Last Updated on August 19, 2020 by Calibre 11

Collectors often reflect on the 1970s as being the most dynamic decade in Heuer’s history, a case that’s easy to mount when you look at the combination of the ground-breaking Chronomatic movement and a roll-call of famous names- Monaco, Carrera, Autavia, Silverstone and Montreal, to name but a few. The other reason that the 1970s stands out is that at the same time as Heuer was developing innovative mechanical chronographs, it was also at the forefront of high-precision digital quartz technology.

The interest in electronics was very much driven by Jack Heuer, who would go on to a long career in the electronics industry after leaving Heuer in 1982. Jack visited Silicon Valley in 1972 and saw first-hand the advances in Microchip technology.While Heuer launched the Microsplit 800 (The world’s first digital stopwatch) in 1972, it would take another three years for Heuer to use the technology in a wristwatch.

The Heuer digital era lasted only seven short years (1975-1982), but during this time there were some incredible watches launched. Back in 1975 it must have seemed that digital technology would be the next wave of watchmaking- and Jack Heuer had no intentions of seeing Heuer left behind in the digital race.

Movements

Broadly speaking, there are two generations of movements used during this period: the Heuer developed movements in the mid-late 1970s and the ESA analogue/ digital hybrid movement of the late 1970s/ early 1980s.

The first generation of Heuer digital watches uses a series of movements developed by Heuer in conjunction with its partners in Silicon Valley, and is comprised of:

Calibre 100: LCD/ LED Chronograph

Calibre 101: LCD, single display; time and date only

Calibre 102: LCD/ LCD Chronograph

Calibre 103: LCD/ LCD Chronograph (Ford RS)

Calibre 104: LCD GMT (Manhattan)

Calibre 105: LCD Chronograph

Calibre 106: LCD Chronograph version of Calibre 101

Calibre 107: LCD GMT (Senator)

The most technically innovative of the movements is the Calibre 100/ 102- the first solid-state digital wrist Chronograph ever made. The Calibre is made up of two separate chips driven by a single 32kHz crystal on a common circuit board (as you can see in the photo above).

The chips were initially made by a US company called Integrated Display Systems (IDS), with Heuer developing its own capability in 1977 when it created a specialist Microchip company called Heuer Micro-Technik SA (HMT).

What’s also obvious from the photo of the Calibre 102 is the fragility of the movement, most notably the exposed thin wires connected to the two chips…only one of these wires had to break for the watch to lose functionality, which explains why so few Chronosplits survive today.

This vulnerability was partly addressed on later movements, such as the Calibre 105 below, which provided better protection to the chips. There are very, very few people who know how to service and repair these movements today, and it’s certainly not something to try at home. The outstanding website Led-forever has some great information on these watches- certainly worth a read.

The rapid changes in technology and the economies of scale available in chip production meant that Heuer’s digital movements quickly became uncompetitive. The solution was to use the ESA 900.231, a combination analogue/ digital movement used by Heuer, Breitling and many others. ESA (Ebauches S.A) was the parent company of ETA, before a name change in the late 1970s saw all movements in the ESA group re-branded as ETA (for example, the Valjoux 7750 become the ETA 7750).

The design advances in the three years following the launch of the Calibre 100 are obvious, although these ESA movements are still fragile compared to the bullet-proof quartz movements of today.

Heuer Chronosplit

The Heuer Chronosplit looked like it dropped down from space when it was launched at Basel Fair in 1975. The design was ultra-modern and a radical departure from the look of any other contemporary Heuer.

The Chronosplit is a genuine tool watch with a focus on delivering an ultra-precise chronograph function- those two windows are not for looks, but reflect the technical limitations of early digital watches.

LCD/ LED

The reason that the Chronosplit has two windows is that early LCD technology could not move fast enough to display the 1/ 100th second accuracy demanded by the Chronosplit- something that LED could deliver. But LED was not practical enough to be used to display the time, as it absorbs too much power. The neat solution was to combine the two technologies- LCD for the time function and an LED Chronograph that was only “live” when it was needed.

In addition to the standard model, there were two special editions of the LCD/ LED Chronosplit, the most famous being the Ferrari-branded version shown below.

The second version is the watch made for Tiffany & Co. Both of these watches command a strong premium today over the standard model, with the Ferrari version being particularly sought.

In addition to the stainless steel model, the Chronosplit was also available in a Gold-plated model.

Chronosplit LCD/ LCD

As LCD technology advanced, there was no longer a need for the LED component of the movement, meaning that second-generation Chronosplits changed to a LCD/ LCD display in 1977. The other obvious change is the addition of menu labels on the screen to help remind owners exactly what each of the five buttons did.

The dual-LCD movement is more reliable than the LED version- just- but the cleaner, purer design of the first Chronosplit is generally viewed as more attractive.

Note that the Chronosplit does not have “Swiss Made” on the dial- the case and bracelet were made in Switzerland, but the value of the movement that contained many parts from the US meant that the watch was categorised as “Assembled in Switzerland”- indeed, some early LCD/ LED Chronosplits were assembled in the US.

Heuer Manhattan

The Manhattan (actually the “Chronosplit GMT Manhattan” as there is a quartz-powered all- analogue version) shares the dual dial layout of the Chronosplit, but replaces the digital time function with a traditional analogue clock. The case design of the Manhattan is just as bold as the Chronosplit, sporting a Bullhead Chronograph layout (pushers on top of the case) and locating the crown under the base of the case.

While the design may have been bold, the movement powering the Manhattan was a step backwards. The digital window is powered by the Heuer Calibre 104, while the analogue watch function uses a quartz Citizen movement. The two movements are in no way integrated, each using their own battery.

Like the Chronosplit, the Manhattan Chronosplit is “Assembled in Switzerland”, while the all-analogue Manhattan quartz carries “Swiss Made” on its dial.

The Manhattan was discontinued in 1982, the year that Heuer was sold to Piaget/ Nouvelle Lemania. Amazingly, the design was brought back by fashion label DKNY (part of LVMH alongside TAG Heuer) in 2005 with the “re-edition” you see above.

Heuer Senator

The Heuer Senator was introduced in 1979 and has the same basic layout as the Manhattan, but with the hexagonal case replaced by a smooth lozenge shaped-case. Like the Manhattan, the Senator was part of the Heuer range until 1982.

Note that the Heuer Senator does proudly carry “Swiss Made” on the dial- it’s likely that the chips for the Calibre 107 in the Senator were sourced from Heuer Micro-Technik rather than from the US, with IDS filing for Bankruptcy in the late 1970s.

Heuer Kentucky

The Heuer Kentucky was launched in 1977 and was one of the first Heuer watches to use the Valjoux 7750 movement- today’s TAG Heuer Calibre 16. In addition to the mechanical Chronograph Kentucky, there were several quartz models, including this ultra-rare twin-screen LCD model from 1979.

There are two LCD Kentuckys, the more common model being the single-screen watch, which uses the Heuer Calibre 105.

Heuer ESA Digitals

In 1978 Heuer launched a second-wave of digital models, this time powered by the ESA 900.231 movement. By 1978 the landscape for digital watches had totally changed. When the Chronosplit was launched in 1975 it sold for $450, a price that reflected its advanced technology. By 1978, digital watches with the same functionality were available for less than $20.

Heuer’s bespoke low-volume movements were simply too expensive to be further developed and so digital movements were now sourced from ESA, which took the same approach as the Manhattan and Senator in combining an analogue watch with a digital Chronograph and other functions- let’s call these the “Twin-Time” digitals.

Carrera Twin-Time

The Carrera Twin-Time took a more conservative approach than the earlier Heuer digitals, looking far more like a “normal” watch than the earlier Heuer digitals.

The Twin-Time Carrera sold for the same price as the automatic version.

Verona Twin-Time

Also available as a Twin-Time model was the Heuer Verona, a niche dress-watch series launched in 1978. Less sporting than the Carrera, the Verona in any form is rare today, and especially rare in digital form.

Heuer 1000 Twin-Time

The Heuer 1000 was the last of the Heuer digital watches, being launched in 1982. Amazingly, by the time the 1000 Twin-Time was launched, it was the only Heuer Digital watch available.

Rare Heuer Digitals

Ford RS Split Lap 77

Perhaps the most…um, striking digital watch made by Heuer is this Ford RS Split Lap 77 LCD/ LCD model from 1977. The watch did not carry any Heuer logos (perhaps wisely), but was designed and made by Heuer, using the Calibre 103 movement.

Oh, and those two discs at the front? That’s where the batteries go.

Heuer Memphis

One of the strangest watches made by Heuer is this Heuer Memphis, a watch about very little is known. In fact, this example owned by Jeff Stein is the only photograph you’ll find showing any Memphis model.

Ref 16061

The blandly named Ref. 16061 digital from 1979 is an interesting design- a very “classic” digital watch design, but one that is very “un-Heuer”. These are very hard to find, with perhaps two or three coming on to the market in the last five years.

Looking Back

Perhaps the most unusual aspect of the digital Heuer era is how revolutionary the first watches were- and how conventional the later designs became. The first digital watches were styled to make a clean break with the past and contained highly advanced, if not exactly reliable, technology. By the time we get to the early 1980s, a “digital” Heuer watch was simply a conventional analogue model with a thin window showing additional functionality. The revolution died as fast as it arrived.

It was the pace of development in Microchips that was to blame, as digital LCD technology quickly became cheap and ubiquitous- a $20 digital from a Gas station was just as accurate as any high-end digital. Digital was no longer advanced, or high-tech…it was simply “cheap”, which is not something any Swiss brand wants to be.

Since those early days, TAG Heuer has launched a number of digital watches, most notably the Microtimer, which shares the same spirit as the original Chronosplit.

Of course, while the digital era died quickly, the quartz era was still going strong, but in a far more conventional manner. Not as many collectors know about the digital Heuers, but the technology in the Chronosplit was as advanced as any of the concept watches made by TAG Heuer today. That Jack Heuer could play as important a part in shaping the mechanical Chronograph market as he did the digital timing market speaks volumes for the innovation of Heuer in the 1970s.

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Photos

Chronosplit module; Ferrari Chronosplit; Tiffany Chronosplit; Gold Chronosplit; Kentucky twin-LCD: http://www.led-forever.com

Calibre 105 module: sportmichael

ESA Y2 movement: http://www.watchesulike.com

DKNY “Manhattan”: http://chronoaddict.blogspot.com.au/2012/02/dkny-heuer-manhattan.html

Kentucky single LCD: Jan- http://www.chronocentric.com/forums/chronotrader/index.cgi?md=read;id=9809

Verona Twin-Time: Darren Stuart: http://www.chronocentric.com/forums/chronotrader/index.cgi?page=1;md=read;id=23831

Heuer 16061: Jarl- http://classicheuers.blogspot.com

Heuer Memphis: Jeff Stein http://www.onthedash.com

Heuer 1000 Diver: http://heuerville.wordpress.com/2010/10/17/heuer-diver-984-424-dual-time-gold

Ford RS Split Lap 77: twilightdivewatches.wordpress. com

Other Photos courtesy of TAG Heuer