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 <[email protected]> > 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" <[email protected]> To: <[email protected]> >> 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 -- [email protected] To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the >> instructions there. _______________________________________________ >> time-nuts mailing list -- [email protected] To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the >> instructions there. >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
