Re: [time-nuts] chip scale atomic clock
Dear all, After very mild amount of homework, I think a followup was due. Magnus Danielson wrote: Peter Vince wrote: 2009/12/26 Robert Lutwak lut...@alum.mit.edu: ... CSAC is intended for portable battery-powered operation. Surely your basement has the space and wallplug power to support an LPRO. (p.s. don't cool the damn thing, heat it). ... Hi Robert, Do I understand you are suggesting heating an LPRO, not cooling it? That seems to go against what I understood, that greater cooling leads to increased life. While not directed to me, these are my understandings: Besides the power applied to heat the Rb lamp, the physical package needs to be at the sweet-spot in temperature, so heating is performed. Looking in the LPRO manual, as found in say: http://www.ham-radio.com/sbms/LPRO-101.pdf and the LPRO repair-guide: http://www.radcomms.net/EFRATOM%20LPRO%20101%20Repair%20Guide.pdf The Rb lamp heats to 110 C and the physical package to 78 C. Notice also figure 1.3 displaying power dissapation as a funciton of baseplate temperature. The simplified model for power consumption in chapter 3.2.3 gives a good hint about what is going on. For 20 degrees the RF lamp consumes about 1,7 W where as for 70 degrees it consumed about 750 mW. Similarly, for 20 degrees the physical package heating consumes about 3,8 W where as for 70 degrees it constumed about 520 mW. Thus, allowing the increase of baseplate temperature from 20 degrees to 70 degrees reduces the Rubidium assembly heating from a total of 5,5 W to 1,3 W. Looking at figure 1.3 and the equation again, we see that about 280 mA derives from the other electronics and that a lower (18 V) supply has significant shift in power. Thus, by paying attention to supplied power and baseplate temperature and cooling (which becomes more important to maintain baseplate below 70 degrees) less power dissapation can be achieved. With that in hand, both passive and active ovenizing could be considered. 5-6 W is significantly lower than 12-13 W and should allow for simpler solutions. There is also hints about how to temperature compensate the LPRO by steering the C-field from a temperature sensor. A sensible ovenization should reduce the need of such approaches, even if possible. Boxing one up similar to that of Thunderbolts may be the way to go. 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] chip scale atomic clock
2009/12/26 Robert Lutwak lut...@alum.mit.edu: ... CSAC is intended for portable battery-powered operation. Surely your basement has the space and wallplug power to support an LPRO. (p.s. don't cool the damn thing, heat it). ... Hi Robert, Do I understand you are suggesting heating an LPRO, not cooling it? That seems to go against what I understood, that greater cooling leads to increased life. As an aside, a newbie question if I may: being so used to Caesium standards being THE reference, I was surprised to hear that the CSAC has an aging mechanism - can you say a few words to explain that please? Peter ___ time-nuts mailing 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] chip scale atomic clock
Peter Vince wrote: 2009/12/26 Robert Lutwak lut...@alum.mit.edu: ... CSAC is intended for portable battery-powered operation. Surely your basement has the space and wallplug power to support an LPRO. (p.s. don't cool the damn thing, heat it). ... Hi Robert, Do I understand you are suggesting heating an LPRO, not cooling it? That seems to go against what I understood, that greater cooling leads to increased life. While not directed to me, these are my understandings: Besides the power applied to heat the Rb lamp, the physical package needs to be at the sweet-spot in temperature, so heating is performed. By lowering the cooling of the physical package, the powerconsumption goes down. So better isolation has to cool of less effect. This stands in contradiction to the lifetime of the electronics, but the physical package and electronics have two different requirements. As an aside, a newbie question if I may: being so used to Caesium standards being THE reference, I was surprised to hear that the CSAC has an aging mechanism - can you say a few words to explain that please? Don't confuse the stability and repeatability of elaborate beam clocks with that of (cheaper) gas cell clocks. Rubidium and Thallium beams has existed but Cesium was a better match for that purpose, Rubidium was found more suitable for the simpler and cheaper gas cell standard. Rubidium excells over Cesium in laser cooled fointains, since it reacts better to the laser cooling. Thus, each technology finds different technological balances with different atoms. May one suspect that the gas cells buffert gas mixture and resulting wall-shift/gas-shift balance is one of the long-term age effects, just as with ordinary rubidium gas cells. Another aspect to consider is that this clock does not have the C-field servo loop which modern cesium beams have. Then again, I think Robert can lecture a mere student (lazy such) to the field like me. 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] chip scale atomic clock
On Dec 26, 2009, at 10:36 AM, Robert Lutwak wrote: I pay pretty close attention to what people in this field are saying, and I've never heard anyone say we'll get to 1e-11 short term stability at 1 second real soon now. 1e-11 at 1 second is the XPRO spec (and 2X better than LPRO or PRS10). There are good (physics) reasons why those units all draw 100X more power than a CSAC. CSAC is intended for portable battery-powered operation. Surely your basement has the space and wallplug power to support an LPRO. (p.s. don't cool the damn thing, heat it). The cats were much happier during the CsIII development (see http:// home.comcast.net/~rlutwak). It was bigger and warmer. Any Cat-Nuts out there who can help me find one with significantly lower SWAP? You know, that gives me an idea...I could justify some interesting equipment if I assured the XYL that it was simply a cat bed heater. As for this heat sinking of a Rb, might it be better to use a refrigerator? More practical. Tom Frank, KA2CDK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] chip scale atomic clock
I read about this a while ago. Has anyone seen anything recent about it, notably desktop or even portable units? Ronald ___ time-nuts mailing 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] chip scale atomic clock
On Sat, Dec 26, 2009 at 8:23 AM, Ronald Held ronaldh...@gmail.com wrote: I read about this a while ago. Researcher Time Line Translations were explained here a few days ago: http://www.xkcd.com/678/ The mouse-overs always have interesting comments... -- http://www.wearablesmartsensors.com/ http://www.softwaresafety.net/ http://www.designer-iii.com/ http://www.unusualresearch.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] chip scale atomic clock
I have one here, on my desktop, at home. It's drawing about 100 mW and performing at about 8e-11/sqrt(tau). At 08:23 AM 12/26/2009, you wrote: I read about this a while ago. Has anyone seen anything recent about it, notably desktop or even portable units? Ronald ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) ___ time-nuts mailing 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] chip scale atomic clock
How good do you want? At 09:13 AM 12/26/2009, you wrote: Hi They still seem to be at the stage of we'll get to good short term stability at 1 second real soon now. Bob On Dec 26, 2009, at 8:23 AM, Ronald Held wrote: I read about this a while ago. Has anyone seen anything recent about it, notably desktop or even portable units? Ronald ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) ___ time-nuts mailing 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] chip scale atomic clock
Hi 1x10-11 at 1 second, going down by tau^0.5. That makes them candidates for the basement system Bob On Dec 26, 2009, at 9:33 AM, Robert Lutwak wrote: How good do you want? At 09:13 AM 12/26/2009, you wrote: Hi They still seem to be at the stage of we'll get to good short term stability at 1 second real soon now. Bob On Dec 26, 2009, at 8:23 AM, Ronald Held wrote: I read about this a while ago. Has anyone seen anything recent about it, notably desktop or even portable units? Ronald ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] chip scale atomic clock
I pay pretty close attention to what people in this field are saying, and I've never heard anyone say we'll get to 1e-11 short term stability at 1 second real soon now. 1e-11 at 1 second is the XPRO spec (and 2X better than LPRO or PRS10). There are good (physics) reasons why those units all draw 100X more power than a CSAC. CSAC is intended for portable battery-powered operation. Surely your basement has the space and wallplug power to support an LPRO. (p.s. don't cool the damn thing, heat it). The cats were much happier during the CsIII development (see http://home.comcast.net/~rlutwak). It was bigger and warmer. Any Cat-Nuts out there who can help me find one with significantly lower SWAP? -RL At 10:08 AM 12/26/2009, you wrote: Hi 1x10-11 at 1 second, going down by tau^0.5. That makes them candidates for the basement system Bob On Dec 26, 2009, at 9:33 AM, Robert Lutwak wrote: How good do you want? At 09:13 AM 12/26/2009, you wrote: Hi They still seem to be at the stage of we'll get to good short term stability at 1 second real soon now. Bob On Dec 26, 2009, at 8:23 AM, Ronald Held wrote: I read about this a while ago. Has anyone seen anything recent about it, notably desktop or even portable units? Ronald ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) ___ time-nuts mailing 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] chip scale atomic clock
Hi Not ment as a knock, just a comment that a lot of work is still being done on getting short term stability closer to a 100~1000X bigger device. Bob On Dec 26, 2009, at 10:36 AM, Robert Lutwak wrote: I pay pretty close attention to what people in this field are saying, and I've never heard anyone say we'll get to 1e-11 short term stability at 1 second real soon now. 1e-11 at 1 second is the XPRO spec (and 2X better than LPRO or PRS10). There are good (physics) reasons why those units all draw 100X more power than a CSAC. CSAC is intended for portable battery-powered operation. Surely your basement has the space and wallplug power to support an LPRO. (p.s. don't cool the damn thing, heat it). The cats were much happier during the CsIII development (see http://home.comcast.net/~rlutwak). It was bigger and warmer. Any Cat-Nuts out there who can help me find one with significantly lower SWAP? -RL At 10:08 AM 12/26/2009, you wrote: Hi 1x10-11 at 1 second, going down by tau^0.5. That makes them candidates for the basement system Bob On Dec 26, 2009, at 9:33 AM, Robert Lutwak wrote: How good do you want? At 09:13 AM 12/26/2009, you wrote: Hi They still seem to be at the stage of we'll get to good short term stability at 1 second real soon now. Bob On Dec 26, 2009, at 8:23 AM, Ronald Held wrote: I read about this a while ago. Has anyone seen anything recent about it, notably desktop or even portable units? Ronald ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] chip scale atomic clock
In message e1noyhh-0005ui...@meow.febo.com, Robert Lutwak writes: The cats were much happier during the CsIII development (see http://home.comcast.net/~rlutwak). It was bigger and warmer. Any Cat-Nuts out there who can help me find one with significantly lower SWAP? Just read a couple of the papers on your site: Impressive work! Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] chip scale atomic clock
Hi I *knew* I'd seen a chart somewhere that was getting close to 1x10-11 at 1 second for the best of the group. It's figure B on page 7 of your FSM 2008 paper. Bob On Dec 26, 2009, at 10:36 AM, Robert Lutwak wrote: I pay pretty close attention to what people in this field are saying, and I've never heard anyone say we'll get to 1e-11 short term stability at 1 second real soon now. 1e-11 at 1 second is the XPRO spec (and 2X better than LPRO or PRS10). There are good (physics) reasons why those units all draw 100X more power than a CSAC. CSAC is intended for portable battery-powered operation. Surely your basement has the space and wallplug power to support an LPRO. (p.s. don't cool the damn thing, heat it). The cats were much happier during the CsIII development (see http://home.comcast.net/~rlutwak). It was bigger and warmer. Any Cat-Nuts out there who can help me find one with significantly lower SWAP? -RL At 10:08 AM 12/26/2009, you wrote: Hi 1x10-11 at 1 second, going down by tau^0.5. That makes them candidates for the basement system Bob On Dec 26, 2009, at 9:33 AM, Robert Lutwak wrote: How good do you want? At 09:13 AM 12/26/2009, you wrote: Hi They still seem to be at the stage of we'll get to good short term stability at 1 second real soon now. Bob On Dec 26, 2009, at 8:23 AM, Ronald Held wrote: I read about this a while ago. Has anyone seen anything recent about it, notably desktop or even portable units? Ronald ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] chip scale atomic clock
Notwithstanding the performance of one physics package, I think it's safe to say that no-one is holding their breath waiting for a 1e-11 CSAC. That figure (5B) shows the Allan deviation of 10 physics packages (measured with optimal laboratory electronics) and you are correct that the best of the bunch is down around 2-3e-11 at 1-second. At that time, with low-power CSAC electronics, the performance of that same physics package was up around 1e-10 and most were in the 2-3e-10 range (see Figure 6), which would have led to a spec somewhere north of there, perhaps 3-4e-10. For your amusement, I just added a more recent paper (from the 2009 FCS/EFTF) to my WWW site. Figure 3 in that paper shows some more recent results with (newer, better, and lower power) electronics but similar physics package architecture. These days, typical CSAC instability is in the range of 8-10e-11 @ 1second, which might lead to a spec in the 1-3e-10 range. -RL At 11:41 AM 12/26/2009, you wrote: Hi I *knew* I'd seen a chart somewhere that was getting close to 1x10-11 at 1 second for the best of the group. It's figure B on page 7 of your FSM 2008 paper. Bob On Dec 26, 2009, at 10:36 AM, Robert Lutwak wrote: I pay pretty close attention to what people in this field are saying, and I've never heard anyone say we'll get to 1e-11 short term stability at 1 second real soon now. 1e-11 at 1 second is the XPRO spec (and 2X better than LPRO or PRS10). There are good (physics) reasons why those units all draw 100X more power than a CSAC. CSAC is intended for portable battery-powered operation. Surely your basement has the space and wallplug power to support an LPRO. (p.s. don't cool the damn thing, heat it). The cats were much happier during the CsIII development (see http://home.comcast.net/~rlutwak). It was bigger and warmer. Any Cat-Nuts out there who can help me find one with significantly lower SWAP? -RL At 10:08 AM 12/26/2009, you wrote: Hi 1x10-11 at 1 second, going down by tau^0.5. That makes them candidates for the basement system Bob On Dec 26, 2009, at 9:33 AM, Robert Lutwak wrote: How good do you want? At 09:13 AM 12/26/2009, you wrote: Hi They still seem to be at the stage of we'll get to good short term stability at 1 second real soon now. Bob On Dec 26, 2009, at 8:23 AM, Ronald Held wrote: I read about this a while ago. Has anyone seen anything recent about it, notably desktop or even portable units? Ronald ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978)
Re: [time-nuts] chip scale atomic clock
So when do we see them on ebay?? ;-) Like the low power aspect. instead of 20-40 watts or more On Sat, Dec 26, 2009 at 11:14 AM, Bob Camp li...@cq.nu wrote: Hi Not ment as a knock, just a comment that a lot of work is still being done on getting short term stability closer to a 100~1000X bigger device. Bob On Dec 26, 2009, at 10:36 AM, Robert Lutwak wrote: I pay pretty close attention to what people in this field are saying, and I've never heard anyone say we'll get to 1e-11 short term stability at 1 second real soon now. 1e-11 at 1 second is the XPRO spec (and 2X better than LPRO or PRS10). There are good (physics) reasons why those units all draw 100X more power than a CSAC. CSAC is intended for portable battery-powered operation. Surely your basement has the space and wallplug power to support an LPRO. (p.s. don't cool the damn thing, heat it). The cats were much happier during the CsIII development (see http://home.comcast.net/~rlutwak http://home.comcast.net/%7Erlutwak). It was bigger and warmer. Any Cat-Nuts out there who can help me find one with significantly lower SWAP? -RL At 10:08 AM 12/26/2009, you wrote: Hi 1x10-11 at 1 second, going down by tau^0.5. That makes them candidates for the basement system Bob On Dec 26, 2009, at 9:33 AM, Robert Lutwak wrote: How good do you want? At 09:13 AM 12/26/2009, you wrote: Hi They still seem to be at the stage of we'll get to good short term stability at 1 second real soon now. Bob On Dec 26, 2009, at 8:23 AM, Ronald Held wrote: I read about this a while ago. Has anyone seen anything recent about it, notably desktop or even portable units? Ronald ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.com rlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu(Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.com rlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu(Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.com rlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu(Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.com rlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu(Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.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] chip scale atomic clock
Hi Thanks, that's one I hadn't seen yet. I did not get Besancon this year. I guess my main point is that *if* the physics package is capable of ~2x10^-11 with good electronics, then what ever you get past that is simply mission related. A different system requirement could take the performance closer to that ideal. Good to see that the RbXO is coming back to life (again). It would have been nice to get it into production back at EGG. Bob On Dec 26, 2009, at 12:30 PM, Robert Lutwak wrote: Notwithstanding the performance of one physics package, I think it's safe to say that no-one is holding their breath waiting for a 1e-11 CSAC. That figure (5B) shows the Allan deviation of 10 physics packages (measured with optimal laboratory electronics) and you are correct that the best of the bunch is down around 2-3e-11 at 1-second. At that time, with low-power CSAC electronics, the performance of that same physics package was up around 1e-10 and most were in the 2-3e-10 range (see Figure 6), which would have led to a spec somewhere north of there, perhaps 3-4e-10. For your amusement, I just added a more recent paper (from the 2009 FCS/EFTF) to my WWW site. Figure 3 in that paper shows some more recent results with (newer, better, and lower power) electronics but similar physics package architecture. These days, typical CSAC instability is in the range of 8-10e-11 @ 1second, which might lead to a spec in the 1-3e-10 range. -RL At 11:41 AM 12/26/2009, you wrote: Hi I *knew* I'd seen a chart somewhere that was getting close to 1x10-11 at 1 second for the best of the group. It's figure B on page 7 of your FSM 2008 paper. Bob On Dec 26, 2009, at 10:36 AM, Robert Lutwak wrote: I pay pretty close attention to what people in this field are saying, and I've never heard anyone say we'll get to 1e-11 short term stability at 1 second real soon now. 1e-11 at 1 second is the XPRO spec (and 2X better than LPRO or PRS10). There are good (physics) reasons why those units all draw 100X more power than a CSAC. CSAC is intended for portable battery-powered operation. Surely your basement has the space and wallplug power to support an LPRO. (p.s. don't cool the damn thing, heat it). The cats were much happier during the CsIII development (see http://home.comcast.net/~rlutwak). It was bigger and warmer. Any Cat-Nuts out there who can help me find one with significantly lower SWAP? -RL At 10:08 AM 12/26/2009, you wrote: Hi 1x10-11 at 1 second, going down by tau^0.5. That makes them candidates for the basement system Bob On Dec 26, 2009, at 9:33 AM, Robert Lutwak wrote: How good do you want? At 09:13 AM 12/26/2009, you wrote: Hi They still seem to be at the stage of we'll get to good short term stability at 1 second real soon now. Bob On Dec 26, 2009, at 8:23 AM, Ronald Held wrote: I read about this a while ago. Has anyone seen anything recent about it, notably desktop or even portable units? Ronald ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) -RL --- Robert Lutwak Symmetricom - Technology Realization Center mhtml:mid:///mailto:rlut...@symmetricom.comrlut...@symmetricom.com (Business) mhtml:mid:///mailto:lut...@alum.mit.edulut...@alum.mit.edu (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (Facsimile) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -RL --- Robert Lutwak
Re: [time-nuts] Chip-scale Atomic Clock !
Could be this: THE *CHIP*-SCALE *ATOMIC CLOCK* – RECENT DEVELOPMENT PROGRESS http://tycho.usno.navy.mil/ptti/ptti2003/paper44.pdf#search=%22usno%20chip%20atomic%20clock%22 http://tycho.usno.navy.mil/ptti/ptti2003/paper44.pdf#search=%22usno%20chip%20atomic%20clock%22 See also the conference papers at: http://www.symmttm.com/info_center_white_papers.asp # The MAC - A Miniature Atomic Clock. # An Ultra-Low-Power Physics Package for a Chip-Scale Atomic Clock. # The Chip-Scale Atomic Clock – Low-Power Physics Package: 2004. # The Chip-Scale Atomic Clock – Recent Development Progress: 2003. # The Chip-Scale Atomic Clock – Coherent Population Trapping vs. Conventional Interrogation: 2002. http://www.symmttm.com/pdf/Precision_Frequency_References/wp_PTTI_2002.pdf Brooks Shera wrote: The excerpt below from GPS World refers to a Chip-scale atomic clock being developed by DARPA. Does anyone know what technology they might be using for such a clock? Atomic Clock Synchronization The U.S. Navy Space and Naval Warfare Systems Center San Diego is incorporating a chip-scale atomic clock into a new GPS receiver design, the Navigation Nugget. read more»The Nugget fuses a GPS software-defined receiver with an inertial measurement unit (IMU), synchronized by an onboard atomic clock, to create a positioning, navigation, and timing-sensor suite capable of withstanding impaired and threatened GPS environments. The chip-scale atomic clock is being developed by Defense Advanced Research Projects Agency. Adding an atomic clock to the GPS/IMU combination will help ground forces in canopy or jammed environments and improve vertical accuracy. A large-scale prototype Navigation Nugget is expected to be field tested in one year. Space and Naval Warfare Systems Center, www.spawar.navy.mil/sandiego/. -Brooks ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Chip-scale Atomic Clock !
Hello, you will find a lots of details at: http://tf.nist.gov/ofm/smallclock/index.htm 73, Jean-Louis Oneto OCA GEMINI - Avenue Copernic - 06130 Grasse - France e-mail: [EMAIL PROTECTED] - Original Message - From: Brooks Shera [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, September 20, 2006 12:48 AM Subject: [time-nuts] Chip-scale Atomic Clock ! The excerpt below from GPS World refers to a Chip-scale atomic clock being developed by DARPA. Does anyone know what technology they might be using for such a clock? Atomic Clock Synchronization The U.S. Navy Space and Naval Warfare Systems Center San Diego is incorporating a chip-scale atomic clock into a new GPS receiver design, the Navigation Nugget. read more»The Nugget fuses a GPS software-defined receiver with an inertial measurement unit (IMU), synchronized by an onboard atomic clock, to create a positioning, navigation, and timing-sensor suite capable of withstanding impaired and threatened GPS environments. The chip-scale atomic clock is being developed by Defense Advanced Research Projects Agency. Adding an atomic clock to the GPS/IMU combination will help ground forces in canopy or jammed environments and improve vertical accuracy. A large-scale prototype Navigation Nugget is expected to be field tested in one year. Space and Naval Warfare Systems Center, www.spawar.navy.mil/sandiego/. -Brooks ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Chip-scale Atomic Clock !
Go check the NIST pages as well. On Wed, September 20, 2006 0:56, Glenn said: Could be this: THE *CHIP*-SCALE *ATOMIC CLOCK* â RECENT DEVELOPMENT PROGRESS http://tycho.usno.navy.mil/ptti/ptti2003/paper44.pdf#search=%22usno%20chip%20atomic%20clock%22 http://tycho.usno.navy.mil/ptti/ptti2003/paper44.pdf#search=%22usno%20chip%20atomic%20clock%22 See also the conference papers at: http://www.symmttm.com/info_center_white_papers.asp # The MAC - A Miniature Atomic Clock. # An Ultra-Low-Power Physics Package for a Chip-Scale Atomic Clock. # The Chip-Scale Atomic Clock â Low-Power Physics Package: 2004. # The Chip-Scale Atomic Clock â Recent Development Progress: 2003. # The Chip-Scale Atomic Clock â Coherent Population Trapping vs. Conventional Interrogation: 2002. http://www.symmttm.com/pdf/Precision_Frequency_References/wp_PTTI_2002.pdf Brooks Shera wrote: The excerpt below from GPS World refers to a Chip-scale atomic clock being developed by DARPA. Does anyone know what technology they might be using for such a clock? Atomic Clock Synchronization The U.S. Navy Space and Naval Warfare Systems Center San Diego is incorporating a chip-scale atomic clock into a new GPS receiver design, the Navigation Nugget. read more»The Nugget fuses a GPS software-defined receiver with an inertial measurement unit (IMU), synchronized by an onboard atomic clock, to create a positioning, navigation, and timing-sensor suite capable of withstanding impaired and threatened GPS environments. The chip-scale atomic clock is being developed by Defense Advanced Research Projects Agency. Adding an atomic clock to the GPS/IMU combination will help ground forces in canopy or jammed environments and improve vertical accuracy. A large-scale prototype Navigation Nugget is expected to be field tested in one year. Space and Naval Warfare Systems Center, www.spawar.navy.mil/sandiego/. -Brooks ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Chip-scale Atomic Clock !
Brooks Shera said the following on 09/19/2006 06:48 PM: The excerpt below from GPS World refers to a Chip-scale atomic clock being developed by DARPA. Does anyone know what technology they might be using for such a clock? Atomic Clock Synchronization The U.S. Navy Space and Naval Warfare Systems Center San Diego is incorporating a chip-scale atomic clock into a new GPS receiver design, the Navigation Nugget. read more»The Nugget fuses a GPS software-defined receiver with an inertial measurement unit (IMU), synchronized by an onboard atomic clock, to create a positioning, navigation, and timing-sensor suite capable of withstanding impaired and threatened GPS environments. The chip-scale atomic clock is being developed by Defense Advanced Research Projects Agency. Adding an atomic clock to the GPS/IMU combination will help ground forces in canopy or jammed environments and improve vertical accuracy. A large-scale prototype Navigation Nugget is expected to be field tested in one year. Space and Naval Warfare Systems Center, www.spawar.navy.mil/sandiego/. There was a tiny Rb standard publicized a while ago. I wonder if this is it? John ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
