Question:
I saw one in a store and it had the wrong time. So they don’t work everywhere. A GPS clock would work better. Following are some GPS clock links… http://www.torpeytime.com/Clocks/GPS-1.htm http://www.absolutetime.com/products/100mod.htm http://www.allclocks.com/gps.htm
Response:
> Has anyone tried these self-setting wall clocks? > Do they work well? > I wonder how often you have to change the batteries in these, since they have > built in radio receivers to constantly sync the clock time. > I would like to hear opinions from people who own these. Thanks
I guess you’re talking about WWVB clocks, which receive the NIST’s time codes on 60-KHz WWVB. Cool clocks, if fraction-of-a-second accuracy isn’t what you need. They work pretty much throughout North America unless you are in a place that has lots of electromagnetic interference (e.g. near a poorly shielded computer monitor) or really abysmal radio reception (e.g. in a metal-skin building). Battery life should be about a year or so in a decently made unit — they use very simple low-power circuits, and they wake up only a few times a week. NIST has a good page on these, with lots of troubleshooting tips and links to manufacturers, at http://www.boulder.nist.gov/timefreq/stations/radioclocks.htm — Chris Green
Response:
>-:Has anyone tried these self-setting wall clocks? >-:Do they work well? >-:I wonder how often you have to change the batteries in these, since they have >-:built in radio receivers to constantly sync the clock time. >-:I would like to hear opinions from people who own these. Thanks
Actually, they only sync to the atomic clock once a day, in the early eveining, according to the instruction sheet. — This space left intentionally blank
Response:
>-:I saw one in a store and it had the wrong time. So they don’t work >-:everywhere. A GPS clock would work better. Following are some GPS clock >-:links… >-:
Were the minutes correct, or was it totally incorrect? I was having a problem with mine until I reset it to the correct time zone. >-:http://www.torpeytime.com/Clocks/GPS-1.htm >-: >-:http://www.absolutetime.com/products/100mod.htm >-: >-:http://www.allclocks.com/gps.htm >-:
– This space left intentionally blank
Response:
> > Has anyone tried these self-setting wall clocks? > Do they work well? > I wonder how often you have to change the batteries in these, since they have > built in radio receivers to constantly sync the clock time. > I would like to hear opinions from people who own these. Thanks > I guess you’re talking about WWVB clocks, which receive the NIST’s > time codes on 60-KHz WWVB. Cool clocks, if fraction-of-a-second > accuracy isn’t what you need.
What good would 10-place accuracy be in a wall clock? BTW, with the proper software you can sync your computer’s clock with the NIST time code. — Cheers, Bev "The object in life is not to be on the side of the majority, but to be insane in such a useful way that they can’t commit you." – Mark Edwards
Response:
do these things use the same radio signal as the old radio shack time cubes? (tune in and listen for the tone..). Those things were often a pain to find a good lcation / orientation to pick up a clear signal. I wonder how they do it now so much more reliably and without the big antenna.
Response:
– Hide quoted text — Show quoted text – >-:> >-:> > Has anyone tried these self-setting wall clocks? >-:> > Do they work well? >-:> > I wonder how often you have to change the batteries in these, since they have >-:> > built in radio receivers to constantly sync the clock time. >-:> > I would like to hear opinions from people who own these. Thanks >-:> >-:> I guess you’re talking about WWVB clocks, which receive the NIST’s >-:> time codes on 60-KHz WWVB. Cool clocks, if fraction-of-a-second >-:> accuracy isn’t what you need. >-: >-:What good would 10-place accuracy be in a wall clock? BTW, with the proper >-:software you can sync your computer’s clock with the NIST time code.
If your computer runs Windows, there are several such free utilities at http://www.thefreesite.com/Free_Software/Free_time_utilities/. Dunno what you have to do to get it to happen in that other OS. — This space left intentionally blank
Response:
> Dunno what you have to do to get it to happen in that other OS.
Linux: ntpdate -SC — Stanley Cline — sc1 at roamer1 dot org — http://www.roamer1.org/ … "Never put off until tomorrow what you can do today. There might be a law against it by that time." -/usr/games/fortune
Response:
> Has anyone tried these self-setting wall clocks? > Do they work well? > I wonder how often you have to change the batteries in these, since > they have built in radio receivers to constantly sync the clock time. > I would like to hear opinions from people who own these. Thanks
I have a Sony clock radio. It plugs in so I don’t know about battery issues. I love it, I never have to correct it or reset it when daylight saving begins/ends, but it isn’t perfect. Reception inside buildings is weak, it can pick up a signal only at night, and tweaking the antenna may be needed. (If you have aluminum studs, copper roof, etc., reception may be impossible.) As others have said, it doesn’t correct itself continuously but only once a day in the evening. One minor problem resulting from this is that when daylight savings begins/ends, the new time is shown starting about 10pm the previous night rather than exactly at 1am or whatever. One time it got confused and was off by two hours for a whole day, so my alarm went off two hours early that morning. (This never happened again.) A specific problem with the Sony is that it doesn’t have battery backup. Better clock radios usually do. Sony felt they didn’t need it because the radio would pick up the time signal as soon as the power comes back on, and indeed it tries to, but during the day the recpetion is poor and it does not succeed. (It keeps trying until it is late evening and then it succeeds, but this is a pain.).
Response:
- Hide quoted text — Show quoted text ->-:> >-:> > Has anyone tried these self-setting wall clocks? >-:> > Do they work well? >-:> > I wonder how often you have to change the batteries in these, since they have >-:> > built in radio receivers to constantly sync the clock time. >-:> > I would like to hear opinions from people who own these. Thanks >-:> >-:> I guess you’re talking about WWVB clocks, which receive the NIST’s >-:> time codes on 60-KHz WWVB. Cool clocks, if fraction-of-a-second >-:> accuracy isn’t what you need. >-: >-:What good would 10-place accuracy be in a wall clock? BTW, with the proper >-:software you can sync your computer’s clock with the NIST time code. > If your computer runs Windows, there are several such free utilities > at http://www.thefreesite.com/Free_Software/Free_time_utilities/. > Dunno what you have to do to get it to happen in that other OS.
ntpdate tock.usnogps.navy.mil;hwclock –systohc HTH. HAND. — Cheers, Bev 0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0o0 Judges are our only protection against a legal system that can afford lots more prosecution than we can afford defense.
Response:
>Has anyone tried these self-setting wall clocks? >Do they work well? >I wonder how often you have to change the batteries in these, since they have >built in radio receivers to constantly sync the clock time. >I would like to hear opinions from people who own these. Thanks
I own three — a wall clock, a travel clock, and a wristwatch. I’m happy with all of them 
Batteries last for years. —
Response:
> > Dunno what you have to do to get it to happen in that other OS. > Linux: ntpdate > -SC
Still better, NTP (ntpd or xntpd). This can even be had for Window$. Micro$oft uses SNTP, which is OK on networks with short and predictable delay. PC clocks are lousy, though, and have to be slewed frequently to keep them accurate when running NTP, or they drift out by sometimes minutes a day when they’re just running ntpdate or the like. Old SPARC boxes running ntpd and synced to a Stratum 2 or 3 NTP server make rock-solid local time servers; they can sit in a corner and mark time to the hundredth of a second for as long as the power stays on. — Chris Green
Response:
> do these things use the same radio signal as the old radio > shack time cubes? (tune in and listen for the tone..). Those > things were often a pain to find a good lcation / orientation to pick > up a clear signal. I wonder how they do it now so much more reliably and > without the big antenna.
No, those Timecubes received WWV and WWVH on their various frequencies in the shortwave band. Those signals were meant primarily for listening to; you’d get the time by listening for the update (I have a memory of reading that the time was sent by Morse Code rather than voice, up until the mid-sixties or so). You could also use it as a frequency standard using various means, including the audio tones that were sent out. As you say, reception was sporadic, which was due to the propogation effects of the shortwave band. That’s why the stations broadcast on multiple frequencies, and the TimeCube allowed for switching between those frequencies, in the hope that at least one of them would be receivable in your location at any given time. At some point they added some method of sending the time digitally, but I wasn’t paying attention by that point. Heathkit sold a clock that used this information to the clock on an almost minute by minute basis, years ago, and called it "The World’s Most Accurate Clock". This new wave of clocks use WWVB, which is down at 60KHz, a very low frequency. Like WWV and WWVH, WWVB is operated by the US National Bureau of Standards (or has the pertinent government branch changed it’s name?), and the time and frequency is derived from a very accurate standard, I think based on cesium. But WWVB, being so low in frequency, has much better penetration than shortwave frequencies, and doesn’t suffer the propogation problems of the higher frequencies. WWVB was always much more a laboratory standard; a lot more people have a shortwave receiver than something that tunes 60KHz, and it never had the "friendliness" of a voice telling you the time. Michael
Response:
> Has anyone tried these self-setting wall clocks? > Do they work well? > I wonder how often you have to change the batteries in these, since they have > built in radio receivers to constantly sync the clock time.
The clock I have from oregon scientific ran for 2 1/2 years on two AA batts. This particular unit also received wireless from a temp sensor in the backyard. Those are neat products and I highly recommend them, especially as gifts for "weather geeks". http:://www.oregonscientific.com
Response:
– Hide quoted text — Show quoted text – >-:148028.news.dfncis.de: >-: >-:> I saw one in a store and it had the wrong time. So they don’t work >-:> everywhere. A GPS clock would work better. Following are some GPS clock >-:> links… >-:> >-:> http://www.torpeytime.com/Clocks/GPS-1.htm >-:> >-:> http://www.absolutetime.com/products/100mod.htm >-:> >-:> http://www.allclocks.com/gps.htm >-: >-:My GPS doesn’t work indoors, or when too much of the sky is obstructed by >-:buildings or leaf cover, so I assume a GPS clock would not either. The >-:devices mentioned by the OP WILL work indoors (in most cases) and do not >-:care about an unobstructed view of the sky.
My GPS works perfectly well indoors, so long as I place the remote antenna in the window – but it’s not particularly useful when I do so, since it’s not hard to track a stationary location. I’d bet that the GPS clocks listed include an external antenna, since it is handy for radio stations and such to know the precise time. — This space left intentionally blank
Response:
– Hide quoted text — Show quoted text -> >-:Has anyone tried these self-setting wall clocks? > >-:Do they work well? > >-:I wonder how often you have to change the batteries in these, since > they have > >-:built in radio receivers to constantly sync the clock time. > >-:I would like to hear opinions from people who own these. Thanks > Actually, they only sync to the atomic clock once a day, in the early > eveining, according to the instruction sheet. > — > If that’s the case, then it’s meaningless over-hype them as > "atomic clocks". A more accurate description would be > to refer to these things as self-correcting clocks. > One would have no idea of how much this "atomic" standard > has drifted since it was last updated or whether it even received > an update. Even it’s constantly phase-locked to the NBS, you > would have to account for the varying delay of the signal path to > your receiver to get the true absolute time. > Oh, for the simpler days when every kitchen had an electric > clock with a 60 cycle per second synchronous motor. If the > power line frequency ever varied, the electric company would > compensate the frequency later so that the clocks kept > "perfect" time.
Digital clocks could do the same. Sample the line frequency and adjust the rate. – Hide quoted text — Show quoted text -> Don
Response:
148028.news.dfncis.de: > I saw one in a store and it had the wrong time. So they don’t work > everywhere. A GPS clock would work better. Following are some GPS clock > links… > http://www.torpeytime.com/Clocks/GPS-1.htm > http://www.absolutetime.com/products/100mod.htm > http://www.allclocks.com/gps.htm
My GPS doesn’t work indoors, or when too much of the sky is obstructed by buildings or leaf cover, so I assume a GPS clock would not either. The devices mentioned by the OP WILL work indoors (in most cases) and do not care about an unobstructed view of the sky.
Response:
>-:Has anyone tried these self-setting wall clocks? >-:Do they work well? >-:I wonder how often you have to change the batteries in these, since they have >-:built in radio receivers to constantly sync the clock time. >-:I would like to hear opinions from people who own these. Thanks > Actually, they only sync to the atomic clock once a day, in the early > eveining, according to the instruction sheet. > —
If that’s the case, then it’s meaningless over-hype them as "atomic clocks". A more accurate description would be to refer to these things as self-correcting clocks. One would have no idea of how much this "atomic" standard has drifted since it was last updated or whether it even received an update. Even it’s constantly phase-locked to the NBS, you would have to account for the varying delay of the signal path to your receiver to get the true absolute time. Oh, for the simpler days when every kitchen had an electric clock with a 60 cycle per second synchronous motor. If the power line frequency ever varied, the electric company would compensate the frequency later so that the clocks kept "perfect" time. Don
Response:
> I run ntpdate whenever I think of it, sometimes days and sometimes weeks > apart, and am never off by more than a few seconds.
Depends on your PC. I run a whole lab of them, and clock bias and jitter vary all over the place. Some keep good time, others drift by minutes a day. Sounds like you got one of the good ones. — Chris Green
Response:
The clock I saw in the store had the minutes and the hours wrong. At the time I lived in a high-rise apartment building, so I figured that if it could not receive signals in the mall, it would not do very well in my apartment either. – Hide quoted text — Show quoted text ->-:I saw one in a store and it had the wrong time. So they don’t work >-:everywhere. A GPS clock would work better. Following are some GPS clock >-:links… >-: > Were the minutes correct, or was it totally incorrect? I was having a > problem with mine until I reset it to the correct time zone. >-:http://www.torpeytime.com/Clocks/GPS-1.htm >-: >-:http://www.absolutetime.com/products/100mod.htm >-: >-:http://www.allclocks.com/gps.htm
Response:
- Hide quoted text — Show quoted text -> > Dunno what you have to do to get it to happen in that other OS. > Linux: ntpdate > -SC > Still better, NTP (ntpd or xntpd). This can even be had for Window$. > Micro$oft uses SNTP, which is OK on networks with short and > predictable delay. > PC clocks are lousy, though, and have to be slewed frequently to keep > them accurate when running NTP, or they drift out by sometimes minutes > a day when they’re just running ntpdate or the like. Old SPARC boxes > running ntpd and synced to a Stratum 2 or 3 NTP server make rock-solid > local time servers; they can sit in a corner and mark time to the > hundredth of a second for as long as the power stays on.
I run ntpdate whenever I think of it, sometimes days and sometimes weeks apart, and am never off by more than a few seconds. — Cheers, Bev "I used to be convinced that MicroSquish shipped crap because they simply didn’t give a flying fuck as long as the sheep kept buying their shit. Now, I’m convinced that they really do ship the best products they are capable of writing, and *that’s* tragic." – John C. Randolph, about MS quality control.
Response:
- Hide quoted text — Show quoted text -> Has anyone tried these self-setting wall clocks? > Do they work well? > There was an article on complexities of their design in the > October 2001 issue of Dr. Dobbs Journal: > http://www.ddjembedded.com/resources/articles/2001/0110m/0110m.htm > Excerpt: > A friend called a while ago and asked if I knew any reason why his > new WWVB-based alarm clock might be off by exactly six hours for > a while, then snap back to agree with his other, nonradio clocks. > Cheers,
That was an interesting article, though I’d pretty much read the same details before. When these clocks came up in another newsgroup some months ago (or maybe it was the issue of clocks that can’t keep time), I posted about how the problem is in some ways because we now have so many clocks. The further you go back in time, the fewer clocks and watches a household would have. And being analog, there wasn’t that whole pickiness of "well, this one is two minutes faster than that one". You often wouldn’t be comparing clocks like that, and you’d glance at a clock and see within a few minutes what time it was, usually more than enough accuracy. I suppose those analog clocks were reasonably good at keeping time, because they weren’t so mass produced, people paid a reasonable amount, and it was seen as something important. Now, there are clocks in everything; your watch, on the bedside, your car radio, the VCR, the computer, the clock radio in the kitchen, the microwave, the coffee maker, and I might as well stop right there. They are all digital readout, so it’s really easy to see exactly what time it’s reading, without worrying about parallax and looking carefully to see if the big hand is three ticks past the five, or only two. That almost begs one to compare clocks, and then the fun begins. An immediate issue is that most of the clocks don’t have a means of setting the seconds. So you could get everything adjusted to the same time, but they could be off by as much as 59 seconds. Suddenly, one clock could be reading 12:01 and the other 12:02, even if they weren’t in fact one minute apart. Then there’s the issue of how well each clock keeps the time. Thirty years ago, if you bought a digital clock, likely it was adjusted carefully so it did keep accurate time. Now, they are far cheaper and they may not even have a means of adjusting the accuracy. Certainly, it’s hard to imagine some guy somewhere carefully adjusting each clock and watch, though you would expect that in the days of mechanical clocks, because labor has now become much more costly than the innards of the clock. So the clocks start going out of sync almost immediately. You can have clocks everywhere, because technology makes them cheap, but that practically guarantees that they won’t all display the same time. And since they aren’t adjusted to keep proper time, then of course with time they won’t be reading "the right time". These "atomic clocks" in some ways seem to be a result of all this. Instead of putting money into making the clocks read properly in the first place, let’s add plenty of high tech stuff so the clocks get reset to the right time each night. It is in some ways a gimmick, because most people don’t need such high accuracy, they merely don’t want all their numerous clocks reading a different time. And that’s not going to be fixed, unless all those clocks in the house also become "atomic clocks", so they will all get reset each night and never have much time to accumulate inaccuracies. Michael
Response:
Has anyone tried these self-setting wall clocks? Do they work well? I wonder how often you have to change the batteries in these, since they have built in radio receivers to constantly sync the clock time. I would like to hear opinions from people who own these. Thanks
Response:
> Has anyone tried these self-setting wall clocks? > Do they work well? > I wonder how often you have to change the batteries in these, since they have > built in radio receivers to constantly sync the clock time. > I would like to hear opinions from people who own these. Thanks
I don’t know how often the batteries need to be changed, but all of the ones I’ve seen only sync the time to WWV/etc once per day. That isn’t to say that the receiver isn’t always running, but a halfway decent design would at least minimize current consumption when it’s not being used. :-) – Rich
Response:
> Has anyone tried these self-setting wall clocks? > Do they work well?
There was an article on complexities of their design in the October 2001 issue of Dr. Dobbs Journal: http://www.ddjembedded.com/resources/articles/2001/0110m/0110m.htm Excerpt: A friend called a while ago and asked if I knew any reason why his new WWVB-based alarm clock might be off by exactly six hours for a while, then snap back to agree with his other, nonradio clocks. Cheers, — In order to understand recursion you must first understand recursion.
Response:
Posted in Microwave Kitchen | 
No Comments » |
Laura — One man’s mundane and boring existence is another man’s Technicolor. -Tick, Strange Days 