La Crosse Technology WS-7390TWC Wireless 433 MHz Weather Station with Atomic Clock

For definitions of the feature icons, please click any icon.

The La Crosse Technology WS-7390TWC is a version of the the WS-7390U that bears the logo of and has been available from The Weather Channel^®. This wireless weather station displays indoor and outdoor temperature plus indoor and outdoor relative humidity. It also has a moon-phase display with tide indicator and a weather-forecasting feature with three forecast icons. Outdoor temperature and humidity are transmitted to the station via the included TX4U remote sensor/transmitter. The station can actually receive signals from a total of three remote sensors (additional remotes are optional and sold separately).

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Styled as a silver bulb-type thermometer in a dark blue plastic case, the wall-mount WS-7390TWC has plenty of convenient features, including an atomic clock. In addition to day/date/time and moon phase with tide indicator, the station displays indoor temperature and humidity, outdoor temperature and humidity (via an included remote transmitter), forecasting icons, and indoor comfort level. Install one or two optional remote transmitters, and get temperature and humidity data from additional locations.

Almost 18 inches tall and over 6 inches wide, the station is dark blue and silver in color and is intended for wall mounting only. Its LCD displays are large for easy reading, and the LCD display contrast can be adjusted for any of 8 different levels.

The station's incredibly accurate radio-controlled atomic clock has day/date/time displays. Time can be displayed as 12-hour or 24-hour, and the clock can be optioned to automatically adjust for daylight saving time.

The station's weather-forecasting feature senses barometric pressure over time and adjusts the indicator icons to provide accurate forecasts based on pressure trends. Another clever feature of the WS-7390TWC is an indoor comfort level indicator with happy and sad face icons.

The station keeps a record of the minimum and maximum indoor and outdoor temperatures and humidity it has recorded, and these are available at the push of a button.

Not only will the station operate with up to three remote sensor/transmitters, three different remotes are available. The TX3U reports outdoor temperature only. The TX4U (the one included with the station) reports both outdoor temperature and humidity. The TX3UP senses temperature via a probe on a 10-foot (3-meter) wire for use in pools, spas, soil, etc.

The station's clock calibrates itself to the world's most accurate clock every night by receiving WWVB radio transmissions. These transmissions contain time information from the U.S. atomic clock source, operated by the U.S. Commerce Department near Boulder, Colorado. The built-in antenna ensures reliable signal reception up to 2000 miles (3200km) from the WWVB transmitter.

Substantial in size with good looks and many convenient features, the WS-7390TWC is ideal for larger rooms and offices. (If you would prefer a black plastic case instead of dark blue, please check out the WS-7390U. Or, if you'd like a case trimmed in real wood, have a look at the three WS-7391U models instead.)

Features:

Clock sets automatically to WWVB radio signal (manual setting is also possible).
12/24 hour time display (hour, minute, second).
Date (calendar) display.
Moon phase display with tide indicator.
Station displays indoor and outdoor temperature and relative humidity with minimum and maximum recordings and time and date of recording (resettable).
Temperature indication selectable for either °F or °C.
Three weather-forecasting icons.
Weather tendency indicators.
Indoor comfort level indicator with happy and sad face icons.
One outdoor temperature and humidity transmitter included; additional transmitters are optional and sold separately.
Can receive and display information from up to three outdoor transmitters.
LCD display contrast selectable for 8 different levels.
Station powered by two AA alkaline batteries (not included), with average life of about 1 year.
Remote transmitter (TX4U) powered by two AA alkaline batteries (not included), with average life of about 1 year.

Station Specifications:

Radio-controlled time signal: WWVB
Recommended operating temperature:
32° to 122°F (0° to 50°C)
Indoor temperature measuring range:
32° to 140°F with 0.2° resolution and 2° accuracy
(0° to 60°C with 0.1° resolution and 1° accuracy)
Outdoor temperature measuring range:
-21.8° to 139.8°F with 0.2° resolution and 2° accuracy
(-29.9° to 59.9°C with 0.1° resolution and 1° accuracy)
Indoor and outdoor relative humidity range:
20% to 95% with 1% resolution and 3% accuracy
Indoor checking intervals:
Indoor temperature: every 10 seconds
Indoor relative humidity: every 1 minute
Outdoor checking interval (remote sensor):
Outdoor temperature: every 1 minute
Outdoor relative humidity: every 1 minute
Outdoor temperature and humidity reception interval (indoor station): 5 minutes
Station dimensions:
6.41 inches (16.3cm) wide
17.71 inches (45.0cm) high
1.22 inches (3.1cm) deep

Remote Thermo-Hygro Transmitter (TX4U) Specifications:

Remote transmission of outdoor temperature and humidity to station via 433 MHz signals
Recommended operating temperature:
-25° to 158°F (-31.6° to 70.0°C)
Temperature measuring range:
-21.8° to 156.2°F with 0.2°F resolution
(-29.9° to 59.9°C with 0.1°C resolution)
Relative humidity range:
20% to 95% with 1% resolution
Checking intervals:
Temperature: every 5 minutes
Relative humidity: every 5 minutes
Transmission interval: every 10 seconds for first 3 minutes, every 1 minute thereafter
Transmission frequency: 433.92 MHz
Transmission range: 80 feet (25m) in open space with no interference
Wall mounting
Power source: two AA (1.5V) alkaline batteries (not included)
Remote transmitter dimensions:
1.6 inches (4.0cm) wide
4.3 inches (11.0cm) high
0.8 inch (2.0cm) deep (not including mounting bracket)
Rain protector dimensions:
2.24 inches (5.7cm) in diameter
4.7 inches (12cm) high
Remote transmitter dimensions with rain protector installed and including mounting bracket:
2.24 inches (5.7cm) wide
4.88 inches (12.4cm) high
2.87 inches (7.3cm) deep


TX4U	TX6U	TX3U	TX3UP
One TX4U comes with the unit.	The TX6U, TX3U and TX3UP may also be used with this unit, up to a total of 3 remotes.

Radio-Controlled Time:

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 Integral Atomic Clock:

The atomic clock integral to the WS-7390TWC 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 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 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 atomic 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 between midnight and 6:00 a.m. 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.

Note: This unit has atomic clock functionality. The atomic clock can receive time broadcasts from the U.S. Atomic Clock transmitter in Colorado and synchronize itself to the U.S. Atomic Clock every night. As long as the signal is strong where the clock is located, the clock will maintain accuracy to a fraction of a second, and reset itself for daylight saving time (unless you choose to disable the DST function). However, if the clock is located where the signal is poor, due to metal in the construction of your building blocking the signal or due to electrical interference from nearby electrical appliances or computers, then the clock may not always receive an adequate signal. Under these conditions, the clock may still synchronize occasionally when weather conditions are ideal, or may need to be set manually.