What time is it?
Discussion
I have been living with my Planet Ocean 45.5 for just over a month now. I LOVE it... It was a 40th birthday gift from my wife, yes I am a lucky man.
The problem is I made the mistake of reading about the COSC certification thing and I seem to be developing 'setting my watch OCD' in order to see just how accurate it really is. It does seem to be within the -4/+6 range, but sometimes it's in the fast range, sometimes it's slow, other days it's bang on. I guess this is normal as wearing patterns change etc, and I am not sure that I am setting it against a reliable source (digital clock radio)
Also my OCD has moved to the next level. Now I want my watch to be accurate at measuring the seconds in the day, AND to be at the right time. This means that I need a reliable source by which to set my watch.
I have tried atomic clock websites, but they often can't agree with each other, so they can't be relied upon
I have tried syncing with the bongs on the radio 4 news - but I am not sure they are broadcast at the right time as digital radio and analogue are out of sync
I have tried setting it against the breakfast TV time - tricky as it has no second display
I am now considering buying a 'radio controlled watch' a Casio Waveceptor type thing, just to set my PO - probably excessive and would not be popular with the wife after she spent a couple of £K on a nice watch for me. Plus are they really that accurate?
Does anybody else share my OCD? What do you do to make sure your watch is right? (and I mean bang-on-right...)
The problem is I made the mistake of reading about the COSC certification thing and I seem to be developing 'setting my watch OCD' in order to see just how accurate it really is. It does seem to be within the -4/+6 range, but sometimes it's in the fast range, sometimes it's slow, other days it's bang on. I guess this is normal as wearing patterns change etc, and I am not sure that I am setting it against a reliable source (digital clock radio)
Also my OCD has moved to the next level. Now I want my watch to be accurate at measuring the seconds in the day, AND to be at the right time. This means that I need a reliable source by which to set my watch.
I have tried atomic clock websites, but they often can't agree with each other, so they can't be relied upon
I have tried syncing with the bongs on the radio 4 news - but I am not sure they are broadcast at the right time as digital radio and analogue are out of sync
I have tried setting it against the breakfast TV time - tricky as it has no second display
I am now considering buying a 'radio controlled watch' a Casio Waveceptor type thing, just to set my PO - probably excessive and would not be popular with the wife after she spent a couple of £K on a nice watch for me. Plus are they really that accurate?
Does anybody else share my OCD? What do you do to make sure your watch is right? (and I mean bang-on-right...)
Radio-controlled wall clock for somewhere in the house, if you need one.
Anything with GPS keeps a very accurate time - as the whole system of establishing location is based on measuring the tiny differences in time signals from different satellites.
fwiw, the clock in my Civic is controlled by the GPS in the sat-nav and always clicks over the hour exactly on the bongs/beeps broadcast on R4 FM.
Anything with GPS keeps a very accurate time - as the whole system of establishing location is based on measuring the tiny differences in time signals from different satellites.
fwiw, the clock in my Civic is controlled by the GPS in the sat-nav and always clicks over the hour exactly on the bongs/beeps broadcast on R4 FM.
Gizmo! said:
Luckily I actually live very near the Greenwich Meridian. So when I set my watch to 'on the hour' by my DAB radio, it actually is 'on the hour'.
As opposed to 'on the hour that it is fifty miles east/west/etc from here'.
Don't make it worse for me... I was happy to be accurate within my time zone... I am going to end up making minor adjustments based on distance from the Greenwich Meridian at this rate... As opposed to 'on the hour that it is fifty miles east/west/etc from here'.
So do you reckon DAB radio is spot on? It very rarely agrees with the atomic clock websites???
skoff said:
Gizmo! said:
Luckily I actually live very near the Greenwich Meridian. So when I set my watch to 'on the hour' by my DAB radio, it actually is 'on the hour'.
As opposed to 'on the hour that it is fifty miles east/west/etc from here'.
Don't make it worse for me... I was happy to be accurate within my time zone... I am going to end up making minor adjustments based on distance from the Greenwich Meridian at this rate... As opposed to 'on the hour that it is fifty miles east/west/etc from here'.
So do you reckon DAB radio is spot on? It very rarely agrees with the atomic clock websites???
I keep meaning to set my Seiko to the exact (ish) time and see how accurate it is. Since I bought it a few months ago I've never had to reset it though, so it's pretty damn good...
NeMiSiS said:
I use www.exacttimenow.com if any of my watches are out of spec re-accuracy they go back under warranty or if out of warranty I pay for calibration
Now that looks like a useful link, thanks. I have set my watch to it, and will see how it does tomorrow.Interestingly, I have a DAB radio in my office and it doesn't agree with exacttimenow.com
All this stuff could drive you mad.
I am still liking the idea of a radio controlled watch though, because, well it's an excuse to buy another watch....
I don't think the DAB network time is particularly accurate. You certainly can't go by the pips on Radio 4 as transmitted on DAB, as there are delays caused by the digital compression/decompression. Pips on analogue radio will be accurate, as there is next to no delay.
Probably the best way to get a clock accurate to UTC is to use one with an MSF receiver. GPS time is not the same as UTC as the mechanics of GPS don't allow the use of leap seconds. The satellites do broadcast a leap second count along with their data stream so the receiver should be able to correct for that, but it doesn't necessarily mean they all do.
Probably the best way to get a clock accurate to UTC is to use one with an MSF receiver. GPS time is not the same as UTC as the mechanics of GPS don't allow the use of leap seconds. The satellites do broadcast a leap second count along with their data stream so the receiver should be able to correct for that, but it doesn't necessarily mean they all do.
tank slapper said:
I don't think the DAB network time is particularly accurate. You certainly can't go by the pips on Radio 4 as transmitted on DAB, as there are delays caused by the digital compression/decompression. Pips on analogue radio will be accurate, as there is next to no delay.
Probably the best way to get a clock accurate to UTC is to use one with an MSF receiver.
So, the radio pips in my car (analogue radio) will be right,or near as makes no odds - the trouble with that is I am usually driving when I hear the pips on R4 in my car, and I am pretty sure setting your watch whilst driving would be frowned upon by the BiB.Probably the best way to get a clock accurate to UTC is to use one with an MSF receiver.
Is a clock with a MSF receiver the same thing as a 'radio controlled' clock/watch? e.g. the Casio Waveceptor previously mentioned, or something like this:
http://www.amazon.co.uk/Precision-PREC0019-Control...
The latter being a seemingly very cheap way to have accurate time..?
MSF is the radio callsign of the time signal transmitter at the National Physics Laboratory. Most radio controlled clocks you get in this country will receive from it. You should get the same accuracy from any of them. The clock you linked there will be no worse than any other and will match up with the pips on (analogue) Radio 4.
Thanks for the detailed knowledge tank slapper
The radio controlled clock seems like a good way to feed my OCD. Not only that, but it will play havoc with my wife. She sets the current bedroom clock to be 5 minutes fast, and the clock in her car to be 15 minutes fast - apparently this helps her to avoid being late.
When I suggest she just gets up 5 minutes earlier, or leaves the house 15 minutes earlier I get one of 'those' looks.
She also will not adjust the clock in her car for BST, so it's pretty much as wrong as it can be...
The radio controlled clock seems like a good way to feed my OCD. Not only that, but it will play havoc with my wife. She sets the current bedroom clock to be 5 minutes fast, and the clock in her car to be 15 minutes fast - apparently this helps her to avoid being late.
When I suggest she just gets up 5 minutes earlier, or leaves the house 15 minutes earlier I get one of 'those' looks.
She also will not adjust the clock in her car for BST, so it's pretty much as wrong as it can be...
I use this to set my automatics if I've let them run down. Always try to get them bang in sync even on non-hacking autos (I just apply a little back pressure on the crown to stop the second hand), I also make sure that as the second hand sweeps past 12 the minute hand is exactly on it's marker.
Lord knows why I do it, it's not as if anyone else is going to notice
Lord knows why I do it, it's not as if anyone else is going to notice
tank slapper said:
I don't think the DAB network time is particularly accurate. You certainly can't go by the pips on Radio 4 as transmitted on DAB, as there are delays caused by the digital compression/decompression. Pips on analogue radio will be accurate, as there is next to no delay.
Probably the best way to get a clock accurate to UTC is to use one with an MSF receiver. GPS time is not the same as UTC as the mechanics of GPS don't allow the use of leap seconds. The satellites do broadcast a leap second count along with their data stream so the receiver should be able to correct for that, but it doesn't necessarily mean they all do.
The point is that the noise of the pips coming out of your DAB radio is subject to compression/tranmission/decompression delay, but the actual packets of data themselves are not: and I'm led to believe that once per second the DAB network transmits a 'heartbeat' type update, either in hh:mm format or hh:mm:ss.sss.Probably the best way to get a clock accurate to UTC is to use one with an MSF receiver. GPS time is not the same as UTC as the mechanics of GPS don't allow the use of leap seconds. The satellites do broadcast a leap second count along with their data stream so the receiver should be able to correct for that, but it doesn't necessarily mean they all do.
Gizmo! said:
The point is that the noise of the pips coming out of your DAB radio is subject to compression/tranmission/decompression delay, but the actual packets of data themselves are not: and I'm led to believe that once per second the DAB network transmits a 'heartbeat' type update, either in hh:mm format or hh:mm:ss.sss.
That time is only as accurate as the multiplex it is receiving from - I can't find any reference that says how they are synchronised. In addition, you are reliant on the software on the radio to make use of any data to accurately set the clock. For example:Pure website said:
You may notice variations in the clocks displayed on PURE DAB radios. Variations in time can be attributed to many events such as encode time (at broadcast) and decode time (at the radio). You may even find multiplexes broadcasting slightly different times, so you will often see the clock shift when you move around stations.
The way it works is the radio looks at the time broadcast once every hour (from the moment it was first turned on), and makes any adjustments to the radio display time at that point. For the other 59 minutes of the hour the radio runs a software clock independent of the broadcast. If the broadcast is not found on the hour check (e.g. the multiplex is off air), the radio will keep running its software clock until the multiplex reappears, and once it reappears the radio will automatically change its clock to meet the clock broadcast time to the nearest minute. It's this adjustment of to the nearest minute which causes variations to be seen between different radios - even when listening to the same multiplex.
You may see variances in the time displayed on your radio - but you should never see variances of more than a couple of minutes.
I guess the short answer is that if you want an accurate clock, buy an accurate clock (or one directly synchronised to one), not something that has a clock as an incidental function.The way it works is the radio looks at the time broadcast once every hour (from the moment it was first turned on), and makes any adjustments to the radio display time at that point. For the other 59 minutes of the hour the radio runs a software clock independent of the broadcast. If the broadcast is not found on the hour check (e.g. the multiplex is off air), the radio will keep running its software clock until the multiplex reappears, and once it reappears the radio will automatically change its clock to meet the clock broadcast time to the nearest minute. It's this adjustment of to the nearest minute which causes variations to be seen between different radios - even when listening to the same multiplex.
You may see variances in the time displayed on your radio - but you should never see variances of more than a couple of minutes.
I would never a DAB radio for accurate time if you knew many times the audio
is compressed multiplexed a/d and d/a converted all adding conversion delays
horrible system.
use a GPS device that system depends on accurate timing to function
so should display time with quite some degree of accuracy.
is compressed multiplexed a/d and d/a converted all adding conversion delays
horrible system.
use a GPS device that system depends on accurate timing to function
so should display time with quite some degree of accuracy.
Gassing Station | Watches | Top of Page | What's New | My Stuff