The GPSII Clock

Compact GPS Satellite Controlled Nixie Tube Clock (GPSII)

200mm L x 80mm H; GPSII was designed to compliment a desk in your residence. The six 15mm digit Nixie Tubes are easily visible from a distance too. GPSII is controlled by an integrated GPS satellite receiver module, decoding transmissions from 28 US government defense satellites orbiting our planet. The NAVigation Satellite Timing and Ranging (NAVSTAR) system was developed to meet the military needs of the United States Department of Defense. The extraordinary ranging accuracy of GPS is the result of an ultra-stable cesium clock reference transmitted by the ground based segments of NAVSTAR. GPSII takes advantage of the NAVSTAR precision timekeeping system to deliver a clock with "beyond question" accuracy. There are no other satellite controlled clocks offering a comparable level of performance, and embedded features at a hobby kit price. GPSII uses a Direct Drive Nixie Tube display. No multiplexing was used. Although more complex; Direct Drive offers the distinct advantages of a brighter digit display, and extended (10+ yr) tube life. This clock was developed as a partnering project with John Miktuk. An engineering team approach will always deliver a superior product to the customer.

GPSII will remain accurate to within a fraction of a second of the GPS Satellite transmission. Far superior to local oscillator and AC line referenced clocks Local Time, Date, Latitude / Longitude coordinates, and the temperature can be configured to scroll across the display at intervals of: 1, 15, 30, 60 minutes Time can be displayed in 12 or 24 hour format. For 12 hour format: a PM indicator is located at the lower left of the display. Date can be displayed in either mm,dd,yy OR dd,mm,yy format. The temperature can be displayed in degrees F or degrees C with quarter degree precision. A pleasing soft chime ton can be enabled to strike at selected intervals, and a choice of chime styles are provided. The scrolling speed can be varied from slow to -fast in a range of the individual steps. And, each of the features can be separately disabled from the periodic scrolling cycle. The colon indicators separating the paired digits can vary their configuration to upper, lower, or independent. This determines whether the Time, Date, Coordinates or Temperature are currently being displayed.

GPSII receives the satellite transmissions using a compact "puck" style 1.5Ghz antenna. Some locations may provide adequate satellite reception inside of a structure, whereas others will require an externally mounted antenna. The antenna is weatherproof, and includes a 10' coaxial lead in for external mounting.

GPSII incorporates a unique method of operation in areas with "spotty" reception due to limited antenna mounting considerations; a secondary time source! In the event of satellite signal loss after successful startup; GPSII will continue operation using an internal 1pps signal pulse supplied from the GPS receiver. The lower right colon lamp will extinguish to indicate the clock is operating from the local reference, then relight when the satellite signal has been restored. If power is lost, a lithium battery will maintain GPS receiver ephemeris, and quickly resume operation when power is restored. No typical cold start TTFF (Time To First Fix) delay is incurred when GPSII is re powered. The initial startup acquire after installation may take 10-30 minutes, location dependent.

The symmetrical component layout attracts your eyes to the electronics inside. Two PCB's arranged in an "L" contain all the electronics for GPSII. The vertical PCB supports the MCU, regulated supply , and the GPS satellite receiver module. The horizontal PCB supports a high voltage power supply, display control and the Nixie Tubes. GPSII operates from a compact 12vdc wall power adapter, accepting 90-260VAC from 47-63 Hz.

GPSII is secured in a handsome clear acrylic enclosure. The cover is removable.

The setup menu and controls are accessed via magnetic reed switches at the top of the clock using an included rod magnet.

GPSII can be programmed to turn off the display during the nighttime hours, and automatically turn on again in the morning.

Click Here to download the GPSII Operation manual in .PDF format.