Wristwatch restoration, servicing and repair

Zodiac Spacetronic (ESA Cal. 9150)…

Battery powered watches are a bit of a rarity on the blog, this Zodiac Spacetronic is only the second.

(Click pictures to enlarge)

The founder of Zodiac, Ariste Calame, set up his first watchmaking workshop in 1864, but it wasn’t until 1908 that he registered the company name “Montres Zodiac”. Joined by his son, Louis Ariste Calame, and various other family members shortly afterwards, the company started to grow and developed strong export connections with the US.

A new factory was opened in Le Locle in 1951 and around that time, two significant models were gaining recognition; the “Autographic”, an automatic model with a power reserve indicator, and the watch for which Zodiac is probably best known, the “Sea Wolf” diver, first introduced in 1953.

Like many companies, the 1960’s and 70’s were the golden era for the brand with many visually and technically interesting models hitting the market, the Super Sea Wolf, Astrographic, and SST (Split Second Timing) models in particular. There were also some great mechanical chronographs sprinkled throughout the line-up, like this Cal. 90 powered model I repaired a couple of years ago.

For much more information about the Zodiac brand and their history, check out the site Vintage Zodiacs.

The Spacetronic model in this post is from the early 1970’s, a period when the line between mechanical and electric/electronic watches was blurring, resulting in hybrid calibres – battery powered watches with a traditional mechanical escapements. The calibre inside this watch is one such hybrid, the ESA Cal. 9150, also known as a “Dynotron”. I’ve written a description of how a Dynotron calibre works in a previous post, anyone interested can read that post here.

The watch arrived in good clean condition. The upper jewel and Incabloc shock spring were missing, but I had parts left over from my previous Dynotron project so that wouldn’t be a problem.  Even with a new battery fitted, the watch showed no signs of life, and on close inspection I could see that the oil had completely dried out, so the first step was to service the movement.

After servicing, the watch would run in two or three positions, but would stop almost immediately in others. Watching the balance wheel in motion revealed that the magnets on the balance wheel were scraping on the induction coils, too much end shake perhaps?

Alas, I wasn’t that lucky as under the microscope I could see that the tip of the upper balance staff pivot had been broken off, possibly at the same time that the shock spring was damaged, so parts would be needed after all. However, my luck was in as a search on eBay quickly unearthed a brand new complete balance.

Once the balance arrived it was plain sailing from there and the movement was back up and running again. The dial and hands were fitted, the case cleaned, and the crystal polished to finish the job.

And finally, just to finish off this post, here’s an advert from 1970 showing the white dialled version of this watch, along with a couple of other models in the range.


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