This one-of-a-kind digital clock was originally a Computer Measurements Company model 614A Universal Preset Counter. It was built in late 1965, upgraded from a 5-digit to a 6-digit display in 1970, and converted to a clock by me in 2002. It uses vintage Nixie tubes, a form of numeric display that has been considered obsolete since 7-segment LED displays became available in the early 70's. However, many people still prefer the aesthetics of Nixies over more modern display technologies, due to their warm neon glow and individually-formed digits. The exterior appearance of the counter is unchanged - including all the control labels, so it isn't immediately obvious that it is now a clock.
The clock measures about 17" wide, 13.5" deep, and 3.5" high. The case was intended to be rack-mountable, however I do not have the rack mounting brackets for it. It weighs about 19 pounds. The Nixie digits are 5/8" tall: none of the pictures here really do them justice, they are much smoother, and a brighter orange color, than my old video camera is capable of capturing.
The clock's features include:
- Selectable 12- or 24-hour time display.
- Datekeeping that is fully Y2K-compliant, and valid through the year 9999. The time and date can be displayed alternately at a user-adjustable rate, or manually at the press of a button.
- Temperature display in both °F and °C, although this may not be that useful to you - the temperature sensor is deep within the clock, and says more about how hot the clock's electronics are running than the ambient room temperature.
- A backup capacitor that will keep the clock running (at somewhat reduced accuracy) for a few minutes during power outages, or moving the clock to a different outlet.
- An alarm, although it's not particularly loud. Unlike the typical alarm clock, the alarm can be shut off for today without having to remember to turn it back on for tomorrow. The alarm is set via the thumbwheel switches on the front of the clock, so the current alarm time is always immediately visible.
- Several forms of random number display, just for fun!
Click here for pictures of the clock's interior, and technical details on its construction.
Click here for the instruction sheet that will be included with the clock (2 pages, in Adobe PDF format - get Acrobat Reader to view).
Click here for details on other unique digital clocks that I've built, or am planning to build.
Please read these details carefully before bidding: this is not the clock for everybody.
- This device is not new, and has accumulated various scuffs & scratches over its years of service. In particular, the top and bottom covers have quite a few scratches due to being stacked with other equipment. I haven't tried to do anything about this, as it's likely that these areas won't even be visible. If they are a problem for you, I'd suggest trying a vinyl upholstery repair kit - the covers are basically black textured contact paper over sheet metal.
- There is an intentional gouge on the front panel where someone once underlined an important voltage limit, and a scratch that I must have made myself while loosening or tightening the nut that holds the FUNCTION switch in place. There is nothing that could be done about these, short of completely replacing the front panel.
- The clock requires 120 volt 60 Hertz AC power, which basically limits its use to the USA and Canada. It will NOT work in countries that use 50 Hz power, even with the use of an adapter, since the power line frequency is the basis for the clock's timing.
- The clock has a cooling fan, which is not entirely quiet - this may be a problem if it is to be placed in a bedroom or other location where noise is undesirable. The fan can be switched off: the original owner's manual requires that the fan be used if the ambient temperature may reach 50°C (122°F), however that recommendation is probably based on running the device 8 or so hours per day, not 24. For longest possible life of the clock, I suggest running the fan regardless of ambient temperature. Note that if you do use the fan, the owner's manual recommends that it be oiled every 6 months.
- The Nixie tubes used in the clock (Amperex ZM1030 or ZM1032) should continue to work for years, however they will eventually wear out, and it won't be easy to replace them - they haven't been made in decades, and are of the relatively uncommon bi-quinary type. The one source of these that I'm currently aware of wants $10 each for used tubes: you can probably do better than that if you regularly search eBay for long enough.