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Bert22306
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CEO
Time standards represent technological state of the art
Bert22306   4/6/2014 6:35:24 PM
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The Smithsonian Institution in Wash DC has had very interesting time standards exhibits over the years. It turns out, the way we tell time and keep time is a good representation of our technological SOTA.

Related to this, a year ago, the signal transmitted by WWVB was upgraded for theoretically easier reception for receivers far from Fort Collins:

http://www.nist.gov/pml/div688/wwvb-030513.cfm

That seems to have eluded the popular press, and worse, I've been finding it difficult or impossible to determine if new "atomic clocks" available today make use of this new phase modulated signal. Would be nice to know. As of now, I've had to rig an extra longwire antenna to my "atomic clock" sitting on the mantlepiece, on the East Coast, to get reasonably reliable reception of WWVB.

Difficulty in reception seems to have caused these radio clocks to disappear from retail stores where I live, in favor of utterly inadequate supposedly "automatic" clocks. Nothing "automatic" about this new breed. All they do is use a lithium cell to keep time when power is removed from the clock, instead of alkaline cells used previously. Big deal. They are very inaccurate.

One wonders why this sort of news never makes the news. Maybe if people knew about this stuff, it would stimulate demand for such clocks and watches, in parts of the country where they essentially don't exist.

R_Colin_Johnson
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Blogger
Re: Time standards represent technological state of the art
R_Colin_Johnson   4/6/2014 7:06:49 PM
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I don't believe that any commercial atomic clocks are yet using the phase modulated signal from WWVB, but the chip sets have been available from Eversetclocks for a year, so it probably won't be long.

markmhel
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Rookie
Re: Time standards represent technological state of the art
markmhel   4/11/2014 7:38:52 PM
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Could be the best part and now they seem to keep this way at all. - Lindsay Rosenwald

Sheepdoll
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Blogger
And the antenna is?
Sheepdoll   4/6/2014 7:19:21 PM
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I have always been fascinated by WWV.  We had a radio that would receive it directly.

When WWVB got popular I got a module, I think it was from Parallax.  The Antenna was so big I never used it.  One of those projects that is waiting for, well to pardon the expression, waiting for the right time.

prabhakar_deosthali
User Rank
CEO
Time stamping at such high accuracy?
prabhakar_deosthali   4/7/2014 8:17:59 AM
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I am just wondering how such a ultra high accuracy time standard can be used for time stamping the financial transactions or for that matter any event, becuase the time taken to receive the signal will be definitely longer .

R_Colin_Johnson
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Blogger
Re: Time stamping at such high accuracy?
R_Colin_Johnson   4/7/2014 1:18:19 PM
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Off the top of my head, I would think that calibration at the receiving end of the time stamp would compensate for the "time taken to receive the signal". 

Anand.Yaligar
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Rookie
Re: Interesting but why?
Anand.Yaligar   4/8/2014 2:42:51 PM
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This is very interesting information. Personally I knew about the NITS-F1 but I would never have that it would be that accurate. Plus or minus a Second spread over a million years! Frankly that should be more than enough. Now the new F2 model clock has taken 10 years to develop only to increase that accuracy by another 100 million years. Please don't tell me that some guys were paid over the 10 years to develop something whose benefits will hardly be enjoyed anytime within the coming 1000 generations of humans.

Anand.Yaligar
User Rank
Rookie
Re: Amazing project
Anand.Yaligar   4/12/2014 10:37:39 AM
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Although the current time standard NIST-F1 with accuracy of +1 or -1 second over 1m years was not that bad, I think the new time standard  NIST-F2 is a grater one. If some applications can use three time greater accuracy, then it means that it is the best.  Its accuracy of within +1 or -1 second over 3m years makes it a great achievement by NIST. Nice job NIST. 



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