Megaquartz 2.4MHz

Already in 1954, after the publication of Max Hetzel’s Swiss patent for the later ‘Accutron‘ (Accuracy + Electronics) movement, the leading people at Omega realised, that electronic watches would be the future. Omega, as one of the leading watch companies, could not afford to be seen as an imitator of the Bulova watch company, for which the patent had been granted (1).

Complex Collaboration

Description of the expertise the Battelle Institute provided for industrial collaborators. Taken from: (6)

Without microelectronic competence, Omega, as part of the SSIH, began negotiations with the Battelle Institute in Geneva in 1956, for a collaboration. The collaborative project was run by Peter Döme and Jakob Lüscher, two leading scientist at the Battelle Institute. The project seemed stuck as between 1965 and 1967 the costs for the development of the new calibre skyrocketed and as Omega, despite gaining experience in electronics on larger scale, had still little competence on the field of electronics of wrist watch size and failed to judge and supervise the progress correctly, which resulted in massive delays (1).

Jean Hoerni. Picture credit: (7)

The slow advancement for the development of the integrated dividers pushed Hans Widmer, then technical director at Omega, to contact the semiconductor pioneer Jean Hoerni, founder of Intersil. Despite the dissatisfaction of the Battelle Institute, Hoerni joined the project and a first working prototype was presented during the International Chronometer Congress in Paris held the 16th – 19th of September 1969 (1).

A few months later more elaborate prototypes were presented at the Basle fair of 1970. Latter models with enormous cases were nicknamed ‘Elephant’ or ‘Mickey Mouse’. Their calibre (cal.: 1500) was run by two batteries for the needed 2.7V of tension (1).

Left: Prototype (P-1) of the Omega Megaquartz 2.4MHz in ‘chronometer competition’ configuration. This version was used for precision testing most probably at the observatory in Neuchâtel. The marketed versions were tested in Besançon. Right: The prototype (P-2) nicknamed ‘Elephant’ with the experimental cal.: 1500 presented at the Basle fair of 1970. Picture credits: (5,2)

Cal.: 1500

Two cal.: 1500. Please note the minute differences in circuitry and mechanical parts between the two movements of the same calibre, underlining the experimental character of these two pieces. Picture credit (3)

The first hurdle taken by the engineers at the Battelle Institute, after signing the collaboration contract with Omega in 1956, was to develop the quartz resonator. The only commercially available quartz resonator with a resonating frequency of 2.359MHz was lenticular in shape, of the size of a small Aspirine tablet and was sourced from the UK (2). The suspension of the quartz resonator would prove very difficult to achieve and would massively delay the manufacture of a working prototype. One can see tight parallels to the development of calibre Beta 21, which industrial production was delayed because of very similar problems. The control of the motor required a very extensive frequency division, the technology of which had hardly been developed yet. It was agreed on a two-stage, analogue frequency division with tuned oscillating circuits by a factor of 6 each, followed by 16 binary sub-stages down to 1 Hz (1).

Cal.: 1510 and Derivates

Left: Cal.: 1510 which is virtually the same as cal.: 1511. Right: Cal.: 1516 with a shortened base plate. The electronic module had additional plastic on the safety cover near the trimmer. The top plate on the motor module exposed the teeth of the centre second gear. And finally, the long motor contact plate was made more flexible to allow removal of the electronic module without taking out the motor module first. Picture and text credit: (4)

Cal.: 1500 was refined to reduce its size but also to receive one instead of two batteries. In the early development for cal.:1510, it was possible to dispense with the analogue frequency division stages used in cal.: 1500 due to a development contract with the CEH. The new divider chain was realised with power saving dynamic circuits developed at CEH (CMOS, first published in September 1969, (8), first working example in 1971 (9)), which caused 12 times a division by a factor of 3, followed by 16 binary divider steps down to 1Hz (1). For the commercial versions of cal.: 1510 the CMOS technology was sourced from Intersil and later from Eurosil.

As true pioneers, the Battelle engineers constantly had to work at the limits of what was physically feasible and explore all conceivable variants, which costed a great deal of time and money. After years of work, all sub-projects converged to the concept of the future ‘Megaquartz’ model with a 2.4MHz oscillating quartz resonator, frequency division with power-saving CMOS electronics and an armature motor to drive the gear train. One other main problem encountered during the development of the definitive calibre was the date mechanism, which usually would drain a lot of energy (500% of what the motor can provide). Peter Döme invented an ingenious, low energy demanding system, still in use today (1).

TSA (time second adjustment). A small side pusher was introduced to hack the second hand with the atomic time signal. Picture credit: (4)

The commercial cal.: 1510 was also equipped with a mechanism to enable the hour to be changed independently of minutes and seconds along with a separate pusher for setting seconds: TSA (Time Second Adjustment). Thereby allowing extremely accurate time signal synchronisations (4).

‘Constellation Megaquartz’ and ‘Marine Chronometer‘

The development of the industrial calibers and the corresponding watches took two years, culminating in the introduction of the models ‘Constellation Megaquartz 2.4MHz’ with cal.: 1510 in 1972 and the model ‘Marine Chronometer 2.4Mhz’ with cal.: 1511, and cal.: 1516 introduced in 1974 and 1976 respectively. The used calibres still being of quite big size and almost square, demanded for a voluminous casing. Although, not comparable with the unpractical design of the ‘Elephant’ prototype, the early marketed models were rather big in size and feature either an integrated bracelet or a leather strap with deployment buckle (1,4).

Left: Omega Constellation Megaquartz 2.4MHz, cal.: 1510 with aventurine dial, 1972. Center: Omega Marine Chronometer 2.4MHz, cal.: 1511, 1974. Right: Omega Marine Chronometer 2.4MHz, cal.: 1516, 1976. Please note the shorter case of the later version (1976) of the Marine Chronometer. Picture credits: (2)

Aftermath

When the Megaquartz equipped with the cal.: 1510 finally came onto the market in 1972, the prices for conventional quartz watches with 32kHz resonator, digital division to 1Hz and Lavet-stepping motor were already massively falling. The production of the standard model remained very modest at about 1000 pieces. In 1974, the first edition of about 900 ‘Marine Chronometers’, certified at the observatory in Besançon, with cal.: 1511 was produced, followed two years later by a second edition of 1800 with cal.: 1516. The production of the ‘Megaquartz 2.4MHz’ was discontinued in 1975/76 (1,4).

More info about the ‘Constellation Megaquartz 2.4MHz’, the ‘Marine Chronometer 2.4MHz’ as well as the presentation of more prototypes and all known variants of these models can be obtained by consulting this excellent site: Omega Megaquartz.

Ref.:

  1. Trueb L. F., Ramm G., Wenzig P.; Die Elektrifizierung der Armbanduhr; Ebner Verlag, 2011
  2. Omega Marine Chronometer Wikipedia
  3. Richon M; Reise durch die Zeit; Omega SA, 2007
  4. Omega Megaquartz
  5. Antiquorum
  6. The Battelle Institute, Geneva. Nature 205, 238 (1965).
  7. Invent.org
  8. Leuenberger F., Vittoz E.; Complementary-MOS low-power low-voltage integrated binary counter, Proceedings of the IEEE, Vol. 57, NO. 9, 9.1969
  9. Piguet Ch.; Integrated Circuit Design Power and Timing Modeling, Optimization and Simulation 12th International Workshop, PATMOS 2002 Seville, Spain, September 11-13, 2002, B. Hochet, A. J. Acosta, M. J. Bellido (Eds.), Springer