As seen in the parent section, the development of the commercial 2.4MHz movement had demanded scientific research reaching the limits of physics and a considerable amount of time and money.
The final result was worth the efforts, as the ‘2.4MHz Marine Chronometer’ model is still the most precise, non – thermo – compensated wristwatch ever made.
The first 2.4MHz prototypes running with cal.: 1500 were big and unpractical. As for the development of the quartz wrist watch in general, the main task was to miniaturise the components and optimise the battery size/life to be able to produce a wearable watch. The earliest known successful attempt is shown below.
Megaquartz 2.4MHz P3 prototype; Cal.: 1510 P-1, cal.: 1500 – 1510 transitional prototype, 1971
Categories: proof of principle (movement), functional prototype (watch)
Description: Symmetric, stainless steel cased prototype with hand finished and brushed surfaces. Polished, rounded ‘bezel’ around mineral crystal. Stainless steel, brushed case back fixed with four screws to the case. Outside adorned with ‘constellation’ symbol and engraved ‘3794’ below. Inside unmarked. Dial made of grey-blue anodised metal with white printed ‘Constellation’ at ’12’ and ‘OMEGA Megaquartz 2.4MHz’ above ‘6’. Metal, baton hour markers, white printed minute marks. Date window at ‘6’, red plastic date wheel. Metal hands, hour and minute hands highlighted in white, all white second hand. Crown with company logo at ‘9’. TSA button below crown.
Dimensions: 39.5 mm (without crown), lug – lug: 46mm, lug width: 20mm
Movement: Cal.: 1500 – 1510 transitional prototype, hand numbered ’53’ on microchip
Additional info: As there are no marks on the movement about the quartz frequency, it has been theorised by the very reputable collector and expert @t_solo_t, that it might be a 4.2MHz movement of which only 2 pieces are known to exist.
This theory has led to an examination of the movement at the ‘Integrated Systems Laboratory’ at the ETHZ (Swiss Federal Institute of Technology, Zurich). An independent expert engineer has examined the movement and has measured the oscillating frequency of the quartz. Repeated measures (>10) with two different probes and using two different measuring devices, have confirmed a maximal quartz oscillation of just under 2.4MHz, which ruled out the theory of the movement being a 4.2MHz piece.
Upon closer examination, the movement of this watch can be considered a ‘missing link’ between cal.: 1500 and the commercial cal.: 1510, as well as a precursor of all low consumption quartz movements:
Differences to cal.: 1500: The main difference which distinguishes this movement from the preceding cal.: 1500 is the frequency division by a very early version of the CEH CMOS technology, first applied in 1971, instead of an analog frequency division or energy consuming microchips as used for all preceding quartz movements including cal.: 1500 and Beta 21. In this regard this movement is also pioneering the use of low consumption microelectronics as used for all later quartz watches independent of the manufacturer.
Differences to cal.: 1510: Some components are clearly hand made, alternate materials have been used in places, the movement bridges are of slightly different shape, the wheels are unfinished (not gilded) and not skeletonised. In addition, by comparing this movement to the marketed cal.: 1510, the ETH engineer confirmed that there are construction differences to cal.: 1510, which mainly concern the circuitry but also the electronic components, which lead to the assumption that this movement might have been made just at the beginning of the collaboration with CEH to use their newly developed CMOS components (1971) and certainly prior to the marketed cal.: 1510 version, which used different CMOS technology sourced from Intersil (USA) and later Eurosil (joint venture of SSIH and Intersil, 1973, (1))
The movement being functionally assembled but not properly finished also indicates, that it was kept in the phase of ‘proof of principle’ and has been cased in a maybe unique, purpose made case to test for functionality while being worn, enabling the whole watch to be categorised as ‘functional prototype’. Ultimately several later prototypes featuring a different, pyramidal case were constructed and allegedly given to employees for functional testing. These prototypes contain cal.: 1510 in different stages of development, but the movements remain very close to the marketed version.
More information about the development of these movements can be found in the parent section.
Acknowledgements: Many thanks to TK of the ‘Integrated Systems Laboratory’ of the ETHZ for thoroughly analysing the movement and for having contributed with his expertise.
Ref.:
Omega Prototypes 