10 ms·

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

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.

psychphysic 3y ago
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).
V__ 3y ago
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?
- freetime2 3y ago
  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.
- pjerem 3y ago
  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.
- layer8 3y ago
  It’s common in clocks, but not in other appliances (nor in cars).
- deleted 3y ago
  [deleted]
nonethewiser 3y ago
And daylight savings?
- chriscjcj 3y ago
  The time code transmitted by WWVB includes two bits to express the state of Daylight Saving Time. 0 = Standard Time 1 = DST Ending 2 = DST in effect 3 = DST Beginning https://en.wikipedia.org/wiki/WWVB#/media/File:WWVB_time_code_format.svg https://en.wikipedia.org/wiki/WWVB#/media/File:WWVB_time_cod... https://en.wikipedia.org/wiki/WWVB https://en.wikipedia.org/wiki/WWVB
  - creeble 3y ago
    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.
- ricc 3y ago
  Radio syncing is perfect for forgetting about setting clocks for DST on/off because the sync automatically does that for you.
  - supportengineer 3y ago
    Somehow my Casio G-Shock Rangeman cannot do this correctly
  - 0cVlTeIATBs 3y ago
    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.
graypegg 3y ago
It does feel like something that’s easy to cut from a bill of materials though, nothing else in the microwave relies on the time being accurate. Probably not expensive to implement, but if you’re building a lot of them, I imagine the ~4cents per unit (maybe more, just guessing) adds up fast.
- bpye 3y ago
  Whilst it maybe doesn’t need to be accurate, I have had an oven that wouldn’t turn on if you didn’t set the time…
  - graypegg 3y ago
    Haha, oh wow that sucks. I’m sure most of those units are all set to 12:00AM by mashing the OK button after every power outage.
  - rwky 3y ago
    The last few ovens we've had do that too. I assume it's something to do with the delayed start function which I never use...
  - Cthulhu_ 3y ago
    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.
- bayindirh 3y ago
  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.
deleted 3y ago
[deleted]
gm3dmo 3y ago
There is already a time signal in the electrical grid: https://www.meinbergglobal.com/english/info/time-synchronization-electrical-systems.htm https://www.meinbergglobal.com/english/info/time-synchroniza... > 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.
- toomuchtodo 3y ago
  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.dhs.gov/sites/default/files/publications/GPS-PNT-Best-Practices-Time-Frequency-Sources-Fixed-Locations-508.pdf https://www.dhs.gov/sites/default/files/publications/GPS-PNT... https://phys.org/news/2011-06-power-grid-disrupt-clocks.html https://phys.org/news/2011-06-power-grid-disrupt-clocks.html https://medium.com/@bramus/grid-time-or-why-are-clocks-in-europe-lagging-behind-by-5-minutes-dbc2dd028bfa https://medium.com/@bramus/grid-time-or-why-are-clocks-in-eu... https://www.entsoe.eu/news/2018/03/06/press-release-continuing-frequency-deviation-in-the-continental-european-power-system-originating-in-serbia-kosovo-political-solution-urgently-needed-in-addition-to-technical/ https://www.entsoe.eu/news/2018/03/06/press-release-continui... https://www.nist.gov/publications/time-and-frequency-electrical-power-lines 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.")
- Aloha 3y ago
  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.
clusmore 3y ago
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.
- ilyt 3y ago
  You can just change timezone on watch and it keeps offset. But yeah, mine has like... one that isn't multiple of 30 minutes
- pkulak 3y ago
  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.
  - namibj 3y ago
    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.
ilyt 3y ago
Have you...used them ? 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.
- gh02t 3y ago
  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.
  - mcny 3y ago
    Now that you mention it, I've never replaced the cmos battery on a computer.
    - ilyt 3y ago
      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
  - paulmd 3y ago
    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. https://en.wikipedia.org/wiki/Utility_frequency#Time_error_correction_(TEC) https://en.wikipedia.org/wiki/Utility_frequency#Time_error_c... 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...".
basking 3y ago
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.
- tysam_and 3y ago
  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
Ekaros 3y ago
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.
- Gud 3y ago
  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.
  - exitb 3y ago
    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.
    - jhoechtl 3y ago
      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.
  - spookie 3y ago
    You can try doing it on clear nights, and outdoors, manually. It works most of the time for me if I'm back on my home country.
  - Ekaros 3y ago
    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.
mmcgaha 3y ago
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.
cbzoiav 3y ago
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.
- agos 3y ago
  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
  - cbzoiav 3y ago
    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.
vbezhenar 3y ago
Probably because it's supported only in a few countries.
paulmd 3y ago
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. https://en.wikipedia.org/wiki/Utility_frequency#Time_error_correction_(TEC) https://en.wikipedia.org/wiki/Utility_frequency#Time_error_c...
lr1970 3y ago
> 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).

psychphysic 3y ago

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).

V__ 3y ago

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?

freetime2 3y ago
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.
pjerem 3y ago
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.
layer8 3y ago
It’s common in clocks, but not in other appliances (nor in cars).
deleted 3y ago
[deleted]

nonethewiser 3y ago

And daylight savings?

chriscjcj 3y ago
The time code transmitted by WWVB includes two bits to express the state of Daylight Saving Time. 0 = Standard Time 1 = DST Ending 2 = DST in effect 3 = DST Beginning https://en.wikipedia.org/wiki/WWVB#/media/File:WWVB_time_code_format.svg https://en.wikipedia.org/wiki/WWVB#/media/File:WWVB_time_cod... https://en.wikipedia.org/wiki/WWVB https://en.wikipedia.org/wiki/WWVB
- creeble 3y ago
  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.
ricc 3y ago
Radio syncing is perfect for forgetting about setting clocks for DST on/off because the sync automatically does that for you.
- supportengineer 3y ago
  Somehow my Casio G-Shock Rangeman cannot do this correctly
- 0cVlTeIATBs 3y ago
  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.

graypegg 3y ago

It does feel like something that’s easy to cut from a bill of materials though, nothing else in the microwave relies on the time being accurate. Probably not expensive to implement, but if you’re building a lot of them, I imagine the ~4cents per unit (maybe more, just guessing) adds up fast.

bpye 3y ago
Whilst it maybe doesn’t need to be accurate, I have had an oven that wouldn’t turn on if you didn’t set the time…
- graypegg 3y ago
  Haha, oh wow that sucks. I’m sure most of those units are all set to 12:00AM by mashing the OK button after every power outage.
- rwky 3y ago
  The last few ovens we've had do that too. I assume it's something to do with the delayed start function which I never use...
- Cthulhu_ 3y ago
  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.
bayindirh 3y ago
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.

deleted 3y ago

[deleted]

gm3dmo 3y ago

There is already a time signal in the electrical grid: https://www.meinbergglobal.com/english/info/time-synchronization-electrical-systems.htm https://www.meinbergglobal.com/english/info/time-synchroniza... > 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.

toomuchtodo 3y ago
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.dhs.gov/sites/default/files/publications/GPS-PNT-Best-Practices-Time-Frequency-Sources-Fixed-Locations-508.pdf https://www.dhs.gov/sites/default/files/publications/GPS-PNT... https://phys.org/news/2011-06-power-grid-disrupt-clocks.html https://phys.org/news/2011-06-power-grid-disrupt-clocks.html https://medium.com/@bramus/grid-time-or-why-are-clocks-in-europe-lagging-behind-by-5-minutes-dbc2dd028bfa https://medium.com/@bramus/grid-time-or-why-are-clocks-in-eu... https://www.entsoe.eu/news/2018/03/06/press-release-continuing-frequency-deviation-in-the-continental-european-power-system-originating-in-serbia-kosovo-political-solution-urgently-needed-in-addition-to-technical/ https://www.entsoe.eu/news/2018/03/06/press-release-continui... https://www.nist.gov/publications/time-and-frequency-electrical-power-lines 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.")
Aloha 3y ago
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.

clusmore 3y ago

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.

ilyt 3y ago
You can just change timezone on watch and it keeps offset. But yeah, mine has like... one that isn't multiple of 30 minutes
pkulak 3y ago
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.
- namibj 3y ago
  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.

ilyt 3y ago

Have you...used them ? 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.

gh02t 3y ago
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.
- mcny 3y ago
  Now that you mention it, I've never replaced the cmos battery on a computer.
  - ilyt 3y ago
    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
- paulmd 3y ago
  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. https://en.wikipedia.org/wiki/Utility_frequency#Time_error_correction_(TEC) https://en.wikipedia.org/wiki/Utility_frequency#Time_error_c... 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...".

basking 3y ago

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.

tysam_and 3y ago
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

Ekaros 3y ago

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.

Gud 3y ago
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.
- exitb 3y ago
  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.
  - jhoechtl 3y ago
    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.
- spookie 3y ago
  You can try doing it on clear nights, and outdoors, manually. It works most of the time for me if I'm back on my home country.
- Ekaros 3y ago
  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.

mmcgaha 3y ago

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.

cbzoiav 3y ago

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.

agos 3y ago
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
- cbzoiav 3y ago
  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.

vbezhenar 3y ago

Probably because it's supported only in a few countries.

paulmd 3y ago

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. https://en.wikipedia.org/wiki/Utility_frequency#Time_error_correction_(TEC) https://en.wikipedia.org/wiki/Utility_frequency#Time_error_c...

lr1970 3y ago

> 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).