Atomic Clock - Wrong Time

Your answer would be correct if there was a switch for DST. My clock has a button to select the deviation from GMT (+_ hours from GMT). It also allow me to turn DST on and off.

My clock isn't processing the radio signal correctly.

Is there a visual cue that tells you that DST is ON or OFF?

I would be looking to see if the clock was responding to user input with that switch.

I am not sure where you are at, but make sure that you have the correct number of hours offset from UCT.

Did you try changing the offset by an hour? Since DST is dependant on both the dateand the political entity you reside in (not every location uses dst) then the clock would need to know both the current date, as well as whether DST is observed in your locality. on top of that congress changed the start and end dates of DST in the US a couple years ago, and if the clock is older than that it won't know anything about that change. My solution would be to advance the offset manually for DST.

On some clocks there is a switch that lets you select your time zone, but the change from/to daylight savings time may have to be manually regulated, because even though you may be located in certain time-zone, not all states within that time-zone will necessarily recognize daylight/standard time. Unless your clock has a table of which states do and don't - and unless your clock 'knows' where it is, it is likely you'll have to change it manually.

How does your clock know it's in California? It could only know one of two ways: it contains a GPS receiver which tells it where it is, or you do.

This may something of note. From NIST:

"Since October 29, 2012 at 1500 UTC (9:00 AM MDT), NIST Radio Station WWVB has been broadcasting a phase modulated (PM) time code that has been added to the legacy AM/pulse-width-modulation signal...

... Disciplined oscillator products that track and lock to the 60 kHz WWVB carrier and were designed to work as frequency standards, will not work with the PM [phase-modulated -ed] signal and have become obsolete. Radio-controlled clocks that are based on synchronous AM demodulation (lock to the carrier), such as the Spectracom NetClock and receivers manufactured by True Time during the 1970s and 1980s, have also become obsolete."

Does this coincide with the problem with your clock?

Mine worked okay until the DST change last fall. I believe it's picking up the signal, because I can manually change the time, but when it syncs up at night, it goes back to the wrong time.

Good find, but I did this already.

I have had two watches that pick up the WWVB 60kHz signal, and they automatically set to the correct time for daylight savings time. As others have suggested, check to see if there is a switch on your clock to disable daylight savings time for folks that live where they don't observe it.

You are correct, while WWV and WWVH still broadcast on 2.5,5,10, 15 and 20 MHz. the one most used is 60 KHz.

My clock has the DST setting and here in CA we have DST, so it's on. Time shows 2:36 am, when it's really 3:36 am. What am I still doing up? Good night everyone!

I don't recall the details but quite a few years ago someone (Bush 43?) changed when Daylight Savings Time started and ended. If you are off by one hour just after a change then I wonder if your clock has a DST change table that conforms to the old standard.

WWV transmits a digital code for encoding the state of leap seconds and DST in the digital time code. So, if DST start/stop dates change, WWV will broadcast that change.

It's up to the user to either enable or disable DST recognition on their clocks.

"Does anybody really know what time it is....?"

Back to clockwork for me. My radio controlled watch went exactly 30 mins out. It changes with the summertime settings etc but is always exactly 30 mins out. I've tried resetting it but to no avail. I have a solution that involves taking the back off .....

On the subject of timekeeping in the UK we have the pips. On the hour the BBC give out an accurate time signal which is a series of pips followed by a long one which is the time marker. With modern technology - digital radios etc the time signal is way out when compared against an old AM or FM radio.

Clockwork - it rocks!

Good idea. I'll do this and let you know if it works. I did try the method Solar Eagle posted and it didn't work. Maybe I need to do a complete reset.

I'll let you guys know if it works.

It worked perfect. There must've been a charged capacitor in the circuit. The odd thing is when I remove the batteries, the unit would default to 12:00 and all settings would be cleared. I thought that would be enough to reset the DST function - that's where I think the error was coming from.

Anyway, it works perfect now. Thanks for the answer!

Its a nice trick, that works probably more than 50% of the time, though I haven't really counted the percentage.

Funnily enough, I fixed an HP printer for a friend of mine today, that would not use black ink anymore....

I am pleased that I was able to help you.....

Exactly WHY it works I can only guess at, so here goes, my guess is that the processor has been badly programmed, and there is a "one way street" with no way out in the code. A situation that the programmer never dreamed could happen.....

Powering off FULLY, allows the code to run clean again/start afresh.....of course this could also mean that the code could error again in a few years time, sadly...

Hopefully not!! But at least you know the fix!

By the way, some devices need several days of no power by the way, so don't ever give up!!!

I have a Mercedes C230 that won't recognize the key. The slunk noise that usually occurs when you put the key in the ignition doesn't happen and the key doesn't turn. I've done everything I can to clear the memory. I've been told that the ECM is bad. I hope not, because it's about $1K to fix it. I'm driving one of our other cars right now.

It works off of National Bureau of Standards WWV clock which doesn't do daylight savings...get your setback by changing your timezone...that worked for me.

I do believe there is something going on I have noticed it for the last two years.when it time to change the clocks the automatic one are a little ahead of all my clocks that have to be manually adjusted. This last time I made sure of this by setting four separate clock at the last time change and sure enough this time change the self adjusting clocks were a had by ten minute s and the manual all read the same time so they were not faulty. There is something!

My atomic clock is 4 minutes behind. I've tried to correct it and it goes back to the 4 minute late time.

Sioscan clocks set off of the National Bureau of Standards, who sets the standard for your 4 minute late time?

I love your answer! I am in Electronic Engineering as well. My clock does the very same thing, and I seriously doubt anything can be done about this issue. The suggestion to move the clock to a northern exposure defeats to point of having this clock for a visual reference of the exact time. In any case, please accept my clock and turn it around next to yours.

I decided to just let my clock sit on my window sill. It at least tells the temperature, but it also doesn't seem accurate. I'm almost to the point of throwing it out ... hmmm that sounds like a good idea!