Atomic Clock

[shovelhead86]

Don't know why they call it atomic. It still needs batteries. I roped the sending unit and drove over it with the Monty. I called the factory this morning and for $20.00 they have one in the mail tomorrow. Very friendly people to deal with.

John

[BB_TX]

I have two inexpensive AcuRite indoor/outdoor thermometers and both have “atomic clocks” in them. Initially I set the time according to my watch not knowing any better. And a short time later there was 3 minutes difference. Tried again and same thing. Finally figured out it was my watch that as wrong.

[rohrmann]

I think 'atomic clock' is not an accurate description. This is from the Wikipedia article talking about actual atomic clocks:


A radio clock is a clock that automatically synchronizes itself by means of government radio time signals received by a radio receiver. Many retailers market radio clocks inaccurately as atomic clocks;[118] although the radio signals they receive originate from atomic clocks, they are not atomic clocks themselves. Normal low cost consumer grade receivers solely rely on the amplitude-modulated time signals and use narrow band receivers (with 10 Hz bandwidth) with small ferrite loopstick antennas and circuits with non optimal digital signal processing delay and can therefore only be expected to determine the beginning of a second with a practical accuracy uncertainty of ± 0.1 second. This is sufficient for radio controlled low cost consumer grade clocks and watches using standard-quality quartz clocks for timekeeping between daily synchronization attempts, as they will be most accurate immediately after a successful synchronization and will become less accurate from that point forward until the next synchronization.[119] Instrument grade time receivers provide higher accuracy. Such devices incur a transit delay of approximately 1 ms for every 300 kilometres (186 mi) of distance from the radio transmitter. Many governments operate transmitters for time-keeping purposes.

[timandsusan]

One Atomic clock signal is transmitted from WWV in Ft. Collins, CO--if my memory serves me. We used it for our testing of EW systems during my working days in San Antonio. Great article on the clock!

[psomers]

Your clock is receiving its sync signal from WWV in Fort Collins, CO. That is where the atomic clock is. It is more than just a standard of time. It is also a standard for frequency. At one time all commercial radio and TV stations had to be able to calibrate from WWV. I once had a 2nd class commercial radio license which all commercial stations had to have one.
Google WWV. Interesting read on what WWV transmits.

[Slow Hand]

I'm retired so I don't have to be that accurate any more. LOL

[jimcol]

Originally Posted by rohrmann

I think 'atomic clock' is not an accurate description. This is from the Wikipedia article talking about actual atomic clocks:


A radio clock is a clock that automatically synchronizes itself by means of government radio time signals received by a radio receiver. Many retailers market radio clocks inaccurately as atomic clocks;[118] although the radio signals they receive originate from atomic clocks, they are not atomic clocks themselves. Normal low cost consumer grade receivers solely rely on the amplitude-modulated time signals and use narrow band receivers (with 10 Hz bandwidth) with small ferrite loopstick antennas and circuits with non optimal digital signal processing delay and can therefore only be expected to determine the beginning of a second with a practical accuracy uncertainty of ± 0.1 second. This is sufficient for radio controlled low cost consumer grade clocks and watches using standard-quality quartz clocks for timekeeping between daily synchronization attempts, as they will be most accurate immediately after a successful synchronization and will become less accurate from that point forward until the next synchronization.[119] Instrument grade time receivers provide higher accuracy. Such devices incur a transit delay of approximately 1 ms for every 300 kilometres (186 mi) of distance from the radio transmitter. Many governments operate transmitters for time-keeping purposes.

Bob,
Thanks for the informative article. It was nice to learn something not Covid related.