Yes, as others have stated this is an old technology. I don't really understand why this is not more common in the modern day. it's not really that expensive to implement and they did it with analog chips back in the day...
Why do we have to set the time on our clock radios or on our microwaves or whatever? Why don't they just always use this Tech. I don't understand. All you have to do is allow people to store an offset for the time zone, and RTC issues are a thing of the past.
My dad has a g-shock that lasted 15 years. He loves it. Model: MTG-M900DA-8CR. I bought him a new one a month ago, snd he almost cried because he was looking for this watch in garage sales. He asked me to set it, we looked and both watches were already set to the correct time down to the second. The face has a solar panel that you can’t see.
Oh....my gosh. That's the exact one I had growing up as a kid for years. Wow. The memories are flooding back now. Wowie. I faithfully charged it in the sun whenever I saw it run low, and one night woke up maybe somewhere between 1 and 3 A.M. to see it syncing. I was maybe, oh a little older than 7-8 at the time.
I felt so overwhelmed with excitement that I ran over and woke my sister up to tell her my watch was syncing with the atomic clock in New York. She did not nearly share my level of enthusiasm over the subject matter at hand.
Of all of the more stereotypically autism-related memories I have of little me, that one is one of my favorites. My passion and excitement at the time was so cute. :') <3
My Protrek basically doesn't sync if I'm at home, and as it tries to start sync after midnight the auto sync near-never works. I installed DCF77-emulator app on phone to get around it.
My radio-synced clock works fine but comes with big (BIC lighter size but double the thickness) external antenna.
Probably much worse in microwave that's somewhere inside the house and not near window
> All you have to do is allow people to store an offset for the time zone, and RTC issues are a thing of the past.
Just to clarify, we're talking about people who couldn't bother to put $0.2 capacitor to hold the RTC battery for the few hours the power is usually down, and you're expecting them to put whole antenna and radio in ?
Yeah, it isn't feature anybody will choose white goods for so it isn't in.
Damn I had never thought of the possibility that you could easily battery back the clock in a microwave/oven/etc despite being fully aware that it's trivial to do. We get a ton of brownouts and I gave up on keeping the clocks set. I want it.
there's also another compromise, my stove will remember the last time it had AC power but it "loses" however many minutes it was out of power. And that can be implemented purely in non-volatile RAM (some kind of non-volatile CMOS register probably) without the actual piezo timing circuit (the clock itself can run off 60 hz utility frequency timebase). Just update the nvram once a minute.
somehow it's way less frustrating to only have to adjust the clock 30 minutes or whatever. you're not gonna be standing there for five minutes holding the button, you know? even though in practice it's not that big a deal and doesn't happen that often, it's a little human nicety.
and if you don't have time to adjust the clock at that exact moment, you can just mentally correct "I was out of power for 30 minutes so it's 30 minutes slow right now" rather than having to remember "I lost power at 3pm so that's 12:00...".
I did, but only on certain batch of servers that stayed in storage for few years before being put to use. On ones that stay powered all the time, pretty much never
My dad loves his. I bought a new one for him after 15 years of use. Both watches were the correct time. He swims a lot in it, and the old one is much smoother than the new one. I love that guy.
Experiences with these things vary a lot, depending on your location, the construction of your home, and (I assume) the cost of the receiver.
I had a ~$15 radio-synchronised clock when I was quite a long way from the transmitter, in a solid brick building. It would get a signal in some locations and orientations in the building.
I don't have firm information on how good the signal reception was, as of course it would keep ticking even if it didn't have a signal.
Just to clarify, I always lived in solid-brick/concrete buildings and never had issues with DCF77 clocks (and never heard of anyone having issues), which usually cost in the 15-30 € range. It’s an inexpensive technology that just works, at least in Western Europe.
> Why don't they just always use this Tech. I don't understand.
The bit's that get your oven to work don't need the time. Adding the bits for this is a cost and a thing that can fail because it can't receive the radio signal that equals a Dead on Arrival for your oven and a service call at least. When it's on a watch it's likely near your wrist which is likely near a window which likely means it can get the radio signal to sync.
Your citation is about using GPS as reference for electrical grid operations/control purposes (very common if your use case can rely on GPS versus local high precision time sources such as a cesium clock). If you were referring to using electrical grid frequency for time keeping, that is a suboptimal solution due to frequency stability nuance.
https://www.nist.gov/publications/time-and-frequency-electri... ("Due to the efforts of Henry Warren, inventor of the Telechron electric clock, electric power companies have been a source of time and frequency reference for the public for over a hundred years. However, advances in technology and changes in the electric power industry have generated a movement within the industry to end the time-reference service.")
As mentioned by a parallel commenter, your link doesnt say what you think it does.
That said, the most power line synchronization is useful for is clocking not time, and to be very honest, its only a consistent clocking source in some places (who perform adjustment to ensure a long term value of 50/60 Hz), which means it can be used to provide a clock source to keep a device in sync, which already knows the time, but cant be used for cold start of a device.
Note that an integer offset is insufficient. For example, Australian Central Standard time is +9:30 and Australian Central Western Standard Time is +8:45. I have a Seiko watch with a similar feature to this and I don't think it would work well in either of these timezones.
That’s not even enough because different zones observe DST at different times, or not at all. You would have to enter your actual time zone, not an offset, like when you install an OS or something. And then if that zone ever changes, which happens a lot, the clock in your microwave will often, or always, be wrong. So now your microwave needs to be internet connected to download tz databases, and what are we even doing here.
Thankfully DCF77 transmits the legal time and date including pre-announcing of skips for the country it operates from: Germany.
And for logistical reasons, the time zone extends quite far beyond the country borders. Co-inciding with where you have truly good reception.
The only thing I can think of is if it was widespread it would be a security risk. Not exactly difficult to broadcast a stronger signal with the wrong time.
Similar problem with GPS being used for clock sync in mobile/cell base stations in much of the US. You can buy an (illegal) jammer off Ali express and bring down a tower for very little money.
I don't know where you live, but here broadcasting such a signal would mean having the police knocking at your door really quickly. Unauthorized broadcasts are taken very seriously
We're talking something the size of a cell phone that can be powered for days on a battery. Hide it near the cell tower and leave. It takes specialist equipment to locate it so by the time someone has figured out what has happened and either got that equipment in or just done a manual search it's been hours to several days.
Or for some mayhem just stick a few of them under seats on public busses / trains set to activate at the same time.
Just looking at those maps should explain part of it. There isn't enough coverage. So you end up with poor experience with substantial amount of people who do not get good signal.
This would likely result in lot of returns, warranty claims and so on. Just not worth it in general.
I have a 15+ years old G-Shock with this feature. When I was in Afghanistan in 2010, I would still occasionally get this signal. I suspect these coverage maps are quite conservative.
Occasionally isn't good. It either has to work consistently or not at all. If someone has wrong understanding what the time is and their clock goes to "wrong" time occasionally it is bad.
And on other hand if marketed people expect such features to work. Even indoors or in basement. Next to window facing right direction in lucky meteorological conditions is tough ask for majority. Geeks will geek out when it works once in a bluemoon. But regular people expect it to work every day or even every week.
I don't understand your point. My watch was not marketed to function in Afghanistan at all. It was made clear the towers are in the US(IIRC two of them), Berlin and Japan.
And I think few people expect their wrist watch to synchronize over radio in a basement... And if they are, they need to understand radio better.
There is little drift on my G-shock anyway. Probably it would still be extremely accurate if it hadn't synced at all during the 7 months I was there.
Completely disagree. All clocks and watches have a degree of uncertainty. Even a once a quarter time sync is enough to improve the accuracy. If you want to be sure you have the correct time, then you check and set against a reference source or press the button to see when last received. What is the harm that would be caused by an occasional sync?
I disagree; a typical quartz watch only has a few seconds of drift per month, so if it only syncs once every few months it's still fine for most wrist watch applications. I never need second accuracy when I want to know what time it is.
I live ~700km from DCF77 and never get the signal indoors. Which is unfortunate in this case, as the watch tries to synchronize at night, when I’m usually at home.
Place your watch away from phone chargers. I live more than 700 km away and get it reliably every night on a small wrist watch once it put my watch away from the phone charger.
My professor is a materials/mechanical engineer and in contact with many auto companies. He told me of the following dialogue:
Prof: Why did you stopped adding passenger side handles? How much one cost?
CarGuy: Around €1.50
Prof: That's not much?
CarGuy: A new car leaves the factory every 60 seconds.
Prof: Oh.
For the lazy, that's €2,160/Day, €64,800/Month, €777,600/year.
I guess, but still, these seemingly large numbers are still a minute percentage (e.g. probably 0.00001%) of overall costs/revenue that are relatively way, way more.
I would understand manufacturing pain, and the ROI just doesn't justify it. But saying that it's solely to do with costs doesn't line up, IMO.
For auto industry, that's big money. VW creates small inserts and adds them to their motor covers for Seat and Skoda. If you pry that logo, there's a molded VW logo on that plastic engine noise cover.
Stellantis shares tons of parts and software. Peugeot 2008 and Opel Mokka is essentially the same car. They share the same shifter, electronics and software stack sans the skin applied to displays and LCD geometry. Even 3008 has the same hardware with the same software. Heck, even the "lane hold" button is exactly the same one in all three cars. Same for parking brake switch, down to the blinking pattern of indicator LED. I bet all three use the same 8 gear auto gearbox, with different ratio sets, too.
After Fiat bought Chrysler, they started to use the same steering wheel in Dodge Charger and Fiat Tipo. Newer Fiats come with Mopar brakes and fluid subsystems (steering, cooling, etc.)
Key fobs are even funnier. In practice, every company uses the same key fob. A Lamborghini has the same fob with a VW Polo, sans the logo. Same for Stellantis group cars.
When you start to notice "chassis sharing" in commercial market vehicles, it stops being funny and starts to become ridiculous.
I know a guy who installed TT's magnetic active shocks to a Golf and got terrific results.
However, I'd rather have a boring car which I don't need to constantly maintain instead of an exciting one which needs a tune-up every weekend but that's just me.
> I guess, but still, these seemingly large numbers are still a minute percentage (e.g. probably 0.00001%) of overall costs/revenue that are relatively way, way more.
Do you realise that your estimate, of €1.50 per car being 0.00001% of the costs, puts the manufacturing cost of a car at €15m?
Why you think manufacturers went into touch surfaces in cars much to dissatisfaction (that eventually caused some to back up) of customers?
Every button needs a bit of plastic moulded, a (good quality) button, backlight, often LED to signal whether it is on or off, and whole control block needs microcontroller to pack it into CAN bus and CAN bus connector to send.
Make whole thing a touch surface and you're saving buck or two on buttons alone and your plastics don't need to articulate (another savings).
Move that to the touchscreen controls, and as screen is already there, more savings!
Strictly speaking a touch screen is massively more complicated than a set of buttons. you now have billions of gates that have to be produced at nanometer scales in some of the most expensive factories on earth. The price to develop and manufacture a touch screen is many times that of a set of buttons. The fact that it is a generic interface drives the cost per unit down quite a bit. it does not hurt that the incredible manufacturing tolerances that must be maintained almost force the automation of the process allowing costs to be even lower.
I just wish we ended up with aircraft style MFD's instead of touch screens. You know those things with a screen and a row of buttons along each side.
> The price to develop and manufacture a touch screen is many times that of a set of
buttons.
It costs them $0 because consumers already expect a touch capable screen for infotaintment.
> I just wish we ended up with aircraft style MFD's instead of touch screens. You know those things with a screen and a row of buttons along each side.
Yeah it's a dream. Anything touch is annoying to use when driving. MFD-like also have advantage of being able to be touch typed, once you know in which menu you are it's always same sequence, and as those are physical buttons it's far harder to miss-press something.
> Strictly speaking a touch screen is massively more complicated than a set of buttons.
But, it's a commodity item, produced in many more numbers w.r.t. a A/C temperature/fan encoder w/custom shape. A bog standard Renault Clio touchscreen is comparable to a good (not high, not top) quality Raspberry Pi screen you can get from RS or AdaFruit.
The screens on Opel Mokka I drove (it has two, one for dash, one for infotainment) were extremely good at sunlight, but the dash one was so small, around 7" IIRC, to control costs. So, even if they don't pay for R&D of the screen itself, the industry is so cost sensitive, that they will cut costs relentlessly to be able to sell more of these things at a lower cost and with higher profit margins.
Also, these LCD dashes has a couple of hidden LED indicator lights around to communicate fatal things in a failsafe manner.
Car manufacturers do not bear the CapEx required to develop these screens, but bear the CapEx required for developing and prototyping physical buttons.
> I just wish we ended up with aircraft style MFD's instead of touch screens. You know those things with a screen and a row of buttons along each side.
kind of insane that a dollar here and there is significant on a $20k car (to premium vehicles like trucks/sports cars being $70-100k). but I guess $20k isn't the number that matters, it's $1 vs the profit margin of the vehicle which is of course much smaller.
But these factories scale. Second, it's only a single component that needs to be installed and tested, reducing labor costs and the number of components that could have an issue. It all adds up / someone's done the math.
Why wouldn’t cost be the sole or most important reason for cutting a non-safety, non-regulated feature?
700k in advertising would make a much bigger impact on revenue than 700k on door handles; unless people are that passionate about door handles that they go somewhere else.
Even if your current advertising budget is orders of magnitude larger, the force multiplier on investing in advertising is bigger than the door handle multiplier. So you’re just burning money.
Of course that’s all very cynical. Make the effort to reward companies that build the best product they can.
I assume it can be hard to judge impact down the line. A lot of car manufacturers cut out physical buttons, which led for the current generation of horrible interfaces where everything is touch screen and you can’t even get a simple rotary knob for the volume.
My understanding is that this is now going back and car manufacturers are reverting this decision.
So yeah, why not spend the saved money on advertising? I don’t know the complexity of such decisions. There are some manufacturers that do take a stand not to cut as many corners. Over time they can become known for their design. Apple (at least until the mid 2010s) I’d say was one such company.
By the way, as was pointed out, £700k seems negligible to companies that size for something that might potentially torpedo a car if enough people hate that part and refuse to buy it based on those grounds. But I’m not an expert.
It is, but on other hand get one executive to present that and get extra 10% bonus because that... It makes sense to push for such change. Tangible numeric change you can present in your performance evaluation.
> nothing else in the microwave relies on the time being accurate.
The real question is why does your microwave gives time in the first place. Sounds like they had a display and didn't know what to show on it while the microwave wasn't actively used, I'd say drop the clock altogether
Yeah honestly! But, if I had to guess, it’s probably built into whatever “microwave controller” SOC is mass manufactured.
The clock was an upsell long ago, but now that the whole device is a commodity product, and the clock is using parts already in the machine, I guess it’s just not worth removing.
That would be amazing. Same with clocks for that matter.
That said, do these radio signals contain the exact time for that timezone or is it more of a synchronization signal that goes "it is now exactly 0 minutes, 0 seconds" once an hour? Since the image shows that the signal crosses some timezone boundaries.
> Why do we have to set the time on our clock radios or on our microwaves or whatever? Why don't they just always use this Tech.
The main reason is lack of reliability or better to say strong dependency of reception success from location of the receiver. My G-shock watch never synchronizes when in kitchen but gets sufficiently strong signal in the bedroom. Wrist watches are more mobile and have better chance to be in a good signal reception spot at least once in a while. A microwave, on another hand, is stationary and if out of luck (weak signal) that it is permanent. Not a good solution for time sync (and possibly complains from dissatisfied customers).
Is it really not common? I don't thing I have seen a digital clock or modern wall clock which doesn't have it. I think my Microwave has it too. Onky my oven doesn't. Is it maybe more common in Europe?
I’m also in Europe (France) and during my entire life I never owned a single appliance with automatic time configuration (except for anything iot of course).
I have seen this automatic radio thing once in a very old alarm clock owned by my grandfather but that was probably in the end of the 90s.
I use a Phillips Smart Sleep alarm clock that doesn’t support this, despite being pretty expensive at around $100. I’m not even sure if the higher end model which costs twice as much and claims to be “connected” supports this feature.
another fun "we had a better solution in the past!" is using the 60hz AC sine wave as a time signal. The timebase is actually corrected for this use-case! there is absolutely no reason to use a piezo timer in any circuit that is plugged in to AC and the drift that typically occurs with piezos is so frustrating.
It's easy enough to implement decoding and there are packaged antenna (ferrite rod and coil) and conditioner (auto gain amplifier with Schmitt trigger output).
It isn't more common because most folks don't need it it. I touch my digital watches twice per year and that is more than enough to keep them close enough. Of my two digital watches, one is 1 minute fast and the other is 45 seconds fast. They will both be fine until this fall when we change time again.
which also means that it is one more bit to set on the receiver (in addition to time zone).
I have many clocks with WWVB time. Many miss signals and become off, one even gets an error once in a while and has the time many hours off. Not all decoders are the same apparently.
Reminds me of the clock I bought which changed MST/MDT automatically, which forced me to adjust it twice a year unlike like all my other clocks, because I lived in Arizona.
I spend most of the time out of range, but the technology is simple and robust enough that you can use headphones or a phone speaker as a very, very short-range transmitter. You hardly need to sync every day, either. I've had most success with https://einoko.github.io/DCF77.js/
I wore a G-Shock Wavecepter while serving in the U.S. Marine Corps. I recall that on both of my shipboard deployments (2004 and 2006) I was very excited to have my watch set time automatically. It indicated that I was finally nearing the U.S. East Coast. It helped to be an aircraft mechanic on night crew, as I was usually on the flight deck when it tried to set time.
Have solar atomic version. Don't wear it much these days. Mostly when I travel. Been on my dresser 2 years collecting dust but gets some sun. Picked it up the other day for a camping trip. It was both charged and had the correct date and time.
My battery has given up the ghost, and it's probably in a box of stuff around here. At the time, putting a new rechargable in it was impossible. I wonder if that's changed now...
Edit: Neglected to mention mine was also solar
There are anecdotal reports of solar Casios going 20+ years on that battery. Which makes sense given that its capacity should just gradually reduce over time - and when you start with full capacity that can drive the watch for over a year (assuming no backlight etc), even if it drops to half that, it's still very much usable.
The newer ones go into sleep mode until they sense some movement. Each morning when I pick up my GW-M5610U-1 (of course with the titanium mod), the display is blank and then fills with data within a second or so. I really like the feeling that although I hopefully have a few more decades to live, this watch may be my trusted companion for the rest of my life.
(time sync over rf is super cool; I would be super interested if anyone has links to field surveys of time signal availability, potential gaps in coverage, and maps of said data.
Thanks for those references! I wanted to see what an SDR radio time signal detector would look like, and looking for "DCF77 sdr python" pointed me in the right direction -> [0] and [1]
A bit unrelated question: there are many web SDRs that let you listen to radio frequencies/stations such as [2]. Are there web / Emscripten SDR decoders that run in-browser? i.e. a full browser listening + decoding experience? For example, decoding a DCF77 time signal, or even just morse code?
I run this for my Citizen Skymaster on a picoPi. It works. Being within receiving distance of JJY in Yokohama IETF, and in Frankfurt near the german transmitter was wonderful, but I have an NTP synced dummy at home with a copper loop antenna and it works fine.
Using the HDMI lead interferes with the rPi GPIO signal being used to supermodulate the RF. As long as you don't drive the HDMI, its fine. I think its possible HDMI is an RF radiator.
The java/javascript trick with headphones works too.
Casio are the best watches I've ever owned. Radio sync on a watch is awesome for creating "drop the mic" moments showing how far out the clocks are on a multi-million dollar machine in a datacenter despite how much the big consultancy thinks they are synced to UTP via "atomic clocks".
If you're interested in buying a Casio watch that does this they tend to be called Waveceptor, I'd recommend looking at one that's also solar powered (tough solar).
I specifically went with a battery model because I was not convinced that the battery in the solar models would actually last that much longer than the battery only model. While you can replace the battery in the solar models it is a proprietary part and considered watchmaker level service, while with the battery model it is normal service with a generic part. So I decided that replacing a battery every 5 years would not actually be that bad compared to trying to find a proprietary part every 10 years(A guess based on forum posts, so worthless).
All of which is a false economy. As I buy what is actually a cheap mass production watch as if it were some sort of heirloom piece that I will be passing down to my grand children. Anyhow, whats the point of being a geek if you can't overthink things sometimes?
Oceanus S100 is absolutely brilliant. Solar powered, radio time sync, titanium (so incredibly lightweight), waterproof, and looks like a dress watch. The only downside is they are only sold in Japan so you have to import them.
The T200 is a great option too- you sacrifice the titanium for stainless steel but get more flexibility as the strap is removable (which IMO makes it more versatile). Beautiful dial too. I own one and I've been looking for watches with similar tinted crystal but haven't been able to find any that do it nearly as well.
I have this watch and I love it. It's incredibly light due to titanium case and strap, and very tough with sapphire glass. Solar powered, so never needs the battery changing, and always accurate due to the radio receiver. And I like that it looks good without being pretentious, or a display of wealth. It's just a Casio, but those who know, know.
Also show up in other series, Protreks have it for example. Althought mine is not great indoors and even outdoors needs a bit of finangling to start the sync
I inherited one of these Casio Waveceptor watches from my father.
It routinely will set itself to a totally random time far into the past/future. I've wondered if maybe contemporary wireless devices interfere with the time sync radio. Another possible factor is the watch itself is ~20 years old.
It's not totally uncommon. I have a Waveceptor and several other clocks that use WWVB.
One works perfectly, most of the others are usually good, one gets off a couple of times a year (so therefore useless), and my Waveceptor has gone nuts maybe a couple of times.
It seems to be all about signal strength (and a little bit about battery strength).
I see at least one of those watches has GPS reception.
I also remember their NTP server being near-continously unreliable and having to change the ntp sync server on every install. I wonder if that's still an issue
I have an alarm clock with this system (or I think it's this, it's from Oregon Scientific) and it has this "automatic clock sync" feature.
I have it disabled. Once it was set to a random time, and I lost an important meeting because the alarm didn't ring at the correct time. The usual time doesn't deviate more than a second or so every few years, when I need to change the batteries and set it again so it's useless.
This automatic feature would be perfect if it acted as a "press this button to setup" or at startup, but the issue is that the messages are sent very sporadically so you either need to wait almost a full day for it to sync (clocks are not always listening, so it needs to coincide the "push" and the "listen") or set it manually.
> This automatic feature would be perfect if it acted as a "press this button to setup"
You press the receive button on the Casio.
> but the issue is that the messages are sent very sporadically so you either need to wait almost a full day for it to sync
The signal is constant. You probably had bad reception. In case of DCF77 it needs one minute to transmit "date + time + parity". I have seen my G-Shock syncing in under two minutes.
They misspelled Mainflingen, where the German DCF77 transmitter is located, as "Mineflingen", which is basically spelled phonetically (for English speakers).
I'm curious why we don't just use GPS's UTC time broadcast to set time? I understand that using GPS to track satellites and find location is power hungry, but I can't imagine that simply receiving a time and setting a clock is any more power hungry than this system.
GPS signals are much higher frequency and very low power and thus don’t work indoors. These HF time signals are way more powerful and can be detected inside buildings.
> GPS signals are much higher frequency and very low power and thus don’t work indoors.
With a $20 antenna placed near the window, together with a modern receiver, it is easy to get nanosecond level of precision for GPS systems. Some receivers even have in-door precision specification.
GPS not only work indoors, in terms of timing, it works actually pretty well indoors.
Yeah but it needs to be charged often. That would be a compelling use case for the radio based timing synchronization that are in less power hungry watches, and I'm curious, if this watch just had GPS for timing and none of the other features, if it's power would last as long or even half as long as the older models.
The H1000 is marketed as a fitness watch and solar powered too. The GPS time sync is not an exclusive feature and I find that it isn't necessary to have it on constantly.
GPS determines a solution for position and time simultaneously. It requires 4 satellites to solve for 4 unknowns (X, Y, Z, t). If you know your position you can solve for time using only 1 satellite, but a watch is always moving so it's position won't be known.
Edit: I would welcome corrections though if I am misunderstanding. Perhaps if you're not interested in precise timing you can read the satellite time from the broadcast signal?
Edit 2: OK, I think I understand your point now. The satellites broadcast their timestamps directly. To find a precise position / time you need to find a correction to the receiver clock. But if you don't need a very precise time, you can just use the satellite timestamp.
you understand the reason, GPS units are expensive and take a lot of power ;)
the GPS module itself is probably bigger than most of these watches, and the module itself probably costs more than most of the watches too! (probably something like $100). even if you can power it, which, the power consumed is probably 3-4 orders of magnitude more than the watch.
on the other hand, you have a point about receiving a signal and setting the clock, and I wonder if you couldn't parasitically drive this off the cell network... is there a local reference clock signal in the cell system that you could pull timestamps from and set the clock? cell signals are much much stronger than GPS and don't require constantly tracking satellites to maintain a fix. and while you still need some RF components (as does this casio watch, it's still acting as a RF demodulator!) they can presumably be much simpler and cheaper and lower-power.
(edit: actually I see some people here commenting some watches apparently do exactly this, so your "use the time reference from a single satellite and accept the skew from lightspeed" idea probably does work, although it's a smartwatch and runs its battery quickly.)
really I think most people do not even need continuous updates though. This is something you could build into a "charge cradle" for the watch and have the time reference sent via a data carrier on the inductive charge signal. which does open GPS sync back up a little bit (although wifi/bluetooth would be cheaper and just as good for most people) since the GPS can live in the cradle too.
people are talking about solar watches etc and to be honest if you've got 1-2 years of battery life who cares about solar? Pop it on the charge cradle once a year and charge it inductively. Inductive charging might actually be simpler/cheaper than even those micro solar panels watches and calculators use, and everyone has gotten into the habit of charging their smart watches overnight anyway. And if you do that, it allows you to do the cosmetics of the watch however you want, since you're not tied to having a big solar panel in part of it.
I’m from
Germany — we drove to Arizona from California a few years ago and were too late for check in which was super annoying. I got a SEIKO Astron watch that synchronizes the time via GPS after that and couldn’t be more satisfied; it also runs on solar and holds a charge of 6 months for when there’s no sun (i.e. Antarctica). This watch is so precise it’s my absolute time reference. When I’m traveling I keep my Apple Watch at home and only wear the SEIKO; the Apple Watch is pointless anyway if you’re stuck in the desert for more than a few days.
I have the all black GW-2310FB. I’ll be honest, the gray digits on black background can be a little impractical in low light (it does have a very good backlit if you press the button). But it looks awesome and I have no regrets. Love it. And for those of you that are militant about your IDE’s dark mode, this could be the watch for you too.
https://www.casio.com/us/watches/gshock/product.GW-2310FB-1/
"A radio station at Rugby was first operated by the Post Office from 1926, with the call-sign GBR. From 19 December 1927, it broadcast a 15.8 kHz time signal from the Royal Observatory which could be received worldwide. It consisted of 306 pulses in the five minutes up to and including 10:00 and 18:00 GMT, with a longer pulse at the start of each minute. "
That was (and still is) a great technology, but in the last couple of years Casio has bluetooth-enabled watches that can sync with your phone (that is syncing with the base station, which syncs with GPS). Bluetooth adds about $10-20 on top, but works indoors and outdoors, day or night or on-demand, all around the world.
(The usual Casio G-Shock time deviation is under 20 seconds per month, so there's that.)
Works flawless in Seoul and Beijing. A month in South Bay and flawless too.
There is no signal for this back home in Singapore. What I do - since we also don't know when they're gonna shut off the radio towers - is use an app on my Tab S8 Ultra, set my watch's time zone to Tokyo, leave watch right next to speaker and go do something else. After some beeps and minutes : my watch time is readjusted.
I've been using a radio controlled clock for many years. At some point I noticed it was more frequently reporting it had been unable to sync properly. I'd never noticed this before. Turned out the UK time signal had moved from Rugby to Anthorn. It really seemed to negatively impact reception.
Same with my pro-trek, aside from not working all that great indoors for sync.
Apparently Garmin have some Smartwatch that actually got low enough to also be pretty much constantly on Solar only power but after owning original Pebble I kinda healed myself from smartwatch hype before the fashion for them even started...
Cool to have this multiband technology, but what about the southern hemisphere? Assuming they have time signal transmitters, too: Do watch manufacturers have different SKUs that can receive signals in the southern hemisphere? Is it possible to have a watch that receives these signals truly worldwide?
I'd be curious to see a proper signal map for this service. I've been the proud owner of a Casio Oceanus for a little over a year now. I can count on one hand the number of times the watch has synchronized via radio.
Keep in mind antenna placement matters with these clocks. Different parts of the room can have very different signal strengths. Away from other electronics and near a window is all better.
Yeah, the signal for this is rather weak so you would need to place your watch at least on a window's line of sight or, if it still doesn't work, right next to a window.
For anyone in the Iberian peninsula, I've had some luck using UK's radio on mine.
Be mindful to try it at night, and if the meteorological conditions allow.
I have a wall clock that syncs with an atomic clock in Colorado, which was cool at first but I live in Arizona now which doesn’t observe daylight savings so it’s often wrong by an hour now.
Or mount another hour hand on it that always tracks an hour ahead of the existing one with a label on which dates it’s applicable during. That’s a clean solution right?
Either get Gshock GWM5610-1 which is solar and synced for good price, or get Garmin Instict Solar for all bells and whistles and also unlimited power in theory.
not working in SEA, though :/ there are some tricks with apps synthesizing a electromagnetic radio signal via speaker activity but i never got this to work.
I have one in the south of Spain and it doesn't work practically anywhere and definitely not where I sleep (since it can be set to synchronise after midnight automatically)
I bought it in part because of this feature and it was quite sad. These quartz watches are good but they still drift substantially after a few months.
Thankfully I heard of the DCF77 emulator app thanks to this thread and I will use it.
Why do we have to set the time on our clock radios or on our microwaves or whatever? Why don't they just always use this Tech. I don't understand. All you have to do is allow people to store an offset for the time zone, and RTC issues are a thing of the past.