Re: [time-nuts] Question about SA.33 Rb clock

Hi > On Oct 17, 2017, at 12:37 AM, Hal Murray wrote: > > > kb...@n1k.org said: >> The gotcha is that the spur spec’s are not always met. As you might guess, >> doing testing over really wide DDS ranges is impractical. Some designs use >> cleanup loops. The gotcha then

Re: [time-nuts] Question about SA.33 Rb clock

On 10/16/17 9:37 PM, Hal Murray wrote: kb...@n1k.org said: The gotcha is that the spur spec’s are not always met. As you might guess, doing testing over really wide DDS ranges is impractical. Some designs use cleanup loops. The gotcha then becomes a spur (say at 0.053 Hz) that is inside the

Re: [time-nuts] Question about SA.33 Rb clock

kb...@n1k.org said: > The gotcha is that the spur spec’s are not always met. As you might guess, > doing testing over really wide DDS ranges is impractical. Some designs use > cleanup loops. The gotcha then becomes a spur (say at 0.053 Hz) that is > inside the cleanup loop bandwidth …. How

Re: [time-nuts] Question about SA.33 Rb clock

Hi > On Oct 15, 2017, at 12:47 PM, Hal Murray wrote: > > > kb...@n1k.org said: >> Today DDS based loops let manufacturers use a *lot* more cells than they >> could use “back in the old days”. > > I'd expect that to produce close in spurs that would be ugly in some >

Re: [time-nuts] Question about SA.33 Rb clock

kb...@n1k.org said: > Today DDS based loops let manufacturers use a *lot* more cells than they > could use “back in the old days”. I'd expect that to produce close in spurs that would be ugly in some applications. Is that info in the data sheet and/or are designers clued in? -- These

Re: [time-nuts] Question about SA.33 Rb clock

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

Re: [time-nuts] Question about SA.33 Rb clock

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

Re: [time-nuts] Question about SA.33 Rb clock

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

Re: [time-nuts] Question about SA.33 Rb clock

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

Re: [time-nuts] Question about SA.33 Rb clock

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

Re: [time-nuts] Question about SA.33 Rb clock

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: