[time-nuts] Question about SA.33 Rb clock
kb8tq at n1k.org
Sun Oct 15 11:22:37 EDT 2017
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”.
> On Oct 15, 2017, at 8:58 AM, Magnus Danielson <magnus at rubidium.dyndns.org> wrote:
> 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.
> 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
>> 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 at febo.com> To: <time-nuts at 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
>> 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
>> lot. Regards. Hui Zhang _______________________________________________ time-nuts mailing list -- time-nuts at 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 at febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
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