Re: [time-nuts] Using digital broadcast TV for timing?
For a history on the color subcarrier you can try: http://www.videointerchange.com/pal_secam_conversions.htm#3.579545 Color Subcarrier Explained Here in Italy, before the digital switchover, our national broadcast company used to sync the PAL color subcarrier to a Cs reference and my company sold 5MHz disciplined oscillators locked to the PAL (or NTSC) color subcarrier using the Philips TDA9181 (or something like that, I can't remember the exact part-number right now). The OCXO was an expensive double oven Oscilloquartz 8666A driven by a 16bit Analog Devices DAC. On Tue, Feb 21, 2012 at 2:33 AM, paul swed paulsw...@gmail.com wrote: Stan By gosh that really is an old one. ABC very well could have been driven by a Rb ref. Though as I mentioned CBS was CS. So a bit hard to believe ABC and NBC were not. But I really simply do not remember. There had been a time when the networks were used for freq dissemination and thats why at least CBS had the CS. An alternate thought could be that it came from a local owned an operated station. And it was adjusted to the network. Some inside pixs would be pretty neat top see. Like you I chose to leave the USNO sticker on my sad but semi operational CS reference. Regards Paul WB8TSL On Mon, Feb 20, 2012 at 7:48 PM, Stan Searing timenuts...@gmail.com wrote: Does anyone know if ABC used Cesium or just Rubidium standards? I have the Tracor 304SC shown in this URL: http://www.bdairfield.com/stan/time-nuts/Tracor-304SC/IMG_4216.JPG I assume the SC in the model number stands for the color subcarrier frequency for NTSC: 3.579545 MHz. The boards seem to be mostly hand wired on turret pins, so I don't think they made very many. I usually try and clean up front panels and remove non-manufacturer stickers, but I thought the ABC New York, Rubidium 1 and ADJ May 21 84 were cool, so the stickers stayed. Under the top cover is a tag that says: Model 304-SC S/N 127 Frequency relative to USFS -300 X 10 ** -10 DATE 10-11-68 The front panel has a 5 MHz output, while the back has a 3.58 MC output. I'm told this unit no longer works. KO4BB does not have the manual on his site, if you know where one is, send me a link off list. If some folks know more about the history of network broadcast color subcarrier frequency standards, I think it's an interesting subject that would be worth hearing more about. Stan On Wed, Feb 8, 2012 at 7:07 PM, paul swed paulsw...@gmail.com wrote: All gone these days in the US. Indeed I can speak to the CBS network it was driven by CS references in the 80s and 90s. I used CBS for aligning my references Xtal oven oscillators that were never ever turned off in a large facility that uplinked all 8 CBS regions and 22 other cable networks. Unfortunately few could get to that color burst signal as devices called frame synchronizers came into play from the 80s to the 90s. They would strip off that burst and insert the local reference of generally much lower quality. As far as todays digital TV signals they can contain significant jitter. But its actually trickier then that and I honestly have to say I am not sure that you might not be able to get something useful. Several interesting points. Many of the television transmitters do use GPS referenced sources. Its an interesting exploration. I simply don't have the time though. Regards Paul WB8TSL On Wed, Feb 8, 2012 at 7:38 PM, jerryfi jerryfi...@yahoo.com wrote: A bit off topic, but historically related back in the 70's, I tapped off the color burst oscillator in my TV (a Heathkit) to get a 3.579545 MHz (315/88 MHz) source to calibrate my homebrew frequency counter. The TV's color burst oscillator was phase locked to the color burst signal on the broadcast signal (which was on the back porch of the hori sync signals). Supposedly, the networks were locked to Cesium standards traceable to NBS for LIVE broadcasts, such as news and sports. Taped programs, of course, were not usable as an accurate source. In any case, that signal served my purposes at the time (providing a reference for calibrating my counter that was more accurate than anything else available to me). I'm not sure if, what, or where analog TV is still broadcast, but I think there are still a few stations (low power) around. You might still be able to use that signal, IF you can dig it out of your old analog TV. ;-) I do have analog tv's hooked up to my cable box - I suspect that live broadcasts would still have an accurate color burst, so maybe I think the other methods discussed here (ie, GPS) would provide easier and more reliable timing sources. ;-) Trying to locate the
Re: [time-nuts] Neutrinos not so fast? (defectove connector)
Indeed cold fusion is here again... in Italy... google Rossi-Focardi, if interested. Yes, I'm actually struggling finding something about this news flash... On Thu, Feb 23, 2012 at 1:35 AM, iov...@inwind.it iov...@inwind.it wrote: I read that the news came from sources familiar with the experiment. Is there any official press release? Or only rumors? Antonio I8IOV ___ time-nuts mailing 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] Neutrinos faster than light update
Maybe I at last found something: http://www.nature.com/news/flaws-found-in-faster-than-light-neutrino-measurement-1.10099 On Thu, Feb 23, 2012 at 1:53 AM, shali...@gmail.com wrote: I saw this just before leaving home and I must admit I posted it before reading it... But by now everyone knows what the problem was! Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Bill Hawkins b...@iaxs.net Sender: time-nuts-boun...@febo.com Date: Wed, 22 Feb 2012 18:42:56 To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Neutrinos faster than light update Ah, Didier, that link is to a thread started in September, 2011. Do I have to sort through the 1000+ comments to find something recent? Bill Hawkins -Original Message- From: Didier Juges Sent: Wednesday, February 22, 2012 5:20 PM http://science.slashdot.org/story/11/09/22/1841217/cern-experiment-indicates -faster-than-light-neutrinos?sdsrc=rel Looks like they found the problem! Didier KO4BB ___ time-nuts mailing 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] Neutrinos not so fast? (defectove connector)
Try this: http://www.nature.com/news/flaws-found-in-faster-than-light-neutrino-measurement-1.10099 On Thu, Feb 23, 2012 at 2:10 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 02/22/2012 11:26 PM, Poul-Henning Kamp wrote: In message9a458dba-3875-43b2-8383-5ca2f86be...@leapsecond.com, Tom Van Baak (lab) writes: Could be on the electrical side of the adapter, not the optical side. It's not impossible to get 60 ns of phase or trigger error with RF connectors. I don't buy that explanation. It's very hard to get 60 ns *consistent* phase or trigger error, with any kind of connector, almost no matter how you go about it. OTDR works just as normal TDR. If the fibre is not connected you get a reflection and not enough transmission. This is what you use OTDRs for. I agree it needs more details to be believable. 20m of extra fiber sounds *much* more plausible. 60 ns is more like 12 m of fibre. SMF-28 has a refraction index of about 1.45 depending on the wavelength of the laser. I use the rule of thumb that 1 ns is 3 dm in free air and 2 dm in coax and fibre, it's usually good enough for reality check calculations. Oh, and it's about 40 feet. Anyway, I would like to see much more detailed description to see that it indeed was due to this error. Also I'd love to see it repeated such that one can see the time error go on and off. Inventing an excuse about a loose connector to cover up the mistake sounds even more plausible. You really don't want to defend your phd dissertation, being known as the idiot who made a fool of both CERN and SanGrasso in one go. This is science, making a spectacular error and then explain it in painstakingly detail can teach a lot more than a otherwise uneventful day at the lab, doing about the same measurement. Learning something means better prepared to avoid it next time. Experience is being built. Still don't know what really happened here, rumours at the best. 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. ___ time-nuts mailing 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] Low-long-term-drift clock for board levelintegration?
Moreover most of actual GPS receivers are indoor capable (once got a lock with the antenna outside). I have briefly tested the uBlox and the NavSync for this feature and it works as expected. On Wed, Feb 22, 2012 at 11:52 AM, pablo alvarez pabloalvarezsanc...@gmail.com wrote: I would not fully trust NTP, and as already explained taking your GPS outside as a reference for just a while is not really going to help. But..why not using GPS inside the building? Some receivers are quite sensitive, so probably you will not need an external antenna to pick up a signal. Probably you may have to throw a cable from floor to floor, or place your antenna close to a window, but this is much simpler than installing an antenna on a roof. You will not get ns accuracy, but to make worse than 100us you will need a hell of a lot of reflections inside your building. Cheers, pablo ___ time-nuts mailing 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] Low-long-term-drift clock for board levelintegration?
Yes, the relation frequency_drift- time_error seems difficult to figure out. I see this misunderstanding daily here at work and haven't yet found a way to explain to my colleagues. I have already used: integral, area, count accumulation but none worked. On Mon, Feb 20, 2012 at 10:37 AM, Tom Van Baak t...@leapsecond.com wrote: I think a box that can't get some external source of time in three years is one that we can pretty well write off as lost. Thank you (several of you, actually) for the clear explanation of the math. http://www.msc-ge.com/en/news/**pressroom/manu/1241-www/3567-**www.htmlhttp://www.msc-ge.com/en/news/pressroom/manu/1241-www/3567-www.html http://www.thinksrs.com/**downloads/PDFs/Catalog/SC10c.**pdfhttp://www.thinksrs.com/downloads/PDFs/Catalog/SC10c.pdf So if I'm reading those specs right, they both offer 2E-10, or 100 microseconds per 500,000,000,000, or 121 microseconds per week. So, if those are affordable (and I haven't yet called to check), that's telling me that in order to be useful in the long term, these boxes need to be getting some reference time from somewhere at least once a week. Hi Bill, Not quite. The 2E-10 isn't a time or frequency *accuracy* spec; it's a *frequency drift* spec. What this means is that the frequency may change by up to 2e-10 per day, day after day... Let's say the oscillator is keeping perfect time now. Then 24 hours from now it may be fast or slow in frequency by 2e-10. If the oscillator is fast by 2e-10 it will be gaining time at the rate of 0.2 nanoseconds per second. That doesn't sound like much but since there are 86400 seconds in a day, that's equivalent to gaining at a rate of 17 microseconds a day. But that's just the first day. The second day the oscillator may be fast by yet another 2e-10. By the end of the day it's now 4e-10 fast so it's now gaining at a rate of 35 microseconds a day, in addition to all the time error from yesterday. Think of frequency changing like an upward *ramp*. The time error accumulates like the *area* under that growing triangle. Hence the quadratic growth of time error (1/2 * drift * t^2). After a week the total time error is over 400 microseconds; you hit your 100 microsecond limit in about 3.5 days. The SC-10 starts at $250, presumably for a low-grade version, not the one you want. The DX-170 looks interesting. Let us know when you get a price quote. Note also the temperature spec; can you maintain the temperature of your device to +/- 1 C? /tvb __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A firmware dump
In my opinion you don't need the power of an IDA-class disassembler to process an 8051-like code. The MCS51 family processors have only 128 or 256 bytes of RAM (and at most 64K ROM) and cannot host complex code. On Fri, Feb 17, 2012 at 10:27 AM, Elio Corbolante elio...@gmail.com wrote: From: Mike McCauley I've been considering ripping the firmware from the mcu as well. I've not got beyond the consideration stages, but i have all the equipment here at work. When you say that the read option is not available. is this because the chip has protection fuses enabled? Id like to help with the disassembly if you can get the binary dump. Don't worry: when I will be able to dump the firmware I will let it on the public domain. BTW, I have the opportunity to use the IDA disassembler (a friend of mine is a licensed user) so I think the disassembly of the code will be rather good. Any knowledge of a public domain 8051 disassembler which can rival IDA in performance/code analysis? _ Elio. ___ time-nuts mailing 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] (no subject)
Yes, never used but no doubt about the power of IDA. My opinion is: you don't need the power of IDA for an MCS51 executable code. On Fri, Feb 17, 2012 at 11:43 AM, Elio Corbolante elio...@gmail.com wrote: Azelio Boriani wrote: In my opinion you don't need the power of an IDA-class disassembler to process an 8051-like code. The MCS51 family processors have only 128 or 256 bytes of RAM (and at most 64K ROM) and cannot host complex code. From your answer I infer you have never thoroughly used IDA and its really powerful disassembler engine... _ Elio. ___ time-nuts mailing 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] FE-5680A firmware dump
OK, then maybe there are ROM bank switching as the MCS51 can't execute beyon the 64K limit. It can be very challenging to follow a code that jumps between 64K ROM banks. Moreover the MCS51 has to address the external RAM by massive pointer use (the famous MOVX @DPTR,A and MOVX A,@DPTR instructions) beyond the 256byte internal easier to address RAM. Yes, you need a good disassembler, aware of bank switching and massive pointer use. On Fri, Feb 17, 2012 at 11:20 AM, Javier Herrero jherr...@hvsistemas.eswrote: Don forget the PSD813 :) It provides 128KB Flash and 8KB RAM... so it can be a bit more complicated Regards, Javier El 17/02/2012 11:09, Azelio Boriani escribió: In my opinion you don't need the power of an IDA-class disassembler to process an 8051-like code. The MCS51 family processors have only 128 or 256 bytes of RAM (and at most 64K ROM) and cannot host complex code. On Fri, Feb 17, 2012 at 10:27 AM, Elio Corbolanteelio...@gmail.com wrote: From: Mike McCauley I've been considering ripping the firmware from the mcu as well. I've not got beyond the consideration stages, but i have all the equipment here at work. When you say that the read option is not available. is this because the chip has protection fuses enabled? Id like to help with the disassembly if you can get the binary dump. Don't worry: when I will be able to dump the firmware I will let it on the public domain. BTW, I have the opportunity to use the IDA disassembler (a friend of mine is a licensed user) so I think the disassembly of the code will be rather good. Any knowledge of a public domain 8051 disassembler which can rival IDA in performance/code analysis? _ Elio. __**_ 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-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-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-5680A firmware dump
Maybe. Take into account that MCS51 OTP processors usually are 8K of code. I use, among the others, the AT89C55 that has 20K of flash ROM. It seems better to use a ROMless 8051 and place the code/tables in the PSD. On Fri, Feb 17, 2012 at 6:17 PM, Bob Camp li...@rtty.us wrote: Hi I'd bet that there's some code in there and some data tables. Without digging in, it's hard to say how big each is. We could easily find that there's 24K of code in the MCS51 and a bunch of tables in the PSD813. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Friday, February 17, 2012 6:06 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] FE-5680A firmware dump OK, then maybe there are ROM bank switching as the MCS51 can't execute beyon the 64K limit. It can be very challenging to follow a code that jumps between 64K ROM banks. Moreover the MCS51 has to address the external RAM by massive pointer use (the famous MOVX @DPTR,A and MOVX A,@DPTR instructions) beyond the 256byte internal easier to address RAM. Yes, you need a good disassembler, aware of bank switching and massive pointer use. On Fri, Feb 17, 2012 at 11:20 AM, Javier Herrero jherr...@hvsistemas.eswrote: Don forget the PSD813 :) It provides 128KB Flash and 8KB RAM... so it can be a bit more complicated Regards, Javier El 17/02/2012 11:09, Azelio Boriani escribió: In my opinion you don't need the power of an IDA-class disassembler to process an 8051-like code. The MCS51 family processors have only 128 or 256 bytes of RAM (and at most 64K ROM) and cannot host complex code. On Fri, Feb 17, 2012 at 10:27 AM, Elio Corbolanteelio...@gmail.com wrote: From: Mike McCauley I've been considering ripping the firmware from the mcu as well. I've not got beyond the consideration stages, but i have all the equipment here at work. When you say that the read option is not available. is this because the chip has protection fuses enabled? Id like to help with the disassembly if you can get the binary dump. Don't worry: when I will be able to dump the firmware I will let it on the public domain. BTW, I have the opportunity to use the IDA disassembler (a friend of mine is a licensed user) so I think the disassembly of the code will be rather good. Any knowledge of a public domain 8051 disassembler which can rival IDA in performance/code analysis? _ Elio. __**_ 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.c om/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/tim e-nuts and follow the instructions there. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nuts https://www.febo.com/cgi-bin/mailman/listinfo/tim e-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] Testing a LPRO RB
There is no mention in the AN1002 (GPS disciplined Stratum 2 clock) of the US patent 7,711,230 and that patent (on optical waveguides) has no mention of temperature correction or tempco extraction... On Thu, Feb 16, 2012 at 8:55 AM, Ulrich Bangert df...@ulrich-bangert.dewrote: Mark, John DuBois and I did quite a bit of work to find a way to unwind the osc parameters from the available unstabilized reported data using SciLab on the log files, but nothing seemed to work reliably. For some information on how to do that have a look at Analog Devices application note AN-1002 and at the there mentioned US patent US 7,711,230. Best regards Ulrich Bangert -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Mark Sims Gesendet: Donnerstag, 16. Februar 2012 01:56 An: time-nuts@febo.com Betreff: [time-nuts] Testing a LPRO RB Lady Heather's osc drift rate calculation does assume that the temperature has been stabilized. John DuBois and I did quite a bit of work to find a way to unwind the osc parameters from the available unstabilized reported data using SciLab on the log files, but nothing seemed to work reliably. Generally the data analysis croaked because of things like noise and matrix singularities. Also, if you do stabilize the temperature, it is very easy to get the osc tempco. Just turn off the stabilization and see how the osc drifts as it warms up. ___ time-nuts mailing 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] Testing a LPRO RB
Now it is clear: you at first wrote US patent 7,711,230: For some information on how to do that have a look at Analog Devices application note AN-1002 and at the there mentioned US patent US 7,711,230. but it is US 6,711,230. On Thu, Feb 16, 2012 at 2:23 PM, Ulrich Bangert df...@ulrich-bangert.dewrote: Nicholls et al are mentioned and they hold the patent as shown in the attached pic... -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Azelio Boriani Gesendet: Donnerstag, 16. Februar 2012 13:35 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] Testing a LPRO RB There is no mention in the AN1002 (GPS disciplined Stratum 2 clock) of the US patent 7,711,230 and that patent (on optical waveguides) has no mention of temperature correction or tempco extraction... On Thu, Feb 16, 2012 at 8:55 AM, Ulrich Bangert df...@ulrich-bangert.dewrote: Mark, John DuBois and I did quite a bit of work to find a way to unwind the osc parameters from the available unstabilized reported data using SciLab on the log files, but nothing seemed to work reliably. For some information on how to do that have a look at Analog Devices application note AN-1002 and at the there mentioned US patent US 7,711,230. Best regards Ulrich Bangert -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Mark Sims Gesendet: Donnerstag, 16. Februar 2012 01:56 An: time-nuts@febo.com Betreff: [time-nuts] Testing a LPRO RB Lady Heather's osc drift rate calculation does assume that the temperature has been stabilized. John DuBois and I did quite a bit of work to find a way to unwind the osc parameters from the available unstabilized reported data using SciLab on the log files, but nothing seemed to work reliably. Generally the data analysis croaked because of things like noise and matrix singularities. Also, if you do stabilize the temperature, it is very easy to get the osc tempco. Just turn off the stabilization and see how the osc drifts as it warms up. ___ time-nuts mailing 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] Morion MV89A pics
OK, I have the pictures of the MV201 (also the MTI Milliren 1555, the OSA8666, the OSA8650S). They are 7M, where can I upload? On Mon, Feb 13, 2012 at 6:47 PM, Azelio Boriani azelio.bori...@screen.itwrote: OK, I'll take pictures of the MV201. On Mon, Feb 13, 2012 at 6:34 PM, Scott Newell newell+timen...@n5tnl.comwrote: At 03:50 AM 2/13/2012, Azelio Boriani wrote: I have always thought the space inside the cover was the outer oven... now I realize this is not quite correct but then the MV201, specified as a double-oven, can't be a double-oven. The MV201 has the crystal under a sort I just checked the MV201 online. Neither the English webpage nor the datasheet claim it's a double oven. The MV180, MV209, MV216, MV268 and the MV89 all appear to be DOXCOs. structure is the only oven and the MV201 can't be a double oven OCXO... I have an MV201 open right now: can take pictures. Please do! -- newell N5TNL ___ time-nuts mailing 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] Morion MV89A pics
OK, uploaded. On Wed, Feb 15, 2012 at 6:58 PM, shali...@gmail.com wrote: www.ko4bb.com/manuals Click on Upload files and follow instructions Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Azelio Boriani azelio.bori...@screen.it Sender: time-nuts-boun...@febo.com Date: Wed, 15 Feb 2012 18:08:17 To: Discussion of precise time and frequency measurement time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Morion MV89A pics OK, I have the pictures of the MV201 (also the MTI Milliren 1555, the OSA8666, the OSA8650S). They are 7M, where can I upload? On Mon, Feb 13, 2012 at 6:47 PM, Azelio Boriani azelio.bori...@screen.it wrote: OK, I'll take pictures of the MV201. On Mon, Feb 13, 2012 at 6:34 PM, Scott Newell newell+timen...@n5tnl.com wrote: At 03:50 AM 2/13/2012, Azelio Boriani wrote: I have always thought the space inside the cover was the outer oven... now I realize this is not quite correct but then the MV201, specified as a double-oven, can't be a double-oven. The MV201 has the crystal under a sort I just checked the MV201 online. Neither the English webpage nor the datasheet claim it's a double oven. The MV180, MV209, MV216, MV268 and the MV89 all appear to be DOXCOs. structure is the only oven and the MV201 can't be a double oven OCXO... I have an MV201 open right now: can take pictures. Please do! -- newell N5TNL ___ time-nuts mailing 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] Morion MV89A pics
I have always thought the space inside the cover was the outer oven... now I realize this is not quite correct but then the MV201, specified as a double-oven, can't be a double-oven. The MV201 has the crystal under a sort of Stonenge-like open structure: if this structure is the inner oven then the outer oven must be the cover. If the cover is the cover then this structure is the only oven and the MV201 can't be a double oven OCXO... I have an MV201 open right now: can take pictures. On Mon, Feb 13, 2012 at 2:28 AM, Tom Knox act...@hotmail.com wrote: Hi Gang; You most likely have this link to Morion with data sheets on all their oscillators, but if you don't: http://www.morion.com.ru/eng/oscillators/ocxo/ Best Wishes; Thomas Knox Date: Sun, 12 Feb 2012 19:11:11 -0600 To: time-nuts@febo.com From: newell+timen...@n5tnl.com Subject: Re: [time-nuts] Morion MV89A pics At 05:45 PM 2/12/2012, Sam wrote: Thanks for the pictures Scott, it was interesting to see under the shell of these. I wasn't expecting the inside to look so hand made. Yep. Some of the surface mount components appear to be hand soldered. I was a little surprised that there was no mechanical frequency trim. Wonder if it's an AT or SC cut rock--anyone know? -- newell N5TNL ___ time-nuts mailing 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] Morion MV89A pics
OK, I'll take pictures of the MV201. On Mon, Feb 13, 2012 at 6:34 PM, Scott Newell newell+timen...@n5tnl.comwrote: At 03:50 AM 2/13/2012, Azelio Boriani wrote: I have always thought the space inside the cover was the outer oven... now I realize this is not quite correct but then the MV201, specified as a double-oven, can't be a double-oven. The MV201 has the crystal under a sort I just checked the MV201 online. Neither the English webpage nor the datasheet claim it's a double oven. The MV180, MV209, MV216, MV268 and the MV89 all appear to be DOXCOs. structure is the only oven and the MV201 can't be a double oven OCXO... I have an MV201 open right now: can take pictures. Please do! -- newell N5TNL __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Morion MV89A pics
Extremely delicate that fluffy contton, try not to tear apart it so that you can place it again on top when closing the MV89. In my opinion the internal oven is the inner one... On Sun, Feb 12, 2012 at 3:14 AM, Scott Newell newell+timen...@n5tnl.comwrote: As requested, pics of the inside of my Morion XO00281M-CT-MV89 MV89A double oven ultra precision OCXO, serial ZA5310, date 03/22. Sorry, I didn't feel like peeling apart the outer oven. Small pics (~50 kB): http://n5tnl.com/time/mv89a/mv89a_1_small.jpg http://n5tnl.com/time/mv89a/mv89a_2_small.jpg http://n5tnl.com/time/mv89a/mv89a_3_small.jpg http://n5tnl.com/time/mv89a/mv89a_4_small.jpg Big pics (~5 MB): http://n5tnl.com/time/mv89a/mv89a_1.png http://n5tnl.com/time/mv89a/mv89a_2.png http://n5tnl.com/time/mv89a/mv89a_3.png http://n5tnl.com/time/mv89a/mv89a_4.png There was some oddly soft and fluffy cotton like insulation between the top of the outer oven and the can. -- newell N5TNL ___ time-nuts mailing 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] Entering Altitude for Thunderbolt
Let the TBolt do its autosurvey and see the difference... then you can correct with a more precise set of coordinates. Or, is the autosurvey not available in the TBolt? OK, Let me take a look at the manual... On Sun, Feb 12, 2012 at 4:42 PM, John Ackermann N8UR j...@febo.com wrote: When manually entering coordinates to the Tbolt, using either Tboltmon or Lady Heather, is the altitude value to be entered as MSL or as GPS? The Trimble docs don't seem to indicate which value is used. Based on the surveys I've done with the Motorola receivers, at my location there appears to be about 30 meters difference between the two. John ___ time-nuts mailing 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] GPS lock of the FE5680. Current experiment and question
This is the simplest part if a microprocessor can be used: by the serial port you get the sawtooth correction in nS to be applied to the sampled data. The sampled data must be converted to nS or the sawtooth correction must be converted in a suitable sampled data correction. It is possible even to hardware correct the PPS with a delay line before using it (see the already mentioned gpstime.com/files/tow-time2011.pdf by Tom Clarck and Rick Hambly). On Sat, Feb 11, 2012 at 1:45 PM, Bob Camp li...@rtty.us wrote: Hi Another way to build an analog phase detector... Next layer on the onion is how to get the sawtooth correction out of the GPS and into your loop. Bob On Feb 11, 2012, at 12:05 AM, Chris Albertson albertson.ch...@gmail.com wrote: All these different suggestions build down to one thing, the precision with which you measure the phase when you sample it each second. The single flip flop will tell you which half cycle. a simple two bit counter made with two '74 FFs tells you which half cycle and with direction. The best maybe is if you let the PPS set a FF and the 10MHz reset it. The FF's output gates a constant current to a capacitor and charges it to some voltage. Then you measure that with a 10-bit ADC. This measures the phase to maybe 1%, gives you direction and is pretty cheap to build Let's see if I have the numbers right? If you check a 10MHz signal once per second with just the FF then you have 1E-7. You would need 1000 seconds for 1E-10. But if you measure phase to 1/10th of a cycle you get to 1E-10 ten faster. Right? 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.
Re: [time-nuts] Leap seconds now showing on GPS satellites
My Z3815A doesn't have a leap second pending... maybe the Furuno GPS receiver hasn't that information or the Z3815A doesn't retrive it. I'll check the HP58503A at work. On Sat, Feb 11, 2012 at 3:52 AM, Hal Murray hmur...@megapathdsl.net wrote: It got here around 2785 seconds UTC after midnight on Feb 10th. (unless I fatfingered something) From a NTP log file while watching a HP Z3801A. The + says insert a leap second. 55967 2401.038 127.127.26.1 T2201202100040023001028 64 0 55967 2465.034 127.127.26.1 T220120210004106300102D 64 0 55967 2529.037 127.127.26.1 T2201202100042103001029 64 0 55967 2593.038 127.127.26.1 T220120210004314300102E 64 0 55967 2657.033 127.127.26.1 T2201202100044183001033 64 0 55967 2721.037 127.127.26.1 T220120210004522300102F 64 0 55967 2785.037 127.127.26.1 T22012021000462630+102F 64 0 55967 2849.033 127.127.26.1 T22012021000473030+102B 64 0 55967 2913.034 127.127.26.1 T22012021000483430+1030 64 0 55967 2977.033 127.127.26.1 T22012021000493830+1035 64 0 55967 3041.033 127.127.26.1 T22012021000504230+1028 64 0 55967 3105.039 127.127.26.1 T22012021000514630+102D 64 0 55967 3169.033 127.127.26.1 T22012021000525030+1029 64 0 55967 3233.033 127.127.26.1 T22012021000535430+102E 64 0 -- These are my opinions, not necessarily my employer's. 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] Removing thermal tape residue?
Maybe a thinner can help... On Sat, Feb 11, 2012 at 5:58 PM, Rob Kimberley robkimber...@btinternet.comwrote: John, Have you tried anything yet? As a first pass I would try something petroleum based to clean. I know this has worked for me in the past. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of John Ackermann N8UR Sent: 11 February 2012 16:53 To: Time-Nuts Subject: [time-nuts] Removing thermal tape residue? Is there a recommended way to remove the residue of what I presume was thermal tape on the heatsinks of my various telco Rb units? It's a slightly tacky light greenish layer. I'm guessing that for a permanent installation one would want to remove that residue, smooth the surface, and replace with new material for best thermal transfer to the heatsink. John ___ time-nuts mailing 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] Removing thermal tape residue?
I can confirm: my LPRO-101 has this thermal conductive green sheet too. I think to retain it instead of getting rid but it is not in perfect shape... On Sun, Feb 12, 2012 at 12:18 AM, Robert LaJeunesse rlajeune...@sbcglobal.net wrote: Try searching for thermally conductive adhesive gap filler to get a good selection of manufacturers like Bergquist, Chomerics, Masterbond, etc. From: John Ackermann N8UR j...@febo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sat, February 11, 2012 1:45:08 PM Subject: Re: [time-nuts] Removing thermal tape residue? ... BTW -- when you search for thermal tape most of the hits are for the tiny square pads used on CPU heatsinks... ___ time-nuts mailing 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] Morion MV89 output level?
Don't be afraid and open up your MV89. I have done this with many MV201 without problems. On Thu, Feb 9, 2012 at 8:25 AM, Sam li...@digitalelectric.com.au wrote: I just powered up one of my MV89A's and measured ~7 dBm into my HP 8920B, but as Tom has mentioned some MV89A's develop a dry joint around the output bypass capacitor http://www.hellocq.net/forum/showthread.php?t=283551 What is the date and revision number on yours? I have 2 here 07/34 and 07/31 both Rev 3 bought from fluke.l Sam Got my replacement FE-5680 and a MV89 in from Nichegeek. I figured I'd better power up and check the MV89 before I let 'em know everything was ok. The MV89 is warming up nicely, the current is down to 290 mA (and still dropping), but the output seems low; about 40 mV RMS as measured on a scope with a 10Meg 10x probe. (Datasheet spec is +7 +/- 2 dBm.) The output is too weak to reliably trigger my 5345A counter. The reference voltage measures 4.90 VDC. If anyone can make a quick measurement on their MV89, I'd appreciate it. thanks! newell N5TNL ___ time-nuts mailing 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] Morion MV89 output level?
I use a hot gun directing heat on the soldered edge. Use a soldering iron and the solder wick as suggested gives the best result, in my opinion. It helps if more than 1 working around the OCXO as at some moment you have to use one or two pins to lift the bottom cover using pliers. I have done this job here at work and recovered the few MV201 that can't heat up (frequency too low at the output). Usually it was a resistor not soldered at one end. In one case there was the crystal inductor not soldered (missing 10MHz at the output) . Heating the bottom avoids the label meltdown too. On Thu, Feb 9, 2012 at 1:46 PM, Stan, W1LE stanw...@verizon.net wrote: Would it be better to apply heat the metal shell or to apply heat the bottom part with the I/O pins ? I would start using a propane gas torch. Heating quickly till I saw the solder flow. Stan, W1LECape Cod On 2/9/2012 6:04 AM, Azelio Boriani wrote: Don't be afraid and open up your MV89. I have done this with many MV201 without problems. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PICTIC II questions
Yes, I was thinking of trying a PICTIC II partial redesign with a Xilinx CPLD, using other type of fast turn off diodes and so on. On Tue, Feb 7, 2012 at 8:28 AM, Attila Kinali att...@kinali.ch wrote: On Sun, 5 Feb 2012 19:55:36 -0900 (AKST) Richard H McCorkle mccor...@ptialaska.net wrote: While using a faster timebase or higher interpolator gain increases the resolution that doesn’t imply the accuracy will also increase. The PICTIC II uses CMOS logic with propagation delays that vary with temperature much more than the ECL logic used in a commercial counter like the SR620, severely affecting the accuracy below about 250ps. The interpolator was modeled after the SR620 design but simplified to use the least amount of hardware possible to reduce the size and cost. As the timebase rate is increased a smaller cap is used so stray capacitance and the capacitance of the switching devices have a larger effect on the charge linearity. The PICTIC II uses software calibration methods that are not as precise as those in a commercial counter so the accuracy is not specified other than to say it works well for GPS monitoring applications at 1ns resolution with a 10 MHz timebase once set up properly. If you want to log GPS data over months at a time then a $50 PICTIC II should be sufficient for purpose. But if you want lab grade accuracy over long time intervals with 25ps resolution then by all means use a lab grade commercial counter like the SR620 and not a PICTIC II! The PICTIC II might not be lab grade, but, frankly, i don't see any big problems in the design itself. Ie if one would replace the slow CMOS logic by something faster, lets say an FPGA (not an expensive highspeed one, but one in the 20-30USD range, available at Digikey/Mouser/..) and increase the clock speed to 100 or even 200MHz, then one ought to get a resolution in the lower ps range. And i guess, that an accuracy of 20-50ps should be acheivable. Or am i missing something? BTW: does anyone know how these days low cost FPGAs perform in terms of jitter? (the data sheets are kind of scarce in that regard). And how do they compare to state of the art ECL logic? Also, does one have a schematics of a current SR620? Didier's site has a schematics, but it's from 1989 and i'd like to see how things are done with currently available components. Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PICTIC II questions
To enhance the PICTIC II performance can step recovery diodes be used? Maybe the fast turn off can boost the switching capabilities of the interpolator for best resolution... On Tue, Feb 7, 2012 at 12:35 PM, Hal Murray hmur...@megapathdsl.net wrote: att...@kinali.ch said: BTW: does anyone know how these days low cost FPGAs perform in terms of jitter? (the data sheets are kind of scarce in that regard). And how do they compare to state of the art ECL logic? Generally, not good. The general problem is that they have a lot of logic and a lot of I/O drivers and shared power/ground pins. Things are messy if you have multiple clocks. Things are better if you only have one clock and better if you don't have any nearby drivers switching at the same time. For a few critical signals, you could reclock in an external FF. -- These are my opinions, not necessarily my employer's. 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] Why a 10MHz sinewave output
Try this for a history about the 50 OHM impedance: http://www.rfcafe.com/references/electrical/history-of-50-ohms.htm On Tue, Feb 7, 2012 at 10:30 PM, Attila Kinali att...@kinali.ch wrote: On Tue, 07 Feb 2012 16:15:44 -0500 Mike Naruta AA8K a...@comcast.net wrote: On 02/07/2012 03:59 PM, Attila Kinali wrote: while TV and radio uses 75R. (there was once a reason for this, but i don't know it). A 4:1 balun takes old 300 ohm twinlead to 75 ohms. Thanks! This explains half it :-) Do you know why a 4:1 balun was used? And do you know why other RF stuff and lab equipment is 50R? Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-.5680A trimming resolution
And then all that can be done is lock the oscillator to a solution derived from the birds... this can explain why a receiver can fail to correctly lock an oscillator or give a strange PPS. That is, it is possible, in case of errors, to have, for example, a PPS displaced by 1mS but state that the solution is good. On Sun, Feb 5, 2012 at 1:31 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 02/02/2012 10:13 AM, Azelio Boriani wrote: OK, got it: no need to lock the receiver clock to birds to get stable data (e.g. Oncore+Cs) but the clock can be locked to birds to get even better data and obtain for free a reference clock (TBolt). The use of a stable clock (not locked to birds) feeding the receiver can show the various errors that affect the downlink having removed the clock instabilities. Not quite right. If you lock up the clock, you do not lock to the birds, but to GPS time or UTC as received over GPS. The observed time of the birds would be a bad solution since you can't see a particular bird continously unless you is in geosync orbit. 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. ___ time-nuts mailing 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] ANFSCD - Synchronizing time in home video recorders
Yes, DLL not DDL I made a mistake. Actually it is not in my schedule to make such a divisor, just for speculation. The main thought here is that, as you pointed out, it can be done avoiding PLL and DLL. On Fri, Feb 3, 2012 at 1:49 AM, Hal Murray hmur...@megapathdsl.net wrote: OK for the PSOC example. At the moment I can try on a Spartan3 because I already have a board with the OCXO. The Spartan3 has the so called DCM, a digital clock generator that can multiply an input clock using its DDL digital delay line. The original context was keeping wall clock time. In that application, jitter on the 32 KHz clock isn't a problem. If I was hacking with a FPGA, I'd make a decimal addition module and chain 7 of them together and see how fast it goes. The idea is to avoid the DLLs, KISS. If it runs at 10 MHz (100 ns), I'd declare victory and try to see how well it works. I'd probably divide by 32K and compare that with another handy PPS. If it doesn't run at 100 ns, I'd probably insert a pipeline FF in the carry chain, or as many as were needed. It won't change the overall result, just delay the output signal by a clock cycle. If that worked, I might try to see how fast I could get it to run. That's just for fun/ego. The obvious target is 100 MHz which just adds one more decimal counter stage and probably several/many pipeline FFs. That should cut the jitter from 100 ns peak-peak to 10 ns. It won't change the overall frequency stability. -- These are my opinions, not necessarily my employer's. 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] Building a GPSDO trouble using Jupiter-T
I have implemented a digital lock detector in my CPLD timing the phase detector itself. It was years ago... let me find the VHDL code so that can give any idea how to implement it for a microprocessor. On Fri, Feb 3, 2012 at 10:58 AM, Roberto Barrios rbarri...@msn.com wrote: Long time ago I built a Jupiter-T companion board that included the loop filter, divider and phase detector for the James Miller GPSDO. It also includes a PIC that monitors the NMEA strings and displays different status data via LEDs, and outputs data via RS232. http://www.rbarrios.com/**projects/10KGPSDO/http://www.rbarrios.com/projects/10KGPSDO/ I used an ISOTEMP OCXO and it worked well.I also tried to implement a lock detection mechanism, first based on timing the phase detector and sencondly monitoring the swings of the EFC. I was not very happy with any of those solutions and finally gave up. Details are in the code. Text is in spanish but you really don't need to read it, it is very, very basic for you time-nuts. If anyone has a suggestion for a better lock detection solution applicable here, I'd love to know about it. Best regards, Roberto EB4EQA -Mensaje original- From: Tom Van Baak Sent: Thursday, February 02, 2012 11:56 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Building a GPSDO trouble using Jupiter-T This thread got started when someone asked if an analog PLL would work for building a GSPDO. For that you do need timing pulses much faster then 1PPS. But the analog PLL are not the way to go for best accuracy. Remarkably, the simplest and still one of the best GPSDO I've tested was the 10 kHz Jupiter and analog PLL-based standard by James Miller. It performed superbly. It's the 4th GPSDO at: http://www.leapsecond.com/**pages/gpsdo/http://www.leapsecond.com/pages/gpsdo/ True, there exist some better GPSDO, and you need digital if you want a hold-over feature, but I wouldn't discourage anyone from trying the analog PLL method. The sheer simplicity might more than make up for a few less ns. Miller's page is at: http://www.jrmiller.demon.co.**uk/projects/ministd/frqstd.htmhttp://www.jrmiller.demon.co.uk/projects/ministd/frqstd.htm http://www.jrmiller.demon.co.**uk/projects/ministd/frqstd0.**htmhttp://www.jrmiller.demon.co.uk/projects/ministd/frqstd0.htm /tvb __**_ 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-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-.5680A trimming resolution
OK, got it: no need to lock the receiver clock to birds to get stable data (e.g. Oncore+Cs) but the clock can be locked to birds to get even better data and obtain for free a reference clock (TBolt). The use of a stable clock (not locked to birds) feeding the receiver can show the various errors that affect the downlink having removed the clock instabilities. On Thu, Feb 2, 2012 at 9:30 AM, Attila Kinali att...@kinali.ch wrote: On Thu, 02 Feb 2012 00:50:39 +0100 Magnus Danielson mag...@rubidium.dyndns.org wrote: I have not seen any such papers yet. Do you have any pointers or hints what to search for? Let me see... yes, here it is: http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA497270 Thanks! Printed and ready to be read :-) Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] ANFSCD - Synchronizing time in home video recorders
Amazing... there is always something to learn from TVB. Now I'll try to derive a 2.048MHz G.703-13 clock from a 10MHz clock. I suspect that the procedure is similar, even if 2048KHz is not quite a power of 2. On Thu, Feb 2, 2012 at 4:35 PM, Tom Van Baak t...@leapsecond.com wrote: Hi Roberto, The motivation for this, I assume most list members know, is to drive cheap quartz stepper motor clocks with precise 32 kHz frequency, one derived from an atomic or GPS 10 MHz. The 10 MHz to 32 kHz PIC divider I wrote uses a sort of binary leap year algorithm to adjust the digital output phase to be as close as possible to the ideal 32.768 kHz phase on each cycle and also to have zero long-term error. I'm not sure how well a multi-level leap year algorithm relates Breseham's algorithm. I tracked down his 1965 plotter article. There might be common ground there. With non-integral ratios like this case, or without external analog components (e.g., PLL), it seems some level of jitter is always unavoidable. So the goal was to make it as mathematically small as possible, and furthermore, to be able to do the math within a half cycle, which is only 15 microseconds. I'll send you an early draft of the PIC code; the version that was most clear before I had to pinch too many cycles and added too many features. Let me know what you think. I also simulated the algorithm on a PC and measured the ADEV and phase noise. That simulation code is file 10m32k.c under: http://www.leapsecond.com/tools/ /tvb - Original Message - From: Roberto Barrios rbarri...@msn.com To: Tom Van Baak t...@leapsecond.com; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, February 02, 2012 5:09 AM Subject: Re: [time-nuts] ANFSCD - Synchronizing time in home video recorders Hi Tom, I'm interested in that divider. Actually, insterested in knowing how it works, not in the .HEX file. Breseham's algorith works but has inherent jitter and I've found no other solutions for situations like that. I'd live to know how it is done. Thank you, Roberto EB4EQA http://www.rbarrios.com -Mensaje original- From: Tom Van Baak Sent: Thursday, February 02, 2012 10:34 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] ANFSCD - Synchronizing time in home video recorders I think I've seen comments about making 32 KHz from 10 MHz in a PIC or AVR. tvb has this web page, but I don't see a 32 KHz option: http://www.leapsecond.com/pic/picdiv.htm Hal, Yes, I have a PIC divider that takes 5 or 10 MHz input and outputs a 32.768 kHz square wave with minimal jitter and no long-term phase offset. Contact me off-line if interested. /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] ANFSCD - Synchronizing time in home video recorders
Yes, shortly after having sent out the message I realized that I was, as usual, too fast. I'm aware that a simple microprocessor can't be used but a Spartan3 can be involved. Then another problem: the 2.048MHz is about 1/5 of the 10MHz so it is not possible. Sofar the way out is: dividing the 10MHz by 625 and then multiplying by 128 using the DCM in the Spartan3... but nothing clever in this method. Sorry, not a valid contribution. On Thu, Feb 2, 2012 at 6:07 PM, Tom Van Baak t...@leapsecond.com wrote: Azelio, 2.048 MHz has a cycle period of just 488.28125 ns so a PIC/AVR is (far) too slow to use the same trick I did on the low frequency 32 kHz. I think you'll have to use a PLL for that one. How about a 16 kHz compare rate: 10 MHz / 625 = 16000 Hz = 2.048 MHz / 128 /tvb - Original Message - From: Azelio Boriani To: Tom Van Baak ; Discussion of precise time and frequency measurement Sent: Thursday, February 02, 2012 8:18 AM Subject: Re: [time-nuts] ANFSCD - Synchronizing time in home video recorders Amazing... there is always something to learn from TVB. Now I'll try to derive a 2.048MHz G.703-13 clock from a 10MHz clock. I suspect that the procedure is similar, even if 2048KHz is not quite a power of 2. On Thu, Feb 2, 2012 at 4:35 PM, Tom Van Baak t...@leapsecond.com wrote: Hi Roberto, The motivation for this, I assume most list members know, is to drive cheap quartz stepper motor clocks with precise 32 kHz frequency, one derived from an atomic or GPS 10 MHz. The 10 MHz to 32 kHz PIC divider I wrote uses a sort of binary leap year algorithm to adjust the digital output phase to be as close as possible to the ideal 32.768 kHz phase on each cycle and also to have zero long-term error. I'm not sure how well a multi-level leap year algorithm relates Breseham's algorithm. I tracked down his 1965 plotter article. There might be common ground there. With non-integral ratios like this case, or without external analog components (e.g., PLL), it seems some level of jitter is always unavoidable. So the goal was to make it as mathematically small as possible, and furthermore, to be able to do the math within a half cycle, which is only 15 microseconds. I'll send you an early draft of the PIC code; the version that was most clear before I had to pinch too many cycles and added too many features. Let me know what you think. I also simulated the algorithm on a PC and measured the ADEV and phase noise. That simulation code is file 10m32k.c under: http://www.leapsecond.com/tools/ /tvb - Original Message - From: Roberto Barrios rbarri...@msn.com To: Tom Van Baak t...@leapsecond.com; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, February 02, 2012 5:09 AM Subject: Re: [time-nuts] ANFSCD - Synchronizing time in home video recorders Hi Tom, I'm interested in that divider. Actually, insterested in knowing how it works, not in the .HEX file. Breseham's algorith works but has inherent jitter and I've found no other solutions for situations like that. I'd live to know how it is done. Thank you, Roberto EB4EQA http://www.rbarrios.com -Mensaje original- From: Tom Van Baak Sent: Thursday, February 02, 2012 10:34 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] ANFSCD - Synchronizing time in home video recorders I think I've seen comments about making 32 KHz from 10 MHz in a PIC or AVR. tvb has this web page, but I don't see a 32 KHz option: http://www.leapsecond.com/pic/picdiv.htm Hal, Yes, I have a PIC divider that takes 5 or 10 MHz input and outputs a 32.768 kHz square wave with minimal jitter and no long-term phase offset. Contact me off-line if interested. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 32768 Hz from 10 MHz
Now I'm thinking that starting with a first run of 8 cycles at 500nS + 2 cycles at 400nS to be repeated for 10 times and then inserting 2 cycles of 400nS, a first approximation of my 2.048MHz can be done. Maybe with a deltaF/F of 10 at -4 for tau 1 second but it can be done. In the very long run the count will be correct and the accuracy gets better tau after tau. Of course there is the source oscillator's limit. On Thu, Feb 2, 2012 at 9:21 PM, Tom Van Baak t...@leapsecond.com wrote: Hi Roberto: By changing the timer count dynamically it's possible to lower the jitter to one timer count. See: http://www.prc68.com/I/PClock.shtml#BA Have Fun, Brooke Clarke Hi Brooke, You're a fellow PIC guy; let me explain. Correct, that method works with a modest interrupt rate to count integer seconds without long-term rounding error; but to generate a total of 32,768 as-consistent-as-possible pulses *per* second is quite different. It's possible to use Bresenham with two integers 10,000,000 and 32,768 but I found no way to perform all the 24-bit calculations on an 8-bit PIC quick enough. Removing the GCD often helps but in this case the accumulator remains 3-bytes wide. To generate 32 kHz you have to toggle a pin and calculate if the next toggle must be 38 or 39 instructions in the future; all the math must occur within 37 instructions. That's why I came up with the binary leap year kind of algorithm; it's as close to math-less as you can get. By comparison, all the decimal dividers (1 Hz, 10 Hz, etc.) that you and I do are trivial because of the common factors with the 10 MHz clock. It's just that 32,768 has no factors of 5. Read the comments in the file 10m32k.c for more details. I'm curious how a 10 MHz-driven high-end DDS would generate 32 kHz with the lowest possible jitter? /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] ANFSCD - Synchronizing time in home video recorders
OK for the PSOC example. At the moment I can try on a Spartan3 because I already have a board with the OCXO. The Spartan3 has the so called DCM, a digital clock generator that can multiply an input clock using its DDL digital delay line. On Thu, Feb 2, 2012 at 8:13 PM, Hal Murray hmur...@megapathdsl.net wrote: t...@leapsecond.com said: I'm not sure how well a multi-level leap year algorithm relates Breseham's algorithm. I tracked down his 1965 plotter article. There might be common ground there. It's the same math as a DDS. If Breseham would land exactly on a grid point after N steps, a DDS will have no long term drift. That means the slope of the Breseham line is N/M where both N and M are integers. For the intermediate steps, both Breseham and DDS come as close as possible: 1/2 grid spacing vs 1/2 clock period. We usually think of DDS as requiring M to be a power of 2 but you don't have to do it that way. One obvious example is to make M a power of 10 by doing decimal adds rather than binary. That should work well with a FPGA but I haven't done it yet. If you start with 10 MHz, that will give you perfect hits on integer audio frequencies. -- These are my opinions, not necessarily my employer's. 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] ANFSCD - Synchronizing time in home video recorders
No doubt, the correct way to generate accurate clocks from an accurate 10MHz is by PLLs. There are DDS too, then there is a strange method that uses a sort of dual (triple? Quadruple? ...) modulus. The advantage is that you don't need another oscillator (the PLL needs a VCO) or the (co)sine lookup and DAC combination: just divide (oddly, of course, inserting/removing cycles every here and there). Maybe the sigma at short tau isn't so good but in the long run it gets better. The derived clock can be used to synchronize equipment that is not so sensitive at short taus. This method can show how can a clock be not so good in the short term but very good in the long term. On Thu, Feb 2, 2012 at 11:10 PM, Clint Turner tur...@ussc.com wrote: Years ago (in the 80's) I needed to lock a homebrew DDS to an accurate, stable 10 MHz reference (a good TCXO in this case) that was set to WWV/H. Considering that the DDS was clocked at 2^24 Hz (16.777216 MHz) this was slightly awkward, but I did it using standard HC and 4000 logic. The convoluted path was: 10 MHz / 625 = 16 kHz (HC40103 as a div-by-125 and an HC4017 as a div-by-5 would work...) 16 kHz * 32 = 512 kHz (using a 4046 and 4040) 512 kHz /125 = 4096 Hz (using 40103 or similar) From there, it was a no-brainer to compare this with the 16.777216 MHz / 4096 with another 4046/integrator - but the same 'HC4040 that did this also had a tap with 32768 kHz on it. With a fairly slow loop and a low-noise 2^24 Hz VCXO, the DDS's clock was both clean and stable - and tuned in 1 Hz steps! A cheap and more-common 4.194304 MHz crystal would work and I suppose that a similar scheme could be used to lock a 32768 Hz VCXO but I've never tried to 'VCXO a tuning-fork crystal before:-) * * * I, too, have an older (Philips) DVR that has lost its time sync since the analogs went dark. For a while, I used the XDS time code that happened to be in the vertical interval of one of its standard definition DTV PBS station's sub-channels (received on a set-top box and modulated onto a TV channel to which the DVR would look for its time code) but this has code since been dropped. Before I discovered this, I dug up the line 21 (IIRC) code specifications and noted that even a PIC could probably generate the proper code, synchronized either from a GPS or a WWVB receiver. I'd thought about putting it on multiple lines and then RF modulating it for the DVR to see, but lost enthusiasm after I discovered the time code on the sub-channel. Since that went away (about a year ago) I've just remembered to set the clock once a month, not being able to quickly find the specs for the time code again online... 73, Clint KA7OEI ___ time-nuts mailing 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] Building a GPSDO trouble using Jupiter-T
Hence the need for a 100PPS from a Motorola, the 800Hz from a uBlox, the 10KHz from the Jupiter T, the 10MHz from the CW12 (the WI version, recently developed thanks to the time-nuts list). Anyway I still think that an analog GPSDO 1PPS based can be done. Maybe not the best accuracy can be obtained but it can be done. I'm sure Robert Pease would have had something to say about this topic. On Thu, Feb 2, 2012 at 11:06 PM, Chris Albertson albertson.ch...@gmail.comwrote: On Thu, Feb 2, 2012 at 6:42 AM, shali...@gmail.com wrote: Magnus, How do they compare in price to the receivers we normally use for timing? Do you see any advantage for a timing receiver to fix faster than once per second? This thread got started when someone asked if an analog PLL would work for building a GSPDO. For that you do need timing pulses much faster then 1PPS. But the analog PLL are not the way to go for best accuracy. -- 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] Building a GPSDO trouble using Jupiter-T
Try this link www.serc.iisc.ernet.in/graduation-theses/babu_09.pdf seems interesting On Wed, Feb 1, 2012 at 1:44 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 01/02/12 01:29, Chris Albertson wrote: On Mon, Jan 30, 2012 at 6:17 PM, Didier Jugesshali...@gmail.com wrote: You have to spend good money to get a GPS receiver capable of calculating it's time and/or position more than once per second. I am not aware of that being done for timing applications, but it is available for navigation GPS receivers, such as those used to track race cars (for a race car, one second is an eternity). I have seen navigation receivers capable of 10 fixes/second, I am sure there are better ones yet. They cost a lot of money. I'm pretty sure those GPS recievers that send out more frequent data, at say 2Hz or 5Hz are just interpolating. It is not more accurate. The GPS sats only send a frame once over 6 seconds. They send at higher rate so that the system using the GPS does not need to know how to dead reckon and can have decent results for simply using last reported position The frames does not relate to the rate of raw-data or solutions. You could track every 1 ms, as it would align with the rate of a full C/A code cycle. Typically these are integrated into complete sub-code symbols, of 20 ms or 50 bauds, so it is not unfair to see that rate of raw-data. The solution can be run as often if CPU time for all the calculations are there. The ephemeris data is designed such that it doesn't need to change often and is re-transmitted regularly, so those bits isn't immediately used for navigation solution by necessity. Their phase is however important. 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. ___ time-nuts mailing 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] FE-.5680A trimming resolution
I have opened the FTS125: the fixed OCXO 20MHz is fed using the EXT_CLK pin 7 on the CW25. Maybe it is possible to drive a CW12 with an external high quality 20MHz but maybe a suitable firmware is then needed. On Wed, Feb 1, 2012 at 10:28 AM, Attila Kinali att...@kinali.ch wrote: On Tue, 31 Jan 2012 16:21:40 -0800 Tom Van Baak t...@leapsecond.com wrote: We're waiting for some brave soul to implement an SDR-based GPS timing receiver; we can all then experiment with the TBolt model instead of the TIC/DAC model of GPSDO. I'm planning that... I don't think it's too difficult to do, given all the information (papers and books) that are available on how to build GPS receivers. But it will be a damn lot of work. So don't hold your breath. It will probably take a couple of years until i even get around to design a board for it, not to mention to write all the code. Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] Building a GPSDO trouble using Jupiter-T
In your opinion, is it possible for a GPS receiver to align the PPS pulse on multiple of the C/A code repetition rate because of (for example) badly received satellite signals? Maybe this can happen, after the initial acquisition, on the following updates. On Wed, Feb 1, 2012 at 10:47 AM, b...@lysator.liu.se wrote: On Tue, 31 Jan 2012 16:29:07 -0800 Chris Albertson albertson.ch...@gmail.com wrote: I'm pretty sure those GPS recievers that send out more frequent data, at say 2Hz or 5Hz are just interpolating. It is not more accurate. The GPS sats only send a frame once over 6 seconds. As Magnus already wrote, once you have a fix, you can use code tracking to get an updated fix up to rates of 1kHz. If you use codeless P(Y) code tracking or carrier phase tracking you can get even higher rates. But, you can only update an already available fix, not calculate a fresh fix from scratch at that rate. This is because carrier phase and codeless P(Y) code tracking has an ambiguity of the phase, which has to be first resolved by a conventional fix. Once you have this, you can use those two techniques to get fixes at high rates. Attila Kinali The classic GPS receiver architecture use early and late correlators to track the correlation peak. You can make fresh single fix solutions as quick as your hardware can cope. However the correlator tracking loops have a limited bandwidth - 5 to 25Hz-ish. It is of limited interest to sample quicker than some 10-40Hz. -- Björn ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] IEEE1588
Interesting: a sort of public grandmaster. I don't think there are any available. I have attended an Oscilloquartz's live meeting on IEEE1588 and, of course, they have shown their expensive production but, in general, it should be useful to find public grandmasters to test with. On Wed, Feb 1, 2012 at 3:09 PM, Daniel Mendes dmend...@gmail.com wrote: All this talk about microcontrollers and IEEE1588 made me get out of the shadow to ask: 1) Are you talking about IEEE1588-2002 or IEEE1588-2008? The former has no use to me, but the later could replace some GPSs in a system i´m designing... 2) If you intend to play with IEEE1588-2008, do you know any affordable source of data? (I think they call them grandmasters or something like that). Thanks Daniel __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FE-.5680A trimming resolution
In my opinion the work done locking the VCTCXO of the Oncore is different from the TBolt OCXO management: the TBolt steers the OCXO based on the received signal instead they locked the Oncore oscillator to a Cs reference. Yes, if all the world is the same then there is no difference: the Cs locks the VCTCXO frequency where it should be as if steered from satellites but how can you drive an OCXO from an Oncore even with hardware modifications?. There is an oscillator offset in the @@Ha status message... maybe by using it? On Thu, Feb 2, 2012 at 12:59 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 01/02/12 15:07, John Ackermann N8UR wrote: There've been numerous threads on the Gnuradio mailing list about code to receive GPS using the Ettus Research USRP hardware. I don't know whether anyone has actually made it work, but it appears that it's been the subject of quite a few academic projects. I bought one of those GNSS samplers, pulled data from the air and actually managed to have my GPS SDR written in C scan the doppler bins and code-phases with FFT correlation techniques (with a little help of FFTW), find a bird and lock the PLL up to it... locked onto the symbols and started spitting out the sub-code info. I wrote all the code myself except for the USB application. I also spent some time to start calculating position and such. I will have to get one of those Ettus Research devices to be able to do anything useful thought. So, it is certainly possible. Takes a few of the software GPS books alongside the ICD-GPS-200 and traditional GPS books to piece together the full suite of references, but it didn't take THAT long to get where I where. 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. ___ time-nuts mailing 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] Building a GPSDO trouble using Jupiter-T
OK, will check the uBlox datasheet, until now I was assuming that the uBlox series was capable of more than 1 fix per second in navigation and in timing. On Tue, Jan 31, 2012 at 3:17 AM, Didier Juges shali...@gmail.com wrote: You have to spend good money to get a GPS receiver capable of calculating it's time and/or position more than once per second. I am not aware of that being done for timing applications, but it is available for navigation GPS receivers, such as those used to track race cars (for a race car, one second is an eternity). I have seen navigation receivers capable of 10 fixes/second, I am sure there are better ones yet. They cost a lot of money. Didier KO4BB On Mon, Jan 30, 2012 at 4:31 AM, Azelio Boriani azelio.bori...@screen.it wrote: OK, now I know and wonder if other GPS receivers that have frequency outputs behave in this manner. For example the Motorola 100PPS output, the uBlox 800Hz, the Navsync variable frequency output and so on. It is possible to compute solutions from GPS satellite at greater than 1 second rate so the phase of these signals should be adjustable at a rate that could minimize the phase jump... this is only my opinion, not the real possibility. On Mon, Jan 30, 2012 at 11:15 AM, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: The 10kHz is continuous but its phase jerked on the second. The new phase is held until the next jerk. Bruce Azelio Boriani wrote: Ah, is it a burst of 10KHz once a second? I don't have a Jupiter-T and I'm a PPS-type discplining fan but I thought it was a continuous 10KHz. On Mon, Jan 30, 2012 at 10:33 AM, Attila Kinaliatt...@kinali.ch wrote: On Sun, 29 Jan 2012 00:50:35 -0600 Ray Xurayxu...@gmail.com wrote: For those who have experience using the Jupiter T GPS: I have bought this http://www.ebay.com/itm/**Navman-jupiter-T-Tu60-GPS-Kit-** 1pps-10khz-GPS-Module-/**260790984470 http://www.ebay.com/itm/Navman-jupiter-T-Tu60-GPS-Kit-1pps-10khz-GPS-Module-/260790984470 Ouch... For that price you get already a new LEA-6T, which is a state of the art timing GPS receiver. Beside having the better sensitivity (more satelites in difficult conditions) it features also an frequency output that can go up to 10MHz (or 8MHz if you want low jitter). Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/**mailman/listinfo/time-nuts 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 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] FE-.5680A trimming resolution
The Navsync FTS125 is an example where the GPS receiver engine (the CW25) is driven by a 20MHz fixed OCXO. At the moment I don't know if the CW25 of the FTS125 has a specific firmware for that but I suspect that it must be so. In my opinion it is best to have a tunable OCXO (like the TBolt) to have the best performance. On Tue, Jan 31, 2012 at 10:19 PM, cfo xne...@luna.kyed.com wrote: On Tue, 31 Jan 2012 21:47:15 +0100, Attila Kinali wrote: STM32-F2/F4 (ST): ST doesn't want to give me the documentation to those. (website fails w/o error message) I have no probs with the ST site (Discovery-F4) http://www.st.com/internet/evalboard/product/252419.jsp You want these for the MCU http://www.st.com/internet/mcu/product/252140.jsp DataSheet http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/ DATASHEET/DM00037051.pdf Errata http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/ ERRATA_SHEET/DM00037591.pdf Reference Manual http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/ REFERENCE_MANUAL/DM00031020.pdf CFO ___ time-nuts mailing 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] Building a GPSDO trouble using Jupiter-T
Timing GPS receivers usually have the sawtooth correction message and I saw an application of a delay line to correct the PPS before using it. Of course if you time the PPSes difference with a time-to-digital you don't need to correct the incoming hardware PPS by a delay line, but to implement an all-analog PPS PLL then it can be done. For those of you who use a 10KHz reference signal there is not even the need for a long time constant in the low pass filter: to average 1000 PPSes you need 1000 seconds but to average 1000 10KHz cycles you need only 0.1 seconds. On Mon, Jan 30, 2012 at 6:15 AM, David davidwh...@gmail.com wrote: The sawtooth error in the PPS output and how they were able to correct it externally was interesting. I have seen that kind of problem before in DDS and other applications. I wonder what other GPS receivers provide either PPS outputs without sawtooth noise or a correction message. On Sun, 29 Jan 2012 20:40:52 -0800, Hal Murray hmur...@megapathdsl.net wrote: What do you mean by average? Do you mean that the GPS and PLL must be kept on for 20 minutes to hours, or did you mean that the PLL loop filter must have a time constant of 20 minutes to several hours? You have to compare the characteristics of the oscillator with the characteristics of your GPS receiver. If your local oscillator is very stable, then you want to average over long times (hours, days). If your local oscillator is a good thermometer and you have a very good GPS receiver, then you want a shorter time constant (minutes) so you can track temperature changes. Do you know about hanging bridges? If not, please read Timing for VLBI by Tom Clark and Rick Hambly. It's got some wonderful graphs. Once you understand those, this discussion will get much more interesting. http://gpstime.com/files/tow-time2009.pdf ___ time-nuts mailing 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] Building a GPSDO trouble using Jupiter-T
Ah, is it a burst of 10KHz once a second? I don't have a Jupiter-T and I'm a PPS-type discplining fan but I thought it was a continuous 10KHz. On Mon, Jan 30, 2012 at 10:33 AM, Attila Kinali att...@kinali.ch wrote: On Sun, 29 Jan 2012 00:50:35 -0600 Ray Xu rayxu...@gmail.com wrote: For those who have experience using the Jupiter T GPS: I have bought this http://www.ebay.com/itm/Navman-jupiter-T-Tu60-GPS-Kit-1pps-10khz-GPS-Module-/260790984470 Ouch... For that price you get already a new LEA-6T, which is a state of the art timing GPS receiver. Beside having the better sensitivity (more satelites in difficult conditions) it features also an frequency output that can go up to 10MHz (or 8MHz if you want low jitter). Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] Building a GPSDO trouble using Jupiter-T
OK, now I know and wonder if other GPS receivers that have frequency outputs behave in this manner. For example the Motorola 100PPS output, the uBlox 800Hz, the Navsync variable frequency output and so on. It is possible to compute solutions from GPS satellite at greater than 1 second rate so the phase of these signals should be adjustable at a rate that could minimize the phase jump... this is only my opinion, not the real possibility. On Mon, Jan 30, 2012 at 11:15 AM, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: The 10kHz is continuous but its phase jerked on the second. The new phase is held until the next jerk. Bruce Azelio Boriani wrote: Ah, is it a burst of 10KHz once a second? I don't have a Jupiter-T and I'm a PPS-type discplining fan but I thought it was a continuous 10KHz. On Mon, Jan 30, 2012 at 10:33 AM, Attila Kinaliatt...@kinali.ch wrote: On Sun, 29 Jan 2012 00:50:35 -0600 Ray Xurayxu...@gmail.com wrote: For those who have experience using the Jupiter T GPS: I have bought this http://www.ebay.com/itm/**Navman-jupiter-T-Tu60-GPS-Kit-** 1pps-10khz-GPS-Module-/**260790984470http://www.ebay.com/itm/Navman-jupiter-T-Tu60-GPS-Kit-1pps-10khz-GPS-Module-/260790984470 Ouch... For that price you get already a new LEA-6T, which is a state of the art timing GPS receiver. Beside having the better sensitivity (more satelites in difficult conditions) it features also an frequency output that can go up to 10MHz (or 8MHz if you want low jitter). Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/**mailman/listinfo/time-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-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-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Building a GPSDO trouble using Jupiter-T
OK, so it is a common practice. On Mon, Jan 30, 2012 at 11:43 AM, ewkeh...@aol.com wrote: Where can you get a LEA-6T for $ 65? Bert Kehren In a message dated 1/30/2012 5:34:56 A.M. Eastern Standard Time, bruce.griffi...@xtra.co.nz writes: The 100PPS output from Motorola receivers is phase jerked every second in the same fashion. Bruce Azelio Boriani wrote: OK, now I know and wonder if other GPS receivers that have frequency outputs behave in this manner. For example the Motorola 100PPS output, the uBlox 800Hz, the Navsync variable frequency output and so on. It is possible to compute solutions from GPS satellite at greater than 1 second rate so the phase of these signals should be adjustable at a rate that could minimize the phase jump... this is only my opinion, not the real possibility. On Mon, Jan 30, 2012 at 11:15 AM, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: The 10kHz is continuous but its phase jerked on the second. The new phase is held until the next jerk. Bruce Azelio Boriani wrote: Ah, is it a burst of 10KHz once a second? I don't have a Jupiter-T and I'm a PPS-type discplining fan but I thought it was a continuous 10KHz. On Mon, Jan 30, 2012 at 10:33 AM, Attila Kinaliatt...@kinali.ch wrote: On Sun, 29 Jan 2012 00:50:35 -0600 Ray Xurayxu...@gmail.comwrote: For those who have experience using the Jupiter T GPS: I have bought this http://www.ebay.com/itm/**Navman-jupiter-T-Tu60-GPS-Kit-** 1pps-10khz-GPS-Module-/**260790984470 http://www.ebay.com/itm/Navman-jupiter-T-Tu60-GPS-Kit-1pps-10khz-GPS-Module-/260790984470 Ouch... For that price you get already a new LEA-6T, which is a state of the art timing GPS receiver. Beside having the better sensitivity (more satelites in difficult conditions) it features also an frequency output that can go up to 10MHz (or 8MHz if you want low jitter). Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/**mailman/listinfo/time-nuts 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 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] Thank you Tom and Rick MUST READ
I'm rather new to this list too but I'm working on precision time and frequency since 1999. Learned more since I've joined the list than before, especially from the practical side: various GPSDOs behaviour, GPS receivers tips and tricks, high performance test equipment to watch for. Papers that are a must. Thank you all. On Mon, Jan 30, 2012 at 12:02 PM, ewkeh...@aol.com wrote: Having been on the list for only three years somehow tow-time 2009 had escaped me. Thank you Tom and Rick for putting together such an informative document. Probably one of the best contributions. Every member of the list should have a copy and I strongly urge those having joined more recently like my self download this. Thanks again Bert Kehren http://gpstime.com/files/tow-time2009.pdf ___ time-nuts mailing 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] Prologix GPIB-ETH - Linux examples ?
Interesting, I've downloaded and taken a look at the example and noted how the Prologix doesn't use the Remote Procedure Call (RPC) method but a simple telnet-like connection. Follow Orin's directions to convert from WINSOCK to Linux-style socket calls. Maybe you should first take a look how to open a simple TCP connection under Linux and you'll find the system calls pointed out by Orin. On Mon, Jan 30, 2012 at 9:28 PM, Orin Eman orin.e...@gmail.com wrote: On Mon, Jan 30, 2012 at 11:23 AM, cfo xne...@luna.kyed.com wrote: I just got my Prologix GPIB-ETH I am 90% Linux Ubuntu based , and would like to get 99% based. So i am looking for some C code examples, implementing the linux networking part. I have sen the Prologix example C/C+ , but it's WINSOCK. There's hardly any difference between Linux sockets and WINSOCK as far as that example code goes. Remove the WSAStartup/WSACleanup calls, change sprintf_s to sprintf, WSAGetLastError() to errno, SOCKET to int and you should be done. That's the easy part. The hard part is handling timeouts as the Prologix doesn't give any indication if a ++read timed out. Orin. ___ time-nuts mailing 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] FE-.5680A trimming resolution
Wow, good work, a very fine reverse engineering attempt. On Sun, Jan 29, 2012 at 12:45 PM, Javier Herrero jherr...@hvsistemas.eswrote: Hello, As it has been discussed in the past days, the architecture of the newer FE-5680A that has been recently purchased by a lot of us does not led to a trimming resolution through the serial port of 1.7854e-7Hz, but rather leds to think that the trimming resolution is in fact 6.80789e-6Hz (relative frequency resolution 6.807e-13). I've hang a logic analyzer to the DDS SPI bus, and an SPI message appears inmediately after updating the offset through the serial port. I've found that the DDS is programmed in two frequencies, separated 1400Hz near exactly, for each serial port offset setting, and that one bit increment in the serial port offset setting is translated to a one-bit increment for both DDS frequencies. The DDS frequencies are alternated at 416.666Hz rate through FSELECT pin, at an invariable 50% duty cycle, presumably to perform synchronous detection in the same way as explained in the FRS-C manual. For example, the following data has been gathered: Serial offset 00 00 00 00 DDS A word: 44 02 62 F6 = 1141007094 = 5 313 228.32219 Hz DDS B word: 43 FD CC 8E = 1140706446 = 5 311 828.32085 Hz Serial offset 00 00 00 01 DDS A word: 44 02 62 F7 = 1141007095 = 5 313 228.32685 Hz DDS B word: 43 FD CC 8F = 1140706447 = 5 311 828.32550 Hz Serial offset 00 00 00 02 DDS A word: 44 02 62 F8 = 1141007096 = 5 313 228.33151 Hz DDS B word: 43 FD CC A0 = 1140706448 = 5 311 828.33016 Hz I've seen that these values seems to vary slightly from time to time in the less significative digits, I've been then change in the order of 2-3 units from one data take to a different one minutes later. I've checked that the unit updates each several seconds the DDS control words, and I've seen changes in the lower significant bits at minutes intervals, although most of the times, same previous words are sent. I suspect this is some form of unit self-compensation, perhaps to temperature changes. Last, I've sent an offset of 1468879 units, that shoudl correspond to a 10Hz frequency change assuming a trimming resolution of 6.90789e-6Hz, and after a temporary unit unlock, it has locked exactly at 10 000 010.000 Hz. So I can conclude that these units are not fully compliant with the manual we are handling, and that the trimming resolution is 6.80789e-6Hz and not the stated 1.7854e-7Hz. Best regards, Javier, EA1CRB ___ time-nuts mailing 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] FE-5680A FAQ update: question about frequency synthesizer architecture
And I think it depends on the two frequencies loaded too. The FSELECT selects between two phase accumulator steps. Maybe the word sent to the Rb is manipulated to obtain two symmetric values to load. On Sat, Jan 28, 2012 at 3:21 PM, Javier Herrero jherr...@hvsistemas.eswrote: El 27/01/2012 19:27, beale escribió: I added a bit to the electronics section of the FE-5680A FAQ as below. http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:fe5680a_faq#electronic (Note- until today, I had the 8 and 6 digits transposed, calling it the fe5860a. But no one noticed :-) The updated section is below. I measured the 20 MHz input and 5.3 MHz output of the DDS, but I'm puzzled by how the tuning resolution (4.6 mHz) of the DDS output is divided by such a large factor to achieve 0.18 uHz resolution at the final 10 MHz output. Can any frequency synthesizer gurus explain how this is done? The frequencies inside the unit are quite similar to those found in the FRS-C, 60 and 5.3125MHz. The FRS-C excites the cavity at 60MHz x 114 - 5.3125MHz = 6.8346875GHz (a bit over the 6.834682608GHz Rb natural resonance - so I suppose that the resonance is driven to 6.8346875GHz using the C-Field), so I understand that the FE-5680A operates in the same way. Since in the multiplication process the 60MHz frequency is multiplied by 114 and the 5.3125MHz only by one, 1Hz offset in the 5.3125MHz frequency will need 1/114Hz offset in the 60MHz signal to obtain the same resonant frequency. I've checked that the DDS is driven by 10MHz, not 20MHz (I've just checked it), so the 5.3125MHz is probably an image and not a fundamental DDS output. Hence, the minimum DDS step is 2.23mHz. A change of 2.23mHz in the 5.3125MHz frequency is compensated by an approximately 20.45uHz change at the 60MHz frequency, and so, a 3.41uHz at the 10MHz output, i.e. one part in 3.41^-13. This lets to a factor of 19 between the adjustment attainable directly by modifiying a 1LSB and the claimed 1.7854^-14 adjustment. Probably this is done by modifying the duty cycle of the FSELECT signal. I suspect that the 416.667 signal at FSELECT is used to produce the modulation on the cavity excitation to perform a synchronous detection (the same way it is done in the FRS-C at 127Hz), to obtain a null, so the null can be slightly moved by variying the duty cycle at FSELECT. I will try to play a bit more this evening :) Best regards, Javier -- Javier Herrero Chief Technology Officer EMAIL: jherr...@hvsistemas.com HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17 FAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.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] establishing your position w/o gps
Yes, the first real push was the Longitude Act (1714) and the Harrison's clocks. On Tue, Jan 24, 2012 at 5:36 PM, Chris Albertson albertson.ch...@gmail.comwrote: On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali att...@kinali.ch wrote: On Tue, 24 Jan 2012 11:04:08 + Poul-Henning Kamp p...@phk.freebsd.dk wrote: In message 20120124115848.312d60bd4fccce4f3e71c...@kinali.ch, Attila Kinali w rites: All this talk about telling the time using stars or the sun made me wonder how did people tell what position their telescopes had back in the days before GPS? Sailingships and trade was what pushed this. At the time of Columbus he was able to know his latitude within a few 10s of miles but even after returning to Europe he did no know how far around the world he had sailed. Was it 1/3rd or 2/3rds? They had no way to know.The problem was that on one had a clock that should keep time well enough. They used hour glasses on board ship for short duration time keeping but those were of no use on a longer ocean crossing. Later they discovered the idea of common view of the moons of Jupiter and they could measure the time from local noon some even on Jupitor while a person back home did the same thing. Later when he got back home they compare notes and then know the difference in longitude. Good ocean going clocks were still centuries away.But in the 1500's they could only know the location after the fact when they returned -- 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] establishing your position w/o gps
Maybe the Longitude Act was issued also because of the disaster occured in 1707 due to a navigation error: the Royal Navy fleet lost 4 of its 15 ships. On Tue, Jan 24, 2012 at 5:50 PM, Azelio Boriani azelio.bori...@screen.itwrote: Yes, the first real push was the Longitude Act (1714) and the Harrison's clocks. On Tue, Jan 24, 2012 at 5:36 PM, Chris Albertson albertson.ch...@gmail.com wrote: On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali att...@kinali.ch wrote: On Tue, 24 Jan 2012 11:04:08 + Poul-Henning Kamp p...@phk.freebsd.dk wrote: In message 20120124115848.312d60bd4fccce4f3e71c...@kinali.ch, Attila Kinali w rites: All this talk about telling the time using stars or the sun made me wonder how did people tell what position their telescopes had back in the days before GPS? Sailingships and trade was what pushed this. At the time of Columbus he was able to know his latitude within a few 10s of miles but even after returning to Europe he did no know how far around the world he had sailed. Was it 1/3rd or 2/3rds? They had no way to know.The problem was that on one had a clock that should keep time well enough. They used hour glasses on board ship for short duration time keeping but those were of no use on a longer ocean crossing. Later they discovered the idea of common view of the moons of Jupiter and they could measure the time from local noon some even on Jupitor while a person back home did the same thing. Later when he got back home they compare notes and then know the difference in longitude. Good ocean going clocks were still centuries away.But in the 1500's they could only know the location after the fact when they returned -- 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] establishing your position w/o gps
I've read the book by Dava Sobel Longitude... not technical but interesting for me. On Tue, Jan 24, 2012 at 6:05 PM, Lee Mushel herbe...@centurytel.net wrote: If you're looking for a really interesting topic to read about, the development of an accurate ship-board clock is really fascinating! And it wasn't done overnight! Lee K9WRU - Original Message - From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, January 24, 2012 10:36 AM Subject: Re: [time-nuts] establishing your position w/o gps On Tue, Jan 24, 2012 at 3:16 AM, Attila Kinali att...@kinali.ch wrote: On Tue, 24 Jan 2012 11:04:08 + Poul-Henning Kamp p...@phk.freebsd.dk wrote: In message 20120124115848.**312d60bd4fccce4f3e71c136@**kinali.ch20120124115848.312d60bd4fccce4f3e71c...@kinali.ch, Attila Kinali w rites: All this talk about telling the time using stars or the sun made me wonder how did people tell what position their telescopes had back in the days before GPS? Sailingships and trade was what pushed this. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] TimeLab and HP53132A
Serial port communication, GPIB or what else? On Sat, Jan 21, 2012 at 3:22 PM, Timeok tim...@timeok.it wrote: Hi all, Do you have some experience with TimeLab connected with a TIC HP53132A? My trouble is as follow: using the default setup and acquiring for 1 hour, I can see on display the graph vary (as magnitude)every 1 second count, like the event counter each second up to 3600,but the x (time) display show 1800 seconds as total acquisition time over a real 3600 seconds spent. Looking the graphic when I start the acquisition I can see a shape modification every second but the time axis advance only 1 second every two real seconds. This happen also with the newest verson of Time Lab. Setting 2 second sample, an other tentative to modify the configuration fail, can some one with the HP53132A help me? luciano Luciano P. S. Paramithiotti IZ5JHJ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. Sent to you using Uebimiau Webmail version 3.11 Developed by Dave and Todd at http://www.manvel.net and http://www.tdah.us ___ time-nuts mailing 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] Leap Second decision postponed
Yes, I was too fast, looked again and found only almanac data. I'll try on my M12. On Fri, Jan 20, 2012 at 2:04 AM, Tom Van Baak t...@leapsecond.com wrote: No, @@Be is just the almanac data. That is not what you want. On the M12 to get all the subframes you use @@Tr. /tvb - Original Message - From: Azelio Boriani azelio.bori...@screen.it To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, January 19, 2012 4:14 PM Subject: Re: [time-nuts] Leap Second decision postponed For the Motorola/iLotus receiver the command is @@Be. But the data returned has no such page 18 of subframe 4. Manual says subframe 4 with pages 2 to 5, 7 to 10 or 25 and subframe 5 with pages from 1to 25. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Leap Second decision postponed
Mmmmh, problem: can't find the @@Tr command details... my M12 gives a response for the @@Tr but at the moment I can't decode it. The Oncore VP has the @@Bl command but the M12 doesn't recognize it. Is the @@Tr an undocumented/secret command? Found a lot of PDFs on the M12 but no @@Tr in them. On Fri, Jan 20, 2012 at 10:08 AM, Azelio Boriani azelio.bori...@screen.itwrote: Yes, I was too fast, looked again and found only almanac data. I'll try on my M12. On Fri, Jan 20, 2012 at 2:04 AM, Tom Van Baak t...@leapsecond.com wrote: No, @@Be is just the almanac data. That is not what you want. On the M12 to get all the subframes you use @@Tr. /tvb - Original Message - From: Azelio Boriani azelio.bori...@screen.it To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, January 19, 2012 4:14 PM Subject: Re: [time-nuts] Leap Second decision postponed For the Motorola/iLotus receiver the command is @@Be. But the data returned has no such page 18 of subframe 4. Manual says subframe 4 with pages 2 to 5, 7 to 10 or 25 and subframe 5 with pages from 1to 25. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Leap Second decision postponed
Of course I have to read the ICD200 but to collect data from the Tr I need the Tr details. For example, the Bl command adds the SVID/frame/page to the data and you must know how to separate the fields (it is very simple, the are at the beginning). OK, I know, I'll have to reverse engineer the Tr command... now I'm collecting data and then I'll compare to the ICD. On Fri, Jan 20, 2012 at 1:53 PM, k4...@aol.com k4...@aol.com wrote: You will need to consult the ICD to decipher the data. Connected by DROID on Verizon Wireless -Original message- From: Azelio Boriani azelio.bori...@screen.it To: Tom Van Baak t...@leapsecond.com, Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Fri, Jan 20, 2012 12:03:59 GMT+00:00 Subject: Re: [time-nuts] Leap Second decision postponed Mmmmh, problem: can't find the @@Tr command details... my M12 gives a response for the @@Tr but at the moment I can't decode it. The Oncore VP has the @@Bl command but the M12 doesn't recognize it. Is the @@Tr an undocumented/secret command? Found a lot of PDFs on the M12 but no @@Tr in them. On Fri, Jan 20, 2012 at 10:08 AM, Azelio Boriani azelio.bori...@screen.it**wrote: Yes, I was too fast, looked again and found only almanac data. I'll try on my M12. On Fri, Jan 20, 2012 at 2:04 AM, Tom Van Baak t...@leapsecond.com wrote: No, @@Be is just the almanac data. That is not what you want. On the M12 to get all the subframes you use @@Tr. /tvb - Original Message - From: Azelio Boriani azelio.bori...@screen.it To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, January 19, 2012 4:14 PM Subject: Re: [time-nuts] Leap Second decision postponed For the Motorola/iLotus receiver the command is @@Be. But the data returned has no such page 18 of subframe 4. Manual says subframe 4 with pages 2 to 5, 7 to 10 or 25 and subframe 5 with pages from 1to 25. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshtt**ps://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-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-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Leap Second decision postponed
OK, thank you for your help. On Fri, Jan 20, 2012 at 11:04 PM, Tom Van Baak t...@leapsecond.com wrote: It's in m12-gps-bit-stream.pdf under www.leapsecond.com/pages/m12/ /tvb - Original Message - From: Azelio Boriani To: Tom Van Baak ; Discussion of precise time and frequency measurement Sent: Friday, January 20, 2012 4:03 AM Subject: Re: [time-nuts] Leap Second decision postponed Mmmmh, problem: can't find the @@Tr command details... my M12 gives a response for the @@Tr but at the moment I can't decode it. The Oncore VP has the @@Bl command but the M12 doesn't recognize it. Is the @@Tr an undocumented/secret command? Found a lot of PDFs on the M12 but no @@Tr in them. On Fri, Jan 20, 2012 at 10:08 AM, Azelio Boriani azelio.bori...@screen.it wrote: Yes, I was too fast, looked again and found only almanac data. I'll try on my M12. On Fri, Jan 20, 2012 at 2:04 AM, Tom Van Baak t...@leapsecond.com wrote: No, @@Be is just the almanac data. That is not what you want. On the M12 to get all the subframes you use @@Tr. /tvb - Original Message - From: Azelio Boriani azelio.bori...@screen.it To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, January 19, 2012 4:14 PM Subject: Re: [time-nuts] Leap Second decision postponed For the Motorola/iLotus receiver the command is @@Be. But the data returned has no such page 18 of subframe 4. Manual says subframe 4 with pages 2 to 5, 7 to 10 or 25 and subframe 5 with pages from 1to 25. ___ time-nuts mailing 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] Leap Second decision postponed
Yes, me too... On Thu, Jan 19, 2012 at 11:20 PM, mike cook michael.c...@sfr.fr wrote: Le 19/01/2012 21:55, k4...@aol.com a écrit : Last time I checked (first of this week) subframe 4 of page 18 in the data stream from the GPS satellites, they are not indicating there is a pending leap second. Last time there was a leapsecond (couple years ago), I think the GPS SV's were anouncing a pending leapsecond about 6 months in advance. Wonder when they will start sending it on GPS? Doug, K4CLE I'd be interested to how how you are extracting this data. ___ time-nuts mailing 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] Leap Second decision postponed
For the Motorola/iLotus receiver the command is @@Be. But the data returned has no such page 18 of subframe 4. Manual says subframe 4 with pages 2 to 5, 7 to 10 or 25 and subframe 5 with pages from 1to 25. On Fri, Jan 20, 2012 at 1:06 AM, k4...@aol.com k4...@aol.com wrote: Hal, Thanks, glad you have such good records. Maybe they are waiting until Jan. 28 to start transmitting it this time. I wonder what the magic formula is as to when they start ? Some had asked how I am able to view the data stream? I have a homemade receiver that's set up where I can record the raw data. Since the previous event, I wrote some software that will notify me when there is a pending leap second and I need them to start transmitting it where I can verify my software is working correctly! Connected by DROID on Verizon Wireless -Original message- From: Hal Murray hmur...@megapathdsl.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thu, Jan 19, 2012 22:47:40 GMT+00:00 Subject: Re: [time-nuts] Leap Second decision postponed Last time I checked (first of this week) subframe 4 of page 18 in the data stream from the GPS satellites, they are not indicating there is a pending leap second. Last time there was a leapsecond (couple years ago), I think the GPS SV's were anouncing a pending leapsecond about 6 months in advance. Wonder when they will start sending it on GPS? I just checked and my Z3801A isn't seeing it yet. Last time, it started getting announced on July 28. -- These are my opinions, not necessarily my employer's. 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. ___ time-nuts mailing 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] 5370A on eBay
Usually the HP5370A or B here is considered for the single shot time interval high resolution feature. The HP5335 is 2nS compared to 20pS of the HP5370. To that extent they are not the same. On Wed, Jan 18, 2012 at 10:05 AM, Roy Phillips phill...@btinternet.comwrote: Chris The HP 5335A is also worth considering and is usually reasonably priced. Roy -Original Message- From: Chris Albertson Sent: Tuesday, January 17, 2012 11:40 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 5370A on eBay On Tue, Jan 17, 2012 at 3:23 PM, Don Lewis dlewis6...@austin.rr.com wrote: Just curious, pls What would be a reasonable price to pay for one of these counters? It seems to depend hugely on the risk you are willing to take. This most resent counter is listed as not functioning as intended, returns not accepted but does show a mostly working display. It might be just fine and work OK. Others are listed as being recently calibrated and come with 30 day warranty I think $250 to $500 for a It may work, but no returns accepted counter and a lot more for one with a warranty. Other counters are cheaper. the HP5328 is very affordable ($50 if you can wait for a deal) but of course is not nearly as nice of a machine. 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-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-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP5384A Freq Counter
I have the HP5384A but it is a plain counter (no time interval). Not so suitable for a time-nut: just like having a voltmeter, useful to have it handy to do the very first test. It has the external reference input and the GPIB interface. On Wed, Jan 18, 2012 at 11:45 AM, Rob Kimberley robkimber...@btinternet.com wrote: I've seen one of these advertised, and wanted to know if any fellow Nuts had any experience. Thanks Rob Kimberley ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] FE-5680A tear down on Youtube
Yes, this catched my eye too... On Wed, Jan 18, 2012 at 1:20 PM, Attila Kinali att...@kinali.ch wrote: On Fri, 13 Jan 2012 12:50:19 -0500 Bob Camp li...@rtty.us wrote: The gizmo on top of the crystal is a rapid transition thermistor. The Russians came up with them for use in OCXO's back in the 1970's. It's there to heat the VCXO crystal, sort of an OCXO. Do you have any references to this? I couldn't find anything on the net. Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] FE-5680A Mechanical Question
A good OCXO left alone. Rbs should have OCXOs inside... On Thu, Jan 12, 2012 at 5:01 PM, John Ackermann N8UR j...@febo.com wrote: I think you have to define better, though. A GPSDRbO will have better holdover performance (e.g., stability when the GPS signal goes away) than one using an OCXO, but the OCXO is quite likely to have better short term stability than the Rb. If holdover isn't an issue, you need to find the Allan Intercept Point (term stolen from David Mills and NTP) to see where the GPS and oscillator ADEV curves cross over. That will tell you how long a loop time constant you want, and will let you look at the combined ADEV for each type of oscillator. You may find that a decent OCXO gives better performance overall than an Rb. John On 1/12/2012 10:37 AM, ewkeh...@aol.com wrote: with the good long term performance of Rb's and the presently available 5680A for $ 40 a Shera Type controller will make available to any one on the list a reference better than a Tbolt for less money than a Tbolt. Repeating my self I would also add a clean up OCXO in order to get the very best. Bert Kehren In a message dated 1/12/2012 8:34:54 A.M. Eastern Standard Time, jlt...@att.net writes: David, I have been following discussions on the list about a GPSDRbO for a year or so. Some interesting challenges and probably best implemented in a 'stable' environment rather than portable operation but as best I can tell, it would require a very stable and good antenna location, stable and clean power, and I was thinking of using something like an LPRO-101 with an Ext C Field input, a Shera type controller, and a GPS timing receiver, though, I suspect there are likely to be some 'multi-tasking' receivers out there that will look at several sources including GPS, GLOSNASS, etc. While the project might be fun, for portable work, it is likely far easier and probably just as good (almost), to use a Tbolt. In any event, something to think about for the future. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-bounces@**febo.comtime-nuts-boun...@febo.com] On Behalf Of David Sent: Wednesday, January 11, 2012 11:12 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] FE-5680A Mechanical Question How would a GPSDRbO work? Phase lock the DDS output to the GPS? Phase lock a VCXO to the GPS and then phase lock to the RbO on loss of GPS lock? On Wed, 11 Jan 2012 22:55:58 -0600, J. L. Tranthamjlt...@att.net wrote: Bill, Brian, Bill, and Peter, Thanks for the info. All I need now is a 'project' to incorporate the unit into. In the back of my mind, I have the thought of a 'box' that will be battery powered or 110 VAC powered (perhaps with an internal SLA battery) and include a GPSDO and Rb unit (possibly a GPSDRbO) for the purpose of a 'reference' for portable operation in the microwave regions. __**_ 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-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-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-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Z3801A's
Yes, recently I've bought a Z3815A from the usual suspects, it works, but seems it was stocked in the moisture (under the rain?)... On Thu, Jan 12, 2012 at 11:21 PM, Bob Camp li...@rtty.us wrote: Hi Neither unit is very common. In the same sort of venue, the 3801's sell for about half of what the 3815's sell for. If the 3801 is re-packaged to look like the instrument version, it's price goes up. On your favorite auction site 3815's typically sell for $400 to $550 delivered to the US from the usual suspects. Single unit auctions from normal people would be well below that, but very uncommon. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Brad Stockdale Sent: Thursday, January 12, 2012 2:18 PM To: time-nuts@febo.com Subject: Re: [time-nuts] Z3801A's Hello all, A few years ago, I bought several HP Z3801A's. When they all arrived, I added the internal jumpers for selecting between RS232 and RS422, and connected them all to antennas and a PC to verify functionality of the units as a whole and their timekeeping abilities. They all worked perfect and fell well within the normal ranges of operation. Since then, I've had a lot of drama in my life. I've changed jobs a couple times, moved a couple times, etc etc. Well, my life is starting to calm down some and I'm trying to get back into my hobbies, one of which is being a time nut. I'm thinking about tracking down a couple Z3815A's and possibly other pieces of hardware to add to my collection. To fund buying the other equipment, I was thinking about getting rid of a couple of my Z3801A's. I usually don't like to get rid of any piece of equipment, but if I was getting rid of one GPSDO so that I can get other related equipment, I don't think I'd feel too much remorse. My question is this... What is the current market value on working and tested Z3801A's? And for that matter, what is the usual market value on Z3815A's? Trying to see if I can make this work somehow. Thank you, Brad Stockdale ___ time-nuts mailing 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] HP Z3817A Reverse Engineering
I had a negative experience with chinese vendors too. Bought a Z3815A, yes works, the GPS unit has heavy rust and the boards shows sign of exposure to high humidity if not rain. Fortunately the E1938A oscillator seems clean and works OK. From fluke I got an LPFRS very different from the pictures and inside there was heavy traces of past rust accumulated on the PCB. He sent another but it is not so much different, only a bit better. On the other hand the GLONASS receiver from fluke is perfectly OK. On Mon, Jan 9, 2012 at 4:07 AM, Ed Palmer ed_pal...@sasktel.net wrote: Hi Bob, I bought mine on eBay from fluke.l for about $114 (including shipping). I don't know if he has any more. He didn't get positive feedback from me. His pictures showed a reasonable, used unit. The unit he shipped was dented badly enough that it was slightly crushed and appeared to have been out in the rain. It does work, but the E1938 seems to be taking a long time to settle down. I hope the crystal wasn't damaged when it took the hit that dented the case. There is no physical damage to any of the boards. I've dealt with him before and was surprised and disappointed that he didn't describe the condition better. Buyer beware. As for your 'lazy' E1938, have you grabbed the schematics and circuit description from http://www.prc68.com/I/**HPE1938.shtmlhttp://www.prc68.com/I/HPE1938.shtml? Ed On 1/8/2012 5:58 PM, Robert Benward wrote: Hi Ed, May I ask where did you get your STLN4096A and what you paid for it? Do they have any more? My E1938 recently crapped out. If I put a substitute 10MHz near the first buffer, the PIC processor comes alive, then I can remove the 10MHz and it begins to oscillate on it's own. I can quickly recycle power and it still oscillates. Let it cool down and I need to repeat the stimulus procedure. Anybody have any ideas? Thanks, Bob - Original Message - From: Ed Palmer ed_pal...@sasktel.net To: Time-Nuts time-nuts@febo.com Sent: Sunday, January 08, 2012 12:20 PM Subject: [time-nuts] HP Z3817A Reverse Engineering I recently purchased a Motorola STLN4096A with the HP E1938A oscillator. I bought it for the oscillator only. Then I got intrigued by the HP Z3817A GPSDO that's included. I've reverse engineered most of it and I've got it running. The 1 PPS is really good ( 1000 measurements, Std. Dev. of 200 ps, min to max range of 1.5 ns) and the HUP is very slowly dropping (currently at 13 us after ~1.5 days) as the oscillator works out the kinks after it's long sleep. It's dropping much slower than my Z3801A did when I first turned it on. There's one input that I haven't been able to figure out. I've got data in and 1 PPS in from the GPS receiver. Everything seems to be working so I'm at a loss what that the other input could be for. There are no clues to it's function because it appears to go into one of the Xilinx chips. Does anyone have any more info on the unit? Has anyone figured out the other input? I have searched the net and the archives. There's very little info or discussion on this unit. Ed __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Z3801A EFC error
I was able only to find the pinout for the Furuno GT74 GPS. On Sun, Jan 8, 2012 at 9:50 PM, Said Jackson saidj...@aol.com wrote: I found the gt74 gps to be lacking in performance in my Z3815. Sorry, no data sheet for it. I simply cut the 1pps output cable, and spliced a ublox receiver 1pps output into it. Then I split the antenna feed to both gps and found 3.3V somewhere for the ublox gps. Works like a charm, z3815 firmware is happy talking to the Furuno, but timing and sensitivity is much better now from the ublox.. Even with a navigation receiver. Sorry, don't remember what pins where 1pps or power, but that's easy to find with a multimeter. Btw: the Z3815 output is very noisy for some reason. Hp did not do a good job on utilizing the E1938 performance here... Said On Jan 8, 2012, at 11:22, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 01/02/2012 09:28 PM, Azelio Boriani wrote: On the usual paybay site there are available some Z3815 with the E1938 oscillator. I have bought one and found the shielding of the Furuno GT74 GPS heavily rusted. Fortunately it is perfectly working and the seller says all are that way. It was the only item found with that type of OCXO. I have found very little information on the Furuno GT74 receiver. Anyone having the usal manual stuff for it? 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. ___ time-nuts mailing 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] HP Z3817A Reverse Engineering
Have you already this? On the TIB (P1) DB-25 connector, I'm fairly confident about these: V+ pins 1 and 21 V- pins 8 and 25 10MHz #1 pins 2/15 xfmr coupled, ~4.6V into 1M 10MHz #2 pins 23/16 xfmr coupled, ~4.6V into 1M 1PPS pin 14 Supply voltage is dictated by Lucent DC-DC converter. Input is 18-36V, 1.9A. Still chasing down the other pins. Currently I am working on a possible disciplining input: input of some kind to U6/3 via 100 ohms pin 18, prob. diff with 4 input of some kind to U6/2 via 100 ohms pin 4, prob. diff with 18 The MMI (J1) DB-9 connector is RS-232, 9600baud, 8n1 and runs a a familiar SCPI interface. On Sun, Jan 8, 2012 at 6:20 PM, Ed Palmer ed_pal...@sasktel.net wrote: I recently purchased a Motorola STLN4096A with the HP E1938A oscillator. I bought it for the oscillator only. Then I got intrigued by the HP Z3817A GPSDO that's included. I've reverse engineered most of it and I've got it running. The 1 PPS is really good ( 1000 measurements, Std. Dev. of 200 ps, min to max range of 1.5 ns) and the HUP is very slowly dropping (currently at 13 us after ~1.5 days) as the oscillator works out the kinks after it's long sleep. It's dropping much slower than my Z3801A did when I first turned it on. There's one input that I haven't been able to figure out. I've got data in and 1 PPS in from the GPS receiver. Everything seems to be working so I'm at a loss what that the other input could be for. There are no clues to it's function because it appears to go into one of the Xilinx chips. Does anyone have any more info on the unit? Has anyone figured out the other input? I have searched the net and the archives. There's very little info or discussion on this unit. 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.
Re: [time-nuts] HP Z3817A Reverse Engineering
OK, I wasn't able to find anything else. Moreover the STLN4096A seems to have a Rb oscillator now from the usual 'bay vendor... so seems confusing as the Z3817A may be the E1938A mounted on the PCB that can discipline it or it is another type of unit or whatever else. No picture found until now using google. Is the Z3817A like the fig.1 picture you can find here: http://www.prc68.com/I/HPE1938.shtml ? On Sun, Jan 8, 2012 at 6:57 PM, Ed Palmer ed_pal...@sasktel.net wrote: Hi Azelio, Thanks, but I already found that. I've moved quite a bit beyond that. That message was one of the few in the archives that had any significant info on this unit. For some reason, I find that surprising. Ed On 1/8/2012 11:33 AM, Azelio Boriani wrote: Have you already this? On the TIB (P1) DB-25 connector, I'm fairly confident about these: V+ pins 1 and 21 V- pins 8 and 25 10MHz #1 pins 2/15 xfmr coupled, ~4.6V into 1M 10MHz #2 pins 23/16 xfmr coupled, ~4.6V into 1M 1PPS pin 14 Supply voltage is dictated by Lucent DC-DC converter. Input is 18-36V, 1.9A. Still chasing down the other pins. Currently I am working on a possible disciplining input: input of some kind to U6/3 via 100 ohms pin 18, prob. diff with 4 input of some kind to U6/2 via 100 ohms pin 4, prob. diff with 18 The MMI (J1) DB-9 connector is RS-232, 9600baud, 8n1 and runs a a familiar SCPI interface. On Sun, Jan 8, 2012 at 6:20 PM, Ed Palmered_pal...@sasktel.net wrote: I recently purchased a Motorola STLN4096A with the HP E1938A oscillator. I bought it for the oscillator only. Then I got intrigued by the HP Z3817A GPSDO that's included. I've reverse engineered most of it and I've got it running. The 1 PPS is really good ( 1000 measurements, Std. Dev. of200 ps, min to max range of1.5 ns) and the HUP is very slowly dropping (currently at 13 us after ~1.5 days) as the oscillator works out the kinks after it's long sleep. It's dropping much slower than my Z3801A did when I first turned it on. There's one input that I haven't been able to figure out. I've got data in and 1 PPS in from the GPS receiver. Everything seems to be working so I'm at a loss what that the other input could be for. There are no clues to it's function because it appears to go into one of the Xilinx chips. Does anyone have any more info on the unit? Has anyone figured out the other input? I have searched the net and the archives. There's very little info or discussion on this unit. 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. ___ time-nuts mailing 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] Getting my Rockwell D200 GPS to work
Just take care that GPS signal is right-hand circularly polarized. For those interested in building GPS antennae I recommend the QFH-type antenna: quite complex but it is the same antenna actually used to transmit from the birds. On Sat, Jan 7, 2012 at 5:02 PM, David davidwh...@gmail.com wrote: I have done the same thing with an amplified patch antenna facing out the window. I wonder in this case if making a rough 1/4 wave antenna out of a very short feedline would be enough for a cheap outdoor sanity check. On Sat, 7 Jan 2012 14:21:09 +, shali...@gmail.com wrote: I test all my GPS receivers with a hockey puck type antenna attached to the wall in my hamshack, which is upstairs, but under the ceiling and the roof and I have never had one fail to lock within reasonable time. With this setup, Thunderbolts occasionally go on holdover, but never for very long. Of course, when I plug them in the external Symmetricom antenna, they typically see more satellites and don't go into holdover. I am in Northwest Florida, so probably at a lower latitude than most of you, so the same setup farther north may not work as well. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Azelio Boriani azelio.bori...@screen.it Sender: time-nuts-boun...@febo.com Date: Sat, 7 Jan 2012 02:00:21 To: Discussion of precise time and frequency measurement time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Getting my Rockwell D200 GPS to work Absolutely yes, the antenna must see the sky, not the ceiling. Even very sensitive GPS receivers must have a good view of the sky for the first fix, then you can bring the antenna indoor. You can try positioning the antenna very near a window for just a test but better a good view. The car roof is okay but you must wait several minutes (12 minutes at most) to let the receiver download the almanac. On Sat, Jan 7, 2012 at 1:54 AM, Don Lewis dlewis6...@austin.rr.com wrote: Maybe I didn't take positioning seriously. The antenna is currently on a shelf above my workbench, there is a ceiling and an upstairs above it. Then the roof. Is it very critical to be outside in order to 'see' the sky? I did take it out once and set the antenna on my car roof, but still no satellites. -Don From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of bownes Sent: Friday, January 06, 2012 6:49 PM To: Discussion of precise time and frequency measurement Cc: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Getting my Rockwell D200 GPS to work Step one...is the antenna in a location where it can see they sky? Sorry if it is a stupid question but you already said it was plugged in. :) On Jan 6, 2012, at 19:24, Don Lewis dlewis6...@austin.rr.com wrote: Can someone please give me some pointers (my first time with a GPS module). A little hand-holding, pls. I bought three of these Rockwell D200 GPS receivers. (It's little GPS PWB with an antenna connector and pins for connecting to the RS232- PC) All three 'appear' to work the same way (no apparent capture of satellites). Here's what I have: 1.VisualGPS installed and running. 2.A small USB-RS232 card installed and appears to be operational. 3.Small GPS active antenna plugged in. 4.VisualGPS monitor just repeatedly displays: $GPGGA,,0,00,,,*66 5.I think I understand this to be NMEA code to mean no satellites have been acquired. 6.The Rockwell D200 draws ~180ma (5V) with no antenna and ~190ma with the small active antenna plugged in. What am I doing wrong? Other than maybe cheap china gps' and antenna??? But it is what I could afford and thought it would be cheap to learn on. ___ time-nuts mailing 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] Getting my Rockwell D200 GPS to work
I made a mistake: I see that block IIR satellites have simple helix. Now I'm trying to locate the PDF where I saw the QFH for use on GPS satellites but maybe only the first generation had the QFH. On Sat, Jan 7, 2012 at 11:42 PM, Erno Peres erniepe...@aol.com wrote: Don, the LabMon sw running only under DOS system..! rgds Ernie -Original Message- From: Don Lewis dlewis6...@austin.rr.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com; shalimr9 shali...@gmail.com Sent: Sat, Jan 7, 2012 6:30 pm Subject: Re: [time-nuts] Getting my Rockwell D200 GPS to work Ernie: Do you have a link, pls, ...to LM49 that will work with WindowsXP? hanks, ...-Don -- Original Message- rom: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On ehalf Of Erno Peres ent: Saturday, January 07, 2012 8:40 AM o: shali...@gmail.com; time-nuts@febo.com ubject: Re: [time-nuts] Getting my Rockwell D200 GPS to work i Don, this type of receiver sometimes need a good 15-20 min to find their place... hey are not very sensitive... lso if the receiver comes-up in NMEA mode then they probably used a spec pplication and it s much better to config the 20 pin connectors to Rockwell-binary ode and use the LabMon 49 software until the receiver alive and then ou can config back to NMEA mode. Rgds Ernie. Original Message- rom: shalimr9 shali...@gmail.com o: Time-Nuts time-nuts@febo.com ent: Sat, Jan 7, 2012 3:21 pm ubject: Re: [time-nuts] Getting my Rockwell D200 GPS to work test all my GPS receivers with a hockey puck type antenna attached to the all my hamshack, which is upstairs, but under the ceiling and the roof and I ave ver had one fail to lock within reasonable time. With this setup, hunderbolts casionally go on holdover, but never for very long. f course, when I plug them in the external Symmetricom antenna, they ypically e more satellites and don't go into holdover. am in Northwest Florida, so probably at a lower latitude than most of you, o e same setup farther north may not work as well. idier KO4BB ent from my BlackBerry Wireless thingy while I do other things... Original Message- om: Azelio Boriani azelio.bori...@screen.it nder: time-nuts-boun...@febo.com te: Sat, 7 Jan 2012 02:00:21 : Discussion of precise time and frequency measurementtime-nuts@febo.com ply-To: Discussion of precise time and frequency measurement time-nuts@febo.com bject: Re: [time-nuts] Getting my Rockwell D200 GPS to work bsolutely yes, the antenna must see the sky, not the ceiling. Even very nsitive GPS receivers must have a good view of the sky for the first fix, en you can bring the antenna indoor. You can try positioning the antenna ry near a window for just a test but better a good view. The car roof is ay but you must wait several minutes (12 minutes at most) to let the ceiver download the almanac. n Sat, Jan 7, 2012 at 1:54 AM, Don Lewis dlewis6...@austin.rr.com wrote: Maybe I didn't take positioning seriously. The antenna is currently on a shelf above my workbench, there is a ceiling and an upstairs above it. Then the roof. Is it very critical to be outside in order to 'see' the sky? I did take it out once and set the antenna on my car roof, but still no satellites. -Don - -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of bownes Sent: Friday, January 06, 2012 6:49 PM To: Discussion of precise time and frequency measurement Cc: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Getting my Rockwell D200 GPS to work Step one...is the antenna in a location where it can see they sky? Sorry if it is a stupid question but you already said it was plugged in. :) On Jan 6, 2012, at 19:24, Don Lewis dlewis6...@austin.rr.com wrote: Can someone please give me some pointers (my first time with a GPS module). A little hand-holding, pls. I bought three of these Rockwell D200 GPS receivers. (It's little GPS PWB with an antenna connector and pins for connecting to the RS232- PC) All three 'appear' to work the same way (no apparent capture of satellites). Here's what I have: 1.VisualGPS installed and running. 2.A small USB-RS232 card installed and appears to be operational. 3.Small GPS active antenna plugged in. 4.VisualGPS monitor just repeatedly displays: $GPGGA,,0,00,,,*66 5.I think I understand this to be NMEA code to mean no satellites have been acquired. 6.The Rockwell D200 draws ~180ma (5V) with no antenna and ~190ma with the small active antenna plugged in. What am I doing wrong? Other than maybe cheap china gps' and antenna
Re: [time-nuts] Thunderbolt? (re simple gpsdo.) capacitors
OK, note taken. Usually large capacitors are not available with tantalum dielectric, it seems that the last is a 1000uF 6.3V. On Fri, Jan 6, 2012 at 6:54 PM, Bob Camp li...@rtty.us wrote: Hi Oddly enough, if you use a tantalum electrolytic as C2, it's not very happy in that circuit. Their leakage with low voltages on them can be pretty nasty. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Thursday, January 05, 2012 5:50 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Thunderbolt? (re simple gpsdo.) capacitors In message CAL8XPmO76XuTETZC=33_v2YWuJGcw8gCvtTDHyae6E4MFb18=g...@mail.gmail.com , Azelio Boriani writes: I have googled extensively trying to find something about the dual capacitor method of reducing the leakage current... nothing found. Please, can you indicate anything for me to learn more? It is very simple: R1 charges C1 to the DC potential and therefore C2 sees (almost) no DC voltage, which means (almost) no leakage current. C2 is still a capacitor for any AC or dV component. I belive I picked this trick up from a datasheet or app-note relating to precision voltage references. Poul-Henning [Some op-amp] -+-R2-+-- || | - C2 | - || +---||---+ R1 | | - C1 - | GND -- 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] Question re neutrinos and GPS
Amen. On Sat, Jan 7, 2012 at 1:04 AM, Mike S mi...@flatsurface.com wrote: On 1/6/2012 6:20 PM, iov...@inwind.it wrote: Now I read on another list, in which the subject is not timekeeping and from a respectable author, that: The GPS is very unlikely to give an accurate speed for anything near the speed of light.. Respectable author? What, does he think they're strapping Garmins to neutrinos to measure their speed? His statement is simply ignorant. ___ time-nuts mailing 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] Getting my Rockwell D200 GPS to work
Try this: http://ke6mto.files.wordpress.com/2010/07/gps2a.pdf but forst here: http://www.weirdstuff.com/cgi-bin/item/20164 On Sat, Jan 7, 2012 at 1:24 AM, Don Lewis dlewis6...@austin.rr.com wrote: Can someone please give me some pointers (my first time with a GPS module). A little hand-holding, pls. I bought three of these Rockwell D200 GPS receivers. (It's little GPS PWB with an antenna connector and pins for connecting to the RS232- PC) All three 'appear' to work the same way (no apparent capture of satellites). Here's what I have: 1. VisualGPS installed and running. 2. A small USB-RS232 card installed and appears to be operational. 3. Small GPS active antenna plugged in. 4. VisualGPS monitor just repeatedly displays: $GPGGA,,0,00,,,*66 5. I think I understand this to be NMEA code to mean no satellites have been acquired. 6. The Rockwell D200 draws ~180ma (5V) with no antenna and ~190ma with the small active antenna plugged in. What am I doing wrong? Other than maybe cheap china gps' and antenna??? But it is what I could afford and thought it would be cheap to learn on. Thanks for your help. -Don ___ time-nuts mailing 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] Question re neutrinos and GPS
And let me say this in italian: Antonio, ma chi ha detto 'sta fesseria? On Sat, Jan 7, 2012 at 1:24 AM, Azelio Boriani azelio.bori...@screen.itwrote: Amen. On Sat, Jan 7, 2012 at 1:04 AM, Mike S mi...@flatsurface.com wrote: On 1/6/2012 6:20 PM, iov...@inwind.it wrote: Now I read on another list, in which the subject is not timekeeping and from a respectable author, that: The GPS is very unlikely to give an accurate speed for anything near the speed of light.. Respectable author? What, does he think they're strapping Garmins to neutrinos to measure their speed? His statement is simply ignorant. ___ time-nuts mailing 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] Question re neutrinos and GPS
...I cannot find that weird text using Google... Antonio, ti ricordi il tunnel della Gelmini? Ecco e' la stessa cosa! On Sat, Jan 7, 2012 at 1:30 AM, Azelio Boriani azelio.bori...@screen.itwrote: And let me say this in italian: Antonio, ma chi ha detto 'sta fesseria? On Sat, Jan 7, 2012 at 1:24 AM, Azelio Boriani azelio.bori...@screen.itwrote: Amen. On Sat, Jan 7, 2012 at 1:04 AM, Mike S mi...@flatsurface.com wrote: On 1/6/2012 6:20 PM, iov...@inwind.it wrote: Now I read on another list, in which the subject is not timekeeping and from a respectable author, that: The GPS is very unlikely to give an accurate speed for anything near the speed of light.. Respectable author? What, does he think they're strapping Garmins to neutrinos to measure their speed? His statement is simply ignorant. ___ time-nuts mailing 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] Getting my Rockwell D200 GPS to work
Absolutely yes, the antenna must see the sky, not the ceiling. Even very sensitive GPS receivers must have a good view of the sky for the first fix, then you can bring the antenna indoor. You can try positioning the antenna very near a window for just a test but better a good view. The car roof is okay but you must wait several minutes (12 minutes at most) to let the receiver download the almanac. On Sat, Jan 7, 2012 at 1:54 AM, Don Lewis dlewis6...@austin.rr.com wrote: Maybe I didn't take positioning seriously. The antenna is currently on a shelf above my workbench, there is a ceiling and an upstairs above it. Then the roof. Is it very critical to be outside in order to 'see' the sky? I did take it out once and set the antenna on my car roof, but still no satellites. -Don - -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of bownes Sent: Friday, January 06, 2012 6:49 PM To: Discussion of precise time and frequency measurement Cc: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Getting my Rockwell D200 GPS to work Step one...is the antenna in a location where it can see they sky? Sorry if it is a stupid question but you already said it was plugged in. :) On Jan 6, 2012, at 19:24, Don Lewis dlewis6...@austin.rr.com wrote: Can someone please give me some pointers (my first time with a GPS module). A little hand-holding, pls. I bought three of these Rockwell D200 GPS receivers. (It's little GPS PWB with an antenna connector and pins for connecting to the RS232- PC) All three 'appear' to work the same way (no apparent capture of satellites). Here's what I have: 1.VisualGPS installed and running. 2.A small USB-RS232 card installed and appears to be operational. 3.Small GPS active antenna plugged in. 4.VisualGPS monitor just repeatedly displays: $GPGGA,,0,00,,,*66 5.I think I understand this to be NMEA code to mean no satellites have been acquired. 6.The Rockwell D200 draws ~180ma (5V) with no antenna and ~190ma with the small active antenna plugged in. What am I doing wrong? Other than maybe cheap china gps' and antenna??? But it is what I could afford and thought it would be cheap to learn on. Thanks for your help. -Don ___ time-nuts mailing 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] FE-5680A performance - 1 PPS output issue
If you use a Tektronix TDS series scope you can set the acquiring to peak detect instead of sample to let the PPS be visible even for long timebase run. That is: usually, with the trigger set to normal and the timebase to 100nS/div or 1uS/div you can see the PPS anyway. If you set the timebase to 100mS/div then you can no longer see the pulse even if the trigger triggers the scan: setting the acquire to peak detect then the pulse returns visible and you can see the repetition rate. On Thu, Jan 5, 2012 at 7:17 PM, Chris Albertson albertson.ch...@gmail.comwrote: On Thu, Jan 5, 2012 at 9:46 AM, beale be...@bealecorner.com wrote: I think there is something funny about the 1 PPS output on pin 6 from the currently available cheap FE-5680A units. I have three of these units. On one unit, on one occasion, I did observe a logic-level 1 PPS pulse, exactly 1 microsecond wide. But after a power cycle it never came back, although the unit indicates a locked condition, and is apparently working. The other two units also seem to work (10 MHz output OK, lock OK) but I have never seen a 1 PPS signal on pin 6 from them. My Tek TDS-210 is easily capable of triggering on and displaying a 1 usec pulse. Is it possible the pulse appears only after a RS-232 command, or after some other special condition? I think the signal is there, it is just very small I tried again this morning. On mine the pulse is there but it's very weak. I can't see it one the scope but I can see the trigger light flash every second if I work to set it just right. I also see an about 0.3V peak to peak, about 60MHz sine wave. I can get the scope to trigger and display the sine wave just fine. I have to use a 10X scope probe or I load the signal to millivolts The PPS signal coming from my Oncore GPS is easy to see on my scope and even on a DMM set to DC Volts The FE-5680's PPS is not usable directly with my counter, I have to amplify it then set the counter to 10X attenuation then mess with the trigger setting so it does not see the 60MHz signal. Maybe I'm lucky that my scope has a BNC output on the back for the vertical amplifier, so I can apply a 20MHz low pass filter and about 20X voltage gain. The documentation I have says pin 6 is N/C but it looks like there is a way to extract a usable PPS but I think I'm going to need and LC filter, some op amps and a one-shot and a TTL level driver. My guess is that pin 6 is either some kind of engineering test/diagnostic signal not intended to use used or the signal is an accident ---Original Message--- From: David davidwh...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] FE-5680A performance Sent: 05 Jan '12 07:49 On Thu, 05 Jan 2012 01:44:13 -0800, Hal Murray hmur...@megapathdsl.net wrote: albertson.ch...@gmail.com said: Have an older Tek 465 scope that is in only fair shape and I see nothing on that pin but milivolt level sine wave of about 60MHz. I can't set the scope to show any hint of a PPS ... I do have a 465. You should be able to see a 1 uSec PPS. 60MHz is about a 6nS rise time and is easily fast enough to see it. Now turn up the Intensity until you can see the pulse. It might help to turn down the room lights. This is the problem. With a 1 second repetition rate, the brightness is going to be very low. The old ways of viewing such a low repetition rate signal include using a hood or dark room, special CRT phosphors, photographic film, MCP (micro channel plate) intensified CRTs, and of course analog storage and later digital storage. ___ time-nuts mailing 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. ___ time-nuts mailing 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] Navsync CW12 - More Info
Great, don't forget to specify what reference your measurements were made from (or did I miss anything from your posts?). We use the CW12 PPS for our GPSDOs. On Thu, Jan 5, 2012 at 6:57 PM, Ed Palmer ed_pal...@sasktel.net wrote: Okay, I've cooled off - a bit. The bottom line is that the 10 MHz output of the CW12 isn't appropriate for what I wanted to do. Ah, the joys of reading and understanding a spec sheet! But let's not throw out the baby with the bathwater. Although the 10 MHz output has it's issues for typical Time-Nut applications, the 1 PPS output is great. Here are some measurements that I've made over the past few years on a few GPS receivers and a couple of GPSDOs. I measure 1000 periods of the 1 PPS and look at the results. Every run gives somewhat different results so I've shown some typical ranges. These measurements were made with an HP 5372A. YMMV. Device .. Std Dev (ns) Range (max-min)(ns) ... Device Type Navsync CW12 4 - 5 .. 20 - 25 ... GPS Rcvr Motorola UT+ 40 - 55 95 - 110 .. GPS Rcvr * see below Rockwell Jupiter 10 50 ... GPS Rcvr ** Motorola M12M ... 10 - 15 40 - 60 ... GPS Rcvr Trimble Thunderbolt . 0.4 - 0.5 .. 2 - 4 . GPSDO HP Z3801A ... 0.3 2 . GPSDO*** * Most of my UT+ 'range' results were in this group, but there were a few at 20 - 30. ** Only one result. *** Only one result. I need to do more testing on the Z3801A As you can see, the Navsync CW12 is by far the best of the GPS Receivers, but nowhere near as good as the GPSDOs. However, imagine using the CW12 to discipline a good OCXO to build your own GPSDO. Or using it to discipline a PRS10 Rubidium or X72 Rubidium oscillator. You can't do it with the 10 MHz output, but the 1 PPS output is another story. 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.
Re: [time-nuts] Navsync CW12 - More Info
OK, thank you. On Thu, Jan 5, 2012 at 8:29 PM, Ed Palmer ed_pal...@sasktel.net wrote: Do you mean the reference oscillator for the 5372A? That was the internal 10811 OCXO. Over a 1000 sec. run, drift wouldn't have any affect on these numbers. Ed On 1/5/2012 12:54 PM, Azelio Boriani wrote: Great, don't forget to specify what reference your measurements were made from (or did I miss anything from your posts?). We use the CW12 PPS for our GPSDOs. On Thu, Jan 5, 2012 at 6:57 PM, Ed Palmered_pal...@sasktel.net wrote: Okay, I've cooled off - a bit. The bottom line is that the 10 MHz output of the CW12 isn't appropriate for what I wanted to do. Ah, the joys of reading and understanding a spec sheet! But let's not throw out the baby with the bathwater. Although the 10 MHz output has it's issues for typical Time-Nut applications, the 1 PPS output is great. Here are some measurements that I've made over the past few years on a few GPS receivers and a couple of GPSDOs. I measure 1000 periods of the 1 PPS and look at the results. Every run gives somewhat different results so I've shown some typical ranges. These measurements were made with an HP 5372A. YMMV. Device .. Std Dev (ns) Range (max-min)(ns) ... Device Type Navsync CW12 4 - 5 .. 20 - 25 ... GPS Rcvr Motorola UT+ 40 - 55 95 - 110 .. GPS Rcvr * see below Rockwell Jupiter 10 50 ... GPS Rcvr ** Motorola M12M ... 10 - 15 40 - 60 ... GPS Rcvr Trimble Thunderbolt . 0.4 - 0.5 .. 2 - 4 . GPSDO HP Z3801A ... 0.3 2 . GPSDO *** * Most of my UT+ 'range' results were in this group, but there were a few at 20 - 30. ** Only one result. *** Only one result. I need to do more testing on the Z3801A As you can see, the Navsync CW12 is by far the best of the GPS Receivers, but nowhere near as good as the GPSDOs. However, imagine using the CW12 to discipline a good OCXO to build your own GPSDO. Or using it to discipline a PRS10 Rubidium or X72 Rubidium oscillator. You can't do it with the 10 MHz output, but the 1 PPS output is another story. 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. ___ time-nuts mailing 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? (re simple gpsdo.) capacitors
I have googled extensively trying to find something about the dual capacitor method of reducing the leakage current... nothing found. Please, can you indicate anything for me to learn more? Thank you On Thu, Jan 5, 2012 at 9:18 PM, WarrenS warrensjmail-...@yahoo.com wrote: Yes almost as long as you include ONE more Resistor, R2 added below. The dual cap thing does not get rid of leakage entirely, but close enough in most cases. That configuration is most useful for slow open loop filters when you want low leakage errors. It may be a bit of an overkill for a closed loop filters when a 10 % leakage would be tolerable. I tested a 10,000 sec TC filter using a 10 meg and 1000 uF, and got under 1% leakage error open loop. ws *** [time-nuts] Thunderbolt? (re simple gpsdo.) capacitors Poul-Henning Kamp phk at phk.freebsd.dk The leakage current noise I measured was way below insignificant when things are properly scaled. Couldn't the double condensor from voltage references trick be used to eliminate the leakage entirely ? [Some op-amp] -+-R2-+-- | | | - | - | | +---||---+ | - - | GND -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 ___ time-nuts mailing 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? (re simple gpsdo.) capacitors
... don't know but judging from the very simple ASCII schematic I'll say no because the lower capacitor is grounded. There is some sort of feedback I can't figure out, too simple that schematic. On Thu, Jan 5, 2012 at 11:27 PM, li...@lazygranch.com wrote: Perhaps the dual cap is a differential implementation of the filter/integrator. ___ time-nuts mailing 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? (re simple gpsdo.) capacitors
Thanks. Me too: now I got it, sort of bootstrap and now I see that R2 is needed because the real filter is R2*C2 and the leakage is not totally compensated if C1 has to move to a new value - R*C1R2*C2. On Fri, Jan 6, 2012 at 12:00 AM, paul swed paulsw...@gmail.com wrote: Poul Thanks have been kind of following this thread and the diagram did not make a lot of sense. I figured I missed part of the thread. But this clears it up nicely. Regards Paul. WB8TSL On Thu, Jan 5, 2012 at 5:49 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote: In message CAL8XPmO76XuTETZC=33_v2YWuJGcw8gCvtTDHyae6E4MFb18= g...@mail.gmail.com , Azelio Boriani writes: I have googled extensively trying to find something about the dual capacitor method of reducing the leakage current... nothing found. Please, can you indicate anything for me to learn more? It is very simple: R1 charges C1 to the DC potential and therefore C2 sees (almost) no DC voltage, which means (almost) no leakage current. C2 is still a capacitor for any AC or dV component. I belive I picked this trick up from a datasheet or app-note relating to precision voltage references. Poul-Henning [Some op-amp] -+-R2-+-- || | - C2 | - || +---||---+ R1 | | - C1 - | GND -- 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] Navsync CW-12 GPS Board - I don't believe it!!
You are right. We use the CW12 (timing version) and it behaves as you depicted. Of course there is also no holdover on its 10MHz output. Only the FTS125 (and similar) have first a fixed OCXO to drive the GPS receiver and then an OCXO to be aligned with the 10MHz to have a real 10MHz with holdover BUT, curiously enough, PPS comes always from the GPS receiver. Never tested the 10MHz being lower... now I'll try from the CW12 and from the FTS125. On Wed, Jan 4, 2012 at 9:50 AM, saidj...@aol.com wrote: These Conner Winfield (Navsync) parts are not GPS Disciplined Oscillators, many folks are initially fooled by this. They use digital phase hopping techniques to generate something close to 10MHz. You can see the 10MHz 100ns phase jump around on a scope. I believe their FTS250 and 125 modules use this output to drive a VCXO cleanup oscillator to try to remove the phase jumps, phase noise, and spurs. From their literature: This ... module has an onboard, programmable NCO oscillator that outputs a synthesized frequency up to 30MHz steered by a GPS receiver So it's a noisy digitally steered NCO, not a clean phase locked analog oscillator. The frequency error can be up to +/-100ppb according to their literature while the unit is trying to align itself to GPS (that's a massive drift of 100ns per second!) I believe the uBlox 6T frequency output is generated in a similar manner. Many folks try these GPS NCO's because they are cheaper than real GPSDO's and seem to work similarly, then find out they don't perform as well... In a message dated 1/4/2012 00:32:33 Pacific Standard Time, hmur...@megapathdsl.net writes: I compared the OCXO output to the 10 MHz output of both a Z3801A and a Tbolt and discovered that the CW-12's 10 MHz output is about 1.5e-11 (i.e. 1.5e-4 Hz) low in frequency. I emailed Navsync and they replied: The CW12 Motorola Binary and NMEA versions both do not phase align the frequency output so the long term drift that Ed is seeing is expected. Is there a timing version that does the right thing? Incredible. It's 'steered by the GPS receiver' - that's a direct quote from the data sheet and the user manual - but it's not quite on frequency and that's fine with them. Is it consistently off that much, or does it wander around the right answer? (perhaps because there is a small dead band in the phase detector) -- These are my opinions, not necessarily my employer's. 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] Navsync CW-12 GPS Board - I don't believe it!!
The output frequency is programmable: try $PRTHS,FRQD,xx.xxxcrlf where xx.xxx is the desired(?) frequency in MHz with 3 decimal places (they say for 10KHz set 0.010). Maybe the slight offset is due to the NCO based on the chipping rate of 10.23MHz: 10.23MHz/2^32*4198404003 is 9.783MHz On Wed, Jan 4, 2012 at 3:49 PM, Mike S mi...@flatsurface.com wrote: On 1/4/2012 9:29 AM, Ed Palmer wrote: What's the point of saying that it's steered by GPS when it's off-frequency. What does that even mean? Does it steer the frequency to keep the error constant? If it's constant, maybe they just need to re-spec it as having a 9.985 MHz output. :-) ___ time-nuts mailing 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] Navsync CW-12 GPS Board - I don't believe it!!
Yes, the error is greater... then maybe the clock of the NCO is not the chipping rate. In the FTS125 the clock for the RX is sourced by a 20MHz OFC5DJ3 fixed OCXO but this doesn't imply that the CW12 has a 20MHz clock... at the moment no other clue comes to mind. On Wed, Jan 4, 2012 at 5:35 PM, Ed Palmer ed_pal...@sasktel.net wrote: On 1/4/2012 9:00 AM, Azelio Boriani wrote: The output frequency is programmable: try $PRTHS,FRQD,xx.xxxcrlf where xx.xxx is the desired(?) frequency in MHz with 3 decimal places (they say for 10KHz set 0.010). Unfortunately, the frequency is programmable only with the NMEA software load. I'm using the Motorola load. If I reflashed to the NMEA load I'd lose the TRAIM functionality. In any case, the setting doesn't have nearly enough resolution to correct such a small error. Maybe the slight offset is due to the NCO based on the chipping rate of 10.23MHz: 10.23MHz/2^32*4198404003 is 9.783MHz Your calculation gives an error of 2.17 mHz. I measured an error of .15 mHz. I tried playing with variations on your calculation but couldn't find one that fit. It would be interesting to find out why the error exists, but I don't think we will ever know for sure. 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.
Re: [time-nuts] Navsync CW-12 GPS Board - I don't believe it!!
Interesting...now i wonder how they can steer the frequency. Usually in C/A GPS receivers the oscillator is not corrected and any drift is accounted for in software: usually you see geographic coordinates out of the receiver. In the Motorola receiver they say the PPS has the granularity of the oscillator (and the negative sawtooth can be used to compensate and obtain greater precision) so no oscillator correction is necessary either: just place the rise of the PPS at the nearest clock transition (and the residual went in the previous sawtooh). Now to correct the frequency output of a CW12 without adjusting the clock the only way is to change the phase accumulator step: maybe the phase accumulator in the CW12 is greater than 32bit... On Wed, Jan 4, 2012 at 6:13 PM, Said Jackson saidj...@aol.com wrote: Hi Ed, Since the oscillator is typically free-running in an NCO, and periodically corrected by phase drops to stay on frequency the error you are seeing may be caused be the offset in your crystal, combined with the limited digital resolution of the NCO trying to correct for this offset. If this is the case, your measured error would change with temperature. Does it do that? If yes, the NCO resolution is not fractionally corrected all the way. Replacing the on board Tcxo with an ocxo hand-tuned to the correct frequency would help, but that sort of defeats the purpose of the product.. Bye, Said Sent from my iPad On Jan 4, 2012, at 7:05, Ed Palmer ed_pal...@sasktel.net wrote: On 1/4/2012 8:49 AM, Mike S wrote: On 1/4/2012 9:29 AM, Ed Palmer wrote: What's the point of saying that it's steered by GPS when it's off-frequency. What does that even mean? Does it steer the frequency to keep the error constant? If it's constant, maybe they just need to re-spec it as having a 9.985 MHz output. :-) Ooo, it's a GPS steered offset generator! Now I get it! :-) 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] crunching numbers from XOR phase detector
You're right there are 3 phase detectors in the 4046: RS and JK flip-flops and and XOR gate. On Wed, Jan 4, 2012 at 6:21 PM, Chris Albertson albertson.ch...@gmail.comwrote: On Wed, Jan 4, 2012 at 12:58 AM, Hal Murray hmur...@megapathdsl.net wrote: Neat. Thanks for sharing. With a XOR, you can't tell which input is higher frequency. I think you can fix that with a second XOR and a delay line. I think you can build a PFD or Phase Frequency Detector with three or four flip flops. This avoid using the delay line and works over a wide range. If I'm not mistaken there is a PFD inside the 74HC4046. It uses flip flops. Be sure to look at the 74HC type not the cd4046. The 75hc type works up to 18MHz. 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] Efratom FRK - no 10Mhz oscillator
circuit. If that doesn't work, then the oscillator circuit is the problem - if it does work, then remove the 10 pF cap and connect the xtal directly between E7 and E8 - if it still works, it's almost certainly a bad xtal. If it worked with the 10 pF cap but not with the E8 connection, then check the control voltage (E9: 0.5V-17V) - if that looks good, then suspect the frequency control circuit. If it's bad, then try hooking it to +5V to verify the oscillator and then troubleshoot the servo board. Regards, Pete On Wed, Dec 21, 2011 at 5:00 AM, Azelio Boriani azelio.bori...@screen.it wrote: 10MHz crystals used in OCXO are designed for the temperature of the oven so it is not possible to find an off-the-shelf suitable crystal. Better find a crystal coming from an OCXO. On Tue, Dec 20, 2011 at 7:10 PM, Peter Bellbell.pe...@gmail.com wrote: Hi, Don It's been quite a while since I worked on a FRK, but from what I remember the only signals going to that oscillator board are power and the control voltage. It might be worth checking the control voltage to see if it's at a plausible value (nominal is 5V, spec range is 1V-16V, IIRC) - if you have a spare xtal around, just try connecting it to the pins on the PCB and see if it starts up. I'm not aware of the xtals being failure prone - I have seen one FRK with a bad one, but having seen the condition of the system it was removed from, that was clearly impact damage. Regards, Pete On Wed, Dec 21, 2011 at 1:29 AM, Don Lewisdlewis6...@austin.rr.com wrote: A little help, pls, from the more experienced. This is my first time into one of these .I have listened and learned from you' all for some time, though. It can be intimidating in this close-packed FRK. I am trying to bring up an Efratom FRK I have had for a while. The 10 MHz oscillator does not start upon power on. Any ideas where to look? I have done the following: * I have it opened-up and applied 24vDC and the current starts up initially at 1.45 amp and slowly goes down to ~.6- .8 amps. * Since I have no 10 MHz output, .so I looked at the oscillator board and nothing out from it. * The 17 volt dc supply-rail is good, and the VCO input signal to the varacter control-circuitry is constantly ramping up and down slowly between ~1volt and ~15 volts. * All the transistors in the oscillator circuit seem ok with a VOM, ..and when I purposely inject a 10Mhz signal into the collector of the 'oscillator' transistor (Q3), .I do get a clean 10Mhz out of the unit (of course it won't lock), .and I haven't even been into the rest of the unit. * I think the crystal is bad, .I took the cover off the crystal oven, it 'looks' ok, . and the crystal heater in the oven is heating and regulating. Any ideas? .does the 10 MHz crystal in these have a history of failing? Can I get a replacement crystal for it easily? How can I test this crystal for pass/fail? Thanks, .just my first test of the waters as a fledging time-nut. Don Lewis Austin, TX ___ time-nuts mailing 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] Navsync CW-12 GPS Board - I don't believe it!!
Interesting... this explains why they use a 20MHz OCXO (without EFC) in the FTS125 to clock the receiver that has an NCO steered that clocks a PLL that synchronize another OCXO (with EFC). Yes, I have opened up an FTS125. On Wed, Jan 4, 2012 at 8:32 PM, Ed Palmer ed_pal...@sasktel.net wrote: On 1/4/2012 11:13 AM, Said Jackson wrote: Hi Ed, Since the oscillator is typically free-running in an NCO, and periodically corrected by phase drops to stay on frequency the error you are seeing may be caused be the offset in your crystal, combined with the limited digital resolution of the NCO trying to correct for this offset. If this is the case, your measured error would change with temperature. Does it do that? Yes, it does. Cooling the unit by using a heatsink causes a significant increase in the output frequency. The change is large enough to be obvious on an oscilloscope where one channel is the 10 MHz from the Z3801A and the other channel is the 10 MHz from the CW12. If yes, the NCO resolution is not fractionally corrected all the way. Replacing the on board Tcxo with an ocxo hand-tuned to the correct frequency would help, but that sort of defeats the purpose of the product.. Yes, it appears that the CW12 is just not appropriate for what I was thinking of doing. However, to be fair, the 1 PPS output is much better than the older receivers. I'll have to think about where I go from here. 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.
Re: [time-nuts] Navsync CW-12 GPS Board - I don't believe it!!
It depends on the option ordered: the FTS125s we have are FTS125-COO (double OCXO) the -CTV option is the TCXO/VCXO option, there is the -COV option too. On Wed, Jan 4, 2012 at 10:08 PM, saidj...@aol.com wrote: Hi Ed, sorry to hear that, contact me off-list and I will try to solve your problem. I tried sending you an email, but my mails must be getting filtered by your spam filter.. bye, Said In a message dated 1/4/2012 11:33:14 Pacific Standard Time, ed_pal...@sasktel.net writes: On 1/4/2012 11:13 AM, Said Jackson wrote: Hi Ed, Since the oscillator is typically free-running in an NCO, and periodically corrected by phase drops to stay on frequency the error you are seeing may be caused be the offset in your crystal, combined with the limited digital resolution of the NCO trying to correct for this offset. If this is the case, your measured error would change with temperature. Does it do that? Yes, it does. Cooling the unit by using a heatsink causes a significant increase in the output frequency. The change is large enough to be obvious on an oscilloscope where one channel is the 10 MHz from the Z3801A and the other channel is the 10 MHz from the CW12. If yes, the NCO resolution is not fractionally corrected all the way. Replacing the on board Tcxo with an ocxo hand-tuned to the correct frequency would help, but that sort of defeats the purpose of the product.. Yes, it appears that the CW12 is just not appropriate for what I was thinking of doing. However, to be fair, the 1 PPS output is much better than the older receivers. I'll have to think about where I go from here. 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] Navsync CW-12 GPS Board - I don't believe it!!
The OCXO used are marked OFC3DJ1AA (fixed) and OVC3CE1AA (with EFC) but no data I have found: only OVC5 and OFC5 series. On Wed, Jan 4, 2012 at 11:04 PM, saidj...@aol.com wrote: yes, see that now, looks like the OCXO option about doubles the price of the unit on Digikey.. In a message dated 1/4/2012 13:56:59 Pacific Standard Time, azelio.bori...@screen.it writes: It depends on the option ordered: the FTS125s we have are FTS125-COO (double OCXO) the -CTV option is the TCXO/VCXO option, there is the -COV option too. ___ time-nuts mailing 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] FE-5680A performance
Wow, have you a TSC5125A? Lucky you... On Wed, Jan 4, 2012 at 11:12 PM, saidj...@aol.com wrote: Hi Graham, the TSC5125A has auto-scaled the plot to 2E-04Hz fractional frequency from 10MHz, or in other words one vertical division is 2E-011 at 10MHz, or 20 parts per trillion, or 0.0002Hz error. I also don't like the way the TSC shows the frequency, and the fact that you can only capture about 9 minutes of information for some reason. Why not show 24 hours or 48 hours of data here? With this in mind, the FE5680A wanders around about +/-6E-011 max in this plot. Hope that helps, Said In a message dated 1/4/2012 13:41:07 Pacific Standard Time, time...@austin.rr.com writes: On 1/4/2012 3:18 PM, _SAIDJACK@aol.com_ (mailto:saidj...@aol.com) wrote: Here is a set of performance plots for the FE5680A that we had measured before. Performance has improved significantly, ADEV is now in the xE-012's. Phase noise and spurs are worse than originally reported, they kind of suck. Frequency over time looks quite nice though, definitely quite useful as a frequency reference. bye, Said Said: Your vertical units per division for the frequency plot don't make sense. Please re-check and let us know. Thanks, --- Graham ___ time-nuts mailing 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
Yes, no TRAIM on the uBlox but I haven't seen the TRAIM alarm kicking in on the Motorola/iLotus M12M so I think that for our experiments the uBlox is fine. Even better, have the two: the Motorola/iLotus and the uBlox. On Tue, Jan 3, 2012 at 2:37 AM, k4...@aol.com k4...@aol.com wrote: The problem with the U-Blox receiver is that it does not have TRAIM as does the Motorola UT+ and some others that are made specifically for timing applications. Just be aware of that when trying to decide on which receiver to use. 73's Doug, K4CLE Connected by DROID on Verizon Wireless -Original message- From: Azelio Boriani azelio.bori...@screen.it To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Mon, Jan 2, 2012 09:42:54 GMT+00:00 Subject: Re: [time-nuts] eBay Ublox I have experience with the LEA5-T in timing mode and, and of course, it works as expected. You can set not only how many samples to take but also the variance to achieve before starting the position-hold/timing mode. On Sun, Jan 1, 2012 at 10:44 PM, Bob Camp li...@rtty.us wrote: Hi I haven't used that particular unit. I have played with similar units. That's pretty old stuff, and does not appear to have timing software in it. I suspect you would do *much* better (both performance and price wise) with something newer. Bob On Dec 31, 2011, at 7:41 PM, lstosk...@cox.net lstosk...@cox.net wrote: UBLOX TIM-CJ module TIM-ST GPS engine Jupiter footprint anyone have any experience with this for timing application? N0UU ___ time-nuts mailing 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] eBay Ublox
Oh no, I was speaking always of timing version GPSes. For non timing version GPSes you loose the position-hold timing mode too. uBlox has T-RAIM in the LEA6-T version. In the block diagram of uBlox GPSes they show the option XTAL/TCXO for their receivers. Although not stated, I believe that the TCXO option is reserved for the timing version hardware. On Tue, Jan 3, 2012 at 6:16 PM, Bob Camp li...@rtty.us wrote: Hi I believe that more than just TRAIM goes away when you get the not a T version of the uBlox receivers. You probably should check the jitter on the 1 pps output ... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Tuesday, January 03, 2012 5:13 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] eBay Ublox Yes, no TRAIM on the uBlox but I haven't seen the TRAIM alarm kicking in on the Motorola/iLotus M12M so I think that for our experiments the uBlox is fine. Even better, have the two: the Motorola/iLotus and the uBlox. On Tue, Jan 3, 2012 at 2:37 AM, k4...@aol.com k4...@aol.com wrote: The problem with the U-Blox receiver is that it does not have TRAIM as does the Motorola UT+ and some others that are made specifically for timing applications. Just be aware of that when trying to decide on which receiver to use. 73's Doug, K4CLE Connected by DROID on Verizon Wireless -Original message- From: Azelio Boriani azelio.bori...@screen.it To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Mon, Jan 2, 2012 09:42:54 GMT+00:00 Subject: Re: [time-nuts] eBay Ublox I have experience with the LEA5-T in timing mode and, and of course, it works as expected. You can set not only how many samples to take but also the variance to achieve before starting the position-hold/timing mode. On Sun, Jan 1, 2012 at 10:44 PM, Bob Camp li...@rtty.us wrote: Hi I haven't used that particular unit. I have played with similar units. That's pretty old stuff, and does not appear to have timing software in it. I suspect you would do *much* better (both performance and price wise) with something newer. Bob On Dec 31, 2011, at 7:41 PM, lstosk...@cox.net lstosk...@cox.net wrote: UBLOX TIM-CJ module TIM-ST GPS engine Jupiter footprint anyone have any experience with this for timing application? N0UU ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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 to read Isotemp OXCO131 part numbers?
Yes, found others but, for example, we use the 131-40 and have the datasheet: can't find it from those URLs. You can find 131-42 131-45 and 131-1000, 1001, 1002 and so on. Our 131-40 was not made for us but decided to use it with the permission of the original customer to increase the order volume. On Tue, Jan 3, 2012 at 11:02 PM, gandal...@aol.com wrote: In a message dated 02/01/2012 23:53:41 GMT Standard Time, azelio.bori...@screen.it writes: Yes, seems difficult to find the differences but I've found at least the 131-2: http://w9fz.com/ham/OCXO131-2Spec.pdf -- Some more here. _http://www.isotemp.com/wp-content/uploads/2011/07/_ (http://www.isotemp.com/wp-content/uploads/2011/07/) and here. _http://www.isotemp.com/wp-content/uploads/2011/10/_ (http://www.isotemp.com/wp-content/uploads/2011/10/) Plus some other info on the associated pages to these links. Regards Nigel GM8PZR ___ time-nuts mailing 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
I have experience with the LEA5-T in timing mode and, and of course, it works as expected. You can set not only how many samples to take but also the variance to achieve before starting the position-hold/timing mode. On Sun, Jan 1, 2012 at 10:44 PM, Bob Camp li...@rtty.us wrote: Hi I haven't used that particular unit. I have played with similar units. That's pretty old stuff, and does not appear to have timing software in it. I suspect you would do *much* better (both performance and price wise) with something newer. Bob On Dec 31, 2011, at 7:41 PM, lstosk...@cox.net lstosk...@cox.net wrote: UBLOX TIM-CJ module TIM-ST GPS engine Jupiter footprint anyone have any experience with this for timing application? N0UU ___ time-nuts mailing 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] Z3801A EFC error
On the usual paybay site there are available some Z3815 with the E1938 oscillator. I have bought one and found the shielding of the Furuno GT74 GPS heavily rusted. Fortunately it is perfectly working and the seller says all are that way. It was the only item found with that type of OCXO. On Mon, Jan 2, 2012 at 8:22 PM, Robert Benward rbenw...@verizon.net wrote: To Jarl and others, A few months ago I wrote about my Z3801A having a EFC error and an inability to generate a lock. With the help of Jarl and others, I was able to correct the situation. I simply disassembled the double oven (what a mess!) and made a manual adjustment to the frequency. Note the fix was simple, but the oven disassembled is a nightmare. The connections to the internal oven is made via thin enameled wires laid upon what appears to be a long (18) foam rubber strip. The enameled wires are suitably spaced and held down onto the gasket with beige polyester tape. After years of use, the glue on the tape is failing and the gasket material loses integrity and rips as it is pealed back. As one peals the gasket, there are exit points for the outer oven heater and sensor, and if not careful these connections can be broken. The EFC and 10MHz connections are via very thin coax spaced among the enamels wires, and although more robust, I was still concerned about damage. All the enamel wires terminate at the oscillator base via feedthroughs, not the typical PCB edge card one finds on the instrument style 10811 oscillator. Probably an OEM style 10811. If anything gets damaged, I don't see why the enameled wires could not be replaced with the Teflon variety, along with a silicon grade foam rubber strip. The innermost insulation wraps the 10811 and looks like it should be a black foam rubber with adhesive back, but what I found looked more like black foam rubber with grease. They slid all over the place and the grease was quite messy. I don't know if the grease is normal or a breakdown of the old adhesive. Other than using some new Kapton tape for reassembly, I didn't change anything else when reassembling. During this fix, the 10MHz out was disconnected from the PCB and as I adjusted the output manually, I could see the EFC banging from one end to the other (between 0 and ~1,000,000 counts). I also confirmed the oscillator's EFC range of +/-2Hz I reconnected the 10MHz and made the manual adjustments. Luckily, my frequency counter had an ovenized oscillator which I had calibrated against the Z3801A before it failed, so I know I had a reasonable reference. I observed the EFC output and adjusted the frequency so I would get a middle range EFC number (~470K). Per Jarl's comments I was worried about the EFC settling point after I reassembled the double oven. Thinking about it, since the internal oven has a temperature control/setpoint, I thought adding additional heat via the outer oven should not change the temperature of the internal oven, but only change the duty cycle of the heater. Once I reassembled the outer oven, I noticed no significant change in the EFC numbers. Now I have a working Z3801A. I watched the EFC for several days and noticed it leveled out quite nicely. My next experiment was to see what duty cycling the Z3801 would do to the overall EFC. I wished to do this to see if I could have a locked 10MHz source without leaving the unit on day and night. This turned out to be a mistake. The Z3801 worked for a few days, but then it went into a holdover mode. I checked the output and it was gone, it seems the oscillator output is no more. After letting it cool down, the oscillator comes back, but dies within minutes. Any ideas on this would be appreciated. Off to my next problem: An HP E1938 hockey puck oscillator. I will leave this to another email. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
