Saturday, February 14, 2009

RT Article: Clock Syncing

Have you ever been frustrated that all the clocks in your house show a different time? Are you scratching your head trying to figure out what time it really is? In this article, I'll show you how to get the real time, and get all your clocks in sync.

The first thing you need to do is to get the accurate time. The first logical question one asks is: where does the official time come from, anyway? The accurate time comes from an atomic clock located at the National Institute Of Standards and Technology (NIST) in Boulder, Colorado. Most modern computer operating systems will synchronize to a time server, which in turn syncs to the atomic clock. In Windows XP, right click on the time (in the bottom right corner of your screen), select adjust date/time, click the "Internet Time" tab, then update now. Another method is to use a shortwave radio. Tune into WWV at 2.5, 5, 10, 15 or 20MHZ. You'll hear a series of beeping noises, then "at the tone, the current time is...". I recommend you sync a digital watch to the computer or WWV. Set the hour, then set the minute one ahead (if it's 2:41, set it for 2:42), then keep resetting the seconds, until it is in sync with the time.

After you sync your watch, go around and do all the clocks in the house. For digital clocks without second indicators, I'd recommend you set it to the current minute, then move it up right as the minute changes. The method involved in setting the digital clock may vary, but you get the idea. For analog clocks, pull the battery out right when the second hand hits zero. Set the hands for a minute or two ahead, then put the battery in right when the actual time catches up to where the clock is set.

How Atomic/Radio Controlled Clocks Work:

While I'm writing an article on keeping accurate time, I should tell you about radio controlled/atomic clocks. These devices, as you can guess, sync to the NIST atomic clock in Boulder, CO, but how? By all the little images of a satellite on the packaging of most units, you'd think it's some kind of satellite, or something new and really high tech, right? Wrong. First of all, the radio signal that these clocks rely on is nothing new. The signal is WWVB broadcasting on 60KHZ from a site in Fort Collonns, CO (along with WWV). The station broadcasts a 1 bit per second data stream which provides the seconds, minutes, hours, day of year, year, as well as leap year and leap second information. Daylight Savings Time data is also included. Because of the low frequency of the station (which is well below AM radio [530-1710KHZ]), and high output power (50KW), it consistently covers the continental United States and southern Canada, while Central America, northern South America at night.

WWVB started broadcasting in 1962, and has been broadcasting in the exact same format since 1965. The transmitting facilities were upgraded in 1997 and completed in 1999, so atomic clock receivers have been around for over 45 years (mostly rackmount industrial units). So, why, you ask, have radio-controlled clocks only become available in the last few years? It's because the higher power of the transmitter, building a receiver that fits into a watch or small clock is now practical. Often times, the receiver can be fitted on a single chip, and a small antenna. After years of creating chipsets, atomic clocks are becoming a standard feature. I surveyed the clock selection at my local Wal-Mart and found $10 models with atomic clock reception. I opted for a $20 Sharp alarm clock that also includes dual alarms, indoor and outdoor temperature sensors, day, date, year and moon phase displays. Oh, and it relies on batteries, so I never have to worry about a power glitch again.

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