Re: [time-nuts] Pulsar Source?
El 30/03/2012 05:02, Jim Lux escribió: and orientation. Sort of like a super star tracker all in one! (You can see why NASA is interested..) And ESA. Last year they published an invitation to tender called Deep Space Navigation with Pulsars, with the following description excerpt: The activity will focus on the study of the use of Pulsars for Deep Space Navigation. Localization of spacecrafts in deep space is today very challenging and, in same cases, not enough precise and/nor reliable. Highly rotating neutron starts (also called Pulsars)generate pulses with high stable periodicity that can be used to locate an object in space. It had quite a low budget assigned... but seems that it had some interest. I think I can get the statement of work if somebody is interested. Best regards, Javier ___ time-nuts mailing 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] Pulsar Source?
act...@hotmail.com said: Forth: The problems I foresee are can an practical algorithm accounting for the complex motion of all these bodies be built ... Radio astronomers are pretty good at that sort of calculation. Google for VLBI. The key step for VLBI is modeling the exact location of each antenna over time. They even include tides in solid rock. (about a foot) I think there is a chicken-egg step in there. You can use a bright object and the known location of several antennas to figure out the location of a new antenna. I assume they iterate. So, if you can figure out the orbital parameters for your receivers, they can do the math. Note the comment from: Little Green Men, White Dwarfs or Pulsars? By S. Jocelyn Bell Burnell http://www.bigear.org/vol1no1/burnell.htm (It's a good read.) So were these pulsations man-made, but made by man from another civilization? If this were the case then the pulses should show Doppler shifts as the little green men on their planet orbited their sun. Tony Hewish started accurate measurements of the pulse period to investigate this; all they showed was that the earth was in orbital motion about the sun. That was back in 1967. -- 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] Opera coordinator has resigned
http://inagist.com/all/185697069783195648/ Personally I'm sorry about such an end of the story. 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.
Re: [time-nuts] Opera coordinator has resigned
On Fri, Mar 30, 2012 at 3:07 PM, iov...@inwind.it iov...@inwind.it wrote: http://inagist.com/all/185697069783195648/ Personally I'm sorry about such an end of the story. There was a meeting in Gran Sasso on Wednesday. You can see some of the slides at http://agenda.infn.it/materialDisplay.py?materialId=slidesconfId=4896 I found particularly interesting the ones by Maximiliano Sioli, where he explained the two mistakes found in the OPERA data acquisition chain and how, after correcting for their best estimate of their effects, the time of flight is compatible with a speed of c. I saw the webcast of the event. Some people did give the OPERA spokesman a hard time, and he admitted to not having fully checked everything they could have. Ah well, everyone makes mistakes. There will be another run with neutrinos spaced by 100 ns in May. If all four experiments in LNGS give the same result this time, I suppose the case will be closed. It will also be very interesting to see the MINOS results. In any event, from a time-nut point of view this is quite exciting. It is the first time neutrino speed is measured with this precision. I think this will pave the way for future experiments using precision geodesy and time transfer. Cheers, Javier ___ time-nuts mailing 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] Opera coordinator has resigned
El 30/03/2012 16:55, Javier Serrano escribió: On Fri, Mar 30, 2012 at 3:07 PM, iov...@inwind.itiov...@inwind.it wrote: http://inagist.com/all/185697069783195648/ Personally I'm sorry about such an end of the story. There was a meeting in Gran Sasso on Wednesday. You can see some of the slides at http://agenda.infn.it/materialDisplay.py?materialId=slidesconfId=4896 Thanks for sharing them I found particularly interesting the ones by Maximiliano Sioli, where he explained the two mistakes found in the OPERA data acquisition chain and how, after correcting for their best estimate of their effects, the time of flight is compatible with a speed of c. The devil is ever in the small things :) It is truly very interesting I saw the webcast of the event. Some people did give the OPERA spokesman a hard time, and he admitted to not having fully checked everything they could have. Ah well, everyone makes mistakes. There will be another run with neutrinos spaced by 100 ns in May. If all four experiments in LNGS give the same result this time, I suppose the case will be closed. It will also be very interesting to see the MINOS results. In any event, from a time-nut point of view this is quite exciting. It is the first time neutrino speed is measured with this precision. I think this will pave the way for future experiments using precision geodesy and time transfer. This is true. And also perhaps the use of neutrinos for time transfer purposes :) Nowadays nort their generation in a controlled way either the detection is easy, but who knows in the future... Regards, Javier ___ time-nuts mailing 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] Yahoo group not receiving email
My internet provider here in the UK is BT, and BT use Yahoo. I do need to check the BT-Yahoo account on my web browser periodically as their spam filtering is a bit aggressive and a few genuine emails (usually from Time Nuts) get put in the Spam bin. Other than that I have few problems. Rob Kimberley -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Mark Spencer Sent: 29 March 2012 22:51 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Yahoo group not receiving emal Interesting. I use yahoo mail to receive email from this list and as far as I am aware I have not had any issues. (Ie. in following threaded conversations it's never been apparent to me that I have missed any of the messages.) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] CW12-TIM vs M12M and the world
I've evaluated various of their products including the 125 NCOs boards, and they are worse than 2ns in real world environments.. The m12+ timing replacement unit also only supports a small subset of the Motorola command set. It was useless as a replacement receiver for our Fury GPSDO when we looked into it. The ilotus M12M is still king of the hill in my opinion. Caveat emptor. Bye, Said Sent From iPhone On Mar 29, 2012, at 0:32, Hal Murray hmur...@megapathdsl.net wrote: The sawtooth error on the Motorola M12+ is about +/- 25ns, while the CW12-TIM has a sawtooth error of +/- 2 ns, so correcting for the sawtooth error is not as critical with the CW12-TIM. The first claim The sawtooth error on the Motorola M12+ is about +/- 25ns is correct but are you absolutely sure that the second claim is correct too? It would mean a factor 10 improvement of the CW12-TIM against the M12 which is hardly believeable. The 25 ns probably comes from period of the the free running clock they are using. It doesn't seem unreasonable to me to get 10x better if they use a GPSDO for the local clock so they can get the PPS edge right where they want it. -- 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] CW12-TIM vs M12M and the world
Hello Ed, Azelio, We should also compare the same parameters. Sawtooth error of the m12+ of +/-25ns is not its standard deviation, it's max/min. Compare that number to your 30ns max/min measurement on the 5372a. Standard deviation of the m12+ is around 2ns with correction. That needs to be compared to the 5ns you measure on the 5372a as that is the best performance you will get from the CW12. Yes the uncorrected 1pps of the m12 is worse, but it is designed to be used with correction. So in the end the m12m still performs better than the CW12. Bye, Said Sent From iPhone On Mar 29, 2012, at 1:56, Azelio Boriani azelio.bori...@screen.it wrote: We (that is my company) use the CW12-TIM (NMEA version) and its PPS wonders as usual, nothing different from a uBlox LEA-5T or the M12M. On Thu, Mar 29, 2012 at 9:32 AM, Hal Murray hmur...@megapathdsl.net wrote: The sawtooth error on the Motorola M12+ is about +/- 25ns, while the CW12-TIM has a sawtooth error of +/- 2 ns, so correcting for the sawtooth error is not as critical with the CW12-TIM. The first claim The sawtooth error on the Motorola M12+ is about +/- 25ns is correct but are you absolutely sure that the second claim is correct too? It would mean a factor 10 improvement of the CW12-TIM against the M12 which is hardly believeable. The 25 ns probably comes from period of the the free running clock they are using. It doesn't seem unreasonable to me to get 10x better if they use a GPSDO for the local clock so they can get the PPS edge right where they want it. -- 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] Opera coordinator has resigned
I have to say that in general I have been staying clear of this thread. But its really a surprise that they are that sloppy and basing the results on a Vectron OCXO. Not that I have ever had a complaint about those. It just seems like the stunt I would do in the basement on my surplus accelerator. Regards Paul. On Fri, Mar 30, 2012 at 12:57 PM, Tom Van Baak t...@leapsecond.com wrote: Hi Javier, Thanks very much for posting the link to the presentations. For those of you who just want a summary of the resolution of the neutrino faster than light problem, here's what happened: 1) For several years an optical cable connector was loose. I have attached photos from pages 7 and 8 of the G._Sirri.pptx where you can see the actual connector and waveforms, before/after. 2) They used a Vectron OCXO to generate timestamps within each 0.6 second measurement cycle. This oscillator was found to be high in frequency by 0.124 ppm. Thus, depending on where within this 0.6 s interval the timestamp was made a timing bias of 0 to 74 ns would occur. Javier -- if you have contacts there, it looks to me like they forgot to include OCXO frequency drift effects into their analysis. What they did was compensate for linear time drift (which assumes a fixed frequency offset). They call the 124.1 ns/s time drift stable since 2008. What evidence do they have for this? We know that OCXO will drift in *frequency* over time; the time drift is quadratic. The time drift rate may be 124e-9 today, but it probably wasn't last month or last year, etc. /tvb There was a meeting in Gran Sasso on Wednesday. You can see some of the slides at http://agenda.infn.it/**materialDisplay.py?materialId=** slidesconfId=4896http://agenda.infn.it/materialDisplay.py?materialId=slidesconfId=4896 I found particularly interesting the ones by Maximiliano Sioli, where he explained the two mistakes found in the OPERA data acquisition chain and how, after correcting for their best estimate of their effects, the time of flight is compatible with a speed of c. I saw the webcast of the event. Some people did give the OPERA spokesman a hard time, and he admitted to not having fully checked everything they could have. Ah well, everyone makes mistakes. There will be another run with neutrinos spaced by 100 ns in May. If all four experiments in LNGS give the same result this time, I suppose the case will be closed. It will also be very interesting to see the MINOS results. In any event, from a time-nut point of view this is quite exciting. It is the first time neutrino speed is measured with this precision. I think this will pave the way for future experiments using precision geodesy and time transfer. Cheers, Javier ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] CW12-TIM vs M12M and the world
Hi Said, On 3/30/2012 10:53 AM, Said Jackson wrote: Hello Ed, Azelio, We should also compare the same parameters. Sawtooth error of the m12+ of +/-25ns is not its standard deviation, it's max/min. Compare that number to your 30ns max/min measurement on the 5372a. Yes, you're right. Thanks for the clarification. Standard deviation of the m12+ is around 2ns with correction. That needs to be compared to the 5ns you measure on the 5372a as that is the best performance you will get from the CW12. Yes the uncorrected 1pps of the m12 is worse, but it is designed to be used with correction. So in the end the m12m still performs better than the CW12. That's why I suggested to the OP that if the Commsync II uses sawtooth correction the CW12 might not improve his performance. The limited command set you mentioned in your other message is another potential problem. Ed Bye, Said Sent From iPhone On Mar 29, 2012, at 1:56, Azelio Borianiazelio.bori...@screen.it wrote: We (that is my company) use the CW12-TIM (NMEA version) and its PPS wonders as usual, nothing different from a uBlox LEA-5T or the M12M. On Thu, Mar 29, 2012 at 9:32 AM, Hal Murrayhmur...@megapathdsl.net wrote: The sawtooth error on the Motorola M12+ is about +/- 25ns, while the CW12-TIM has a sawtooth error of +/- 2 ns, so correcting for the sawtooth error is not as critical with the CW12-TIM. The first claim The sawtooth error on the Motorola M12+ is about +/- 25ns is correct but are you absolutely sure that the second claim is correct too? It would mean a factor10 improvement of the CW12-TIM against the M12 which is hardly believeable. The 25 ns probably comes from period of the the free running clock they are using. It doesn't seem unreasonable to me to get 10x better if they use a GPSDO for the local clock so they can get the PPS edge right where they want it. ___ time-nuts mailing 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] Opera coordinator has resigned
There are failures and there are failures. A negative result is a failure that is worth reporting. A failure due to an improperly mated connector... not so much. When doing a complex experiment, you have to be an absolute SOB about everything. You cannot inspect in quality. YMMV, -John On 03/30/2012 04:55 PM, Javier Serrano wrote: On Fri, Mar 30, 2012 at 3:07 PM, iov...@inwind.itiov...@inwind.it wrote: http://inagist.com/all/185697069783195648/ Personally I'm sorry about such an end of the story. There was a meeting in Gran Sasso on Wednesday. You can see some of the slides at http://agenda.infn.it/materialDisplay.py?materialId=slidesconfId=4896 I found particularly interesting the ones by Maximiliano Sioli, where he explained the two mistakes found in the OPERA data acquisition chain and how, after correcting for their best estimate of their effects, the time of flight is compatible with a speed of c. I saw the webcast of the event. Some people did give the OPERA spokesman a hard time, and he admitted to not having fully checked everything they could have. Ah well, everyone makes mistakes. There will be another run with neutrinos spaced by 100 ns in May. If all four experiments in LNGS give the same result this time, I suppose the case will be closed. It will also be very interesting to see the MINOS results. As in any research, even a failure is worth reporting, as people can learn from it. Many forget this and tend to select their results which can be a danger as you can go into bad science that way. In any event, from a time-nut point of view this is quite exciting. It is the first time neutrino speed is measured with this precision. I think this will pave the way for future experiments using precision geodesy and time transfer. Will be quite interesting to follow. 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] CW12-TIM vs M12M and the world
Hi Ed, no problem. It's an issue when some companies claim 2ns, when it's really 5ns. Or show phase noise plots that seem to be measurements of just the oscillator removed from the board and measured in a clean-room environment, not measurements of the module with all the digital control noise and spurs etc added.. bye, Said In a message dated 3/30/2012 10:29:32 Pacific Daylight Time, ed_pal...@sasktel.net writes: Hi Said, On 3/30/2012 10:53 AM, Said Jackson wrote: Hello Ed, Azelio, We should also compare the same parameters. Sawtooth error of the m12+ of +/-25ns is not its standard deviation, it's max/min. Compare that number to your 30ns max/min measurement on the 5372a. Yes, you're right. Thanks for the clarification. Standard deviation of the m12+ is around 2ns with correction. That needs to be compared to the 5ns you measure on the 5372a as that is the best performance you will get from the CW12. Yes the uncorrected 1pps of the m12 is worse, but it is designed to be used with correction. So in the end the m12m still performs better than the CW12. That's why I suggested to the OP that if the Commsync II uses sawtooth correction the CW12 might not improve his performance. The limited command set you mentioned in your other message is another potential problem. 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.
Re: [time-nuts] CW12-TIM vs M12M and the world
Actually I don't have a good reference (Z3815A): I'm still preparing my first disciplined Rb and have 2 Fluke PM6681s. I'm waiting for my SR620, it should be on its way to Italy right now. I have 2 TBolts but not yet turned on. What kind of reference have you used? On Fri, Mar 30, 2012 at 8:10 PM, saidj...@aol.com wrote: Hi Ed, no problem. It's an issue when some companies claim 2ns, when it's really 5ns. Or show phase noise plots that seem to be measurements of just the oscillator removed from the board and measured in a clean-room environment, not measurements of the module with all the digital control noise and spurs etc added.. bye, Said In a message dated 3/30/2012 10:29:32 Pacific Daylight Time, ed_pal...@sasktel.net writes: Hi Said, On 3/30/2012 10:53 AM, Said Jackson wrote: Hello Ed, Azelio, We should also compare the same parameters. Sawtooth error of the m12+ of +/-25ns is not its standard deviation, it's max/min. Compare that number to your 30ns max/min measurement on the 5372a. Yes, you're right. Thanks for the clarification. Standard deviation of the m12+ is around 2ns with correction. That needs to be compared to the 5ns you measure on the 5372a as that is the best performance you will get from the CW12. Yes the uncorrected 1pps of the m12 is worse, but it is designed to be used with correction. So in the end the m12m still performs better than the CW12. That's why I suggested to the OP that if the Commsync II uses sawtooth correction the CW12 might not improve his performance. The limited command set you mentioned in your other message is another potential problem. 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] Opera coordinator has resigned
On Fri, Mar 30, 2012 at 7:42 PM, J. Forster j...@quikus.com wrote: There are failures and there are failures. A negative result is a failure that is worth reporting. A failure due to an improperly mated connector... not so much. That is saying to anyone who wants to do a similar experiment in the future that they need at least two redundant systems. I believe that is quite a valuable lesson. Concerning the OCXO, one has to bear in mind that this experiment was not meant to measure time of flight, but rather neutrino oscillations. The message for me here is that it's good to publish all your designs, including gateware sources, as soon as possible, but I don't know how compatible that is with today's highly competitive scientific world. So I think there is an important lesson behind each one of the two issues. Of course this is easy to see from outside and after the fact. Cheers, Javier ___ time-nuts mailing 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] CW12-TIM vs M12M and the world
Has anyone compared the M12M to the M12+? Thanks for all the input, it is really appreciated. best wishes; Thomas Knox CC: time-nuts@febo.com From: saidj...@aol.com Date: Fri, 30 Mar 2012 09:53:17 -0700 To: time-nuts@febo.com Subject: Re: [time-nuts] CW12-TIM vs M12M and the world Hello Ed, Azelio, We should also compare the same parameters. Sawtooth error of the m12+ of +/-25ns is not its standard deviation, it's max/min. Compare that number to your 30ns max/min measurement on the 5372a. Standard deviation of the m12+ is around 2ns with correction. That needs to be compared to the 5ns you measure on the 5372a as that is the best performance you will get from the CW12. Yes the uncorrected 1pps of the m12 is worse, but it is designed to be used with correction. So in the end the m12m still performs better than the CW12. Bye, Said Sent From iPhone On Mar 29, 2012, at 1:56, Azelio Boriani azelio.bori...@screen.it wrote: We (that is my company) use the CW12-TIM (NMEA version) and its PPS wonders as usual, nothing different from a uBlox LEA-5T or the M12M. On Thu, Mar 29, 2012 at 9:32 AM, Hal Murray hmur...@megapathdsl.net wrote: The sawtooth error on the Motorola M12+ is about +/- 25ns, while the CW12-TIM has a sawtooth error of +/- 2 ns, so correcting for the sawtooth error is not as critical with the CW12-TIM. The first claim The sawtooth error on the Motorola M12+ is about +/- 25ns is correct but are you absolutely sure that the second claim is correct too? It would mean a factor 10 improvement of the CW12-TIM against the M12 which is hardly believeable. The 25 ns probably comes from period of the the free running clock they are using. It doesn't seem unreasonable to me to get 10x better if they use a GPSDO for the local clock so they can get the PPS edge right where they want it. -- 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. ___ time-nuts mailing 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] Opera coordinator has resigned
On Fri, Mar 30, 2012 at 7:42 PM, J. Forster j...@quikus.com wrote: There are failures and there are failures. A negative result is a failure that is worth reporting. A failure due to an improperly mated connector... not so much. That is saying to anyone who wants to do a similar experiment in the future that they need at least two redundant systems. I believe that is quite a valuable lesson. Not quite, IMO. You need to do sanity checks. When you are doing science in unknown territory, you need to eliminate everything you can, as a source of error. Remember the problems Perkin Elmer had with the Hubble mirror? Concerning the OCXO, one has to bear in mind that this experiment was not meant to measure time of flight, but rather neutrino oscillations. The message for me here is that it's good to publish all your designs, including gateware sources, as soon as possible, but I don't know how compatible that is with today's highly competitive scientific world. Was there any real competition to this experiment? Seems like they have a lot of very, very big, expensive, unique hardware that can't exactly be bought at Radio Shack. Which is more important? Getting it fast, or getting it right? -John = So I think there is an important lesson behind each one of the two issues. Of course this is easy to see from outside and after the fact. Cheers, Javier ___ time-nuts mailing 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] Opera coordinator has resigned
May anybody out there explain why the connector was simply photographed, and not put in place, on October 13, that is one month before the updated version (Nov 17) of the Opera paper? 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.
Re: [time-nuts] Opera coordinator has resigned
I suppose that when it was photographed, nobody noticed it. After noticed that it was no correctly plugged-in, the past pictures were reviewed and found that in fact it was not fully plugged in :) El 31/03/2012 01:04, iov...@inwind.it escribió: May anybody out there explain why the connector was simply photographed, and not put in place, on October 13, that is one month before the updated version (Nov 17) of the Opera paper? 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] Opera coordinator has resigned
Hi: I take a lot of photos for my web pages and every now and then I go back and find something that was in a photo that I missed when it was taken. It's quite possible that the displayed photos were cropped from larger images showing more of the system. Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/Brooke4Congress.html Javier Herrero wrote: I suppose that when it was photographed, nobody noticed it. After noticed that it was no correctly plugged-in, the past pictures were reviewed and found that in fact it was not fully plugged in :) El 31/03/2012 01:04, iov...@inwind.it escribió: May anybody out there explain why the connector was simply photographed, and not put in place, on October 13, that is one month before the updated version (Nov 17) of the Opera paper? 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. ___ time-nuts mailing 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] Opera coordinator has resigned
On 3/30/12 4:16 PM, Javier Herrero wrote: I suppose that when it was photographed, nobody noticed it. After noticed that it was no correctly plugged-in, the past pictures were reviewed and found that in fact it was not fully plugged in :) We do this all the time at JPL. You have someone come in and take lots of pictures, sort of en masse. If something goes wrong, then you go back and look at the pictures. Sometimes it's a tiny detail that wasn't noticeable until you knew what to look for. (and we've also had loose connector problems.. thankfully not in space that I'm aware of, but I've had more than one SMA that wasn't fully torqued. You can't tell the difference by looking whether it was finger tight or torqued. But after rolling the rack of gear around and shipping it across country a couple times.) El 31/03/2012 01:04, iov...@inwind.it escribió: May anybody out there explain why the connector was simply photographed, and not put in place, on October 13, that is one month before the updated version (Nov 17) of the Opera paper? 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. ___ time-nuts mailing 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 Z3801A Sale
Larry, There really is nothing much to this modification. The Z3801A is already designed to easily work on either interface, but most units are configured for RS-422 as the default. It takes perhaps a half-hour to remove a few zero-ohm SMD resistors and solder in a header strip. The simple procedure is described and illustrated here: www.ad6a.com/Z3801A.html 73, Eric Lemmon WB6FLY -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Larry McDavid Sent: Friday, March 30, 2012 8:44 PM To: Timenuts Subject: [time-nuts] HP Z3801A Sale On 2/16/2012 Brad Stockdale announced here on Time-Nuts that he had a HP Z3801A GPSDO for sale. I corresponded with Brad several times and he reported that he sold one Z3801A to a list member and that this unit had been modified to provide RS-232 rather than RS-422. Brian subsequently sold me another Z3801A that was not modified to provide RS-232 communication; I have not yet received that Z3801A. I would like to correspond off-list with the buyer of the modified Z3801A; I will appreciate a contact to my email address used here. -- Best wishes, Larry McDavid W6FUB Anaheim, CA (20 miles southeast of Los Angeles, near Disneyland) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] Opera coordinator has resigned
. On Mar 30, 2012 10:45 PM, paul swed paulsw...@gmail.com wrote: I have to say that in general I have been staying clear of this thread. But its really a surprise that they are that sloppy and basing the results on a Vectron OCXO. Not that I have ever had a complaint about those. It just seems like the stunt I would do in the basement on my surplus accelerator. Their accelerator _was_ in their basement ;) Regards Paul. On Fri, Mar 30, 2012 at 12:57 PM, Tom Van Baak t...@leapsecond.com wrote: Hi Javier, Thanks very much for posting the link to the presentations. For those of you who just want a summary of the resolution of the neutrino faster than light problem, here's what happened: 1) For several years an optical cable connector was loose. I have attached photos from pages 7 and 8 of the G._Sirri.pptx where you can see the actual connector and waveforms, before/after. 2) They used a Vectron OCXO to generate timestamps within each 0.6 second measurement cycle. This oscillator was found to be high in frequency by 0.124 ppm. Thus, depending on where within this 0.6 s interval the timestamp was made a timing bias of 0 to 74 ns would occur. Javier -- if you have contacts there, it looks to me like they forgot to include OCXO frequency drift effects into their analysis. What they did was compensate for linear time drift (which assumes a fixed frequency offset). They call the 124.1 ns/s time drift stable since 2008. What evidence do they have for this? We know that OCXO will drift in *frequency* over time; the time drift is quadratic. The time drift rate may be 124e-9 today, but it probably wasn't last month or last year, etc. /tvb There was a meeting in Gran Sasso on Wednesday. You can see some of the slides at http://agenda.infn.it/**materialDisplay.py?materialId=** slidesconfId=4896 http://agenda.infn.it/materialDisplay.py?materialId=slidesconfId=4896 I found particularly interesting the ones by Maximiliano Sioli, where he explained the two mistakes found in the OPERA data acquisition chain and how, after correcting for their best estimate of their effects, the time of flight is compatible with a speed of c. I saw the webcast of the event. Some people did give the OPERA spokesman a hard time, and he admitted to not having fully checked everything they could have. Ah well, everyone makes mistakes. There will be another run with neutrinos spaced by 100 ns in May. If all four experiments in LNGS give the same result this time, I suppose the case will be closed. It will also be very interesting to see the MINOS results. In any event, from a time-nut point of view this is quite exciting. It is the first time neutrino speed is measured with this precision. I think this will pave the way for future experiments using precision geodesy and time transfer. Cheers, Javier ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. On Mar 30, 2012 10:45 PM, paul swed paulsw...@gmail.com wrote: I have to say that in general I have been staying clear of this thread. But its really a surprise that they are that sloppy and basing the results on a Vectron OCXO. Not that I have ever had a complaint about those. It just seems like the stunt I would do in the basement on my surplus accelerator. Regards Paul. On Fri, Mar 30, 2012 at 12:57 PM, Tom Van Baak t...@leapsecond.com wrote: Hi Javier, Thanks very much for posting the link to the presentations. For those of you who just want a summary of the resolution of the neutrino faster than light problem, here's what happened: 1) For several years an optical cable connector was loose. I have attached photos from pages 7 and 8 of the G._Sirri.pptx where you can see the actual connector and waveforms, before/after. 2) They used a Vectron OCXO to generate timestamps within each 0.6 second measurement cycle. This oscillator was found to be high in frequency by 0.124 ppm. Thus, depending on where within this 0.6 s interval the timestamp was made a timing bias of 0 to 74 ns would occur. Javier -- if you have contacts there, it looks to me like they forgot to include OCXO frequency drift effects into their analysis. What they did was compensate for linear time drift (which assumes a fixed frequency offset). They call the 124.1 ns/s time drift stable since 2008. What evidence do they have for this? We know that OCXO will drift in *frequency* over time; the time drift is quadratic. The time drift rate may be 124e-9 today, but it probably wasn't last
Re: [time-nuts] HP Z3801A Sale
On 3/30/12 8:43 PM, Larry McDavid wrote: On 2/16/2012 Brad Stockdale announced here on Time-Nuts that he had a HP Z3801A GPSDO for sale. I corresponded with Brad several times and he reported that he sold one Z3801A to a list member and that this unit had been modified to provide RS-232 rather than RS-422. Brian subsequently sold me another Z3801A that was not modified to provide RS-232 communication; I have not yet received that Z3801A. I would like to correspond off-list with the buyer of the modified Z3801A; I will appreciate a contact to my email address used here. The mod is trivial. 3 jumpers on a set of pads for dip switches at the back of the PC board. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
