Re: [time-nuts] Ublox neo-7M GPS
Thanks all for the replies to my initial query as to whether anyone had any firsthand experience with this device. The replies have been helpful. It is also clear that what some see as an apple, others see as an orange. A simple common truth perhaps which becomes very obvious when comparing the discussions of two groups each with a different focus where the subject is the same, in this case the Ublox Neo-7M. The other group which started my question has it's focus in the frequency domain and as to whether or not this device was suitable or not for use as a variable frequency signal source. That group has made some measurements and came to similar conclusions as some of those offered here. Cheers, Graham ve3gtc This electronic message, as well as any transmitted files included in the electronic message, may contain privileged or confidential information and is intended solely for the use of the individual(s) or entity to which it is addressed. If you have received this electronic message in error please notify the sender immediately and delete the electronic message. Any unauthorized copying, disclosure or distribution of the electronic message is strictly forbidden. NAV CANADA accepts no liability for any damage caused by any virus and/or other malicious code transmitted by this electronic communication. Le présent message électronique et tout fichier qui peut y être joint peuvent contenir des renseignements privilégiés ou confidentiels destinés à l’usage exclusif des personnes ou des organismes à qui ils s’adressent. Si vous avez reçu ce message électronique par erreur, veuillez en informer l’expéditeur immédiatement et supprimez le. Toute reproduction, divulgation ou distribution du présent message électronique est strictement interdite. NAV CANADA n’assume aucune responsabilité en cas de dommage causé par tout virus ou autre programme malveillant transmis par ce message électronique. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] LEA-6T Software.
Hi All, Just purchased a LEA-6T based board to play with (It's a Synergy Systems SSR-6Tru). The Ublox web site has some documentation regarding the setup of these units. In the documentation are some screenshots of what appears to be a utility for configuration. I haven't seen it on the Ublox web site yet. Do any of you know what that software might be, and where one would get it? The unit is a few weeks out on delivery, so wanted to see what I could to to prepare for it's delivery. What other utilities and software are available what would pair with these units? FYI, I run windows based software. Also, I have a low cost antenna coming. It's one of the Synergy systems puck type amplified antennas. I remember some time back a bit of chatter about improving GPS antennas for timing, by providing some sort of guard ring or choke to prevent low angle reception. Are there any good links anyone could provide on what may be worth building or playing with. Keep in mind, I live in snow country (~300 inches/year) so a something that gathers a lot of snow could be undesirable! :) Thanks, Dan ___ time-nuts mailing 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] LEA-6T Software.
Hi Dan, I think you're looking for the u-center software. Finding software on that site can be difficult, so it's easier to resort to a websearch. There's a link to the latest software on this page. http://www.u-blox.com/en/evaluation-tools-a-software/u-center/u-center.html As to the antenna, google diy gps choke ring to get the fundamentals. Walmart sells a set of Wilton stackable aluminum pie pans that seem to be a pretty good fit for our needs. I've done a few experiments, but haven't set it up because I didn't find a suitable platform for the antenna puck to rest on and haven't wanted to spend the time to make something. Something made out of steel would be ideal for the magnetic mount of a puck antenna, if that's what you have. Bob From: Dan Kemppainen d...@irtelemetrics.com To: time-nuts@febo.com Sent: Monday, August 25, 2014 9:48 AM Subject: [time-nuts] LEA-6T Software. Hi All, Just purchased a LEA-6T based board to play with (It's a Synergy Systems SSR-6Tru). The Ublox web site has some documentation regarding the setup of these units. In the documentation are some screenshots of what appears to be a utility for configuration. I haven't seen it on the Ublox web site yet. Do any of you know what that software might be, and where one would get it? The unit is a few weeks out on delivery, so wanted to see what I could to to prepare for it's delivery. What other utilities and software are available what would pair with these units? FYI, I run windows based software. Also, I have a low cost antenna coming. It's one of the Synergy systems puck type amplified antennas. I remember some time back a bit of chatter about improving GPS antennas for timing, by providing some sort of guard ring or choke to prevent low angle reception. Are there any good links anyone could provide on what may be worth building or playing with. Keep in mind, I live in snow country (~300 inches/year) so a something that gathers a lot of snow could be undesirable! :) Thanks, Dan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] EFC info on Trimble 34310-T OXCO
I found the parameters for the X72's 1PPS input. The range of Tau is 5 - 10,000 seconds, or about 2 hrs, 45 min. at the longest setting. It defaults to 400 seconds. However, mine doesn't have the firmware to enable the 1PPS input, so it really doesn't matter. Out of curiosity, does anyone know of any Rb units that can be programmed to a 24 hr (or longer) Tau, either by EFC or 1PPS input? Dave M Bob Camp wrote: Hi It is not what is done in the Efratom Rb’s. Their pps input is set up to get things on frequency / on time quickly. The assumption is that you plug it into a pps to get it “right” and then take off on your mission. That takes them into the short (for a Rb) time constant region. Bob On Aug 24, 2014, at 5:56 PM, Brooke Clarke bro...@pacific.net wrote: Hi Bob: I think that's what's done in the SRS PRS10 http://www.prc68.com/I/PRS10.shtml Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Bob Camp wrote: Hi If you lock an Rb to GPS, you need / want / should do it with a *very* long time constant. Numbers in the one day to several days range are commonly seen. If you lock it up with a tighter (shorter time constant) loop, it will just wander around as it follows the GPS input. That’s what would happen if you hook your Rb to your Trimble and turn on the disciplining on the Rb. It will significantly degrade the stability of the Rb. If you have a temperature stable environment (or create one) you can get some very good results with an (good) Rb locked to a (good) GPS via a proper long time constant setup. It’s not easy, but it can be done. 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] Tracor Now Tracking
A while ago I asked about dephasing WWVB. Since them I have tried many things and finally found one that works. I use my WWVB trf receiver with the squaring chip at its output. This gives me a dephased 120 KHz signal. In reading the Tracor manual about their MSK converter I discovered that they do a frequency conversion first using the 100 KHz coherent output at the Tracor’s rear panel. I did the same trick with the 120 KHz signal using a MiniCircuits mixer, which outputs the 20 KHz difference frequency. Then this can be used as input for the Tracor. Tracor is happy with this signal and is tracking fine. 73, John, KA5QEP ___ time-nuts mailing 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] Practical Survey-In Accuracy?
I would call that done. Henry On Sat, Aug 23, 2014 at 4:38 PM, Bob Stewart b...@evoria.net wrote: I've had the LEA-6T sitting in survey-in mode for about 17 hours, and at this point, the u-center software says that the Mean 3D Std Dev is 0.109 meters. Given that my antenna is just a puck at the peak of the attic (never got around to adding the DIY choke-ring), has this reached the silly number phase, or should I let is simmer overnight before calling it done? Bob - AE6RV ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] EFC info on Trimble 34310-T OXCO
Charles Steinmetz wrote: Dave wrote: does anyone know of any Rb units that can be programmed to a 24 hr (or longer) Tau, either by EFC or 1PPS input? The SRS PRS10 has a very versatile PPS input that can discipline its frequency with a truly comprehensive array of adjustments (to the point of potential bafflement). The PRS10 and a good PPS source can make an excellent GPSDO. (Note that the PRS10 is, by itself, one of the best compact Rb oscillators available.) The PRS10 manual has a good explanation of the PPS operation at pp.14-17 and 33-36: http://www.thinksrs.com/downloads/PDFs/Manuals/PRS10m.pdf Best regards, Charles Thanks for that, Charles. I've seen a number of articles about the PRS-10, but never really read them closely. I'll download the manual and see if I can understand what it's all about. I might have to put a PRS10 on my wish list. Thanks again, Dave M ___ time-nuts mailing 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] EFC info on Trimble 34310-T OXCO
Dave wrote: does anyone know of any Rb units that can be programmed to a 24 hr (or longer) Tau, either by EFC or 1PPS input? The SRS PRS10 has a very versatile PPS input that can discipline its frequency with a truly comprehensive array of adjustments (to the point of potential bafflement). The PRS10 and a good PPS source can make an excellent GPSDO. (Note that the PRS10 is, by itself, one of the best compact Rb oscillators available.) The PRS10 manual has a good explanation of the PPS operation at pp.14-17 and 33-36: http://www.thinksrs.com/downloads/PDFs/Manuals/PRS10m.pdf Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] EFC info on Trimble 34310-T OXCO
Hi The only Rb’s I know of that go out to the 24 to 72 hour tau’s are full blown GPSDO Rb’s. Bob On Aug 25, 2014, at 1:53 PM, Dave M dgmin...@mediacombb.net wrote: I found the parameters for the X72's 1PPS input. The range of Tau is 5 - 10,000 seconds, or about 2 hrs, 45 min. at the longest setting. It defaults to 400 seconds. However, mine doesn't have the firmware to enable the 1PPS input, so it really doesn't matter. Out of curiosity, does anyone know of any Rb units that can be programmed to a 24 hr (or longer) Tau, either by EFC or 1PPS input? Dave M Bob Camp wrote: Hi It is not what is done in the Efratom Rb’s. Their pps input is set up to get things on frequency / on time quickly. The assumption is that you plug it into a pps to get it “right” and then take off on your mission. That takes them into the short (for a Rb) time constant region. Bob On Aug 24, 2014, at 5:56 PM, Brooke Clarke bro...@pacific.net wrote: Hi Bob: I think that's what's done in the SRS PRS10 http://www.prc68.com/I/PRS10.shtml Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Bob Camp wrote: Hi If you lock an Rb to GPS, you need / want / should do it with a *very* long time constant. Numbers in the one day to several days range are commonly seen. If you lock it up with a tighter (shorter time constant) loop, it will just wander around as it follows the GPS input. That’s what would happen if you hook your Rb to your Trimble and turn on the disciplining on the Rb. It will significantly degrade the stability of the Rb. If you have a temperature stable environment (or create one) you can get some very good results with an (good) Rb locked to a (good) GPS via a proper long time constant setup. It’s not easy, but it can be done. 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.
Re: [time-nuts] Practical Survey-In Accuracy?
Hi There are some periodic errors in GPS that only get averaged in after a = 48 hour survey. It’s not so much a specific error level in meters as much as averaging in all the “issues”. Bob On Aug 23, 2014, at 7:38 PM, Bob Stewart b...@evoria.net wrote: I've had the LEA-6T sitting in survey-in mode for about 17 hours, and at this point, the u-center software says that the Mean 3D Std Dev is 0.109 meters. Given that my antenna is just a puck at the peak of the attic (never got around to adding the DIY choke-ring), has this reached the silly number phase, or should I let is simmer overnight before calling it done? Bob - AE6RV ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] Practical Survey-In Accuracy?
Hi Bob, Thanks for the info. I'll have to run a long test to see what the difference is. Maybe I can capture the XYZ coordinates to the PC during the run. Bob From: Bob Camp kb...@n1k.org To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, August 25, 2014 4:54 PM Subject: Re: [time-nuts] Practical Survey-In Accuracy? Hi There are some periodic errors in GPS that only get averaged in after a = 48 hour survey. It’s not so much a specific error level in meters as much as averaging in all the “issues”. Bob On Aug 23, 2014, at 7:38 PM, Bob Stewart b...@evoria.net wrote: I've had the LEA-6T sitting in survey-in mode for about 17 hours, and at this point, the u-center software says that the Mean 3D Std Dev is 0.109 meters. Given that my antenna is just a puck at the peak of the attic (never got around to adding the DIY choke-ring), has this reached the silly number phase, or should I let is simmer overnight before calling it done? Bob - AE6RV ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Anyone Familiar with a Trimble 46865 Board?
I have been offered what appears to be a Trimble GPSDO board. The model number is 46865-00-BM. From the photos, the board appears to be about the same size and layout as my NTBW50AA and includes a Trimble STP2254 10 MHz TCXO module, a USB port, and the same type of backplane connectors as the Nortel unit. I cannot find anything about it on the web - even to figure out what it was originally used for. Is anyone on the list familiar enough with this particular board to point me to some reference information? Thank you, Bob, K0BT ___ time-nuts mailing 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] Anyone Familiar with a Trimble 46865 Board?
Hi I’d say you have it figured out pretty well. It’s a TCXO based board for a “short holdover” cell site or something like that. There is a good chance that it’s got the same plusses and minuses as the GPSTM plus the degraded ADEV from the TCXO. Bob On Aug 25, 2014, at 5:04 PM, Bob Armstrong k...@cox.net wrote: I have been offered what appears to be a Trimble GPSDO board. The model number is 46865-00-BM. From the photos, the board appears to be about the same size and layout as my NTBW50AA and includes a Trimble STP2254 10 MHz TCXO module, a USB port, and the same type of backplane connectors as the Nortel unit. I cannot find anything about it on the web - even to figure out what it was originally used for. Is anyone on the list familiar enough with this particular board to point me to some reference information? Thank you, Bob, K0BT ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
