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60 kHz (2022)

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Re: 60 kHz (2022)

#121

Post by aeonik »

lloeki wrote: post #95
anyfoo wrote: post #5

Earlier quoted context omitted.

I stand corrected, it seems to indeed have been the US Navy that pioneered time signals. France followed up a few years later. I don’t know who had the first system accessible to civilians, but at this point we’d just be arguing details.

From the link: > Radio time signals for setting chronometers were sent from stations such as NAA in Arlington, Virginia, which began broadcasting in 1913. The time was supplied from a direct communication line with the clocks of the U.S. Naval Observatory in Washington, D.C. In combination with another low-frequency installation mounted on the Eiffel Tower in Paris, the towers had the range to cover the North Atlanti…

Nice find!

This turns out to be quite an interesting rabbit hole.

It's definitely earlier than I would have guessed regardless.

Re: 60 kHz (2022)

#122

Post by tanepiper »

zh3 wrote: post #105
tanepiper wrote: post #97

> I’m not particularly patriotic, but this kind of thing feels particularly American. Maybe that tinge of patriotism is why Americans don't even bother to see if something isn't an American invention - https://en.wikipedia.org/wiki/Time_from_NPL_(MSF) - they'll just claim it anyways since they barely read outside their borders. Radio 4 would also like a word: https://en.wikipedia.org/wiki/Greenwich_Time_Signal

Radio 4 is particularly interesting, as it carries additional 25bps data [0] using for radio teleswitch operation [1] - a service whose days are numbered. Quite fun to receive this signal, as it's trivial to build a 198KHz receiver and to recover the data stream (+ time signal) using a signal, e.g. mix it with a 200KHz signal and process the resultant 2Khz audio tone. [0] https://www.bbc.co.uk/rd/publications/rdrepor…

Radio 4 is also the station that if there is no communication with mainland UK, and Radio 4 no longer broadcasting, submarine commanders were to assume the country was attacked and destroyed.

https://en.m.wikipedia.org/wiki/Letters_of_last_resort

Re: 60 kHz (2022)

#123

Post by lxgr »

quintushoratius wrote: post #119
lxgr wrote: post #63

Earlier quoted context omitted.

Oh, is there no “DST in effect” flag in the signal? As I understand it, the US switches at the same day across the country (for the states that do have it), so that should theoretically be possible.

Not every region of the continental US respects DST.

I know, but if it does, it switches on the same day as all the others, which could be encoded in the signal, and it seems like it is [1].

So instead of a switch to “add an hour”, there could be one that says “add an hour if the signal says DST is currently in effect”.

[1] https://en.wikipedia.org/wiki/WWVB#Amplitude-modulated_time_...

Re: 60 kHz (2022)

#125

Post by sokoloff »

someguydave wrote: post #33
anyfoo wrote: post #2

> I’m not particularly patriotic, but this kind of thing feels particularly American. ??? America has no doubt done some very remarkable things (the moon landing, the first backward compatible color TV standard), but I don't think this is a notable example of that. I think everyone in Europe was familiar with even wristwatches getting the time from "airwaves". At least in Germany, watches were a very common thing sin…

Digital communications is America’s gift to the world, look up Claude Shannon

I think the Englishman George Boole deserves significant credit as well.

Re: 60 kHz (2022)

#126

Post by ToValueFunfetti »

tanepiper wrote: post #97

> I’m not particularly patriotic, but this kind of thing feels particularly American. Maybe that tinge of patriotism is why Americans don't even bother to see if something isn't an American invention - https://en.wikipedia.org/wiki/Time_from_NPL_(MSF) - they'll just claim it anyways since they barely read outside their borders. Radio 4 would also like a word: https://en.wikipedia.org/wiki/Greenwich_Time_Signal

>The first radio time signal, sent by telegraphic code, was broadcast in September 1903 by the United States Navy. Most sources list Navesink, New Jersey as the site of this broadcast, but the reference clock was located at the United States Naval Observatory (USNO) in Washington, DC. The first regularly scheduled time broadcasts began on August 9, 1904* from the Navy Yard in Boston. By the end of 1905, the Navy had transmitted time signals from stations in several other cities, including Norfolk, Newport, Cape Cod, Key West, Portsmouth, and Mare Island in California

(PDF) https://tf.nist.gov/general/pdf/2131.pdf

*Another source said August 9, 1905

Re: 60 kHz (2022)

#128

Post by [deleted] »

anaidioschrono wrote: post #30
wglb wrote: post #18

Earlier quoted context omitted.

By "atomic" clocks (for example https://www.amazon.com/Crosse-Technology-WT-3129B-Atomic-Ana... ), and older brands of watches. I think there are also older industrial applications using this technology to syncronize.

I love these clocks! I've had a few in every house I've lived in, from all along the West Coast and Midwest.

[deleted]

Re: 60 kHz (2022)

#130

Post by pavel_lishin »

MadnessASAP wrote: post #42
joshellington wrote: post #29

Earlier quoted context omitted.

That would have absolutely been myself, wardriving at 16 (back in the early aughts). Sending nonsensical print jobs and then setting everyone’s clocks to 4:20.

I'm in my mid 30s and I still regularly tell unattended Google Homes and Alexa's to set an alarm for 4 AM.

I'm not that malicious, I just like picking up friends' unattended phones and snapping a goofy selfie for them to discover later.
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