Life For Nixies
digital clocks get their glamour from the Nixie tube, the mother of electronic
Zorpette, Senior Editor
They were tagged
with the unfortunate name NIX-1, for Numeric Indicator Experimental-1.
But by the time they hit the streets, in 1954, they had been nicknamed
Nixie, and they arrived just in time to become the warm, reassuring face
of electronics' heady adolescence. They went on to literally light up the
New York Stock Exchange, cruise under the sea aboard Navy submarines, and
wink by the hundreds at NASA mission controllers guiding rockets to the
A Nixie is basically
a set of diodes in a glass tube containing a little neon gas. The cathodes
are numerals, lined up one behind the other. Voltage applied to one ionizes
the surrounding neon, and the numeral seems to light up.
If it is possible
for an electronic component to be beloved, surely Nixie tubes were. With
their graceful digits glowing a pleasing orange, they lent a touch of class
to all kinds of 1950s and 1960s electronica, from voltmeters to desk calculators.
But in the end, like long-playing records and British sports cars, Nixies
were eclipsed by more practical and rugged successors. They lost ground
in the 1970s, ultimately to seven-segment LEDs.
Nixies are staging a spirited comeback. Home hobbyists have given the design
cognoscenti something new to covet: a digital clock with a Nixie-tube display.
Several organizations in the United States and Europe are selling them
ready-made for prices between US $250 and $1200. The photos that follow,
of clocks by hobbyists, testify to the ingenuity and creativity that these
builders are bringing to their clocks.
The new appreciation
of Nixies is due in no small measure to one Mike Harrison, a consultant
near London who designed an elegant, robust, and versatile clock circuit
based on inexpensive components and posted it on his Web site (http://www.netcomuk.co.uk/~wwl/nixclock.html).
The site has had 100 000 hits over the past couple of years, Harrison reports.
have not been manufactured in the United States or Europe for a quarter
century, treasure hunters still occasionally stumble upon a trove of tubes
in a warehouse. Garden-variety unused Nixies can still be bought for $8-$20
a tube (or even less on eBay). But connoisseurs now treat some remaining
stocks like vintage wine, bidding as much as $450 apiece for certain rare
and coveted tubes (typically giants up to 15 cm long).
in their heyday Nixies were seldom used in clocks. A set of tubes and the
required chips would have priced a clock too far above the mechanical kind.
Such a timepiece isn't exactly cheap today, either, but now it seems an
ideal if belated use for Nixies. Not only do the tubes put a delicate and
whimsical face on the most utilitarian of appliances, their authentically
retro look is a vivid reminder of the passage of time. They call to mind
an era when horn-rimmed eyeglasses and pocket protectors were more than
cheap Hollywood props.
little electronic campfires," says Walter Shawlee II, an IEEE associate
member and owner of Sphere Research Corp. (Kelowna, B.C., Canada) (http://www.sphere.bc.ca/),
an instrumentation contracting company that also sells Nixies and other
technology artifacts. Contemplating the enduring appreciation of Nixies,
Shawlee adds, "People have this wistful longing for the stuff that looks
WEINER, Los Angeles
built his first clock in a shop class in high school in 1972: six Nixie
tubes in a lovingly crafted mahogany case. It was the start of something
big. In the 30 years since, he has built 100 clocks, he estimates, most
of them with a Nixie display. His mantel clock [below, left] is a fine
example of "out with the old, in with the new." First he extracted the
eight-day wind-up mechanism from an antique clock. Then he replaced it
with an electronic circuit wired to a six-Nixie-tube display. The clock
circuit, as in most of his creations, is based on a 10-MHz crystal oscillator,
with ICs to divide the frequency down to 1 Hz.
test-board clock [above, right] is mounted on what is known in art circles
as a "found object"--in this case, refuse from an aerospace contractor.
It is an IC test board with several hundred contact points. His granite-base
clock [right] is outfitted with B-7971 tubes, a large, later-model alphanumeric
tube used primarily in stock-exchange boards. The hard part of building
the clock "had nothing to do with electricity," Weiner recalls. "It was
drilling the holes in the granite."
Some day, Weiner--who
keeps six clocks in his bedroom--may run out of Nixies, but that day is
distant. An ardent devotee of eBay, he has accumulated a cache of 450 tubes.
V at the Flick of a Wrist
Nixie clock small enough to wear on your wrist? It was a challenge Jeff
Thomas couldn't pass up [right, top]. The idea for the watch "came from
the movie Brazil--a strange flick where technology had become stalled,
distorted," he explains. "A friend had seen this movie and asked if a Nixie
wristwatch had ever been made." Turned out it hadn't been done. After all,
how do you produce, within the space of a wristwatch, the tubes' 200 Vdc?
"One day I was
playing with a disposable flash camera," Thomas goes on. "I noticed that
the circuit used to generate the high-voltage dc for the flash comprised
only three components: a transistor for oscillation, a tapped transformer,
and a diode rectifier. The circuit generated 200 V at 2 mA from a single
AA battery. Ah ha!" The next pieceof the puzzle came to him at an auction
of military equipment at Hickam Field in Hawaii, where he ran across 80
aspirin-sized NL-7977 Nixie tubes from National Electronics.
He used them
to make 30 watches and gave some away as gifts. Once he was wearing his
own in a shopping mall when a teenager asked, "Dude, is that one of those
recent economic dry spell to advantage (his company, Resonant Instruments,
manufactures semiconductor wafer probing equipment), Thomas also put together
a series of desk clocks [right]. He gave away seven and sold another 20
faster than he could make them. Still, the Nixie look isn't for everyone.
Thomas's wife banished his own clock to a desk in his study. clockpage.html
Long and Short of It
Loughton, Essex, UK
It was only
a matter of time before Mike Harrison, who has long been interested in
spark-gap tubes, thyratrons, and other exotic electronic glassware, turned
his attention to Nixie tubes. When he did, the results were extreme: his
habit of building ever larger clocks culminated in a unit adorned with
rare East German Z568M tubes boasting digits 50 mm tall [right, top]. Sockets
for the tubes are long gone, so he made his own, using a printed-circuit
board and receptacles from a dismantled D connector. The time-keeping circuit
is the sturdy, versatile one Harrison designed and posted on his Web site
the big clock, he resolved to make a tiny one for his car [above, foreground,
and at right]. Through a fellow tube collector, he obtained some small
Japanese Nixie tubes and crafted a surface-mounted circuit based on three
stacked pc boards. The clock, which measures 80 by 25 by 45 mm, has a built-in
dc-dc converter to step the car's 12 V up to the 200 V required by the
As a child,
Ralf Spettel was enchanted with a few mysterious glass tubes he kept in
a drawer. When he grew older, he found out they were called Nixie tubes,
and after a few Web searches, he learned how to make them glow. The next
step, of course, was to build a clock. His large radio-controlled clock
[right] synchronizes itself with signals from the atomic clock at the Physikalisch-Technische
Bundes- anstalt in Braunschweig, Germany.
too lazy to set the correct time," he says--not very convincingly because
he was industrious enough to produce an elegant design based on a 90S8515
microcontroller and impeccable circuit boards. In a new version of the
clock [not shown], he dispensed with the calendar function and put a smaller
versIon of the clock, also radio controlled, in a handsome wood case.
in the World?
way for an electronic clock to keep time is to count cycles of house current,
and that's what many Nixie-tube clocks do. But not Katsushi Matsubayashi's.
His receives signals from the U.S. Defense Department's Global Positioning
System (GPS) satellites. The orbiters provide the clock with not only submillisecond
accuracy but also the date and the clock's latitude, longitude, altitude,
speed, and bearing.
the position data aren't much use to Matsubayashi, who keeps his clock
in his rather stationary office at the Tokyo National College of Technology,
where he is an associate professor of mechanical engineering. But the clock
has been a big hit there: "Some teaching colleagues feel nostalgic towards
it; some students are surprised at GPS, and get interested in vacuum tubes,
which they have never seen before," he writes.
to decide what kind of case to put the clock in, he got sharply differing
views from co-workers. "The teaching staff in mechanical engineering suggested
that the circuit should be clearly seen from the outside, whereas those
in electrical engineering suggested the circuit should not be seen from
the outside," Matsubayashi reports. "If gears or motors had been used,
their suggestions might have been reversed."
Ipswich, Suffolk, UK
There are basically
two ways to switch the 200 Vdc that light a digit in a Nixie tube. You
can use a cheap small-signal transistor, or you can splurge and use a 74141
IC, which has the high-voltage transistors built in. Geoff Tomlin rejected
both approaches and opted for an evocative assemblage of rotary switches.
As a high school senior in 1969, inspired by an article in an electronics
magazine, Tomlin built a clock using military surplus rotary switches to
apply the high voltage to the appropriate Nixie digit in sequence. The
time reference is a one- revolution- per-minute synchronous motor; gears
divide this time reference to turn the hour and minute rotary switches
at the proper rates.
stop there. He designed other electromechanical assemblies based on diodes,
switches, or impulse counters to automatically keep track of the day, month,
and year (for another 8000 years--how's that for youthful optimism?). However,
he could not get the day and year selectors to work properly before he
went off to college and became an EE with the telephone company. He never
forgot his clock, though, and now, 33 years later, he pledges to "get it
fully working." The year 9999 awaits.
South Manchester, UK
bedside clock [below left, foreground] is probably a lot nicer than yours.
The clock not only has an alarm, but chimes gently every 15 minutes, except
when Bleads is in bed, between 11 p.m. and 10 a.m. The circuit also automatically
dims the display at night by strobing it rapidly on and off. The clock
is based on a PIC16F84 microcontroller, which counts the cycles of the
50-Hz house current where he lives.
The chimes and
alarm are both software-generated square waves. For the chimes, he simulated
the decaying sound of a bell's "ding" by changing the ratio of the square
wave's on and off parts. "The chimes are very useful when I'm busy, as
they remind me when it's time to go to the pub," he reports. His new clock
[above, right] uses 46-mm Russian Nixies and consolidates the circuitry
on one circuit board. "It does seem bizarre to be driving antique tubes
from modern microprocessors," he concedes. "But that's half the fun."
KONRAD METZNER/DODOCUS/JASON WISE/GETTY IMAGES/DAVID KAMPFNER/GETTY IMAGES/DAVID
KAMPFNERTOP: RALF SPETTEL/KOLCHI KOMASHIDA/GETTY IMAGES/PETER J. TAYLOR/GETTY