Photographing 1969 Ultra-Chron 8309

Risto

I wish I could open this watch to photograph the movement, but not sure if a local watchmaker can do this without risking breaking the crystal.

Neeb

I managed to open mine a couple of days ago, but I did it very, very carefully.

- The bezel needs to be removed first - I used a piece of razor blade at a point between the bottom lugs to open up a crack initially. Fortunately it's not as tight as many other bezels, to the extent that I was (just) able to snap it back on again with my fingers.

- Similarly, the crystal was not too tight. I used one of those claw pullers, but didn't need to crank it up very hard. I didn't feel I was at great risk of cracking the crystal (compared to a King Seiko 5246-6010 the tightness was nothing!). The thing you really need to watch out for is to very carefully position the puller. There's a tiny raised ridge that's part of the case that you could very easily mistake for the base of the crystal, and if any of the claws are external to that you'll damage the case, and possibly also scratch the lugs. It's worth spending some time positioning the puller and checking the position all round with a loupe before tightening it.

- There's a loose ring at the edge of the dial that just falls out. The stem is the split type, and while it might be OK just to pull the crown off of the stem, if you pull it to the hand setting positon and orientate it with the split slot vertical, you can carefully lift the movement out and detach the crown at the same time.

<edit> Is yours definitely a calibre 6651 rather than 431? If so that's really interesting given the close caseback serial numbers of our two watches, and really helps to narrow the period when the transition occurred. Would be interesting to see what your movement serial number is! I'm planning to get an extract from the archives for mine at some point.

Spruce

I’m afraid I’m gate-crashing this thread.

My Ultra Chron is a 1969 cal 431 with a 15****** serial so not 1970s

I’m always impressed by the quality of the dials (and the watches generally) because 1960s/1970s Longines dials don’t seem to deteriorate like many other 50+ year old makes - no bubbles, no patina, and rarely re-dialled.

So far as mine is concerned, it was a pretty spontaneous purchase on OF from @JohnSteed because I liked the case shape and the 4 o’clock date window

Risto

Excellent post! I want to have it opened up, but I don't have the crystal puller. Local watchmakers don't really have experience with these (ex-USSR country, after all). I am not sure it's not cal 431, but the seconds hand has some jerky movement, like big jerks, and doesn't look as smooth as my 36000vph King Seiko (45). I want to shoot some studio photos of the movement. Love your description of how to open it up!

I edited the post title to the year 1969.