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 <mag...@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 co
n
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 lo
n
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, Than
ks
a
lot. Regards. Hui Zhang _______________________________________________
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