Atomic Nixie Tube Clock

The genuine Atomic Nixie Tube Clock

This is a variant of the venerable NixiSat clock. A Rubidium Atomic Oscillator serves as the timing reference.

It appears similar to the NixiSat, except for the machined billet alloy base. The standardized NixiSat software was modified to include a manual time setting capability, and allow for an external 1PPS signal source to increment the nixie time display. All of the usual NixiSat menu features are included in this one-off special atomic nixie clock. The tubes are Z5680 by RFT.

Following the CNC machining process, the stepped base components are ground for appearance and "bright dipped". A clear hard anodize finish would forever seal the diamond like sparkle. The internal base has been pocket milled to accommodate the Rubidium standard and a concealed circuit board used to power and buffer the FE-5680A output.

Image of the FE-5680A Rubidium Atomic Oscillator installed to a recess pocket area under the clock. The Atomic oscillator consumes 15vdc @ 700ma (2A during warmup cycle) after lamp stabilization. An image of the oscillator module is at bottom of this page. You can visit the Frequency Electronics website here.

The pigtail to the right of the FE-5680A is the digital temperature sensor for the scrolling clock display.

Rear view. All of the clock electronic components are visible. The three 44 pin PLCC sockets are the Microchip 16F877A 20 mhz MCU, and two Supertex HV5530PJ high voltage 32 channel serial shift registers. It is Direct Drive clock design. The cover is assembled from five bonded acrylic panels, edge milled and flame polished. Very nice. And perfectly clear.

Even thought the FE-5680A has attachment holes around the circumference of the base, only four screws are needed to attach it to the clock base. The pocketed area is needed to accommodate the DB9 connector at one end of the FE-5680A.

Not shown: A small remote UPS module maintains power to the clock in the event of utility power failure.

Close up showing the Frequency Electronics FE-5680A Rubidium Atomic Oscillator module. This model supports programming for a number of different output frequencies from 1Hz to 10Mhz. It has been configured to output 1Hz as a short duty square wave for this Nixie Clock application.

Only one Atomic Nixie Tube Clock was assembled. It has been running continuously since 2004, without adjustment.