UTC or GMT - which is mose accurate?

John_Gray

Slithery wrote: »

If you need an accurate clock then get a Linux machine running ntpd with a GPS receiver attached then sync all of your clients directly from it. It's the only way to be sure...

Something like this, you mean?

chiny

John_Gray wrote: »

Something like this, you mean?

Eek, no... not on MSE Cheapskates here use a Raspberry Pi, with a USB GPS from Banggood (although a GPS HAT would be better) and open source ntp. Something like this. It works better by being placed in a bubblewrap envelope. Accuracy is usually within one microsecond.

A little OTT perhaps...

Frozen_up_north

Anyone with an analogue communications receiver can listen to time signals easily, it’s how clocks on ships were set before GPS. Beware that radios incorporating DSP (digital signal processing) either in the radio itself or if listening via a computer will add delay to the pips.

MSF, in the UK, on 60KHz and RWM from Moscow on 4996KHz and 9996KHz, give a pip every second with a different one each minute.

For a list of these stations see: https://www.meinbergglobal.com/english/glossary/time-signal-transmitter.htm

You can listen via a web based receiver in Holland, although the pips will be delayed and not accurate. This is the web site for listening on a smart phone, it works on my iPhone: websdr.ewi.utwente.nl:8901/m.html

In the drop down box select CW and in the frequency box enter 60 (KHz) and you will hear MSF on 60KHz. MSF is audible 24 hours a day on that site, RWM is strong this morning on 9996. Don’t forget that listening via the web will delay the transmission by several seconds.

RumRat

Why the obsession? Is the watch going to be used for something that needs pin point accuracy? I doubt it....It'll be looked at 5 or 6 times a day and the second hand will be ignored totally......
Life will have passed by quickly enough without checking on it's progress every 5 minutes....;)

unforeseen

The only reason that I have radio controlled clocks and watches is because it means less clocks to adjust twice a year. Now if I can get my oven and microwave to incorporate RC clocks then I'd be happy - no more adjustments even after power cuts.

onomatopoeia99

Tarambor wrote: »

Even at the speed of light they travel 185 miles a second. If you're getting a time signal from WWV which is US based then you could be receiving the signal over 30 seconds after it has been transmitted.

Oh my :rotfl::rotfl::rotfl:. So much error!



I know there are delays when they are interviewing people in the US on the news, but that's a couple of seconds and due to the signal being bounced off satellites in geostationary orbit (which would need over 100 seconds just to reach the satellite at the value of c you posit).

Frozen_up_north

unforeseen wrote: »

Now if I can get my oven and microwave to incorporate RC clocks then I'd be happy - no more adjustments even after power cuts.

After a power cut, on our Panasonic microwave you hit the “Stop/Cancel” button and it then just displays “:”... job done, easy. Who needs a clock on every kitchen appliance? It’s so last century.

John_Gray

Frozen_up_north wrote: »

Who needs a clock on every kitchen appliance? It’s so last century.

I agree! When all our appliances are connected to the internet I hope they can all use NTP to get the time correct to the nearest fraction of a second! No possibility then of burnt toast! :j

unforeseen

Frozen_up_north wrote: »

After a power cut, on our Panasonic microwave you hit the “Stop/Cancel” button and it then just displays “:”... job done, easy. Who needs a clock on every kitchen appliance? It’s so last century.

You do if you want it to start cooking at a set time without you being present.

wongataa

tempus_fugit wrote: »

I think you mean 185,000 miles a second. Light can get to the moon and back in just a few seconds.

It's closer to 186000 miles per second. The actual value is 299792458 metres per second.