actually I have the 70's beat by a decade in terms of playing with home made ECG gear…. Bob On Feb 20, 2013, at 2:39 AM, Ed Breya e...@telight.com wrote: If you only need cardiac pulse rate, an optical pulse-oximeter type interface - but without the oximetry part - would be much simpler than an ECG system, and it doesn't need galvanic connection. If you need more than that, then ECG methods should suffice. Back in the 1970s, there was a lot of interest in biofeedback and TM techniques, using ECG and EEG. Common feedback signals were sound and light related to the detected physiological signals. A chart display is a good visual feedback with dynamics too, and it records the events for further study, so you can investigate the QRST details and whatever else is interesting. Detecting and processing the signals is nearly trivial now with modern electronics - it wasn't even that hard back then. If you study what's transpired over the last forty years, you'll get a pretty good idea of the whole history of the field, and the technologies involved. Nowadays of course, the PC can take care of most of the processing and feedback/indicator functions. For a DIY, I'd recommend for each channel run the high-gain instrumentation amplifier into a V-F or FM converter to translate the signal into a workable frequency range like a few hundred Hz, then use a sound card and SW to post-process. Copy front-end interface ideas from the real stuff - professional medical equipment - to make sure it's safe to hook up to your own hide. If you don't need absolute details, you can AC-couple the physiological signals into the V-F process with appropriate time constants, to avoid the drift, and average in SW. I doubt that interest in this area has waned over the decades, so it's likely there are all kinds of cooler, newer stuff available off-shelf, so you may be able to find it ready to go - and even way beyond what you had in mind. Ed ___ 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] any time nuts in Cleveland ?
fts or ftc On Thu, Dec 20, 2012 at 11:35 AM, Chris Howard ch...@elfpen.com wrote: FTC-4060 -- Doc Bill Dailey KXØO ___ 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] Comparing PPS from 2 GPS units
Yes it does. Sent from my iPad On Dec 14, 2012, at 10:47 PM, Hal Murray hmur...@megapathdsl.net wrote: saidj...@aol.com said: Time-Nuts, anyone willing to write this for the benefit of all? Does python run on Windows? If so, give me samples of input data and what you want as output. -- 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. ___ 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] Thunderbolt oven / non-stable operating temperature
If it is used for tempco it should affect the temp by stabilizing offset with temp changes correct? Maybe a more correct approach would be to disconnect it and test. Has been awhile since I read that testing stuff. Doc Sent from mobile On Dec 11, 2012, at 6:39 AM, Charles P. Steinmetz charles_steinm...@lavabit.com wrote: Bill wrote: Well, perhaps you are not looking close enough. That is you need to be observing at a finer level of comparison. The changes, observed here and at another location, are in parts in 10-10 to 10-11 range, sometimes larger. At one of the locations there was a direct correlation to the air conditioning cycle. It is not clear what part of my message you are referring to. My main point was that the information from the DS1620 temperature sensor does not appear to be used internally by the Tbolt. In my observation, subjecting the sensor alone (thermally isolated from the rest of the Tbolt) to wide temperature swings (-10 to +120 C) did not produce any observabe effect on the operation of the Tbolt. If the temp sensor data were used internally by the Tbolt, one would expect a significant effect from such a wide swing -- one that couldn't be missed. If that large and fast a reported temperature swing produced effects only at the e-10 or 11 level, I would attribute it to imperfect thermal isolation of the Tbolt from the temperature stimulus (i.e., stimulus affecting the oven temperature or EFC circuitry of the Tbolt), not as the Tbolt's response to the temperature change reported by the DS1620 sensor. If you were referring to my side point -- that allowing slow changes to the Tbolt housing temperature does not appear to be materially different from regulating the housing temperature -- my observations were that this was true down to at least 5e-13. Of course, there are two variables -- total swing and rate of change. By slow, I mean a rate of change of 0.25C per hour or less [DS1620 reported temperature]. My diurnal swings are no more than 2C per day and usually less [DS1620 reported temperature] (they can be as much as 5 or 6C seasonally, but those changes happen over weeks). A/C cycling likely subjects the Tbolt to a significantly greater rate of change than what I mean by slow, even if basic precautions are taken (e.g., putting it in a cardboard box). Best regards, Charles ___ 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] PTTI 2012, part 2
I used to work on oxygen clean systems... that cleaning is done primarily with liquid freon (R-113 and ultrasound - may be hard to get now). The Vacuum stuff is expensive but off the shelf. The complicated part to me is the lasers and microwave... in addition to the super-stable oscillator you need to take maximum advantage of this stuff. Seems like a lot more than plumbing to me. If you look at the papers on portable rubidium fountains they are significantly bigger than a shoebox (65 cm). Doc KX0O On Tue, Dec 4, 2012 at 8:06 AM, paul swed paulsw...@gmail.com wrote: OK now that I am setting out to build one. Would the challenge for a amateur be that the components you build with are basically dirty. Some how on the copper pipe it would need to be clean and then brazed I might guess. All of that makes for a dirty element. To the vacuum. I used to make vaccuum pumps out of old refrigerator motors. That would be the first stage of pump down. But how do you take it down below that? Then I speculate you use a ion pump to get rid of the stuff that remains. Regards Paul. On Tue, Dec 4, 2012 at 7:37 AM, Bob Camp li...@rtty.us wrote: Hi I went through a similar process quite a while ago. The dimensions of the actual fountain can be quite small. One could make one the size of a shoe box and still have it perform quite well. Bob On Dec 3, 2012, at 2:07 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote: In message AB5B0278225B4BD483382A39E6834203@pc52, Tom Van Baak writes: - USNO rubidium fountains While many national labs have developed cesium fountains (for accuracy), USNO has been gradually building rubidium fountain clocks (for stability) and 4 of them are now fully operational. The ADEV of these clocks gets well under 1e-16. The paper will have all the details but the note I made was that with 20 months of data, the stability was near 5e-17 at tau 4 months. That's 100x better than a commercial cesium standard; better than all of USNO's other 70 cesium clocks and 15 H-masers combined. Yes, I've added rubidium fountain to my automated eBay searches. I happened to miss a turn (or something...) and stumbled into the building where they keep those fountains when I visited USNO some months ago. WhatI found most remarkable about them were how compact they were, I still expected fountains to be room size, but these were rack-sized. I asked what the material cost would be and if a competent amateur would be able to do something like that, and the clear message was that the single biggest problem was the vacuum for a vessel that size (when you can't use ferromagmnetic materials) and getting the optical bench calibrated. Apart from that it's just some plumbing - Loran/UrsaNav CW instead of very low duty cycle Loran pulses would improve S/N [...] Actually, it probably will not. The one smart thing about the LORAN signal is S/N, which means that LORAN for timing purposes is incredible insensitive to noise and at the same time, incredible transmitter power economy. The one caveat is that the GRI has to be a good number, preferably a four (or more!) digit prime number. (You need to grok moduls-arithmetic to really appreciate this, but its the magnitude of the prime factors of the product of the GRI and the disturbing CW which counts: The smaller the are, the harder it is to filter the CW-RFI out.) This is why Europe switched to 4-digit GRIs and almost totally solved CW-RFI by doing so, and why the Russian Chayka at GRI 8000 is totally useless near anything resembling a transmitter. -- 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. ___ 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. -- Doc Bill Dailey KXØO ___ 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] PTTI 2012, part 2
Agreed and they probably wouldn't use a cryogenic sapphire oscillator. Sent from mobile On Dec 4, 2012, at 8:34 AM, Bob Camp li...@rtty.us wrote: Hi Indeed, you likely won't get USNO grade with a shoe box sized part. You can get one to work and do quite good ADEV. No, I haven't done it, I'm just going on what I've been told. The main point being that for a basement project - smaller is probably lower cost. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Tuesday, December 04, 2012 9:19 AM To: Discussion of precise time and frequency measurement; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2 In message CAMPhiorJihW9z6-q0+Qfd+GPLjs6e8_ovWrDxQoxV=92hgj...@mail.gmail.com , Bill Dailey writes: If you look at the papers on portable rubidium fountains they are significantly bigger than a shoebox (65 cm). Diameter is controlled by dispersion of the launched atoms (=recovery rate) and the layers of shielding. 65cm looked like close to a minimum for USNO grade, amateurs could probably make do with less shielding. -- 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. ___ 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] PTTI 2012, part 2
No MIT here. Sadly. Sent from mobile On Dec 4, 2012, at 8:49 AM, paul swed paulsw...@gmail.com wrote: Basements the key. So for me bigger is better. Heck if its a rack thats ok. It gets interesting in what types of components you can use if you are willing to go larger. Great point on the laser and optics. Funny thing is for small change you can actually get used optics bench components at least at the last MIT flea I ran across the items. They were snapped up by the way. From what I have seen of time-nuttery and Hydrogen masers I am actually not all that sure its beyond this group. Regards Paul On Tue, Dec 4, 2012 at 9:34 AM, Bob Camp li...@rtty.us wrote: Hi Indeed, you likely won't get USNO grade with a shoe box sized part. You can get one to work and do quite good ADEV. No, I haven't done it, I'm just going on what I've been told. The main point being that for a basement project - smaller is probably lower cost. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Tuesday, December 04, 2012 9:19 AM To: Discussion of precise time and frequency measurement; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2 In message CAMPhiorJihW9z6-q0+Qfd+GPLjs6e8_ovWrDxQoxV=92hgj...@mail.gmail.com , Bill Dailey writes: If you look at the papers on portable rubidium fountains they are significantly bigger than a shoebox (65 cm). Diameter is controlled by dispersion of the launched atoms (=recovery rate) and the layers of shielding. 65cm looked like close to a minimum for USNO grade, amateurs could probably make do with less shielding. -- 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. ___ 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] PTTI 2012, part 2
I will build one right away.. but I didnt see your request. My problem is surface mount components (the multipin or no leads)... I am not confident in that. but I would certainly try. I am not a programmer and also figure somebody with more soldering skills than those I have picked up ruining things would be desired. I am always willing to try not to ruin something. Doc KX0O On Tue, Dec 4, 2012 at 4:25 PM, ewkeh...@aol.com wrote: Paul Frankly I do not think I will live long enough to see a time nut build a fountain Rb. Over the four years I have watched many smoke and mirror projects with nothing coming out of is. In German we have a saying: paper is patient. We should walk before we run. Many members did buy a FE 5680, how many do you think are in operation, if, there would be discussions about its temperature performance. take a close look on page 7 figure 5 of the brochure, I also see it. Personally I use a Shera loop. But that is an overkill and for some to complex since it requires direct analog C field control. My real focus is on controlling FRK-H, M100 and HP 5065. What is needed is a coordinated effort to start with temperature control, a simple GPSDO only taking care of aging using RS232 interface an analog loop for controlling something like a Morion. Stability and accuracy could be in the 1 E-12 range, low cost able to be assembled by 90% of list members, but then I proposed it once before looking for some one to develop the filter. No response, it is clear that very few are willing or able to actually build something. When Corby wrote about his experience with the dual mixer / counter, large response and we will have a complete documentation set, but when I asked for a few that would be willing to build one right away, I would make complete kits, I got one response. Sad, but that is the reality. How many FE 5680A door stops do you think are out there? How many PICTICII's do you think are in use? Bert Kehren Miami. In a message dated 12/4/2012 9:49:29 A.M. Eastern Standard Time, paulsw...@gmail.com writes: Basements the key. So for me bigger is better. Heck if its a rack thats ok. It gets interesting in what types of components you can use if you are willing to go larger. Great point on the laser and optics. Funny thing is for small change you can actually get used optics bench components at least at the last MIT flea I ran across the items. They were snapped up by the way. From what I have seen of time-nuttery and Hydrogen masers I am actually not all that sure its beyond this group. Regards Paul On Tue, Dec 4, 2012 at 9:34 AM, Bob Camp li...@rtty.us wrote: Hi Indeed, you likely won't get USNO grade with a shoe box sized part. You can get one to work and do quite good ADEV. No, I haven't done it, I'm just going on what I've been told. The main point being that for a basement project - smaller is probably lower cost. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Tuesday, December 04, 2012 9:19 AM To: Discussion of precise time and frequency measurement; Bill Dailey Subject: Re: [time-nuts] PTTI 2012, part 2 In message CAMPhiorJihW9z6-q0+Qfd+GPLjs6e8_ovWrDxQoxV=92hgj...@mail.gmail.com , Bill Dailey writes: If you look at the papers on portable rubidium fountains they are significantly bigger than a shoebox (65 cm). Diameter is controlled by dispersion of the launched atoms (=recovery rate) and the layers of shielding. 65cm looked like close to a minimum for USNO grade, amateurs could probably make do with less shielding. -- 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. ___ 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. -- Doc Bill Dailey KXØO ___ time-nuts mailing list -- time-nuts
Re: [time-nuts] eBay Ublox
Very nice write up. I went down a similar road with my fury and Ubuntu... And then with FreeBSD on a soekris box. Have you tried refclock drivers instead of gpsd? I use gpsd on Ubuntu but decided to use refclock route instead for FreeBSD. I have an overall feeling that at us and ns levels gpsd doesn't perform as well... No evidence but is does seem like it should be inherently slower... Probably much more important on the free bsd soekris implementation. Doc Sent from my iPad On Nov 21, 2012, at 2:45 AM, David J Taylor david-tay...@blueyonder.co.uk wrote: -Original Message- From: paul swed Sent: Tuesday, November 20, 2012 9:34 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] eBay Ublox any luck on the ntp server? == If it's me you are asking, yes, Paul, here's the server: http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html and here's the performance with the u-blox NEO-6M (I know that's a Navigation and not a Time GPS). http://www.satsignal.eu/mrtg/performance_raspi-1.php When recompiling NTP /and/ installing SNMP, there was a +20 microsecond transient, followed by a -14 microsecond transient during recovery. That was just before 16:00 UTC the day before yesterday, and is just disappearing off the left end of the graph as I write (08:40 UTC, Wednesday). Otherwise well within 5 microseconds, with the unit just sitting out in the open. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ 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] eBay Ublox
Yep. You are right. May help only in the serial data... And irrelevant. Doc ___ 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] Phase Shifter
Does anybody have any knowledge of these beasts? I just bought a Vectronics DP 638.8 RF phase shifter for a project. Wondering if anyone has an idea of pinout/operation. I cant find a datasheet or anything on it. it appears to be a 24-30 volt and have 3 different frequency ranges dc-3GHz, 3-8 GHz, and 8-12.4 GHz.. -- Doc Bill Dailey KXØO ___ 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] Measuring gpsdo vs itself
Thanks guys, Like usual more complicated than I thought. I was hoping that this would cancel any stability issues common to both the reference and the signal thus giving me best case ability. I seem to be getting numbers too good to be true so there must be a hitch. I get an ADEV 5x10-13 at 1 s mostly linear to 7x10-16 at 10,000 s with a small hump at 20s-80s. Figured there was some kind of gotcha. Doc On Mon, Nov 5, 2012 at 2:26 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 11/05/2012 06:30 AM, Tom Van Baak wrote: Ah, I see what you mean now. Yes, that setup can give you a rough estimate of the counter's noise floor. I can't give you specific numbers but one danger with this sort of test is that the input and the timebase are artificially locked together (i.e. fixed phase relationship) through the common reference. Your measurements may thus show artificially less noise than a real-life case of independent input(s) and reference. This can happen if your sub-ns counter is based on interpolators. Because the input and the timebase are locked in phase, the counter lands near the same point of the interpolator scale on every single measurement, rather than experiencing the noise (and non-linearity) of the entire scale. It's a little more complex than interpolator non-linearities alone. You also need to include cross-talk between the signals. This cross-talk is usually higher between A and B inputs than from reference, but never the less. You would need to sweep the trigger input delays to illustrate these non-linearities. From a single measurement you can get both a better or worse number compared to the average which is what you would expect to see for free-running signals. So, you can get a rough idea about the baseline, but it is not a sufficient method. See the SR620 manual for a plot of non-linearities. Cheers, Magnus __**_ 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. -- Doc Bill Dailey KXØO ___ 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] Measuring gpsdo vs itself
If I use a gpsdo as my reference and feed the same 10MHz into a counter does that yield the reference independent noise floor of the measuring system? Seems to me it would look like an ideal reference with respect to the measuring system. Thanks, Doc KX0O ___ 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] Measuring gpsdo vs itself
I guess what I am saying is if I discipline the counter with 10MHz and then measure the same 10MHz. Just making sure we are on the same page. Doc Sent from my iPad On Nov 4, 2012, at 10:22 PM, Tom Van Baak t...@leapsecond.com wrote: Bill, This is usually a good idea, since the counter then has both a good short- and long-term stable/accurate timebase, inherited from the GPSDO. It means the internal timebase of the counter is no longer a factor in measurement stability or accuracy. There are exceptions to this, but I'll guess your setup is not one of them. This configuration is especially good for 1PPS TI measurements since it means a short 100 ns TI measurement is just as accurate as a long 0.99900 s measurement. I'm not sure I'd call this a reference independent system; it's simply using a GPSDO as the reference instead of the internal XO timebase of the counter. /tvb - Original Message - From: Bill Dailey docdai...@gmail.com To: Time Nuts time-nuts@febo.com Sent: Sunday, November 04, 2012 7:19 PM Subject: [time-nuts] Measuring gpsdo vs itself If I use a gpsdo as my reference and feed the same 10MHz into a counter does that yield the reference independent noise floor of the measuring system? Seems to me it would look like an ideal reference with respect to the measuring system. Thanks, Doc KX0O ___ 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] Adjusting HP 5065A frequency
Anybody in the middle of the country (Kansas City) have a maser or 5065a? I want to test my super-charged gpsdo but don't have the tools. Doc KX0O Sent from my iPad On Oct 21, 2012, at 11:43 AM, ewkeh...@aol.com wrote: John I agree with your observations. Before my time nuts time I did make the mistake of getting rid of my 5065A since I did have a Shera disciplined FRK and had gotten hold of quite a few HP5061A's and FTS 4000's. Big mistake. Gave no attention to A/V. Phase noise yes but I went about it by focusing on a low noise 100 MHz XO PLL as part of low noise signal generators, my key interest. Recently how ever I was given a 5065A RVFR and thanks to Corby I know its performance and I am combining it with later technology, M1000, temperature control and a modified Shera, hoping for some outstanding results. If you are interested contact me off list and I send you some pictures. Will take some time to complete because of some other time nuts projects one of which I hope Corby will report on. Bert Kehren In a message dated 10/21/2012 11:58:56 A.M. Eastern Daylight Time, j...@febo.com writes: Hi Edgardo -- One slightly frustrating thing about the 5065A is that its frequency settability isn't as good as its short term stability. I believe the manual says that the small divisions on the C-field counter dial are 2x10e12, and it's hard to set closer than that. A good 5065A is a remarkable piece of gear, with medium term stability over, say, 1K to 100K seconds that is very hard to beat by anything other than a maser. As best I can measure mine against a number of other sources (no maser here, sigh), it is around 1e13, maybe a bit better, over that range. That's an order of magnitude better than any of the telco Rbs. This is just a guess, but from some data that tvb and others have reported, I suspect that external tempco is the main limiter for medium term stability in the 5065A. It would be interesting to see one in a temperature-controlled environment vs. one that's not. John On Oct 21, 2012, at 11:11 AM, Edgardo Molina xe1...@amsat.org wrote: Dear Corby, Good morning. Thank you for the detailed instructions to bring the 5065A close to desired frequency. I couldn't have a cleaner explanation of the process. Yesterday evening I tried adjusting the C field in small steps using a mixer, lpf and two oscillators setup as my current frequency counter is not able to resolve de small increments/decrements of frequency adjustment. Still I could detect the adjustments as I performed them. The response is quite fast. I have been told that these units are really stable compared to the small telecom Rb units. I heard a comment that the 5065A is even more stable than the new Symmetricom units using the X72 Rb module. Have you ever measured such differences in stability? Thank you. Regards, Edgardo Molina Dirección IPTEL www.iptel.net.mx T : 55 55 55202444 M : 04455 20501854 Piensa en Bits SA de CV Información anexa: CONFIDENCIALIDAD DE INFORMACION Este mensaje tiene carácter confidencial. Si usted no es el destinarario de este mensaje, le suplicamos se lo notifique al remitente mediante un correo electrónico y que borre el presente mensaje y sus anexos de su computadora sin retener una copia de los mismos. Queda estrictamente prohibido copiar este mensaje o hacer usode el para cualquier propósito o divulgar su en forma parcial o total su contenido. Gracias. NON-DISCLOSURE OF INFORMATION This email is strictly confidential and may also be privileged. If you are not the intended recipient please immediately advise the sender by replying to this e-mail and then deleting the message and its attachments from your computer without keeping a copy. It is strictly forbidden to copy it or use it for any purpose or disclose its contents to any third party. Thank you. On Oct 19, 2012, at 5:55 PM, cdel...@juno.com wrote: Edgardo, You do use the C-field adjust to put a 5065A On frequency. The Factory values are a moot point after all these years! Just incrementaly adjust the c-field control in small steps while observing the frequency comparison. The only thing that might happen is that you reach one end of the C-field pot before getting to the frequency you want. If that is the case you will need to set the synthesizer switch to the next value in the chart. (either up or down depending on which way you ran out of room.) Then start over with the c=field adjustment. If you switch the synthesizer setting you will need to remove power momentarily to reset the synthesizers lock indication circuit. Otherwise pushing the logic reset button to get the green light wont work. Corby Woman
Re: [time-nuts] GPSDO three cornered comparisons
I would like a treatise on ti reported by gpsdo's. Sent from my iPad On Oct 21, 2012, at 7:39 PM, Tom Van Baak t...@leapsecond.com wrote: David, This is problematic, since the Z38xx software is not really measuring the output of the GPSDO. Instead it's taking the internally reported PLL time error measurements from the disciplining loop and pretending they are a measure of real performance as measured against a real frequency standard. However, this PLL data can be used to see how well the loop is working; that in itself can be interesting. For example, differences in an ADEV plot of the PLL error term can be used to reveal the time constant used by the PLL. So one can still use the ADEV-style calculation on the phase error of a closed PLL; but don't confuse this with the actual performance of the GPSDO as a time/frequency standard. Does this make sense, or shall I explain more? Or, if you have some raw data you can send me off-line I'll take a look at it. Thanks, /tvb - Original Message - From: David Hooke dho...@gmail.com To: time-nuts@febo.com Sent: Sunday, October 21, 2012 4:44 PM Subject: Re: [time-nuts] GPSDO three cornered comparisons Tom, The ADEVs I quoted are from the Z83xx software, so I assume it's comparing time from the GPS system to it's own oscillator's output, in the same way that LH does. I've been monitoring the basic stuff you suggested. It's because I don't have a known reference to compare the units with that I want to use the 3-corner method to start sorting the wheat from the chaff. david I have an HP 58503A and a Symmetricom 58503B which are behaving quite differently to one another using a common antenna. Using Z38xx, there's almost an order of magnitude difference between the reported ADEVs at 40k seconds (HP:7e-13, Sym:5e-12). Both have 10811 oscillators and are Where are you getting the reported ADEVs? What counter, what reference, what software? Did you happen to periodically log any SCPI data during the runs, so that you can compare SV counts, signal strengths, TI averages, and so on? In general it might be good to have a quick look at this mundane data first. /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] Thermistor on OCXO
If I wanted to try to compensate for temperature variation of my OCXO... where would I attach a thermistor? What would be a good method of attachment to best respresent the OCXO temp without opening the OCXO and without an undue influence of ambient temperature? The OCXO in question is Datum C... was thinking of using thermal epoxy to hold it down and then putting some insulating material (suggestions) on top of it. -- Doc Bill Dailey KXØO ___ 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] Thermistor on OCXO
I am using a fury board with on off board oscillator. So a thermistor is representing ocxo current. Right now without tempco I have 1.7 ns sd in ti. If I can eliminate bumps when the temperature changes slightly I can back the efc gain down below my current setpoint of 0.5. Right now if I go any lower on efc gain the thermal changes perturb the system a bit too much. When the temp is constant I can bring the efc gain way down...and therefore the sd to close to 1 ns. What I am trying to achieve is a much more stable and narrow time interval. Current performance is pretty close to as good as it gets for a gpsdo but I think I can do a little better. Sent from my iPad On Oct 17, 2012, at 5:55 PM, Azelio Boriani azelio.bori...@screen.it wrote: Yes, usually increasing temperature increases frequency, so if you see an oven current increase then slightly take down the EFC (and the other way around if the current decreases). On Thu, Oct 18, 2012 at 12:47 AM, Rick Karlquist rich...@karlquist.comwrote: Bill Dailey wrote: If I wanted to try to compensate for temperature variation of my OCXO... where would I attach a thermistor? What would be a good method of attachment to best respresent the OCXO temp without opening the OCXO and without an undue influence of ambient temperature? The OCXO in question is Datum C... was thinking of using thermal epoxy to hold it down and then putting some insulating material (suggestions) on top of it. -- Doc Bill Dailey KXØO Probably easier to monitor oven current and use it to tweak the set point of the oven or tweak the EFC line of the oscillator. As I explained in my 1997 FCS paper on zero gradient ovens, the gradient is the main thing limiting thermal gain. If you have a serious gradient problem, then locating the thermistor far away from the crystal (probably much farther away than the internal one) isn't likely to be productive. The other issue to be aware of is that at some point, the tempco of the electronics comes in play, as explained in my 1997 FCS paper on bridge stabilized oscillators. Increasing the thermal gain of the 10811 beyond 1,000 doesn't improve the tempco because of oscillator circuit pulling. You could possibly improve the tempco by using oven current to tweak the set point. This might cancel out circuit pulling drift, regardless of what was going on with the crystal. I've never actually tried this, but it would be good research project well within the ability of any time nut. Rick Karlquist N6RK ___ 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] Centering ocxo
ok.. So that may very well be true of this unit. Electrical tuning is 3E-7 0 - 5v (+/-). It also lists a digital tuning range of +- 3Hz at 10MHz. Correct me if I am wrong but that appears to mean 3Hz electrical and 6Hz digital tuning range. I am not doing digital tuning but thought I would throw that out there. I have been trying to optimize parameters on this Fury board but it seems my optimization has just been increasing the deviation. Running 1.8 ns sd overnight with an average TI of about 26ns (was with my optimized settings)...the original settings were giving me a much lower deviation...I didnt log it but looking at the graph of frequency in excel I would say probably between 0.1-0.6 ns. I just put it back on the original settings and am letting it settle now. Was adjusting Dampening, EFCSCALE and DAC gain. My observations reveal dampening makes it a bit slower to respond and perhaps settles it some, The efcscale seems to act as pure gain on top of the baseline dac gain which is essentially determined by the tuning range as you referred to. What I saw with a low efcscale is that the TI was higher but the SD lower... with efc scale higher the TI was lower but the SD suffered. Since my goal here is low noise and very good short term stability I prefer the lower efcscale (low gain with low SD). Let me know if I have any gross conceptual errors here or if I am looking at this properly. Doc KX0O On Tue, Oct 2, 2012 at 11:54 PM, Hal Murray hmur...@megapathdsl.net wrote: docdai...@gmail.com said: I am ok for awhile but how do you center the efc of an ocxo? I understand there is something (screw) to adjust the ocxo so it is approximately on freq with 2.5v efc. Specific oscillator datum-c. I have he datasheet but doesn't say coarse frequency adjust this screw or some such. There may not be a coarse adjustment. If the tuning range is big enough to cover the aging over your design life, you don't need one. There is a tradeoff between adjustment range and the number of bits you need in a DAC to get a required accuracy. Suppose I have an adjustment range of 1 Hz (peak to peak) on a 10 MHz oscillator. That's 1 part is 10^7. If I have a 10 bit DAC, I can adjust to 1 part is 10^10. A 20 bit DAC can get to 1 part is 10^13. But if the tuning range is 10 Hz, the same 20 bit DAC setup only gets you to 1 part is 10^12. -- 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. -- Doc Bill Dailey KXØO ___ 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] Centering ocxo
Thanks Said. This is a learning experience but it is fun watching it settle down. I will stop fiddling with the settings and just let it do it's thing. I am watching the output with my qs1r direct digital to spectrumlab. This way I don't have to worry about any audio glitches. I have been recording frequency every minute the entire time to see what it is doing. Sent from mobile On Oct 3, 2012, at 10:39 AM, Said Jackson saidj...@aol.com wrote: Doc, You are on the right track, efc scale affects SD as you can see. The phaseco parameter is used to push down the average TI to 0ns. Higher values push faster. If your ocxo is still drifting (aging and or retrace) it will take about 48 hours for the aging measurement and correction to kick in, and bring the offset down to 0ns. Bye Said Sent From iPhone On Oct 3, 2012, at 3:46, Bill Dailey docdai...@gmail.com wrote: ok.. So that may very well be true of this unit. Electrical tuning is 3E-7 0 - 5v (+/-). It also lists a digital tuning range of +- 3Hz at 10MHz. Correct me if I am wrong but that appears to mean 3Hz electrical and 6Hz digital tuning range. I am not doing digital tuning but thought I would throw that out there. I have been trying to optimize parameters on this Fury board but it seems my optimization has just been increasing the deviation. Running 1.8 ns sd overnight with an average TI of about 26ns (was with my optimized settings)...the original settings were giving me a much lower deviation...I didnt log it but looking at the graph of frequency in excel I would say probably between 0.1-0.6 ns. I just put it back on the original settings and am letting it settle now. Was adjusting Dampening, EFCSCALE and DAC gain. My observations reveal dampening makes it a bit slower to respond and perhaps settles it some, The efcscale seems to act as pure gain on top of the baseline dac gain which is essentially determined by the tuning range as you referred to. What I saw with a low efcscale is that the TI was higher but the SD lower... with efc scale higher the TI was lower but the SD suffered. Since my goal here is low noise and very good short term stability I prefer the lower efcscale (low gain with low SD). Let me know if I have any gross conceptual errors here or if I am looking at this properly. Doc KX0O On Tue, Oct 2, 2012 at 11:54 PM, Hal Murray hmur...@megapathdsl.net wrote: docdai...@gmail.com said: I am ok for awhile but how do you center the efc of an ocxo? I understand there is something (screw) to adjust the ocxo so it is approximately on freq with 2.5v efc. Specific oscillator datum-c. I have he datasheet but doesn't say coarse frequency adjust this screw or some such. There may not be a coarse adjustment. If the tuning range is big enough to cover the aging over your design life, you don't need one. There is a tradeoff between adjustment range and the number of bits you need in a DAC to get a required accuracy. Suppose I have an adjustment range of 1 Hz (peak to peak) on a 10 MHz oscillator. That's 1 part is 10^7. If I have a 10 bit DAC, I can adjust to 1 part is 10^10. A 20 bit DAC can get to 1 part is 10^13. But if the tuning range is 10 Hz, the same 20 bit DAC setup only gets you to 1 part is 10^12. -- 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. -- Doc Bill Dailey KXØO ___ 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] Z38XX parameters
Maybe a dumb question. Just got my new oscillator hooked up to my Fury board. Using the z38xx program of Ulrichs. Can someone help me wrap my head around the pps TI /s? It seems to be confusing me. May dovetail into the counter thread. Doc KX0O Sent from mobile ___ 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] Centering ocxo
I am ok for awhile but how do you center the efc of an ocxo? I understand there is something (screw) to adjust the ocxo so it is approximately on freq with 2.5v efc. Specific oscillator datum-c. I have he datasheet but doesn't say coarse frequency adjust this screw or some such. Doc KX0O Sent from my iPad ___ 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] RFX GPSDO - Anybody played with one of these?
On Oct 1, 2012, at 4:45 AM, Javier Herrero jherr...@hvsistemas.es wrote: El 01/10/2012 11:22, Hal Murray escribió: t...@westwood-tech.com said: information appeared to be non-existent. IMHO for pretty much *everything* that is for sale, if you have to ask for the price it is a scam. Yes, when it says call for pricing, I usually drop interest. But I wouldn't say scam. How about not targeted at my corner of the market? I can think of several reasons for not publishing a price. 1) The product doesn't really exist yet. They have done the research but haven't finished up and handed off to manufacturing. They are looking for initial customers so they can tune things to fit what customers really need (and are willing to pay for). You want the tall skinny version? Fine, we'll make that first. How tall? 2) The product is tricky to use. They want to make sure it will work well in your application. 3) The product has lots of interacting options/parameters. They only stock a few combinations. If you want to buy more than a handful, you can get a better price by picking the right options. 4) The price varies a lot as a function of the quantity. They prefer to quote you as a function of the volume you request, and don't want you to be dissappointed it they publish a 1000+ price and you only want 10, or to make you think that it is too expensive if you want 1 but you think that the price, based on single quantites, is too expensive 5) International marketing policies. They want, for example, their US distributor to quote you, and will not provide you a direct factory pricing. 6) Contractual or legal reasons. If they have contracted to build them for someone they may have given them special pricing and they don't want anybody to know what that special pricing was. If that price was negotiated well and was very high whoever they sold it to may realize their price was a different kind of special than they thought. ___ 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] RFX GPSDO - Anybody played with one of these?
That isn't bad Sent from my iPhone and Hunter Lambert is my hero! On Oct 1, 2012, at 11:27 AM, Don Latham d...@montana.com wrote: Hello Hal and all: Here's the answer I got: Don, A single unit would set you back $465.00 and delivery would be in the region of 6 weeks. Best Regards Steven Wilson (#21490;#24093;#25991;) Technical Director RFX Limited Unit 11A, Oakbank Park, Livingston, West Lothian, Scotland,EH53 0TH, U.K. Tel - +44 (0)1506 439222, Fax - +44 (0)1506 439333 email/skype: steven.wil...@rfx.co.uk www.rfx.co.u Perhaps time-nuts would be interested in a group purchase? Don Latham Hal Murray t...@westwood-tech.com said: information appeared to be non-existent. IMHO for pretty much *everything* that is for sale, if you have to ask for the price it is a scam. Yes, when it says call for pricing, I usually drop interest. But I wouldn't say scam. How about not targeted at my corner of the market? I can think of several reasons for not publishing a price. 1) The product doesn't really exist yet. They have done the research but haven't finished up and handed off to manufacturing. They are looking for initial customers so they can tune things to fit what customers really need (and are willing to pay for). You want the tall skinny version? Fine, we'll make that first. How tall? 2) The product is tricky to use. They want to make sure it will work well in your application. 3) The product has lots of interacting options/parameters. They only stock a few combinations. If you want to buy more than a handful, you can get a better price by picking the right options. -- 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. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. De Erroribus Medicorum, R. Bacon, 13th century. If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] RFX GPSDO - Anybody played with one of these?
Well over 1000. Can still buy them Sent from my iPhone and Hunter Lambert is my hero! On Oct 1, 2012, at 11:53 AM, Chris Albertson albertson.ch...@gmail.com wrote: On Mon, Oct 1, 2012 at 9:27 AM, Don Latham d...@montana.com wrote: A single unit would set you back $465.00 and delivery would be in the region of 6 weeks. I Wonder what price the T-Bolts sold for new in single quantities. Maybe more than $465? 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. ___ 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 Orignal Cost
BTW this device is not nearly as good as a thunderbolt. Closer to that gpstcxo development kit that Jackson Labs is offering (HPSDR guys are using it I think). The short term and long term stability quite frankly doesn't appear to be in the same league as the Thunderbolt although someone would need to test one. On Mon, Oct 1, 2012 at 12:36 PM, johncr...@aol.com wrote: Hello all - I Wonder what price the T-Bolts sold for new in single quantities. Maybe more than $465? I ran across this some time ago - Perhaps someone has a better number but the later ones seem to go for $ 1500 for the kit with the antenna from a distributor. Note that this is a later model than the one offered surplus. Google Trimble Thunder bolt cost and found among other things... Trimble Embedded Components - TOPP Group, Inc - Data Solutions www.toppcompanies.com/tds/tds-**component-models.htmhttp://www.toppcompanies.com/tds/tds-component-models.htm Trimble GPS Developer Kits - Inquire about available volume discounts. TTPart no, Mfr.Part no. Description, PDF, Price List ... 35349-00, Thunderbolt Starter Kit: inlcudes Thunderbolt, bullet antenna, 75 foot cable, power connector, $1,595.00 ... I think this is a 12 channel receiver. I suspect that years ago the 8 channel was about the same. 73 john k6iql __**_ 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. -- Doc Bill Dailey KXØO ___ 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] Symmetricom 58532A and 58536A group delay figures
I think the usually quote worse case. Sent from my iPhone and Hunter Lambert is my hero! On Sep 30, 2012, at 12:03 PM, Hal Murray hmur...@megapathdsl.net wrote: j...@febo.com said: My recollection was a bit off -- we saw about 22ns on the two-port 58535a and about 15ns on the 8-port 58517A. I would guess the 4-port unit would be similar. Interesting that it's so far off from the 40 ns in the data sheet. -- 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. ___ 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] E1938A PN measurments
Bert, When you do tests like this, how long do you let the oscillators settle prior to testing? Doc Sent from my iPad On Sep 30, 2012, at 4:23 PM, ewkeh...@aol.com wrote: Rick I have some 10811's all below 1 E-12 in the 1 to 100 sec. range, a few as low as 4 E-13 at 10 seconds. How low have you seen, I have the opportunity to test 40+ units and hope to find a few even better ones. Any guidance will be appreciated. My best reference is 3 E-13 so any thing as good or better would have to be tested by some one else after initial test. Bert Kehren . In a message dated 9/30/2012 3:49:33 P.M. Eastern Daylight Time, rich...@karlquist.com writes: I only measured one 10811. However, John Vig's tutorial (available at IEEE UFFC) rather categorically states that piezoelectric resonators have flicker noise of frequency. What I measured was most closely related to phase noise, as opposed to Allan Deviation. Phase noise of 10811's is more consistent unit to unit than ADEV and certain more consistent than aging. BTW, ADEV at HP was measured against a special 10811 that was 500 Hz off frequency. I was never able to find out how they arrived at this golden unit. But it seems clear that it could not have been the best ever unit for ADEV, thus the real golden units that came down the pike were simply rated as ADEV too good to measure. I tried to get a project started where we would use a frequency synthesizer to do the offset. Then we could take the best units and compared them against each other. Then, as well accumulated test data, the cream would gradually rise to the top and we would have some true golden units. The problem was that there ADEV at those levels wasn't a money spec. Rick On 9/30/2012 12:16 PM, Ed Palmer wrote: Would this characteristic be similar across all 10811s or would there be as much unit to unit variation as there is for aging and Allan Deviation? Ed On 9/30/2012 11:03 AM, Richard (Rick) Karlquist wrote: I recently modified an old 10811 to bring out the crystal leads on miniature coax (instead of having them connect to the oscillator circuit). This allowed me to measure the crystal's inherent flicker noise of frequency. The measurements indicate that the 10811 phase noise out to at least 100 Hz is entirely due to the crystal. An interesting aspect of flicker noise of frequency is that Allan deviation is independent of tau. Thus, just one number describes the crystal noise. Rick On 9/30/2012 4:44 AM, Bob Camp wrote: Hi Close in, it looks like it's pretty much the crystal and the loading of the bridge oscillator. Bob On Sep 29, 2012, at 11:46 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: The E1938A uses a crystal that is basically the same as the 10811 crystal except that it is in a reduced height package. However the phase noise is not as good as a 10811 due to broadband noise in the automatic frequency control circuit. By the time I discovered this, it was too late to try to fix it. Rick Karlquist N6RK E1938A designer ___ 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.
Re: [time-nuts] E1938A PN measurments
I have a corby ocxo (datum-c) that I am coupling with a fury oem board soon (need some connectors). I wish someone with good measurement equipment lived nearby. I would like to measure this vs my standard fury. I think the ocxo is mid 10-13 at 1s. Anybody near Kansas City? Doc Sent from my iPad On Sep 30, 2012, at 7:02 PM, ewkeh...@aol.com wrote: Doc The units I mentioned have been done by Corby, but I let units run two weeks before I do any test. In the future when I do the 40+ two a week running parallel and the best rerun after 4 week soak. Bert In a message dated 9/30/2012 7:55:43 P.M. Eastern Daylight Time, docdai...@gmail.com writes: Bert, When you do tests like this, how long do you let the oscillators settle prior to testing? Doc Sent from my iPad On Sep 30, 2012, at 4:23 PM, ewkeh...@aol.com wrote: Rick I have some 10811's all below 1 E-12 in the 1 to 100 sec. range, a few as low as 4 E-13 at 10 seconds. How low have you seen, I have the opportunity to test 40+ units and hope to find a few even better ones. Any guidance will be appreciated. My best reference is 3 E-13 so any thing as good or better would have to be tested by some one else after initial test. Bert Kehren . In a message dated 9/30/2012 3:49:33 P.M. Eastern Daylight Time, rich...@karlquist.com writes: I only measured one 10811. However, John Vig's tutorial (available at IEEE UFFC) rather categorically states that piezoelectric resonators have flicker noise of frequency. What I measured was most closely related to phase noise, as opposed to Allan Deviation. Phase noise of 10811's is more consistent unit to unit than ADEV and certain more consistent than aging. BTW, ADEV at HP was measured against a special 10811 that was 500 Hz off frequency. I was never able to find out how they arrived at this golden unit. But it seems clear that it could not have been the best ever unit for ADEV, thus the real golden units that came down the pike were simply rated as ADEV too good to measure. I tried to get a project started where we would use a frequency synthesizer to do the offset. Then we could take the best units and compared them against each other. Then, as well accumulated test data, the cream would gradually rise to the top and we would have some true golden units. The problem was that there ADEV at those levels wasn't a money spec. Rick On 9/30/2012 12:16 PM, Ed Palmer wrote: Would this characteristic be similar across all 10811s or would there be as much unit to unit variation as there is for aging and Allan Deviation? Ed On 9/30/2012 11:03 AM, Richard (Rick) Karlquist wrote: I recently modified an old 10811 to bring out the crystal leads on miniature coax (instead of having them connect to the oscillator circuit). This allowed me to measure the crystal's inherent flicker noise of frequency. The measurements indicate that the 10811 phase noise out to at least 100 Hz is entirely due to the crystal. An interesting aspect of flicker noise of frequency is that Allan deviation is independent of tau. Thus, just one number describes the crystal noise. Rick On 9/30/2012 4:44 AM, Bob Camp wrote: Hi Close in, it looks like it's pretty much the crystal and the loading of the bridge oscillator. Bob On Sep 29, 2012, at 11:46 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: The E1938A uses a crystal that is basically the same as the 10811 crystal except that it is in a reduced height package. However the phase noise is not as good as a 10811 due to broadband noise in the automatic frequency control circuit. By the time I discovered this, it was too late to try to fix it. Rick Karlquist N6RK E1938A designer ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] BPSK Receiver GPS Antenna siting
I don't think it is legal to prohibit flag poles Sent from my iPhone and Hunter Lambert is my hero! On Sep 28, 2012, at 8:16 AM, Bob Camp li...@rtty.us wrote: Hi Flag poles are prohibited. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Randy D. Hunt Sent: Thursday, September 27, 2012 10:24 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] BPSK Receiver GPS Antenna siting On 9/27/2012 4:20 PM, Bob Camp wrote: Hi At least in my back yard, a 6' tall tripod would be very noticeable from a number of directions. There are many others in similar situations. If I were to interpret the restrictions literally as written, an antenna that was inside the house, but visible through an open window is also a violation. Bob On Sep 27, 2012, at 7:11 PM, johncr...@aol.com wrote: Various comments - Hal mentioned SNR for the scheme I suggested. A PLL can be a coherent demodulator of arbitrary bandwidth. Thus the PLL at the output of the doubler can have a small bandwidth since at that point there is no PSK, it having been removed by the doubler. So given a stable VCXO you can probably get down to 1 Hz and thereby achieve a good SNR. There is a lot of stuff out there on phase tracking receivers that do exactly that. You know the frequency so the loop does not have to search far and the BW can be increased for acquisition and closed up for tracking. On writing reams of code - my point was that it is not required to used the admittedly more powerful software techniques to do this job - I noted that one reason to write reams of code is for the fun of it, this is after all a hobby. GPS Antenna Siting - Lets not make this so hard. Mine is at 6 ft elevation and is blocked to an elevation angle of 20 to 30 degrees by a house within 15 ft and a forest of trees. I have room and no restrictions but I also have severe thunderstorms - so the house plays lightning protect for the antenna. My T bolt tracks a Rb to better than 1e-12 over 24 hours with no serious 10 MHz phase bumps as plotted on a strip chart recorder. So - Put your antenna at 6 ft in back yard. Start out on a photo tripod - who is gonna notice? set up a t bolt at EL=5 AMU=0 Damping = 1.2 and Time Constant = 100 sec. get the t bolt manual get Tbolt monitor get Lady Heather and read all that stuff. Run Lady Heather antenna survey (command SAS) for at least two days - you get a map of signal level in dBc vs elevation Reset the Tbolt elevation mask to reject anything that is shown as blocked using the signal level map. Likewise experiment with the AMU setting to reject the weak = poor signals. Mine works good with AMU all the way up to 10 as fewer good satellites are better than lots of weak ones. The satellites are in high orbits so masking those below 25 degrees is OK and the AMU sets the acceptable signal level - at AMU 10 my setup throws out those below about 40 dBc - the strong guys go up to 50. This is a function of you antenna performance so some experimentation is required. -73 john k6iql ___ 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. Put up a flagpole. Randy, KI6WAS ___ 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] Link to 50's 60's test equipment that I would like to get rid of
There is a comma in equipment messing that link up Sent from my iPad On Sep 28, 2012, at 7:54 PM, jim s j...@jwsss.com wrote: There is a space after 49em which messes up a copy if you don't watch out. I tried bitly and and tinyrul couldn't get it to work with the contracted link. They aren't storing something. http://www.eevblog.com/forum/buysellwanted/vintage-50%27s-60%27s-test-equipm,ent-available/msg149549/#msg149549em The above is inserted as both the text and as an html link in my email, maybe it will work. If you copy it be sure you copy from http... thru 549em and don't get anything but the line wrap in your copy and paste. both George's original URL and the original of his one quoted below worked, with the caveat about the trailing space. Jim On 9/28/2012 4:28 PM, George Race wrote: I just entered the following, from below, and it worked. http://www.eevblog.com/forum/buysellwanted/vintage-50%27s-60%27s-test-equipm ent-available/msg149549/#msg149549em I think the problem may be that it wrapped around and you have extra possibly in the middle. George ___ 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] REF osc distribution.
What is the port to port isolation and price Sent from my iPad On Sep 6, 2012, at 2:21 AM, Gaudin Luc lgau...@naelcom.com wrote: Hello, We have a product that have been specially design for these : NGA-DIS http://naelcom.fr/app/download/5788490907/Data+sheet+NGA-DIS+V1.0.pdf Regards, Luc -Message d'origine- De : time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] De la part de Bob Camp Envoyé : mardi 4 septembre 2012 18:23 À : 'Discussion of precise time and frequency measurement' Objet : Re: [time-nuts] REF osc distribution. Hi Lots of choices: 1)do you need 1 pps distributed? 2)do you need 100 KHz, 1MHz, 5MHz (or really odd frequencies) for anything? 3)how many 10 MHz gizmos do you have? 4)Do you need / want to receive 10 MHz radio signals while distributing 10 MHz? (same question for other frequencies if you use therm). 5)What are you running the signals to? / how clean does the phase noise need to be? 6)What are you running the signals to? / how good does the short term stability need to be? 7)(same)/ how good does the isolation need to be? 8)(same)/ do you need redundancy or anything else unusual? For simple need to run a frequency counter needs, video amps are often the easy choice. For more demanding gear, you can have very complex distribution systems. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Rui Martins Sent: Tuesday, September 04, 2012 9:23 AM To: time-nuts@febo.com Subject: [time-nuts] REF osc distribution. Hi, At the moment my GPSTM have 1.3e-012 in alan deviation and it's time to connect to the equipements. Which is the best way to do it? CT1EBHT Rui Jorge Martins 73! ___ 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.
Re: [time-nuts] 60 Hz line quirks, anybody recognize this stuff?
Firefox is notorious for screwing up audio in windows. I have had OS of problems with this. I actually think its something o o with networking. Sent from my iPad On Sep 1, 2012, at 5:16 PM, Chuck Forsberg WA7KGX N2469R c...@omen.com wrote: On 09/01/2012 02:17 PM, Magnus Danielson wrote: On 09/01/2012 08:35 AM, Hal Murray wrote: The context is using the 60 Hz line for timing. I'm feeding 60 Hz from a wall wart transformer into a modem control signal that the kernel PPS stuff watches. Mostly, it works as expected, but occasionally, it picks or drops a cycle. In order to understand what was going on, I fed the same signal into the audio input and setup a job to capture the audio. Here is an example of a pick: http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Aug-09-a-pick.png http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Aug-09-a0.png http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Aug-09-a1.png OK, that somewhat makes sense. Something happened several days ago. I used to get picks/drops rarely, say ballpark of 1 a month. Now I'm getting 10 or 20 per day. So I started looking closer. I'm now seeing stuff like this. I've got lots and lots of examples. I added a second PC with different hardware. It sees the same stuff. Does anybody recognize this? http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-01-a0.png http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-01-b0.png http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-01-c0.png http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-01-d0.png http://www.megapathdsl.net/~hmurray/time-nuts/line/2012-Sep-01-e0.png It's interesting to notice that you have about the same distance from the middle in all 5 examples. It's like you trigger a diode drop for a while. Notice that there is a small slope towards zero. 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. I have noticed many stalls in Windows lately, possibly the result of Flash and Firefox not getting along. The first plot suggests a multitasking related problem. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ 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] Is this a cesium frequency standard?
The PRS10 by SRS has serious shortcomings at short tau. I don't understand why but there is a huge hump in the adev. That's why I avoided one. Sent from my iPhone On Aug 23, 2012, at 10:42 AM, paul swed paulsw...@gmail.com wrote: OK have been staying clear of the replies. Thats a lot of money for a RB of who knows what age and no support. Those are $25 value items you are taking all of the risks. And yes indeed you can get RBs for $25 a bit low in the lamp life. But do rejuvenate nicely. FRS class. Brand new ones I think from SRS are that cost, consume a fraction of the power, great documentation, warranty, and modern control interfaces. What on earth would shipping and customs be?? Cute boat anchor though a real waste of anything. Regards Paul WB8TSL On Thu, Aug 23, 2012 at 11:32 AM, Michael Perrett mkperr...@gmail.comwrote: I have found Google translate does a pretty good job on translating manuals - and it is free Michael On Thu, Aug 23, 2012 at 6:40 AM, Richard Parrish calc...@swbell.net wrote: The seller of the 'Russian' equipment said that the CCHB-74 frequency standard is a rubidium unit. Manual is in Russian but he can translate part of the manual into English for an additional fee. Thanks, Richard Parrish Cal Center Inc 1622 Griffith Ave Terrell, Texas 75160-4905 calc...@swbell.net 214-577-3515 -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of David Kirkby Sent: Thursday, August 23, 2012 3:18 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Is this a cesium frequency standard? There's a seller on ebay by the name of electro-radio-device-high-precision, which have some odd things. Some seem as if they would be 19th century items, but are sold as new. http://stores.ebay.co.uk/electro-radio-device-high-precision?_trksid=p4340.l 2563 I suspect his stuff was desgned for the Russian military. Everything he sells is described as analog of Lutron, Advantest, Avtech, HP Agilent, NoiseCom, General Radio, Boonton, Anritsu, Fluke and general Electric, but has the same or better characteristics. I thought this one was interesting though http://www.ebay.co.uk/itm/5MHz-1MHz-100kHz-Frequency-standard-CCHB-74-an-g-A gilent-HP-/330758945645?pt=LH_DefaultDomain_0hash=item4d02c4fb6d It has lots of knobs to twiddle, so it might be a cesium, though the specs don't seem good enough for a cesium, with a relativa e error of +/- 2 x 10^-11 at shipping. That seems more like a rubidium spec. He has some bizzare stuff, like a power meter which works to 53 GHz, but has banana plugs on it. I guess the sensor is connected to the banana plugs, though he does not mention it needing an external sensor. http://www.ebay.co.uk/itm/0-03GHz-53GHz-1mkWatt-10mWatt-Power-meter-M3-22-an -g-Agilent-HP-Marconi-GenRad-/230821610924?pt=LH_DefaultDomain_0hash=item35 be0a45ac Some of his stuff seems very over priced, like a 400-1200 MHz sig gen with an error of 1% for $1580, but other things seem quite reasonable. If you need a sig gen at 70 GHz, he has them. Anyway, its worth checking out his auctions, as he has some test equipment which is very different from what one normally sees - and it some cases to what one would want to see! Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Is this a cesium frequency standard?
published and experimental data as compared to 5065a. Large hump with max at 2 minutes.. perplexing to me because it seems perfect in about every other way. On Thu, Aug 23, 2012 at 11:35 AM, Azelio Boriani azelio.bori...@screen.itwrote: Have you observed the hump yourself or is it published data? If you made the measure, what reference clock did you use? I have (at work, in another department) a new PRS10, hope to get it back... On Thu, Aug 23, 2012 at 6:00 PM, Bill Dailey docdai...@gmail.com wrote: The PRS10 by SRS has serious shortcomings at short tau. I don't understand why but there is a huge hump in the adev. That's why I avoided one. Sent from my iPhone On Aug 23, 2012, at 10:42 AM, paul swed paulsw...@gmail.com wrote: OK have been staying clear of the replies. Thats a lot of money for a RB of who knows what age and no support. Those are $25 value items you are taking all of the risks. And yes indeed you can get RBs for $25 a bit low in the lamp life. But do rejuvenate nicely. FRS class. Brand new ones I think from SRS are that cost, consume a fraction of the power, great documentation, warranty, and modern control interfaces. What on earth would shipping and customs be?? Cute boat anchor though a real waste of anything. Regards Paul WB8TSL On Thu, Aug 23, 2012 at 11:32 AM, Michael Perrett mkperr...@gmail.com wrote: I have found Google translate does a pretty good job on translating manuals - and it is free Michael On Thu, Aug 23, 2012 at 6:40 AM, Richard Parrish calc...@swbell.net wrote: The seller of the 'Russian' equipment said that the CCHB-74 frequency standard is a rubidium unit. Manual is in Russian but he can translate part of the manual into English for an additional fee. Thanks, Richard Parrish Cal Center Inc 1622 Griffith Ave Terrell, Texas 75160-4905 calc...@swbell.net 214-577-3515 -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of David Kirkby Sent: Thursday, August 23, 2012 3:18 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Is this a cesium frequency standard? There's a seller on ebay by the name of electro-radio-device-high-precision, which have some odd things. Some seem as if they would be 19th century items, but are sold as new. http://stores.ebay.co.uk/electro-radio-device-high-precision?_trksid=p4340.l 2563 I suspect his stuff was desgned for the Russian military. Everything he sells is described as analog of Lutron, Advantest, Avtech, HP Agilent, NoiseCom, General Radio, Boonton, Anritsu, Fluke and general Electric, but has the same or better characteristics. I thought this one was interesting though http://www.ebay.co.uk/itm/5MHz-1MHz-100kHz-Frequency-standard-CCHB-74-an-g-A gilent-HP-/330758945645?pt=LH_DefaultDomain_0hash=item4d02c4fb6d It has lots of knobs to twiddle, so it might be a cesium, though the specs don't seem good enough for a cesium, with a relativa e error of +/- 2 x 10^-11 at shipping. That seems more like a rubidium spec. He has some bizzare stuff, like a power meter which works to 53 GHz, but has banana plugs on it. I guess the sensor is connected to the banana plugs, though he does not mention it needing an external sensor. http://www.ebay.co.uk/itm/0-03GHz-53GHz-1mkWatt-10mWatt-Power-meter-M3-22-an -g-Agilent-HP-Marconi-GenRad-/230821610924?pt=LH_DefaultDomain_0hash=item35 be0a45ac Some of his stuff seems very over priced, like a 400-1200 MHz sig gen with an error of 1% for $1580, but other things seem quite reasonable. If you need a sig gen at 70 GHz, he has them. Anyway, its worth checking out his auctions, as he has some test equipment which is very different from what one normally sees - and it some cases to what one would want to see! Dave ___ 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
Re: [time-nuts] Is this a cesium frequency standard?
Agreed... my point is it *may* be significantly better depending on the application ... the 5065a comes to mind.. if it is substantially similar to a 5065a (which I don't know that it is) it may be worth it. I know a very good 5065a can run substantially above $2500 and many find it worth it. I have seen improved and verified 5065a's in the $3,500 range and if you need what they offer they are worht that. On Thu, Aug 23, 2012 at 11:49 AM, David Kirkby david.kir...@onetel.netwrote: On 23 August 2012 16:42, paul swed paulsw...@gmail.com wrote: Brand new ones I think from SRS are that cost, consume a fraction of the power, great documentation, warranty, and modern control interfaces. What on earth would shipping and customs be?? A PRS-10 is a *lot* cheaper - From $1495 http://www.thinksrs.com/products/PRS10.htm compared to his $4980, which does make it exceeding expensive given it's only a rubidium. I wonder if he sells boat anchors? Dave ___ 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. -- Doc Bill Dailey KXØO ___ 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] Is this a cesium frequency standard?
I meant 2 seconds On Thu, Aug 23, 2012 at 11:35 AM, Azelio Boriani azelio.bori...@screen.itwrote: Have you observed the hump yourself or is it published data? If you made the measure, what reference clock did you use? I have (at work, in another department) a new PRS10, hope to get it back... On Thu, Aug 23, 2012 at 6:00 PM, Bill Dailey docdai...@gmail.com wrote: The PRS10 by SRS has serious shortcomings at short tau. I don't understand why but there is a huge hump in the adev. That's why I avoided one. Sent from my iPhone On Aug 23, 2012, at 10:42 AM, paul swed paulsw...@gmail.com wrote: OK have been staying clear of the replies. Thats a lot of money for a RB of who knows what age and no support. Those are $25 value items you are taking all of the risks. And yes indeed you can get RBs for $25 a bit low in the lamp life. But do rejuvenate nicely. FRS class. Brand new ones I think from SRS are that cost, consume a fraction of the power, great documentation, warranty, and modern control interfaces. What on earth would shipping and customs be?? Cute boat anchor though a real waste of anything. Regards Paul WB8TSL On Thu, Aug 23, 2012 at 11:32 AM, Michael Perrett mkperr...@gmail.com wrote: I have found Google translate does a pretty good job on translating manuals - and it is free Michael On Thu, Aug 23, 2012 at 6:40 AM, Richard Parrish calc...@swbell.net wrote: The seller of the 'Russian' equipment said that the CCHB-74 frequency standard is a rubidium unit. Manual is in Russian but he can translate part of the manual into English for an additional fee. Thanks, Richard Parrish Cal Center Inc 1622 Griffith Ave Terrell, Texas 75160-4905 calc...@swbell.net 214-577-3515 -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of David Kirkby Sent: Thursday, August 23, 2012 3:18 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Is this a cesium frequency standard? There's a seller on ebay by the name of electro-radio-device-high-precision, which have some odd things. Some seem as if they would be 19th century items, but are sold as new. http://stores.ebay.co.uk/electro-radio-device-high-precision?_trksid=p4340.l 2563 I suspect his stuff was desgned for the Russian military. Everything he sells is described as analog of Lutron, Advantest, Avtech, HP Agilent, NoiseCom, General Radio, Boonton, Anritsu, Fluke and general Electric, but has the same or better characteristics. I thought this one was interesting though http://www.ebay.co.uk/itm/5MHz-1MHz-100kHz-Frequency-standard-CCHB-74-an-g-A gilent-HP-/330758945645?pt=LH_DefaultDomain_0hash=item4d02c4fb6d It has lots of knobs to twiddle, so it might be a cesium, though the specs don't seem good enough for a cesium, with a relativa e error of +/- 2 x 10^-11 at shipping. That seems more like a rubidium spec. He has some bizzare stuff, like a power meter which works to 53 GHz, but has banana plugs on it. I guess the sensor is connected to the banana plugs, though he does not mention it needing an external sensor. http://www.ebay.co.uk/itm/0-03GHz-53GHz-1mkWatt-10mWatt-Power-meter-M3-22-an -g-Agilent-HP-Marconi-GenRad-/230821610924?pt=LH_DefaultDomain_0hash=item35 be0a45ac Some of his stuff seems very over priced, like a 400-1200 MHz sig gen with an error of 1% for $1580, but other things seem quite reasonable. If you need a sig gen at 70 GHz, he has them. Anyway, its worth checking out his auctions, as he has some test equipment which is very different from what one normally sees - and it some cases to what one would want to see! Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https
