[time-nuts] NIST

Mike Cook michael.cook at sfr.fr
Mon Aug 13 05:55:09 EDT 2018


> Le 13 août 2018 à 11:09, Dana Whitlow <k8yumdoober at gmail.com> a écrit :
> 
> Craig,
> 
> The original main reason for WWVB had nothing to do with syncing our
> "atomic"
> wristwatches and clocks.  It was for keeping local frequency standards
> honest, for
> which continuous coverage throughout the day and night was desirable (if not
> always achievable).  But for that application, a one-shot daily sync was
> not really
> good enough (for most users).  Stations that used WWVB for serious purposes
> used
> outdoor electrostatically-shielded loop antennas, usually up on the roof,
> to get
> enough signal enough of the time.

     This function of disseminating a frequency reference is not mentioned at all in the NIST request for information document, nor in  Microsemi’s response.
I expect most calibration labs have their own 5071As  but that is not quite the same as having a NIST traceability. My Certificate of Calibration from SRS for one of my PRS10 rubidium standards indicates:
«  Stanford Research Systems, Inc. certifies that this instrument has been calibrated to manufacturer specifications and accuracy at an ambient temperature of 23° +/- using instruments and standards which are traceable to the National Institute of Standards and Technology. «    
I expect the big labs send their instruments of to Boulder for calibration, but there must be some smaller outfits still phase locking off WWVB. We in Europe have MSF, DCF and TDF for which off air frequency references are /were available and which are probably still being used.
How would this frequency traceability work if WWVB/WWVH pass to a private enterprise?   



> 
> 
> On Sun, Aug 12, 2018 at 10:40 AM, Craig Kirkpatrick <craigk46 at comcast.net>
> wrote:
> 
>> I agree with Bob that shutting down WWVB would not go over well with the
>> voters but losing WWV and WWVH will mainly be noticed only by HAMs.
>> 
>> Dana, I’m puzzled by what you wrote.  I have 8 clocks and 2 wristwatches
>> that sync with WWVB.  When band conditions are poor they miss a sync for a
>> day but still they are good quartz clocks so the time readout is still OK.
>> When the band conditions are good again they sync up once per day usually
>> around 2am (according to the manual for my wristwatch).  I can easily tell
>> the sync status on all but 4 of my clocks and they sync successfully about
>> 90% of the overnight times.  My wristwatches are Citizen models that charge
>> by solar which is nice since I have a perfectly in sync watch that never
>> needs to be opened to change a battery.
>> 
>> I do like the idea of a GPS to WWVB timecode radio transmitter.  I think
>> that would sell well to folks on the fringe of coverage for WWVB such as
>> Florida, Hawaii, and Alaska or other parts of the globe.  I’ve found the
>> real limitation to reception of WWVB is local 60kHz noise in the home.  For
>> instance if I have a fan running to cool things in my shack then my WWVB
>> clocks will not sync successfully.
>> 
>> I hope Nick Sayer is reading this and getting the idea to make a GPS to
>> WWVB timecode radio transmitter, clever gent that he is.  :-)
>> 
>> Best Wishes,
>> Craig
>> KI7CRA
>> 
>>> On Aug 11, 2018, at 7:48 PM, Dana Whitlow <k8yumdoober at gmail.com> wrote:
>>> 
>>> I fear the worst.  The line in the website simply stated something like
>>> "shutting down
>>> the transmitters in Colorado and Hawaii", which would seem to include the
>>> whole
>>> enchilada.
>>> 
>>> For the wall clocks, GPS should work well if people are willing to go to
>>> battery-
>>> backed AC power.  But not so good for wristwatches, where the expectation
>>> is to
>>> run at uW power levels.  I for one would be very irritated at having to
>>> take my watch
>>> off my wrist and put it on a charging stand every night.  So if this
>>> shutdown comes
>>> to pass, I'll be looking for an inexpensive GPS-to-WWVB converter, or at
>>> least
>>> plans for building one.
>>> 
>>> Dana
>>> 
>>> 
>>> On Sat, Aug 11, 2018 at 8:12 PM, Bob Albert via time-nuts <
>>> time-nuts at lists.febo.com> wrote:
>>> 
>>>> With any luck, the current administration will successfully push the USA
>>>> down technically.  Denying global warming, shutting off time signals,
>> and
>>>> so on, is great stuff.
>>>>   On Saturday, August 11, 2018, 6:10:12 PM PDT, Bob kb8tq <
>> kb8tq at n1k.org>
>>>> wrote:
>>>> 
>>>> Hi
>>>> 
>>>> One would *guess* that stopping WWVB (and killing mom and pop’s “atomic
>>>> clocks”) would not be a reasonable thing to do.
>>>> It gets a lot of voters mad. I doubt that very many voters (percentage
>>>> wise) would notice WWV and WWVH going away ….
>>>> 
>>>> Bob
>>>> 
>>>>> On Aug 11, 2018, at 9:00 PM, jimlux <jimlux at earthlink.net> wrote:
>>>>> 
>>>>> On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
>>>>>> I'd say it does get more detailed, with the $49M in cuts described
>>>> generally in groups here:
>>>>>> https://www.nist.gov/director/fy-2019-presidential-budget-
>>>> request-summary/fundamental-measurement-quantum-science-and
>>>>>> One item: "-$6.3 million supporting fundamental measurement
>>>> dissemination, including the shutdown of NIST radio stations in Colorado
>>>> and Hawaii"
>>>>> 
>>>>> I wonder if that's WWVB, or WWV & WWVH
>>>>> 
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