To find out more about WWVB radio controlled clocks, please download this 64-page PDF booklet:You may also receive a printed copy by or by calling (303) 497-4343.By now, you have probably seen or own a radio controlled clock. These clocks are sold in all forms: as wall clocks, desk clocks, travel alarms, and wristwatches. They have a tremendous advantage over conventional clocks, they are always right! When working properly, radio controlled clocks always display the correct time, down to the exact second. This means that you should never have to adjust them. During the transition from standard time to daylight saving time (DST) they 'spring forward' one hour, and when DST is finished they 'fall back' one hour.Due to technology advances and the economies of scale, radio controlled clocks are now very inexpensive, often costing just a few dollars more than conventional clocks.

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This page provides information about radio controlled clocks, including,. How They WorkSome manufacturers refer to their radio controlled clocks as 'atomic clocks', which isn't really true.

An atomic clock has an atomic oscillator inside (such as a cesium or rubidium oscillator). A radio controlled clock has a radio inside, which receives a signal that comes from a place where an atomic clock is located.In the United States, the signals received by radio controlled clocks originate from, which is located near Fort Collins, Colorado. WWVB broadcasts on a frequency of 60 kHz. Your radio controlled clock actually has a miniature radio receiver inside, which is permanently tuned to receive the 60 kHz signal.The 60 kHz signal is located in a part of the radio spectrum called LF, which stands for low frequency. This is an appropriate name, because the FM radio and TV broadcasts that we are accustomed to listening to use frequencies thousands of times higher.

The lowest frequency received by any of the other radios in your house is probably 530 kHz, the bottom of the AM broadcast band. Even that frequency is nearly 10 times higher than the WWVB signal.At 60 kHz, there isn't enough room on the signal (bandwidth) to carry a voice or any type of audio information. Instead, all that is sent is a code, which consists of a series of binary digits, or bits, which have only two possible values (0 or 1). These bits are generated at WWVB by raising and lowering the power of the signal.

They are sent at a very slow rate of 1 bit per second, and it takes a full minute to send a complete time code, or a message that tells the clock the current date and time. When you turn a radio controlled clock on, it will probably miss the first time code, so it usually takes more than one minute to set itself (sometimes 5 minutes or longer) depending on the signal quality and the receiver design.Once your radio controlled clock has decoded the signal from WWVB, it will synchronize its own clock to the message received by radio. Before it does so, it applies a time zone correction, based on the time zone setting that you supplied. The time broadcast by WWVB is Coordinated Universal Time (UTC), or the time kept at the Prime Meridian that passes through Greenwich, England. While a few users like their clocks to display UTC (ham radio operators, for example), most prefer to display local time.

This means that the time in your area is corrected by the number of hours shown in the table. Time ZoneDifference from UTC During Standard TimeDifference from UTC During Daylight TimePacific-8 hours-7 hoursMountain-7 hours-6 hoursCentral-6 hours-5 hoursEastern-5 hours-4 hoursOnce your radio controlled clock has synchronized, it won't decode the signal from WWVB again for a while.

Most clocks only decode the signal once per day, but some do it more often (for example, every 6 hours). Those that decode the signal just once per day usually do it at midnight or in the very early hours of the morning, because the signal is easiest to receive when it is dark at both WWVB and at the site where the clock is located. In between synchronizations, the clocks keep time using their quartz crystal oscillators.

A typical quartz crystal found in a radio controlled clock can probably keep time to within 1 second for a few days or longer. Therefore, you shouldn't notice any error when you look at your clock display, since it will appear to be on the right second, even though it has probably gained or lost a fraction of a second since the last synchronization. Where They WorkWWVB radio controlled clocks should be able to work in most places in North America.

The red areas on the coverage maps below show where a WWVB radio controlled clock should be able to synchronize. Note that the red area is largest at night, and smallest in the daytime (click on the map to see a larger image).

For example, 0600 UTC is about midnight in the central United States. Credit:NIST2200 UTC coverage mapThese maps are based on a field strength of 100 microvolts per meter, which in theory should be a large enough signal for most receivers to work with. In fact, some receivers have much better sensitivity (20 or 30 microvolts per meter). However, simply having a large signal doesn't mean that the receiver will work. What really matters is the signal-to-noise ratio, or the size of the signal compared to the size of the electrical noise near the same frequency. Raising the noise level is just as harmful as reducing the signal level.

For example, if the radio controlled clock is near a source of interference (like a computer monitor) the noise level will increase, and the clock might not be able to synchronize. If the radio controlled clock is in a building with a metal roof, much of the signal will be blocked. Therefore, the signal level will be reduced, and the clock might not be able to synchronize.Therefore, use the coverage maps as a rough indicator only. We have heard from many owners of radio controlled clocks whose clocks do not work inside the coverage area shown on the maps. This is probably due to a local source of interference.

We have also heard several reports from Alaska that the clocks work fine, even though Alaska is outside the coverage area shown on the maps. This is probably due to the low amount of radio 'background' noise found in a sparsely populated area. What to Do When They Don't WorkNIST provides the signal received by your radio controlled clock, but we cannot provide technical support for the clocks themselves. We didn't manufacture them, and we are not familiar with all the models or all of their features. We recommend that you save the instruction sheet that came with your clock, so you can refer to in the future if necessary. Having said that, we can offer a few general tips about what to do if your radio controlled clock isn't displaying the correct time. My clock doesn't synchronize at allMost WWVB radio controlled clocks work great, as evidenced by the hundreds of thousands of units that have been sold throughout the United States.

However, if your radio clock or receiver isn't working, we suggest:. If your clock uses batteries, check them and replace if necessary. If you have a desk top unit, try rotating it 90 degrees. If you have a wall clock try mounting it on a wall perpendicular to the one it is currently on (e.g. If it is on a north-south wall try an east-west wall). The antennas are directional and you might be able to improve the signal strength by turning the antenna. Place the clock along a wall or near a window that faces Fort Collins, Colorado.

Locate the clock at least 1 or 2 meters away from any computer monitors, which can cause interference (some monitors have a scan frequency at or near the WWVB carrier frequency of 60 kHz). If nothing else works, take the clock outdoors at night and power it down (remove the batteries or unplug it), then power it up again to force it to look for the WWVB signal. If it works outdoors but not indoors, you probably have a local interference problem inside your house or building.

If it doesn't work outdoors at night, it's probably best to return it and try a different model. The shielding provided by a metal building might prevent the clock from working. For example, if you live in a mobile home or a house with steel siding, the clock might not work. If you think your clock is defective, ask the manufacturer or dealer about obtaining a replacement.My clock is off by one or more hoursRemember, minutes and seconds are the same in all time zones within the WWVB coverage area; only hours are different. If your clock is off by one or more hours, it probably has to do with a time zone setting. Make sure you have properly selected your time zone using the instructions that came with your radio controlled clock.If you live in an area that does not observe Daylight Saving Time (Arizona or Hawaii), make sure that DST is disabled on your radio controlled clock. Not all clocks have this feature, so you might have to select another time zone to make your clock display the correct time when DST is in effect.Some radio controlled clocks only allow you to select four different time zones (Pacific, Mountain, Central, and Eastern).

Some clocks allow you to select any time zone, even those time zones that are outside the coverage area. When purchasing a clock, make sure that it can handle your time zone. For example, we've heard from a few users who purchased clocks in Hawaii but can't select the Hawaiian Time Zone. My clock is off by a few minutes or secondsThis can be due to a number of different problems as listed below:Reception Problem - If your clock isn't currently receiving the signal, the time will 'drift' and gradually get further and further from the correct time. Remember, if the signal isn't being received, your clock isn't radio controlled any longer, it's just a regular quartz clock. Its accuracy will depend on the quality of the quartz crystal. Most quartz clocks can keep time to 1 second per day or better, but some will be off by several seconds per day.Most digital radio controlled clocks have an indicator on the display that tells you if the signal is being received properly.

Some analog clocks have an audio indication (a usa-button you can push that indicates through a series of tones or beeps if the signal is there). If you are not sure if the signal is being received, try powering down the clock (unplug it or remove the batteries), then turn it on again to see if it can synchronize. If it doesn't, see the tips above for improving your reception.Alignment Problem - If you have an analog clock, it's possible that the hands aren't properly aligned. This could cause the clock to be off by a second or more even if it is receiving the signal properly. The clock might not have been properly aligned at the factory, or it might have been jostled during shipment, causing the hands to move. Some manufacturers explain how to align the hands on their instruction sheet.

If you aren't sure how to do this, and the small error bothers you, it's best to return the clock.Checking your clock - There is no need to check a properly working WWVB clock, it should always display the correct time. However, you might want to check it if you suspect you have a problem. You can check your clock by using the, or by listening to using a shortwave radio or telephone (dial 303-499-7111).When checking an analog clock, make sure you are looking straight at the clock face, and not viewing it from an angle. If you view if from an angle, you can think it's off by a few seconds, even if it's not.

This is similar to trying to read the speedometer from the passenger seat of a car, and thinking the speed is faster or slower than it actually is. We switched to Daylight Saving Time, and my clock didn't changeThis is probably due to a reception problem. Your clock hasn't received the signal recently, so it didn't know about the time change. Most digital radio controlled clocks have an indicator on the display that tells you if the signal is being received properly. Some analog clocks have an audio indication (a usa-button you can push that indicates through a series of tones or beeps if the signal is there). If you are not sure if the signal is being received, try powering down the clock (unplug it or remove the batteries), then turn it on again to see if it can synchronize.

If it doesn't, see the tips above for improving your reception.Also, some clocks have a way to disable Daylight Saving Time. Make sure it isn't disabled if your area observes DST. My clock switched to Daylight Saving Time, but we don't observe DST where I liveThere is most likely an on/off toggle for DST. Turn it off if your area does not observe DST.

About how to do this. If there isn't a way to turn DST off, you may have to change your time zone setting during DST to make your clock display the correct time.

Quick set up instructions.These instructions are for the brands we offer including Howard Miller and Seiko Clocks. These may or may not work for other brands.

We do not have any instructions for other brands outside of Howard Miller and Seiko clocks.Welcome to the world of radio controlled timekeeping technology. We hope you will enjoy the convenience of never having to set your clock again and the confidence of knowing exactly what time it is. Insert 1 fresh AA, LR6 1.5 volt ALKALINE battery. Press button to select a time zone. During the night your clock will automatically set itself.For a better understanding of how and why your clock works please continue reading.Nothing is more precisely measured than time!And nothing keeps track of time more precisely and trouble free than our radio controlled clocks. Since the beginning of time, man has been fascinated with the measurement of time and has devised more accurate machines to trap and measure time. Today, time is precisely measured in the United States by the most accurate clock in North America, the Atomic Clock of the US National Institute of Standards and Technology, Time and Frequency Division in Boulder, Colorado.

A team of atomic physicists continually measures every second of every day to an accuracy of ten billionths of a second per day. These physicists have created an international standard, measuring a second as 9,192,631,770 vibrations of a Cesium 133 atom in a vacuum. This atomic clock regulates the WWVB radio transmitter located in Fort Collins, Colorado, where the exact time signal is continuously broadcast throughout the United States at 60 kHz to take advantage of stable long wave radio paths found in that frequency range. Radio waves at these low frequencies use the earth and the ionosphere as a wave-guide and follow the curvature of the earth for long distances.The built in antenna system will receive the WWVB signal anywhere in North America within 2000 miles of Fort Collins where long-wave radio reception is undisturbed. A microprocessor activates the receiver and processes the time signal from Fort Collins overnight.Through the radio signals, our radio controlled clocks always keep precise time. The changeover from standard time to daylight savings time, and vice versa, takes place automatically with the same precision.Additional detailsTo set up your clock simply install one fresh AA, LR6 ALKALINE battery. Due to the nature of long wave radio signals it is normally not possible to receive a signal during the day so it is best to install the battery late in the evening.

Select your time zone by pressing one of the four time zone buttons PT-Pacific Time, MT-Mountain Time, CT-Central Time, ET-Eastern Time. The time zone buttons may be pressed any time after installing the batteries. If multiple buttons are pressed the clock will set to the time zone selected last. If no time zone is selected the clock will default to Pacific Time. Another time zone can be selected during or after the clock has set itself.

Your clock can only set itself to one of the four time zones stated above. For time zones outside of PT, MT, CT or ET you must manually set the time using the Manual Time set button on the back of the movement.Daylight Savings Time Adjustment.If you live in Indiana or Arizona you will wish to disable the DST function.

After setting your clock press the small button labeled 'DST' located just above and between the ET and CT Time Zone buttons on the back of the movement. Your clock will no longer observe DST.Manual SettingAtomic Clocks may also be set manually and be very accurate. Simply insert the battery, press your time zone and then press the flap just above the left side of the battery.

Hold until you reach the correct time and then release. Your clock is now an accurate quartz clock until it will find the signal. Your Atomic clock will still continue to look for the signal and start adjusting itself automatically.When the battery is installed the second hand will advance eight seconds (two seconds per step x four steps). The clock is now searching for a signal. For the initial setting, it is recommended to stand the clock in an upright position near a window.

Within five minutes the clock will either receive the WWVB signal and set itself to the exact time, or it will determine that the signal is not receivable at its current location and time of day. If a signal is not receivable it will fast-forward the hands to the 4, 8, or 12 o’clock position and search for WWVB each hour until a signal is received. If the time is manually set the clock will continue to periodically search for a signal and automatically reset the hands when the signal is received.Select a location to place your radio controlled clock where it will be at least six feet away from a TV, computer, air conditioner or other household electrical appliances. The optimal location is near a window. Windows facing Colorado providing the best signal.

Vrd-vc20 manual. The WWVB time signal will easily penetrate Masonry and wood-framed buildings. WWVB will penetrate almost every residential building and most steel buildings if they have adequate windows. It is not possible, however, for WWVB to penetrate most indoor shopping malls and rooms in the center of large office buildings that do not have windows. In buildings that WWVB cannot penetrate you may set the time using the manual time set button.

When the clock is exposed to the WWVB signal it will automatically set the hands to the exact time.Our Rwave, Atomic, Radio Controlled clocks do not receive or process radio-controlled time signals from Germany’s DCF 77, Japan’s J Ga AS, or England’s MSFs atomically regulated transmitters. Our Radio Controlled clocks can be manually set and used anywhere.If your clock did not set the first time or after daylight savings time change, try the following instructions:1) Take out the battery and place the battery in backward for about 10 seconds, then replace it again in the correct position.2) Just after replacing the battery, press the Time Zone button for about 5 seconds on the back that corresponds with the time zone where you are located.3) Shortly after the hands should start turning 20 times their normal speed and stop at 4:00 or 8:00 or 12:00. This means the clock is now looking or waiting for the signal and the clock movement is good.4) Place the clock near a westerly window overnight and then the clock should reset overnight and read the correct time.If you had previously pushed the manual mode flap (switch), take a pen or paperclip and make sure it is pulled out in the off position.If you live in the Eastern Time Zone, you should manually set your clock using the following procedure:1. Take the battery out of the clock.2. Press the manual time setting tab on the back of the clock 15 times.3. Put the battery back into the clock.4.

The clock will go to 4:00, 8:00, or 12:00 and stay there while waiting for the signal.5. Immediately after your clock stops at 4:00, 8:00, or 12:00, push and hold the manual time set tab until you get to the correct time.If you release the button at the incorrect time, take the battery out and start again.These clocks will automatically continue to check and adjust after April 1.For more information on the NIST and radio controlled time, see TroubleshootingThe wonderful advantage of owning a radio-controlled clock is that it is virtually trouble-free. If the clock receives a clear signal it will set itself perfectly.

If it does not receive a signal consider the following:Battery - The clock must have a fresh battery to receive and process the time signal.Location - Try a different location, ideally near a window. It should be at least six feet from computers, TVs, air conditioners, other Radio-Controlled clocks and other electrical appliances that cause interference.Weather - Electrical storms between you and Colorado during the night will interfere with the WWVB signal.Daylight Savings TimeThe National Institute of Standards and Technology and WWVB encode a special DST 'bit' in the WWVB transmission for DST. Your Radio Controlled clock will read this information and automatically advance the hands one hour in the spring and eleven hours in the fall.Arizona and IndianaIf you live in an area that does not recognize DST you must press the (unmarked) DST button for one second to deactivate your clock’s DST program. To reactivate the DST program simply press the DST button again for one second.Frequently Asked QuestionsQ. How long will the battery last?A.

A good AA alkaline battery will last over one year. If your clock is located in an area with little interferencewhere it can quickly receive a signal the battery can last much longer than one year.Q. Can a Radio Controlled clock be used outdoors?A.

Yes, but only in a dry environment and in a temperature range between 41 F and 131 F. The clock is NOTwater-resistant.Q. Can the Radio Controlled clock be wired to control timing circuits?A. Why does the second-hand move only once every two seconds?A. When the battery drops below 1.25 volts the clock indicates that it is time to change the battery by advancing the second hand in two-second steps. The operating voltage range is 1.25 to 1.75 volts.Grandfather Clocks - Atomic Clocks - Wall Clocks25% - 50% OFF EVERYDAYFree Nationwide Shipping and Delivery on 97% of our selections.