Re: [time-nuts] BC637PCI and OCXO
Le 7 févr. 2014 à 00:18, d0ct0r a écrit : Hello, Does anybody seen any links to the information how to implement external OCXO to Symmetricom PCI TFP BC635/BC637 ? check the Symmetricom datasheets. You don't mention the version you are needing info for , IRIG/GPS.. Anyway, all that I glanced at show an Exr. 10MHz ref input on pin 1 of the sub-D 15 connector. Digital, 40% to 60% or sine, 0.5V to 8V p-p, 10kOhm. ex. http://www.symmetricom.com/resources/download-library/documents/datasheets/bc637pci-v2 -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] BC637PCI and OCXO
Magnus, What kind of problems did you have with it? I have a couple of BC635PCI boards that I've been using for a while with my own LabVIEW-based register driver. I've noticed some interesting behavior after board reset (loses lock for 8 sec to 3.5 min), and after changing the mode (disrupts lock/phase bits for ~5 sec and freq bit between 4-60 min). Rev H of the user's guide has the schematics if anybody needs them. -Bob On 02/06/2014 11:03 PM, Magnus Danielson wrote: The BC637PCI already have a VCXO onboard, but you add a OCXO on the outside to get much better results. It was the original poster that needed help. My problems with the BC637PCI was that one of my boards didn't respond completely as documented. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] BC637PCI and OCXO
I played with this around five or six years ago but unfortunately my notes from that time are likely to be buried somewhere still waiting to be scanned or indexed. All the necessary information though is in the user and SDK manuals, connections for the 10MHz external input and EFC output are on the 15 way I/O connector and there's even demo software which I'm pretty sure was all I used to make the necessary adjustments. One manual, pre Symmetricom, even has what looks to be a full set of schematics. I've just run the software again to check but it won't do much if it can't find the card so would need to fire up another PC with a spare slot to check further. I wasn't really happy at the time with my attempts to condition an external Vectron OCXO, it was certainly better than using the internal oscillator but there were some odd jumps and drifts using either which suggested these might be artifacts of the board itself rather than the Vectron OCXO. I've since acquired another BC637PCI, and want to try both again with other oscillators, but that's quite some way down a very long to do list, now reminded though I might take a quick look later:-) In the meantime, I have got copies of manuals and software etc and will get those zipped up today and make them available for download. Regards Nigel GM8PZR In a message dated 07/02/2014 03:36:46 GMT Standard Time, t...@patoka.org writes: Hello, Does anybody seen any links to the information how to implement external OCXO to Symmetricom PCI TFP BC635/BC637 ? -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Rb as source for ADEV?
Hi If you want one second ADEV (or something close to it) you need a beat note that’s above 1Hz. If one second is not of interest, then lower is fine. If you want to use a normal OCXO as the offset oscillator, you need to be inside it’s trim range (either high or low). That rules out anything much over 10 Hz at 10 MHz unless you have some unusual OCXO's. Most 10 MHz OCXO’s will tune a hertz or more off of 10 MHz. Digital Rb’s like the 5680 will make it a bit further if you pick which side you tune to. You are after another 3 or 4 digits ( ppb’s - ppt’s) . 10 Hz might (but won’t) get you another 6 digits. Any offset you get by tuning a good OCXO will do what you need to do. Yes there are other more complicated ways to do this. Yes they can get you to a lower floor. If you are looking at an Rb or most GPSDO’s, there’s no need for anything more complicated. 90% of it is audio and non-critical in terms of layout. If you did it on a real board and bought the parts in any sort of quantity, raw cost could be below $10 without the connectors. And before I get clobbered again, no I’m not trying to sell the boards. Bob On Feb 6, 2014, at 9:47 PM, Hal Murray hmur...@megapathdsl.net wrote: Bob Camp li...@rtty.us: Offset the local reference one hertz or so and let the 5334 do it’s thing. Any hints on how to get a good oscillator that's off by 1 Hz from 10 MHz? How did you pick 1 Hz? Is 10 Hz offset better? How about 0.1 Hz? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] How I got my FE-5680A to lock in Sydney, Australia
Hi, I second the idea about a mechanical issue. When I opened my FRS-C I found that one of the connector pins had never been soldered, it only made mechanical contact with the PBC. Perhaps it showed an intermittent failure and was retired with low hours. Ignacio EB4APL On 07/02/2014 3:54, Ed Palmer wrote: Hi Jim, On 2/6/2014 3:32 PM, Jamieson (Jim) Rowe wrote: Hi again folks, You may (or may not) recall that a month or so ago, I asked for any information that might be available regarding how to fix a ‘used’ FE-5680A rubidium module from China (via ebay) which was tested by the supplier in China as working OK, but would not seem to lock up to rubidium here in Sydney. There wasn’t a great deal of info available, it seems, so I kept on checking ideas myself – mostly with no luck. The module would never lock, but kept cycling back and forth between about 9.999770MHz and 10.36MHz – ‘searching’ for a lock, but never finding it. Anyway, a couple of days ago I was reading more about the operation of rubidium vapour oscillators, and noticed that the ‘filter cell’ is very sensitive to magnetic fields – hence the mu-metal shielding case, and also for the ‘C-tuning’ coil. And I wondered if the main reason why the FE-5680A had apparently worked in China, but wouldn’t lock up in Sydney (Australia) might be caused by the fact that Quangzhou (China) is in the northern hemisphere while I’m ‘down under’ in the southern hemisphere – where the earth’s field is presumably somewhat different, in terms of both strength and direction. So I decided to test this in a crude way, by inverting the FE-5680A and seeing what happened. And – lo and behold – it locked up within 2.5 minutes, and stayed locked until I turned off the power and let it go cold again. The next morning I applied power again, and within 3 minutes it locked up again with no problems. And it’s been locked up now for over 48 hours... My first thought was to make a typical 'down-under' joke and suggest you run the 5680A upside down, but you beat me to it! :) So it seems that the different magnetic field here may have been the problem – either that, or it may have received a ‘jolt’ in transit, which prevented in from locking unless it was inverted. But how do I tell which of these explanations is right, without ‘opening her up’ again and looking for some kind of subtle physical fault? Another idea: perhaps the mu-metal shield case had acquired a small dose of magnetisation in transit (via a physical shock, or from a strong field metal detector). I guess in this case that I would have to remove the two halves of the case, and bake them in a furnace to demagnetise them again. My very limited knowledge regarding mu-metal is that it is so magnetically 'soft' that it can't be magnetized. If it was somehow magnetized, inverting the unit wouldn't make any difference, would it? Or should I just run the FE-5680A upside down permanently – the simple but ‘crude’ answer? I don't believe for a second (pun intended) that the earth's magnetic field has any effect on the locking of your 5680A. It's just not strong enough. The same applies to the C-field which can only nudge the frequency one way or another by a small amount. Since flipping the unit DID make a difference, my money would be on a trivial, boring mechanical issue inside the unit. Could be a bad solder joint, broken wire, floating piece of debris, or something like that. Worst case might be a broken glue joint somewhere in the physics package. That could be ugly. I would definitely open it up and see if anything falls out. I’m not sure if this FE-5680A has the ‘C-tuning’ gizmo fitted, or wired up. Am I right in thinking that another approach might be to try varying the tuning via the RS-232C serial port? Does this work via the C-tuning coil anyway, or by tweaking the DDS? The RS-232 commands affect the DDS - assuming your unit does have one. It will have no effect on the locking, only on the output frequency. A few years ago I bought a dead Datum SLCR Rb standard. It's a cousin to the LPRO. I thought I'd learn some things by trying to fix it. The problem was intermittent. I tore it apart and found that one of the legs of the crystal had never been soldered! Never overlook the obvious. I hope a much more experienced time nut can provide a few answers, please. Maybe the blind leading the blind is a closer description. Ed Jim Rowe ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] BC637PCI and OCXO
Whilst sorting through my BC637PCI files earlier I realised for the first time that an ISO file I'd downloaded in 2010, described by Symmetricom as BC635/637 driver, is actually a full software and documentation CD, presumably what was then being supplied with new hardware. Ether that or I had been aware and it's something else that's slipped through the sieve:-) As well as the Windows SDK and more recent versions of the BC635 and BC637 demo software this file also contains later versions of the legacy demo software than I'd used previously, perhaps making most, if not all, of the earlier software obsolete, although the pre Symmetricom manuals, especially the one with the schematics, are certainly worth having. Now it's quite possible I'm the only one who wasn't aware of this, but in case it's not just me, and as I can't locate the original again to quote a URL, I've uploaded a file that contains this ISO, the extracted files from the same, plus my original collection of earlier software and documentation. This is quite a large file, approx 235MB, so for anyone who might only be interested in the earlier files I've also uploaded those as a smaller file of approx 52MB. BC637PCI_Full.rar 234.5 MB https://mega.co.nz/#!6dgVzBQI!A8y-qffQo4X5OYViTz97ZyiFn05zaPPfxCwoGLDu0Kg BC637PCI_Reduced.rar 50.2 MB https://mega.co.nz/#!iUQiwK7R!wyRPeBnkS4o1iADZGp7c-ZS6hHNbNqEEb8p1KKbr-ZU Any problems with the downloads or files please let me know and, as always, please feel free to upload elsewhere. Regards Nigel GM8PZR In a message dated 07/02/2014 03:36:46 GMT Standard Time, t...@patoka.org writes: Hello, Does anybody seen any links to the information how to implement external OCXO to Symmetricom PCI TFP BC635/BC637 ? -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] BC637PCI and OCXO
It seems I have first generation of that card. And I was thinking to use that card as a source of 1PPS and 10MHZ - not to feed it from another reference. I though it is possible to do some modding to replace VCXO by OCXO. PCI Board Revision ID : 18 (0x12), Firmware Version : DT10041V11 On 2014-02-07 03:00, mike cook wrote: Le 7 févr. 2014 à 00:18, d0ct0r a écrit : Hello, Does anybody seen any links to the information how to implement external OCXO to Symmetricom PCI TFP BC635/BC637 ? check the Symmetricom datasheets. You don't mention the version you are needing info for , IRIG/GPS.. Anyway, all that I glanced at show an Exr. 10MHz ref input on pin 1 of the sub-D 15 connector. Digital, 40% to 60% or sine, 0.5V to 8V p-p, 10kOhm. ex. http://www.symmetricom.com/resources/download-library/documents/datasheets/bc637pci-v2 -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- WBW, V.P. ___ time-nuts mailing 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] BC637PCI and OCXO
The information you need is more in the description of the software commands, this will tell you how to switch between the internal and external oscillators and how to vary the conditioning parameters and I'm pretty sure, although it's been a while so might be wrong, that some of the software contains menus to make this more straightforward. As long as what you have has already been configured as a BC637, ie existing firmware is aware that the GPS module is fitted, then there's no further change required to attach an external oscillator, as per above all the commands to do this are already available. In manual version K see page 6-4 and 6-15 for info on command 0x25, set disciplining gain. See page 3-6 section 3-5 on Hardware Menu option in the software keep on reading the manuals:-) Regards Nigel GM8PZR In a message dated 07/02/2014 18:06:55 GMT Standard Time, t...@patoka.org writes: Thanks everybody for the bit of information ! I have a Revsion C and Revision K manuals. In Revison K its only one note about OCXO: An internal 10 MHz VCXO (Voltage Controlled Crystal Oscillator) is disciplined to the reference source. The VCXO output drives all timing functions on the card. The VCXO output and a 1pps signal are provided as outputs. The TFP is also capable of disciplining an external voltage controlled oscillator. As an option, the TFP board can be ordered with an OCXO (Oven Controlled Crystal Oscillator) installed. As far as I understood, if I'll implement external OCXO to my BC637, I'll need to change FW on the card to make it work. If so, its not an option for me, since I just bought that card from auction and there is no way to obtain new microcode for it. Off-topic: Aside of that OCXO implementation, I would like to ask some direction from time-nuts community about the relatively simple way to compare two 1PPS signals using some MCU. Lets say I have T-Bolt and BC637. Each has 1PPS and I would like to see the phase difference between of that two. Of course it is some instruments already available for that, but I have not own that one (yet). I am thinking to connect both 1PPS to Timers input in capture mode on MCU. Then register first raising edge, start counting of ticks until second timer will not catch another signal raise. Then number of ticks will indicate the difference. But may be it is more elegant way to do that comparison ? Thanks ! Regards, V.P. On 2014-02-07 03:38, gandal...@aol.com wrote: I played with this around five or six years ago but unfortunately my notes from that time are likely to be buried somewhere still waiting to be scanned or indexed. All the necessary information though is in the user and SDK manuals, connections for the 10MHz external input and EFC output are on the 15 way I/O connector and there's even demo software which I'm pretty sure was all I used to make the necessary adjustments. One manual, pre Symmetricom, even has what looks to be a full set of schematics. I've just run the software again to check but it won't do much if it can't find the card so would need to fire up another PC with a spare slot to check further. I wasn't really happy at the time with my attempts to condition an external Vectron OCXO, it was certainly better than using the internal oscillator but there were some odd jumps and drifts using either which suggested these might be artifacts of the board itself rather than the Vectron OCXO. I've since acquired another BC637PCI, and want to try both again with other oscillators, but that's quite some way down a very long to do list, now reminded though I might take a quick look later:-) In the meantime, I have got copies of manuals and software etc and will get those zipped up today and make them available for download. Regards Nigel GM8PZR In a message dated 07/02/2014 03:36:46 GMT Standard Time, t...@patoka.org writes: Hello, Does anybody seen any links to the information how to implement external OCXO to Symmetricom PCI TFP BC635/BC637 ? -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
Re: [time-nuts] BC637PCI and OCXO
My first card at least is a Datum card so quite old now, and that was fine doing what you want to do.. You really will need to read the manuals in some detail and I do suggest downloading the larger of the two files I uploaded, that will give you the latest versions of the Demo programs that allow adjustment of the card, as well as the earlier versions of the same and all the manuals For some things, with earlier versions anyway, it's better to use the BC635 version of the Demo software, as that comes with a built in help section which the BC637 version lacks. I'll try and get a card installed so I can run the software properly again and if so will come back with more information later. Regards Nigel GM8PZR In a message dated 07/02/2014 18:25:22 GMT Standard Time, t...@patoka.org writes: It seems I have first generation of that card. And I was thinking to use that card as a source of 1PPS and 10MHZ - not to feed it from another reference. I though it is possible to do some modding to replace VCXO by OCXO. PCI Board Revision ID : 18 (0x12), Firmware Version : DT10041V11 On 2014-02-07 03:00, mike cook wrote: Le 7 févr. 2014 à 00:18, d0ct0r a écrit : Hello, Does anybody seen any links to the information how to implement external OCXO to Symmetricom PCI TFP BC635/BC637 ? check the Symmetricom datasheets. You don't mention the version you are needing info for , IRIG/GPS.. Anyway, all that I glanced at show an Exr. 10MHz ref input on pin 1 of the sub-D 15 connector. Digital, 40% to 60% or sine, 0.5V to 8V p-p, 10kOhm. ex. http://www.symmetricom.com/resources/download-library/documents/datasheets/bc637pci-v2 -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] BC637PCI and OCXO
Great ! Super ! Thanks a LOT ! Also, Symmetricom shared the resource for the latest version of that driver [BCPCI-V830 build 120]. http://www.symmetricom.com/bus-level-timing-sdk-and-driver-downloads/ I tried that on Ubuntu 12.04.3 LTS x86_64, kernel 3.2.0-58-generic. And its works for me. To whom it may interested, previously I tried to use WinDriver I take directly from Xilinx site [basically Jungo's WinDriver v11.5.0] and Legacy version of BC635PCI driver [BCPCI-V700 build 111], and it was working perfectly fine too. On the same 64bit Linux machine. Regards, V.P. On 2014-02-07 12:07, gandal...@aol.com wrote: Whilst sorting through my BC637PCI files earlier I realised for the first time that an ISO file I'd downloaded in 2010, described by Symmetricom as BC635/637 driver, is actually a full software and documentation CD, presumably what was then being supplied with new hardware. Ether that or I had been aware and it's something else that's slipped through the sieve:-) As well as the Windows SDK and more recent versions of the BC635 and BC637 demo software this file also contains later versions of the legacy demo software than I'd used previously, perhaps making most, if not all, of the earlier software obsolete, although the pre Symmetricom manuals, especially the one with the schematics, are certainly worth having. Now it's quite possible I'm the only one who wasn't aware of this, but in case it's not just me, and as I can't locate the original again to quote a URL, I've uploaded a file that contains this ISO, the extracted files from the same, plus my original collection of earlier software and documentation. This is quite a large file, approx 235MB, so for anyone who might only be interested in the earlier files I've also uploaded those as a smaller file of approx 52MB. BC637PCI_Full.rar 234.5 MB https://mega.co.nz/#!6dgVzBQI!A8y-qffQo4X5OYViTz97ZyiFn05zaPPfxCwoGLDu0Kg BC637PCI_Reduced.rar 50.2 MB https://mega.co.nz/#!iUQiwK7R!wyRPeBnkS4o1iADZGp7c-ZS6hHNbNqEEb8p1KKbr-ZU Any problems with the downloads or files please let me know and, as always, please feel free to upload elsewhere. Regards Nigel GM8PZR In a message dated 07/02/2014 03:36:46 GMT Standard Time, t...@patoka.org writes: Hello, Does anybody seen any links to the information how to implement external OCXO to Symmetricom PCI TFP BC635/BC637 ? -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- WBW, V.P. ___ time-nuts mailing 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] BC637PCI and OCXO
Now I have the plan. Thanks ! I'll try to connect external OCXO to that 15-pin connector, then using provided utility, I could switch to external oscillator. I think here is settings for externally connected source of 10Mhz: 12. Select Clock Source - 0. Internal 1. External Probably I'll need to do some adjustment using so-called Advanced settings: Advanced Menu: 1. Control Jam-Sync 2. Force Jam-Sync 3. Set Clock Value 4. Load D/A Converter 5. Set Disciplining Gain 6. Disconnect Battery to RTC Chip 0. Back to main menu Regards, V.P. On 2014-02-07 13:39, gandal...@aol.com wrote: My first card at least is a Datum card so quite old now, and that was fine doing what you want to do.. You really will need to read the manuals in some detail and I do suggest downloading the larger of the two files I uploaded, that will give you the latest versions of the Demo programs that allow adjustment of the card, as well as the earlier versions of the same and all the manuals For some things, with earlier versions anyway, it's better to use the BC635 version of the Demo software, as that comes with a built in help section which the BC637 version lacks. I'll try and get a card installed so I can run the software properly again and if so will come back with more information later. Regards Nigel GM8PZR In a message dated 07/02/2014 18:25:22 GMT Standard Time, t...@patoka.org writes: It seems I have first generation of that card. And I was thinking to use that card as a source of 1PPS and 10MHZ - not to feed it from another reference. I though it is possible to do some modding to replace VCXO by OCXO. PCI Board Revision ID : 18 (0x12), Firmware Version : DT10041V11 On 2014-02-07 03:00, mike cook wrote: Le 7 févr. 2014 à 00:18, d0ct0r a écrit : Hello, Does anybody seen any links to the information how to implement external OCXO to Symmetricom PCI TFP BC635/BC637 ? check the Symmetricom datasheets. You don't mention the version you are needing info for , IRIG/GPS.. Anyway, all that I glanced at show an Exr. 10MHz ref input on pin 1 of the sub-D 15 connector. Digital, 40% to 60% or sine, 0.5V to 8V p-p, 10kOhm. ex. http://www.symmetricom.com/resources/download-library/documents/datasheets/bc637pci-v2 -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- WBW, V.P. ___ time-nuts mailing 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] BC637PCI and OCXO
Aside of that OCXO implementation, I would like to ask some direction from time-nuts community about the relatively simple way to compare two 1PPS signals using some MCU. Lets say I have T-Bolt and BC637. Each has 1PPS and I would like to see the phase difference between of that two. Of course it is some instruments already available for that, but I have not own that one (yet). I am thinking to connect both 1PPS to Timers input in capture mode on MCU. Then register first raising edge, start counting of ticks until second timer will not catch another signal raise. Then number of ticks will indicate the difference. But may be it is more elegant way to do that comparison ? Thanks ! Regards, V.P. Yes, that's very simple and works well, up to the period of the MCU clock driving the timer, e.g., a 200 MHz MCU gives you 5 ns resolution on the capture register. If you need under 5 or 10 ns, the next level is adding analog interpolation to the signal. There have been many discussions about this on the list. Search for Richard's PICTIC, for example. Depending on the complexity you want and the amount of calibration or re-calibration you employ, you can get down to hundreds or even tens of ps this way. Most of us just buy surplus time interval counters on eBay. You can get 1 or 2 ns counters for $50 to $200 on a good day. Or for casual time interval work, a two channel digital oscilloscope. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] How I got my FE-5680A to lock in Sydney, Australia
The entry in the FE5680 FAQ on this subject may be helpful, if you haven't tried it already. http://ko4bb.com/dokuwiki/doku.php?id=precision_timing:fe5680a_faq#what_if_my_5680a_output_does_not_lock_up_after_several_minutes I have 3 of those units; one did not lock until I adjusted the trim-cap C217 to bring the free-running frequency of the oscillator into range. If you have a reasonably accurate counter you can check if this is the problem or not by seeing if the output frequency (which ramps up and down prior to lock) crosses through 10.00 MHz or not. Mine did not. ___ time-nuts mailing 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] BC637PCI and OCXO
Sounds like you cracked it, and beat me to it:-) I just dug out a PCI expansion chassis, the quickest option for now, and have one card up and running but have discovered, as a left over from my playing earlier, that installing the later software, what Symmetricom calls its BC635/637 configurator program, causes earlier versions of the software to fail at startup, even with the latest one uninstalled, so that's something to watch out for:-( The later stuff does seem to offer all the options of the earlier software though, and as you've no doubt discovered the oscillator parameters you mention are accessed through the BC635 software rather than the BC637 version. On the version I'm running at least, verion 10 of the configurator at the moment, there is a menu option to switch between internal and external oscillators on the Hardware menu in standard configuration and the other options as you say are available in advanced with the oscillator switching no longer showing. Interesting to see the rolling time displayed down to microseconds, although my eyes do struggle a bit to keep up with that, but rather a shame that for now I seem to be stuck in June 1994! I am getting the impression though that this particular software is expecting a later version of the card, this card is showing in Device Manager as a BC635/7PCI-eV2, which it certainly isn't, and the software is offering to adjust the DDS frequency for me, which would be nice but I don't remember it having DDS either. Time to have a software clearout methinks and to start over. Have fun:-) Nigel GM8PZR In a message dated 07/02/2014 19:12:34 GMT Standard Time, t...@patoka.org writes: Now I have the plan. Thanks ! I'll try to connect external OCXO to that 15-pin connector, then using provided utility, I could switch to external oscillator. I think here is settings for externally connected source of 10Mhz: 12. Select Clock Source - 0. Internal 1. External Probably I'll need to do some adjustment using so-called Advanced settings: Advanced Menu: 1. Control Jam-Sync 2. Force Jam-Sync 3. Set Clock Value 4. Load D/A Converter 5. Set Disciplining Gain 6. Disconnect Battery to RTC Chip 0. Back to main menu Regards, V.P. On 2014-02-07 13:39, gandal...@aol.com wrote: My first card at least is a Datum card so quite old now, and that was fine doing what you want to do.. You really will need to read the manuals in some detail and I do suggest downloading the larger of the two files I uploaded, that will give you the latest versions of the Demo programs that allow adjustment of the card, as well as the earlier versions of the same and all the manuals For some things, with earlier versions anyway, it's better to use the BC635 version of the Demo software, as that comes with a built in help section which the BC637 version lacks. I'll try and get a card installed so I can run the software properly again and if so will come back with more information later. Regards Nigel GM8PZR In a message dated 07/02/2014 18:25:22 GMT Standard Time, t...@patoka.org writes: It seems I have first generation of that card. And I was thinking to use that card as a source of 1PPS and 10MHZ - not to feed it from another reference. I though it is possible to do some modding to replace VCXO by OCXO. PCI Board Revision ID : 18 (0x12), Firmware Version : DT10041V11 On 2014-02-07 03:00, mike cook wrote: Le 7 févr. 2014 à 00:18, d0ct0r a écrit : Hello, Does anybody seen any links to the information how to implement external OCXO to Symmetricom PCI TFP BC635/BC637 ? check the Symmetricom datasheets. You don't mention the version you are needing info for , IRIG/GPS.. Anyway, all that I glanced at show an Exr. 10MHz ref input on pin 1 of the sub-D 15 connector. Digital, 40% to 60% or sine, 0.5V to 8V p-p, 10kOhm. ex. http://www.symmetricom.com/resources/download-library/documents/datasheets/bc637pci-v2 -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow
Re: [time-nuts] BC637PCI and OCXO
Thanks everybody for the bit of information ! I have a Revsion C and Revision K manuals. In Revison K its only one note about OCXO: An internal 10 MHz VCXO (Voltage Controlled Crystal Oscillator) is disciplined to the reference source. The VCXO output drives all timing functions on the card. The VCXO output and a 1pps signal are provided as outputs. The TFP is also capable of disciplining an external voltage controlled oscillator. As an option, the TFP board can be ordered with an OCXO (Oven Controlled Crystal Oscillator) installed. As far as I understood, if I'll implement external OCXO to my BC637, I'll need to change FW on the card to make it work. If so, its not an option for me, since I just bought that card from auction and there is no way to obtain new microcode for it. Off-topic: Aside of that OCXO implementation, I would like to ask some direction from time-nuts community about the relatively simple way to compare two 1PPS signals using some MCU. Lets say I have T-Bolt and BC637. Each has 1PPS and I would like to see the phase difference between of that two. Of course it is some instruments already available for that, but I have not own that one (yet). I am thinking to connect both 1PPS to Timers input in capture mode on MCU. Then register first raising edge, start counting of ticks until second timer will not catch another signal raise. Then number of ticks will indicate the difference. But may be it is more elegant way to do that comparison ? Thanks ! Regards, V.P. On 2014-02-07 03:38, gandal...@aol.com wrote: I played with this around five or six years ago but unfortunately my notes from that time are likely to be buried somewhere still waiting to be scanned or indexed. All the necessary information though is in the user and SDK manuals, connections for the 10MHz external input and EFC output are on the 15 way I/O connector and there's even demo software which I'm pretty sure was all I used to make the necessary adjustments. One manual, pre Symmetricom, even has what looks to be a full set of schematics. I've just run the software again to check but it won't do much if it can't find the card so would need to fire up another PC with a spare slot to check further. I wasn't really happy at the time with my attempts to condition an external Vectron OCXO, it was certainly better than using the internal oscillator but there were some odd jumps and drifts using either which suggested these might be artifacts of the board itself rather than the Vectron OCXO. I've since acquired another BC637PCI, and want to try both again with other oscillators, but that's quite some way down a very long to do list, now reminded though I might take a quick look later:-) In the meantime, I have got copies of manuals and software etc and will get those zipped up today and make them available for download. Regards Nigel GM8PZR In a message dated 07/02/2014 03:36:46 GMT Standard Time, t...@patoka.org writes: Hello, Does anybody seen any links to the information how to implement external OCXO to Symmetricom PCI TFP BC635/BC637 ? -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- WBW, V.P. ___ time-nuts mailing 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] Lady Heather command question
These commands are entered while LH is up and running, not on the command line. See this old (September 2011) message http://www.febo.com/pipermail/time-nuts/2011-September/059113.html for example. On Fri, Feb 7, 2014 at 5:52 AM, Michael Baker mp...@clanbaker.org wrote: Thank you Azelio, for your response to my question regarding how to get Lady Heather to display the signal-strengths vs AZ and EL. I have been trying to figure out how to get LH to display the signal strength diagram. I have been entering 'SAS' ret into the command line. LH responds by clearing off the ADEV lists but then starts the ADEV lists all over again. Where do the SAS, SAD, SAE, SAA, SAW, SAC commands and their function explanation appear? I do not see them listed anywhere. What is the correct procedure for entering the commands? Are you saying I should enter ' SAS/SAD/SAE/SAA ' (ret)...? In other words, enter all the commands in sequence separated by the forward slash (/)...? Thanks-- Mike Baker ** Azelio Boriani said: Use: S A S signal S A D data S A E elevation S A A azimuth S A W S A C to clear the view -- The duty of a Patriot is to protect his country from its government. - Thomas Paine ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] BC637PCI and OCXO
As far as I understood, in many modes (except GPS mode), we need to set date/time manually. Also, I found the link for the direct oscillator replacement part: http://www.mti-milliren.com/pdfs/210.pdf I think in the documentation, Symmitricom mentioned this particular model. Now I know how it looks like. But unfortunately its not straight process just to use my Hakko to exchange the crystals. Its required to change the microcode as well. So, that is not an option. The only way is to use external OCXO connected to pin 1 of the 15-pin connector. And I'll try it. Thank you all for all the information ! Regards, V.P. On 2014-02-07 14:55, gandal...@aol.com wrote: Sounds like you cracked it, and beat me to it:-) I just dug out a PCI expansion chassis, the quickest option for now, and have one card up and running but have discovered, as a left over from my playing earlier, that installing the later software, what Symmetricom calls its BC635/637 configurator program, causes earlier versions of the software to fail at startup, even with the latest one uninstalled, so that's something to watch out for:-( The later stuff does seem to offer all the options of the earlier software though, and as you've no doubt discovered the oscillator parameters you mention are accessed through the BC635 software rather than the BC637 version. On the version I'm running at least, verion 10 of the configurator at the moment, there is a menu option to switch between internal and external oscillators on the Hardware menu in standard configuration and the other options as you say are available in advanced with the oscillator switching no longer showing. Interesting to see the rolling time displayed down to microseconds, although my eyes do struggle a bit to keep up with that, but rather a shame that for now I seem to be stuck in June 1994! I am getting the impression though that this particular software is expecting a later version of the card, this card is showing in Device Manager as a BC635/7PCI-eV2, which it certainly isn't, and the software is offering to adjust the DDS frequency for me, which would be nice but I don't remember it having DDS either. Time to have a software clearout methinks and to start over. Have fun:-) Nigel GM8PZR In a message dated 07/02/2014 19:12:34 GMT Standard Time, t...@patoka.org writes: Now I have the plan. Thanks ! I'll try to connect external OCXO to that 15-pin connector, then using provided utility, I could switch to external oscillator. I think here is settings for externally connected source of 10Mhz: 12. Select Clock Source - 0. Internal 1. External Probably I'll need to do some adjustment using so-called Advanced settings: Advanced Menu: 1. Control Jam-Sync 2. Force Jam-Sync 3. Set Clock Value 4. Load D/A Converter 5. Set Disciplining Gain 6. Disconnect Battery to RTC Chip 0. Back to main menu Regards, V.P. On 2014-02-07 13:39, gandal...@aol.com wrote: My first card at least is a Datum card so quite old now, and that was fine doing what you want to do.. You really will need to read the manuals in some detail and I do suggest downloading the larger of the two files I uploaded, that will give you the latest versions of the Demo programs that allow adjustment of the card, as well as the earlier versions of the same and all the manuals For some things, with earlier versions anyway, it's better to use the BC635 version of the Demo software, as that comes with a built in help section which the BC637 version lacks. I'll try and get a card installed so I can run the software properly again and if so will come back with more information later. Regards Nigel GM8PZR In a message dated 07/02/2014 18:25:22 GMT Standard Time, t...@patoka.org writes: It seems I have first generation of that card. And I was thinking to use that card as a source of 1PPS and 10MHZ - not to feed it from another reference. I though it is possible to do some modding to replace VCXO by OCXO. PCI Board Revision ID : 18 (0x12), Firmware Version : DT10041V11 On 2014-02-07 03:00, mike cook wrote: Le 7 févr. 2014 à 00:18, d0ct0r a écrit : Hello, Does anybody seen any links to the information how to implement external OCXO to Symmetricom PCI TFP BC635/BC637 ? check the Symmetricom datasheets. You don't mention the version you are needing info for , IRIG/GPS.. Anyway, all that I glanced at show an Exr. 10MHz ref input on pin 1 of the sub-D 15 connector. Digital, 40% to 60% or sine, 0.5V to 8V p-p, 10kOhm. ex. http://www.symmetricom.com/resources/download-library/documents/datasheets/bc637pci-v2 -- WBW, V.P. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- WBW, V.P.
[time-nuts] More 60Hz graphs
A histogram of the frequency samples: http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/freq-hist.png The x positions are fudged by 0.02 Hz so multiple dots on the same point don't land on top of eachother and hide the ones on the bottom. Another dip big enough to get below 59.9 Hz: http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/2014-Jan-26-a-dip.png An example of a bug: http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/2013-Dec-26-a-bug.png The kernel code that collects the data and prints it via the /sys file system is missing a lock. Occasionally, the count is off by one. I assume the printout code gets the new time and old count. That turns one of my samples into being low in frequency and the following one being high in frequency. The offsets are big enough to stand out. [I haven't looked at the code to verify this.] This also provides an overall sanity check. If counts are getting lost due to interrupts being locked out for too long, that will stand out like this. Similar for extra counts due to noise. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] GPSDO?
Went today to Orlando Fl. Hamcom and blught for $ 15 a GWGT 0300 GPSDO. There where 3 more. If any one in Orlando and is interested contact me off list and I give you direction. There was also a HP unit for $ 200. Does any one have info on the unit. Garmin GPS and ISOTEMP OCXO. Sent from Samsung tablet ___ time-nuts mailing 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 I got my FE-5680A to lock in Sydney, Australia
Could be the C coil Sent from Samsung tabletEB4APL eb4...@cembreros.jazztel.es wrote:Hi, I second the idea about a mechanical issue. When I opened my FRS-C I found that one of the connector pins had never been soldered, it only made mechanical contact with the PBC. Perhaps it showed an intermittent failure and was retired with low hours. Ignacio EB4APL On 07/02/2014 3:54, Ed Palmer wrote: Hi Jim, On 2/6/2014 3:32 PM, Jamieson (Jim) Rowe wrote: Hi again folks, You may (or may not) recall that a month or so ago, I asked for any information that might be available regarding how to fix a ‘used’ FE-5680A rubidium module from China (via ebay) which was tested by the supplier in China as working OK, but would not seem to lock up to rubidium here in Sydney. There wasn’t a great deal of info available, it seems, so I kept on checking ideas myself – mostly with no luck. The module would never lock, but kept cycling back and forth between about 9.999770MHz and 10.36MHz – ‘searching’ for a lock, but never finding it. Anyway, a couple of days ago I was reading more about the operation of rubidium vapour oscillators, and noticed that the ‘filter cell’ is very sensitive to magnetic fields – hence the mu-metal shielding case, and also for the ‘C-tuning’ coil. And I wondered if the main reason why the FE-5680A had apparently worked in China, but wouldn’t lock up in Sydney (Australia) might be caused by the fact that Quangzhou (China) is in the northern hemisphere while I’m ‘down under’ in the southern hemisphere – where the earth’s field is presumably somewhat different, in terms of both strength and direction. So I decided to test this in a crude way, by inverting the FE-5680A and seeing what happened. And – lo and behold – it locked up within 2.5 minutes, and stayed locked until I turned off the power and let it go cold again. The next morning I applied power again, and within 3 minutes it locked up again with no problems. And it’s been locked up now for over 48 hours... My first thought was to make a typical 'down-under' joke and suggest you run the 5680A upside down, but you beat me to it! :) So it seems that the different magnetic field here may have been the problem – either that, or it may have received a ‘jolt’ in transit, which prevented in from locking unless it was inverted. But how do I tell which of these explanations is right, without ‘opening her up’ again and looking for some kind of subtle physical fault? Another idea: perhaps the mu-metal shield case had acquired a small dose of magnetisation in transit (via a physical shock, or from a strong field metal detector). I guess in this case that I would have to remove the two halves of the case, and bake them in a furnace to demagnetise them again. My very limited knowledge regarding mu-metal is that it is so magnetically 'soft' that it can't be magnetized. If it was somehow magnetized, inverting the unit wouldn't make any difference, would it? Or should I just run the FE-5680A upside down permanently – the simple but ‘crude’ answer? I don't believe for a second (pun intended) that the earth's magnetic field has any effect on the locking of your 5680A. It's just not strong enough. The same applies to the C-field which can only nudge the frequency one way or another by a small amount. Since flipping the unit DID make a difference, my money would be on a trivial, boring mechanical issue inside the unit. Could be a bad solder joint, broken wire, floating piece of debris, or something like that. Worst case might be a broken glue joint somewhere in the physics package. That could be ugly. I would definitely open it up and see if anything falls out. I’m not sure if this FE-5680A has the ‘C-tuning’ gizmo fitted, or wired up. Am I right in thinking that another approach might be to try varying the tuning via the RS-232C serial port? Does this work via the C-tuning coil anyway, or by tweaking the DDS? The RS-232 commands affect the DDS - assuming your unit does have one. It will have no effect on the locking, only on the output frequency. A few years ago I bought a dead Datum SLCR Rb standard. It's a cousin to the LPRO. I thought I'd learn some things by trying to fix it. The problem was intermittent. I tore it apart and found that one of the legs of the crystal had never been soldered! Never overlook the obvious. I hope a much more experienced time nut can provide a few answers, please. Maybe the blind leading the blind is a closer description. Ed Jim Rowe ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
Re: [time-nuts] Rb as source for ADEV?
All my 10811 will do 20 Hz. Sent from Samsung tabletHal Murray hmur...@megapathdsl.net wrote: Bob Camp li...@rtty.us: Offset the local reference one hertz or so and let the 5334 do its thing. Any hints on how to get a good oscillator that's off by 1 Hz from 10 MHz? How did you pick 1 Hz? Is 10 Hz offset better? How about 0.1 Hz? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] GPS W/10KHz
List, Wrote: where is a good source of GPS receiver modules I need one which has 10kHz output to phase lock a quartz oscillator. Fluke.1 Motorola ONCORE M12+T timing gps receiver 1pps 100hz eBay item number:290656401551 Also RDR There is another china seller that has them(10KHz) with leads for $90 but is almost impossible to find. Last time I searched it took me a hour. But he has a wide assortment. I forgot to bookmark his site. Regards, Perrier ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
