Development of the "Casquette" how Girard Perregaux named this model internally began in 1974 in GP's own electronic department. Based on a high precision so called elecronic mother clock with nixie tube display to control subordinated clock units the next step was a small desktop clock where already macrolon was used for the housing. Finally the Casquette could be launched for sale in January 1976 and was produced until November 1978. Being even that innovative and courageous to invest in the development of a special module like for some of the other LED watch manufacturers to do so the production of this watch might not have been very profitable in the end. But today we owe them a spacy seventies LED watch design.

Link to gpsteel.jpg

Three Versions were available:

Ref. Number Version Historical price Units produced
9934 18k rolled gold SFr 775,- 2.200
9931 Stainless steel SFr 680,- 4.000
9939 Macrolon SFr 555,- 2.000

All versions were available with matching leather straps and several styles of braceletts, the width of the front and rear lugs being different Link
to gpbands2.jpg Picture. The grey macrolon (an especially strong and light glass-fibre strengthened polymer the first time to be used in wrist watch manufacturing) model with a different style macrolon bracelett - featuring a tricky construction which holds the band links together by two nylon strings inside Link to gpmakr.jpg Picture. All versions have solid steel case backs, slightly curved for handsome fit on the wrist. Link
to gpcurve2.jpg Picture

While most of the other LED watch manufacturers bought modules from supplyers like Frontier, Hughes Aircraft, National Semiconductor, Esa (even made a possibly suitable drivers style module) or others Girard Perregaux invested in developing and manufacturing own modules for the Casquette. Three module calibers were produced: 395, 396, and 397. The circuitry of the earlye type 395 was mounted on a ceramic board only a part of the wiring was made by a flexible board. Like it was typical for early seventies modules it had discrete display driver transistors.
Link to gp395.jpg Picture The circuitry of the modules 396 and 397 was equipped with chips which have all semiconductors on board and was completely mounted on flexible boards, quite revolutionary at that time. Module 396 is featuring a 12 hour display, date without month and day of the week. The latest module 397 has a 24 hour display and date without month. Probably due to limited data capacity of the chip it has no day of the week, the resources seem to be used up by the additional 12 hours. See also in the setting instructions Link to gpinstr.jpg Picture that funny enough the space in the setting mode for the day of the week is still there but simply left empty; the user might suspect the module is defective when nothing lights up. Of both 396 and 397 exists an earlyer version where time and date are bright and the seconds are darker. Later the power consumption was reduced by darkening the display functions down to an uniform level. This was a general tendency towards the end of the LED aera probably to compete with the powersaving LCD technology. Compared to other brands the GP modules appear to be a compact, quite solid and well manufactured construction. Link to gp397.jpg Picture For example they were the only ones I know of to use pre aged quartz crystals, the reason for excellent timekeeping performance still today.

Author: Juergen Hofstaedter


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