Dear group:   I have got a SA.33 Rb module from a second hand GPS clock, at first it works well, but soon after it was damaged that beacuse I was trying to install a heat sink on it, unfortunately I used screws which its size too long, so maybe the screws drilled into inside Rb lamp or inside circuit something? I don't know. I am not expecting this Rb can be receoveyed, I am just hope there is no some martirial hamfully leaked out. TVB gave me some information about this Rb module and a papers on this website: http://tycho.usno.navy.mil/ptti/2002papers/paper52.pdf I have read the paper for two times, but I am confused now, the paper described a principle of CSAC clock in 2002, in the papger CSAC was described that it is based on CPT technology, and the CPT is based on a VCSEL and a very small Cesium Cell and other implement necessarily. My question is the SA.3x(or SA.2x) also used this method? In my impression the SA.3x series clock is called Rubidium clock, and the SA.45 is a real Cesium CSAC? So if SA.3x or SA.2x used the technique which mentioned in  paper52, can we say there is some Cesium material in SA.3x? I am totally confused, do anyone can give me some advice? Any information will be appreciated, Thanks a lot. Regards. Hui Zhang

Hi Hui Zhang, > in the paper CSAC was described that it is based on CPT technology > My question is the SA.3x(or SA.2x) also used this method? Yes. Here's another good read; and it also includes photos of the inside of your SA.33: http://www-users.york.ac.uk/~jke1/Atomic_Clocks/Papers/Commercial%20CPT.pdf > In my impression the SA.3x series clock is called Rubidium clock, > and the SA.45 is a real Cesium CSAC? Your use of the phrase "real cesium" may be the source of your confusion. The SA.3x uses rubidium and the SA.4x uses cesium. They are all real atoms. These modern MAC / CSAC atomic standards compete with high-end DOCXO quartz oscillators with respect to factors like temperature, stability, and drift. They do not compete with traditional laboratory rubidium or cesium standards. You may be thinking that because some CPT clocks use cesium instead of rubidium that they are special or more accurate, but this is not the case. None of these compact low-power laser / VCSEL / CPT -based frequency standards are primary standards. /tvb ----- Original Message ----- From: "Jar Sun via time-nuts" <time-nuts@febo.com> To: <time-nuts@febo.com> Sent: Saturday, October 07, 2017 8:27 PM Subject: [time-nuts] Question about SA.33 Rb clock Dear group: I have got a SA.33 Rb module from a second hand GPS clock, at first it works well, but soon after it was damaged that beacuse I was trying to install a heat sink on it, unfortunately I used screws which its size too long, so maybe the screws drilled into inside Rb lamp or inside circuit something? I don't know. I am not expecting this Rb can be receoveyed, I am just hope there is no some martirial hamfully leaked out. TVB gave me some information about this Rb module and a papers on this website: http://tycho.usno.navy.mil/ptti/2002papers/paper52.pdf I have read the paper for two times, but I am confused now, the paper described a principle of CSAC clock in 2002, in the papger CSAC was described that it is based on CPT technology, and the CPT is based on a VCSEL and a very small Cesium Cell and other implement necessarily. My question is the SA.3x(or SA.2x) also used this method? In my impression the SA.3x series clock is called Rubidium clock, and the SA.45 is a real Cesium CSAC? So if SA.3x or SA.2x used the technique which mentioned in paper52, can we say there is some Cesium material in SA.3x? I am totally confused, do anyone can give me some advice? Any information will be appreciated, Thanks a lot. Regards. Hui Zhang _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.

Hi, On 10/12/2017 06:06 PM, Tom Van Baak wrote: > Your use of the phrase "real cesium" may be the source of your confusion. The SA.3x uses rubidium and the SA.4x uses cesium. They are all real atoms. These modern MAC / CSAC atomic standards compete with high-end DOCXO quartz oscillators with respect to factors like temperature, stability, and drift. They do not compete with traditional laboratory rubidium or cesium standards. > > You may be thinking that because some CPT clocks use cesium instead of rubidium that they are special or more accurate, but this is not the case. None of these compact low-power laser / VCSEL / CPT -based frequency standards are primary standards. To follow up on that, even "rubidium" and "cesium" is a bit of misnomers, since you should really say "rubidium optically pumped gas cell clock" and "cesium atomic beam clock", you can build gas cells with cesiums and you can build atomic beams with rubidium. Traditionally rubidium have been very easy to build optically pumped clocks with, but today you can also do that with cesium, which is what the VCSEL based CPT clocks really is. All gas-cells will have the issues of frequency pulling, regardless of rubidium, cesium or other atom being used. The different technologies have different benefits and for some implementation aspects have made different atoms being more preferred over others. As we moved to fountains, rubidium turned out to be a better choice. Cheers, Magnus

Hi Tom and Magnus: Thanks for your reply and informations. I was wrong about all SA.3x things, I thought SA.3x was a traditional Rb87 optically pumped structure rather than CPT concept clock, because I noticed that SA series consums more power(5W at locked), not less power consumption(less 100mW) on the paper of CSAC. Another mistake I made was that I thought only Cs could be used in CSAC or MAC. Thanks for pointing that out, now I'm clear ith that. Regards. Hui Zhang On 2017-10-13 00:06 , Tom Van Baak Wrote: Hi Hui Zhang, > in the paper CSAC was described that it is based on CPT technology > My question is the SA.3x(or SA.2x) also used this method? Yes. Here's another good read; and it also includes photos of the inside of your SA.33: http://www-users.york.ac.uk/~jke1/Atomic_Clocks/Papers/Commercial%20CPT.pdf > In my impression the SA.3x series clock is called Rubidium clock, > and the SA.45 is a real Cesium CSAC? Your use of the phrase "real cesium" may be the source of your confusion. The SA.3x uses rubidium and the SA.4x uses cesium. They are all real atoms. These modern MAC / CSAC atomic standards compete with high-end DOCXO quartz oscillators with respect to factors like temperature, stability, and drift. They do not compete with traditional laboratory rubidium or cesium standards. You may be thinking that because some CPT clocks use cesium instead of rubidium that they are special or more accurate, but this is not the case. None of these compact low-power  laser / VCSEL / CPT -based frequency standards are primary standards. /tvb ----- Original Message ----- From: "Jar Sun via time-nuts" <time-nuts@febo.com> To: <time-nuts@febo.com> Sent: Saturday, October 07, 2017 8:27 PM Subject: [time-nuts] Question about SA.33 Rb clock Dear group: I have got a SA.33 Rb module from a second hand GPS clock, at first it works well, but soon after it was damaged that beacuse I was trying to install a heat sink on it, unfortunately I used screws which its size too long, so maybe the screws drilled into inside Rb lamp or inside circuit something? I don't know. I am not expecting this Rb can be receoveyed, I am just hope there is no some martirial hamfully leaked out. TVB gave me some information about this Rb module and a papers on this website: http://tycho.usno.navy.mil/ptti/2002papers/paper52.pdf I have read the paper for two times, but I am confused now, the paper described a principle of CSAC clock in 2002, in the papger CSAC was described that it is based on CPT technology, and the CPT is based on a VCSEL and a very small Cesium Cell and other implement necessarily. My question is the SA.3x(or SA.2x) also used this method? In my impression the SA.3x series clock is called Rubidium clock, and the SA.45 is a real Cesium CSAC? So if SA.3x or SA.2x used the technique which mentioned in paper52, can we say there is some Cesium material in SA.3x? I am totally confused, do anyone can give me some advice? Any information will be appreciated, Thanks a lot. Regards. Hui Zhang _______________________________________________ time-nuts mailing 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.

Hi, It used to be a simple division, but these days there is several different options on how to build an atomic reference and what atom to use in what setup. There is a myriad of issues under the hood, so there is many different outcomes. There is also some interesting set of products, and using the old simplified description to capture it is now bound to be at risk of mistakes. Rather, let's look at performance, cost, size and power to understand the difference between different options. Cheers, Magnus On 10/15/2017 06:11 AM, Hui Zhang via time-nuts wrote: > Hi Tom and Magnus: Thanks for your reply and informations. I was wrong about all SA.3x things, I thought SA.3x was a traditional Rb87 optically pumped structure rather than CPT concept clock, because I noticed that SA series consums more power(5W at locked), not less power consumption(less 100mW) on the paper of CSAC. Another mistake I made was that I thought only Cs could be used in CSAC or MAC. Thanks for pointing that out, now I'm clear ith that. Regards. Hui Zhang On 2017-10-13 00:06 , Tom Van Baak Wrote: Hi Hui Zhang, > in the paper CSAC was described that it is based on CPT technology > My question is the SA.3x(or SA.2x) also used this method? Yes. Here's another good read; and it also includes photos of the inside of your SA.33: http://www-users.york.ac.uk/~jke1/Atomic_Clocks/Papers/Commercial%20CPT.pdf > In my impression the SA.3x series clock is called Rubidium clock, > and the SA.45 is a real Cesium CSAC? Your use of the phrase "real cesium" may be the source of your confus > ion. The SA.3x uses rubidium and the SA.4x uses cesium. They are all real atoms. These modern MAC / CSAC atomic standards compete with high-end DOCXO quartz oscillators with respect to factors like temperature, stability, and drift. They do not compete with traditional laboratory rubidium or cesium standards. You may be thinking that because some CPT clocks use cesium instead of rubidium that they are special or more accurate, but this is not the case. None of these compact low-power  laser / VCSEL / CPT -based frequency standards are primary standards. /tvb ----- Original Message ----- From: "Jar Sun via time-nuts" <time-nuts@febo.com> To: <time-nuts@febo.com> Sent: Saturday, October 07, 2017 8:27 PM Subject: [time-nuts] Question about SA.33 Rb clock Dear group: I have got a SA.33 Rb module from a second hand GPS clock, at first it works well, but soon after it was damaged that beacuse I was trying to install a heat sink on it, unfortunately I used screws which its size too long, > so maybe the screws drilled into inside Rb lamp or inside circuit something? I don't know. I am not expecting this Rb can be receoveyed, I am just hope there is no some martirial hamfully leaked out. TVB gave me some information about this Rb module and a papers on this website: http://tycho.usno.navy.mil/ptti/2002papers/paper52.pdf I have read the paper for two times, but I am confused now, the paper described a principle of CSAC clock in 2002, in the papger CSAC was described that it is based on CPT technology, and the CPT is based on a VCSEL and a very small Cesium Cell and other implement necessarily. My question is the SA.3x(or SA.2x) also used this method? In my impression the SA.3x series clock is called Rubidium clock, and the SA.45 is a real Cesium CSAC? So if SA.3x or SA.2x used the technique which mentioned in paper52, can we say there is some Cesium material in SA.3x? I am totally confused, do anyone can give me some advice? Any information will be appreciated, Thanks a > lot. Regards. Hui Zhang _______________________________________________ time-nuts mailing 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. >

Hi One of the odd things about typical Rb standards is that the cells come out of manufacturing with a “spread” of frequencies. The more of the spread you can use, the fewer cells you throw away. Today DDS based loops let manufacturers use a *lot* more cells than they could use “back in the old days”. Bob > On Oct 15, 2017, at 8:58 AM, Magnus Danielson <magnus@rubidium.dyndns.org> wrote: > > Hi, > > It used to be a simple division, but these days there is several different options on how to build an atomic reference and what atom to use in what setup. There is a myriad of issues under the hood, so there is many different outcomes. There is also some interesting set of products, and using the old simplified description to capture it is now bound to be at risk of mistakes. > > Rather, let's look at performance, cost, size and power to understand the difference between different options. > > Cheers, > Magnus > > On 10/15/2017 06:11 AM, Hui Zhang via time-nuts wrote: >> Hi Tom and Magnus: Thanks for your reply and informations. I was wrong about all SA.3x things, I thought SA.3x was a traditional Rb87 optically pumped structure rather than CPT concept clock, because I noticed that SA series consums more power(5W at locked), not less power consumption(less 100mW) on the paper of CSAC. Another mistake I made was that I thought only Cs could be used in CSAC or MAC. Thanks for pointing that out, now I'm clear ith that. Regards. Hui Zhang On 2017-10-13 00:06 , Tom Van Baak Wrote: Hi Hui Zhang, > in the paper CSAC was described that it is based on CPT technology > My question is the SA.3x(or SA.2x) also used this method? Yes. Here's another good read; and it also includes photos of the inside of your SA.33: http://www-users.york.ac.uk/~jke1/Atomic_Clocks/Papers/Commercial%20CPT.pdf > In my impression the SA.3x series clock is called Rubidium clock, > and the SA.45 is a real Cesium CSAC? Your use of the phrase "real cesium" may be the source of your conf > us >> ion. The SA.3x uses rubidium and the SA.4x uses cesium. They are all real atoms. These modern MAC / CSAC atomic standards compete with high-end DOCXO quartz oscillators with respect to factors like temperature, stability, and drift. They do not compete with traditional laboratory rubidium or cesium standards. You may be thinking that because some CPT clocks use cesium instead of rubidium that they are special or more accurate, but this is not the case. None of these compact low-power laser / VCSEL / CPT -based frequency standards are primary standards. /tvb ----- Original Message ----- From: "Jar Sun via time-nuts" <time-nuts@febo.com> To: <time-nuts@febo.com> Sent: Saturday, October 07, 2017 8:27 PM Subject: [time-nuts] Question about SA.33 Rb clock Dear group: I have got a SA.33 Rb module from a second hand GPS clock, at first it works well, but soon after it was damaged that beacuse I was trying to install a heat sink on it, unfortunately I used screws which its size too lon > g, >> so maybe the screws drilled into inside Rb lamp or inside circuit something? I don't know. I am not expecting this Rb can be receoveyed, I am just hope there is no some martirial hamfully leaked out. TVB gave me some information about this Rb module and a papers on this website: http://tycho.usno.navy.mil/ptti/2002papers/paper52.pdf I have read the paper for two times, but I am confused now, the paper described a principle of CSAC clock in 2002, in the papger CSAC was described that it is based on CPT technology, and the CPT is based on a VCSEL and a very small Cesium Cell and other implement necessarily. My question is the SA.3x(or SA.2x) also used this method? In my impression the SA.3x series clock is called Rubidium clock, and the SA.45 is a real Cesium CSAC? So if SA.3x or SA.2x used the technique which mentioned in paper52, can we say there is some Cesium material in SA.3x? I am totally confused, do anyone can give me some advice? Any information will be appreciated, Thanks > a >> lot. Regards. Hui Zhang _______________________________________________ time-nuts mailing 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.

Hi Bob, It's not all that odd, we know why, but getting sufficient control over manufacturing cost more than means to overcome it by other aspects of design. The wall-shift, the exact composition of gases and the pull of the cavity is known features of any gas-cell. The drawbacks however allows for a much more economical setup than a beam setup, so it fits a need for stability. Cheers, Magnus On 10/15/2017 05:22 PM, Bob kb8tq wrote: > Hi > > One of the odd things about typical Rb standards is that the cells come out of manufacturing > with a “spread” of frequencies. The more of the spread you can use, the fewer cells you > throw away. Today DDS based loops let manufacturers use a *lot* more cells than they > could use “back in the old days”. > > Bob > > >> On Oct 15, 2017, at 8:58 AM, Magnus Danielson <magnus@rubidium.dyndns.org> wrote: >> >> Hi, >> >> It used to be a simple division, but these days there is several different options on how to build an atomic reference and what atom to use in what setup. There is a myriad of issues under the hood, so there is many different outcomes. There is also some interesting set of products, and using the old simplified description to capture it is now bound to be at risk of mistakes. >> >> Rather, let's look at performance, cost, size and power to understand the difference between different options. >> >> Cheers, >> Magnus >> >> On 10/15/2017 06:11 AM, Hui Zhang via time-nuts wrote: >>> Hi Tom and Magnus: Thanks for your reply and informations. I was wrong about all SA.3x things, I thought SA.3x was a traditional Rb87 optically pumped structure rather than CPT concept clock, because I noticed that SA series consums more power(5W at locked), not less power consumption(less 100mW) on the paper of CSAC. Another mistake I made was that I thought only Cs could be used in CSAC or MAC. Thanks for pointing that out, now I'm clear ith that. Regards. Hui Zhang On 2017-10-13 00:06 , Tom Van Baak Wrote: Hi Hui Zhang, > in the paper CSAC was described that it is based on CPT technology > My question is the SA.3x(or SA.2x) also used this method? Yes. Here's another good read; and it also includes photos of the inside of your SA.33: http://www-users.york.ac.uk/~jke1/Atomic_Clocks/Papers/Commercial%20CPT.pdf > In my impression the SA.3x series clock is called Rubidium clock, > and the SA.45 is a real Cesium CSAC? Your use of the phrase "real cesium" may be the source of your con > f >> us >>> ion. The SA.3x uses rubidium and the SA.4x uses cesium. They are all real atoms. These modern MAC / CSAC atomic standards compete with high-end DOCXO quartz oscillators with respect to factors like temperature, stability, and drift. They do not compete with traditional laboratory rubidium or cesium standards. You may be thinking that because some CPT clocks use cesium instead of rubidium that they are special or more accurate, but this is not the case. None of these compact low-power laser / VCSEL / CPT -based frequency standards are primary standards. /tvb ----- Original Message ----- From: "Jar Sun via time-nuts" <time-nuts@febo.com> To: <time-nuts@febo.com> Sent: Saturday, October 07, 2017 8:27 PM Subject: [time-nuts] Question about SA.33 Rb clock Dear group: I have got a SA.33 Rb module from a second hand GPS clock, at first it works well, but soon after it was damaged that beacuse I was trying to install a heat sink on it, unfortunately I used screws which its size too lon >> g, >>> so maybe the screws drilled into inside Rb lamp or inside circuit something? I don't know. I am not expecting this Rb can be receoveyed, I am just hope there is no some martirial hamfully leaked out. TVB gave me some information about this Rb module and a papers on this website: http://tycho.usno.navy.mil/ptti/2002papers/paper52.pdf I have read the paper for two times, but I am confused now, the paper described a principle of CSAC clock in 2002, in the papger CSAC was described that it is based on CPT technology, and the CPT is based on a VCSEL and a very small Cesium Cell and other implement necessarily. My question is the SA.3x(or SA.2x) also used this method? In my impression the SA.3x series clock is called Rubidium clock, and the SA.45 is a real Cesium CSAC? So if SA.3x or SA.2x used the technique which mentioned in paper52, can we say there is some Cesium material in SA.3x? I am totally confused, do anyone can give me some advice? Any information will be appreciated, Thanks >> a >>> lot. Regards. Hui Zhang _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. >