This is primarily a travel blog in which I write about traveling in our motorhome. Our travels have

Nacogdoches, TX, United States
I began this blog as a vehicle for reporting on a 47-day trip made by my wife and me in our motorhome down to the Yucatan Peninsula and back. I continued writing about our post-Yucatan travels and gradually began including non-travel related topics. I often rant about things that piss me off, such as gun violence, fracking, healthcare, education, and anything else that pushes my button. I have a photography gallery on my Smugmug site (

Saturday, November 16, 2013

How (Not) to Set an Atomic Clock

I have a SkyScan Atomic Clock with Outdoor Wireless Temperature and Moon Phase, Model 87800-87801.  Yes, in addition to time and temperature (indoors and outdoors) it shows the phase of the moon in an LCD display.  I have never had much interest in moon phases and I was surprised to learn that there are eight (or maybe it was twelve) moon phases.  I know about the full, crescent, and quarter moons, but waxing, waning, and gibbous have been tossed into the mix to make it more confusing.  I have no idea what gibbous means.

This morning the LCD displays on the clock looked like hieroglyphics.  Nothing was readable.  The batteries in the clock had finally given up the ghost and needed replacement.  I did so with two brand new AA batteries and the diplays changed from hieroglyphics to blinking dashes and colons (my colon seems to blinks at times).   Now I would have to I reset the clock, which is something I only do once every couple of years or so and I can never remember the correct procedure.  I went to the manufacturer’s website and downloaded the thirteen-page manual, the four-page Quick Reference, and the two-page Quick Guide. The four-page Quick Reference just scrunches up the instructions in the manual real close together in a smaller font while the two-page Quick Guide just scrunches up the Quick Reference. The word “Quick” in both instances was a misnomer.  There was nothing “Quick” about anything.

I will not bore you by covering all thirteen pages of instructions.  However, there are a few interesting things about setting this clock that I would like to tell you about.

There are four display options for my atomic clock.  I can select either
month & date/weekday/seconds/outdoor temperature, month & date/weekday/indoor temperature/seconds, month & date/seconds/indoor temperature/outdoor temperature, or month & date/weekday/indoor temperature/outdoor temperature.  I think I will just stay with whatever the default display is.

The clock is not an analog clock (it has no hands).  It is a digital clock (a clock with blinking lights).  It looks relatively simple, as there are only four buttons (SET, +, ALM, and SNZ) on the clock.  It may only have four buttons, but the number of combinations possible with those four must be a few thousand, which are all included in setting the clock.
Using only those four buttons it is possible to adjust the time zone (8 possible),   Daylight Savings Time (ON or OFF),  Language (English, French, Spanish, or German), Hour, Minute, Year (from 2000 to 2049), Month, Date, Day of Week, Military or Civilian Time, and Temperature (C° or F°).

After changing the batteries I was ready to begin resetting the clock.  NO, wait.  The instructions said “DO NOT PRESS ANY BUTTONS FOR 10 MINUTES” after changing the batteries.  I guess they are serious because it was in bold print.  I wondered why a ten-minute wait was required so I kept reading the instructions and NOT pressing any buttons for ten minutes.  I learned that the ten-minute wait is required to give the atomic clock time to establish contact with the mother ship.

The mother ship is actually an NIST (National Institute of Standards and Technology) radio station with the call letters WWVB and is located in Ft. Collins, CO.  The WWVB radio station receives its data from the NIST atomic clock located in Boulder, CO, which it then transmits to my atomic clock on a continuous radio signal at a frequency of 60 KHz throughout the US.  By the way, I had a HAM radio receiver when I was a kid and anytime I needed the correct time I just tuned it to WWV, which at that time was operated by the National Bureau (not Institute) of Standards. I would hear a click once per second and each minute a voice would announce, “National Bureau of Standards, WWV; when the tone returns [time] Eastern Standard Time.”

It’s so much more complex these days.  A team of atomic physicists continually measures every second of every day to an accuracy of ten billionths of a second a day.  These physicists use an international standard, measuring a second as 9,192,631,770 vibrations of a Cesium 133 atom in a vacuum.  All of this just to make sure I’m not late for my dental appointment.

The WWVB signal can be received by any atomic clock up to 2,000 miles away from the mother ship on 60 KHz and a signal from the outside temperature sensor on 433 MHz.  I considered checking with the FCC (Federal Communications Commission) to ask if I needed any special kind of license for my clock, but then I remembered that I already have a radio operator’s license and it is still valid from my flying days, so I should be OK.

The instructions went on to say that the clock will automatically set itself to the correct time, day, and date after it makes successful contact with the mother ship.  Then I read further.  The “automatic” part happens only IF YOU LIVE IN THE EASTERN TIME ZONE.  If you live in another time zone there is very little that is automatic about setting the clock.  By the way, the clock company is located in Virginia, which is in the Eastern Time Zone.  They made it easy on themselves.  I do not live in the Eastern Time Zone and must resort to the thirteen-page manual to reset my clock.

The clock not only favors those living in the Eastern Time Zone, but will also set itself to DST (Daylight Savings Time) “ON” upon its initial contact with the mother ship.  Unless, that is, I live in Arizona or parts of Indiana, which I don’t.  I will have to set the time zone to the number of hours that my time zone (Central) is from GMT (Greenwich Mean Time).  No sweat.  What time is it in Greenwich?

According to the manual, the initial contact between the clock and mother ship may take overnight (so I needn’t be in a big hurry to check the time or temperature).  The manual recommended that while waiting on the clock and the mother ship to make contact that I should place the clock in a window facing Colorado as opposed to a state such as Florida or New Jersey.

The reason it may take overnight for my clock to talk to the mother ship is because reception is generally not possible during daylight hours due to the interference of the sun and the nature of the Earth’s ionosphere.  Reception may also be poor if the clock is located within a ferro-concrete room (such as a bomb shelter) or within the proximity of metal window frames.  This concerns me because my window frames are metal.

I also found that if I use other electrical products such as headphones or speakers operating on the 433 MHz frequency they could prevent correct signal transmission and reception.  Even my neighbors can mess up my clock if they are using electrical devices operating on 433 MHz.  I need to remember to ask them not to use any electrical devices operating on this frequency.  Do you know what frequency your headphones or speakers operate on?  

After my clock makes successful contact with the mother ship I should see the ‘Radio Reception’ icon appear above the blinking colons (it may need a colonoscopy if it doesn’t).  Once I see the icon over the blinking colons I may then relocate the clock to my desired location facing any state of my choosing.  I have not yet chosen a state.

I will need to mount my atomic clock on a wall to prevent it from moving up and down, as the manual warns that a change in elevation can result in inaccurate temperature readings for 12 to 24 hours after the change.  The instructions suggest that the clock be hung on a wall (perhaps facing Rhode Island?) to prevent the clock from moving up and down.  The instructions also suggest using a “straightedge” and “horizontally space three screw positions 2.36 inches apart” on the wall.  I don’t have a straightedge that can measure 2.36 inches.  What would that be in quarters, eighths, sixteenths, or thirty-seconds of an inch?

If I am successful, my atomic clock will attempt to communicate with the mother ship every hour on the hour from 12:00 am through 6:00 am each day (even on weekends and holidays). 

The manual also warns that once the 433 MHz signal (between the clock and the outside transmitter) is received correctly, not to re-open the battery cover of either the outdoor transmitter or atomic clock, as the batteries may spring free from the contacts and force a false reset.  It would then be necessary for me to start the process all over.

NOTE:  I have not yet been able to reset the clock.  I think I will buy another HAM radio receiver.


Croft Randle said...

I had one of those once but got rid of it after I held a Geiger counter against my forehead!

Robert & Carol Ann Martin said...

We actually have two such clocks and they are different brands so have to use TWO manuals!