Model WT-5442 Atomic Projection Alarm Clocks with Indoor/Outdoor Temperature and Weather Forecast, By La Crosse Technology

This clock features multiple display modes for the second line of its LCD display (below the main hour-and-minutes display). Initial (default) display mode for clock setup is day.date.year and outdoor temperature. The 6 regular display modes are:

• Month.date.year and outdoor temperature.
• Clock seconds and outdoor temperature.
• Alarm 1 time and outdoor temperature.
• Alarm 2 time and outdoor temperature.
• Indoor temperature and outdoor temperature.
• Day.month.date and outdoor temperature.

The WT-5442's atomic clock also has dual alarm settings with adjustable snooze from 1 to 59 minutes.

In addition to displaying indoor and outdoor temperatures, the WT-5442 provides accurate weather forecasts by means of its three indicator icons and a barometric pressure trend arrow. The weather-forecasting feature senses barometric pressure over time and adjusts the indicator icons to provide accurate forecasts based on pressure trends. The sun icon predicts improving weather, the sun-and-clouds icon predicts fair weather, and the clouds-and-rain icon predicts worsening weather. The predictions are about 75% accurate for 12 to 24 hours.

Designed for table or shelf placement, the clock can be powered from the included ac adapter (for continuous projection) or optionally from three AA batteries. The TX6U remote transmitter is powered from two AA batteries.

Features:

• Sets automatically to WWVB radio signal (manual setting is also possible).
• 12-hour or 24-hour time display.
• Calendar display.
• Six regular LCD display modes, all of which include outdoor temperature. Additional displayed information can be month.date.year, clock seconds, alarm 1 or 2 time, indoor temperature, or day.month.date. 
• Three projection modes: time only, outdoor temperature only, or alternating between the two.
• Projection is continuous with ac powering.
• Projection is initiated via pushbutton and 3 seconds in duration with battery powering (pushbutton projection is also available with ac powering).
• Projection auto-focusing for display from 3 to 10 feet away on ceiling or wall.
• Projected display can be rotated 360° in 90° increments for proper viewing.
• Projector case rotates 180° to further orient the projected display.
• Three different intensity settings for projected display, plus an "off" setting. With battery powering, "off" is the only option; the intensity is not adjustable and the projection is via pushbutton (not continuous).
• Dual alarm settings with adjustable 1- to 59-minute snooze function.
• Time zone setting (13 available) with map display for U.S. time zones.
• Daylight saving time ON/OFF option.
• Indoor temperature display in either °F or °C.
• Outdoor temperature display (via 433 MHz transmission) in either °F or °C.
• Three weather-forecast icons plus a barometric pressure tendency arrow.
• Electro-luminescent backlight for LCD display (2-second duration initiated by pushbutton).
• Integral base for table/shelf/desktop placement.
• Clock powered by ac adapter (included) or by three AA 1.5V alkaline batteries (not included), with normal life of about 1 year.
• Remote TX6U wall-mount temperature transmitter powered by two AA 1.5V alkaline batteries (not included), with normal life of about 1 year.

Specifications:

• Indoor temperature measuring range:
  32° to 122°F with 0.2°F resolution
  (0° to 60°C with 0.1°C resolution)
• Outdoor temperature measuring range:
  -21.8° to 157.8°F with 0.2°F resolution
  (-29.9° to 69.9°C with 0.1°C resolution)
• Temperature checking intervals:
  Indoor: every 10 seconds
  Outdoor: 3 time in 10 minutes
• Transmission distance:
  maximum 82 feet (25 meters)
• Clock dimensions:
  5.5 inches (140 mm) wide
  4 inches (102 mm) high
  1.5 inches (38 mm) deep (including base)
• LCD display dimensions:
  2.5 inches (64 mm) wide
  2 inches (51 mm) high
  Time number height: 0.75 inch (1.9cm)
• TX6U remote sensor/transmitter dimensions:
  1.57 inches (40 mm) wide
  5.04 inches (128 mm) high
  0.9 inch (23 mm) deep
• Power source:
  AC adapter (included):
  120Vac, 60Hz input
  6Vdc, 100mA output
  Optional: three 1.5V AA alkaline batteries (not included)

The NIST (National Institute of Standards and Technology, Time and Frequency Division) maintains a radio station, WWVB, in Ft. Collins, Colorado. The WWVB radio station derives its signal from the NIST atomic clock in Boulder, Colorado. A team of atomic physicists is continually measuring 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.

WWVB (the station’s identification just like any other radio station) continuously broadcasts time and frequency signals at 60 kHz. The carrier frequency provides a stable frequency reference traceable to the national standard. There are no voice announcements on the station, but a time code is synchronized with the 60 kHz carrier and is broadcast continuously at a rate of 1 bit per second using pulse width modulation. The time code contains the year, day of year, hour, minute, second, and flags that indicate the status of Daylight Saving Time, leap years, and leap seconds.

The La Crosse Technology WT-5442 Digital Atomic Projection Alarm Clock with Temperatures and Forecast Display:

The La Crosse Technology Digital Atomic Projection Alarm Clock with Temperature and Forecast Display maintains its incredible accuracy by automatically tuning into the WWVB radio signal. The built-in antenna ensures reliable signal reception up to 2000 miles (3200km) from the WWVB transmitter. As a result, the La Crosse Technology clock will calibrate to the atomic clock not only throughout the mainland U.S. but also in much of Canada. You need only insert the batteries, wait until the signal is received, and program the desired additional settings. In locations outside of WWVB range, the LaCrosse clock can be manually set and will provide the high degree of accuracy of any quality quartz clock.

In a nutshell, here's how the the La Crosse clock works: The clock's antenna is specifically tuned for optimal reception of the 60 kHz time signal. The time signal received on the antenna is demodulated by an onboard receiver, which sends the information to the clock's CMOS microprocessor for decoding. Once your clock has automatically set its time for the first time, it ensures continuing accuracy by automatically tuning into the WWVB radio signal once per day at midnight. As long as your clock is kept within transmitter range, it will continue to display the absolutely precise time, automatically adjusting for summer time/winter time changeovers if the daylight savings time option is ON. Should you move your clock out of transmitter range for an extended period of time, the clock will continue to operate as a highly accurate quartz-controlled clock. Upon re-entering the transmitter range, your clock will correct itself again to the precise WWVB time signal.