CL-D4 - Viking Electronics

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Digital Wireless Synchronized Clock with 4" Tall Numbers

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Product Details

The CL-D4 Digital Clock is part of Viking’s Wireless Clock System that provides reliable, accurately synchronized clocks for your entire facility. Eliminating dedicated clock wiring can save you thousands of dollars on installation and also allows for easy retrofitting of an existing installation. While most wireless systems are limited to the range of the transmitter, Viking’s system is not. Each clock acts as a repeater (transceiver), meaning the secondary clocks both receive and re-transmit the signal, maximizing signal transmission distances. The system is comprised of a CTG-2A master clock, a CL-RFT clock RF transmitter and analog or digital wireless slave clocks. Working on Viking’s 915-928MHz frequency hopping technology eliminates interference with other wireless products and requires no FCC license, eliminating extraneous fees. The received signal remains strong even under the effects of noise, obstructions or long distances which tend to decrease the signal to noise ratio. Installation is a cinch for our wireless clocks, just insert the batteries or connect power and hang them. That’s it.

Viking’s CL Series wireless clocks include automatic calibration, as well as diagnostics that allow the user to view the signal strength, how long since the last time the clock received a signal, a comprehensive analysis of the clock itself and remaining battery life. The 12 and 16 inch wireless analog clocks receive and retransmit an RF clock sync signal every 4 hours (standard mode) or 12 hours (economy mode) allowing for a battery life of 5 years or 8 years respectively. The 2.5 and 4 inch digital clocks are powered by an included power adapter and receive and retransmit an RF clock sync signal every minute. Viking also offers a complete line of accessories for the clocks, such as: double mount housings, wire guards, and digital clock surface mount housings.


  • Wirelessly synchronize all clocks in your facility
  • Schools
  • College Campuses
  • Restaurants
  • Churches
  • Theaters
  • Auditoriums
  • Dormitories
  • Office buildings
  • Factories



  • Built-in repeater receives and re-transmits clock sync signal each minute
  • 915 – 928 MHz frequency hopping technology
  • Internal antenna
  • Built-in diagnostic mode for easy maintenance
  • Receives the RF Sync signal once a minute
  • Immediate correction for time change
  • 12 or 24 hour format
  • Two levels of adjustable brightness
  • Loss of communication alert
  • Can be surface mounted (see CL-SMD4) or double mounted (see CL-DMD4)
  • Optional wire guards (see CL-WGD4)


  • Input Voltage: 120VAC / 13.8VAC 1.25A UL listed adapter included or 16 – 28VDC / 14 – 28VAC
  • Average Current Consumption (max brightness): 190 mA @ 24VAC
  • Bezel Dimensions: 6.75″ (172mm) x 13.31″ (338mm)
  • Display Digit Dimensions: 4.0″ (102mm) tall
  • Shipping Weight: 3.5 lbs (1.59 kg)
  • Temperature: 32°F to 90°F (0°C to 32°C)
  • Humidity: 5% to 95% non-condensing
  • Input Sensitivity: -103 dBm
  • Operating Frequency: 915 – 928 MHz frequency hopping technology
  • Transmitter (Repeater) Power Output: 0.25 Watt (8 dBm), transmits up to 500 ft in open space
  • Compliance: FCC compliant, part 15, section 15,247 (no license required)
  • Bezel Color: Anti-glare red
  • Brightness: Two levels, adjustable
  • Display Color: Vibrant Red
  • Display Format: 12 or 24 hour mode
  • Number of Digits: 4 digits
  • Visibility: 100 ft. (30.48 m)
  • Mounting: Surface Mount with CL-SMD4 or Double Mount with CL-DMD4


  • FCC Part 15