This Week’s Featured Watch #64 – Cosmotron X8 4-480040

I’ve been looking out for the date version of the 0840 Cosmotron since I hadn’t previously found an example – designated the 4840, models with this movement were launched in 1970 and run at 21,600 beats per hour. Since my funds were limited,  I took a punt on a ‘junk’ model on Yahoo Japan, especially because it has the date window at the more unusual 6 o’clock position. Described as not working, even after a battery change, it also had a damaged crystal. After checking that a new crystal was still available, and knowing that I could get it looked at at a later date by Paul at ‘Electric Watches’ I nabbed it, the only bidder, at just ¥1,800 – about £10 ($15). So not a huge loss if it were to prove beyond rescue. On arrival I could see that the dial and hands were in good condition – the hands are an unusual ‘see through’ frame design:

The cracked glass and wear to the case show it has been well used – the case also shows evidence of an original brushed finish.  But the dial and hands are nice:

I have found before that it is always worth trying a new battery even when a seller has already tried one. Here’s a shot of the 12 jewel movement, which thankfully appeared to be in clean condition, with new battery installed:

And to my delight it fired up! 🙂  Not only did it start to run, but it also keeps good time, and the date change works just fine. So this was turning into a bargain – and a new acrylic crystal made specifically for this model was soon ordered, again at little cost. The damage to the old crystal is even more obvious with the movement removed:

There’s no guarantee that crystals are still available, but Sternkreuz still stock one for this model:


This is a compression fit crystal, and fits directly into the case without a bezel. I’ve not fitted one like this before, so the ‘crack’ as the press located it in place was a bit unnerving! But all was well:

I cleaned and very lightly polished the case to revive it a little, and after re-installing the movement, here’s the result:

The case back is good condition, and shows a production date of April 1970:

So, the gamble in buying a ‘junk’ watch has paid off – always a nice feeling 🙂

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7 Responses to This Week’s Featured Watch #64 – Cosmotron X8 4-480040

  1. Greetings Stephen, I enjoy your Watch Blog. I am a keen collector of Citizen and Seiko higher end watches. I thought you might be interested to see what I just bought on Ebay. It is an Electronic Chrono Master , and I attach a link which should take you to my purchase page. regards, Stephen Loomes, Australia

  2. Mike Wilensky says:


    • Mike Wilensky says:

      In addition, I, too, like the orange sweep second hand. I really like some color in my watch dials(not too much as that is distracting), as color livens up the whole watch experience, sadly, lacking in most of today’s wrist watches.

  3. mikko says:

    Stephen, that really looks nice. I like the orange secondhand,It pops out nicely from otherwise simple back ground.Simple and beatifull!

    • sweephand says:

      Hi Mikko, I really like it too, been wearing it all week. Keeps good time and it gives a warm feeling to have a nice watch for only a little money!!


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