Saturday, December 28, 2013

Seiko 7A28-7040 Quartz Chronograph

A friend sent me his 7A28-7040 to bring back to life.  Having never seen one in person before, I was happy to help him out.

The Seiko 7A28 (date only) 7A38 (day/date) was actually a historically significant caliber as it was the first quartz analog chronograph.  Yep, another Seiko first.  The movement is fully jeweled with 15 jewels and is rate adjustable.  The chronograph has resolution to 1/10 of a second and the 1/10 second subdial at 3 o'clock actually spins for the first couple of minutes of use (see video below).

Overall construction on this particular model is fairly simple.  A nice surprise is the entire case and bracelet are lightly bead blasted to produce an interesting matte finish.  The bezel is bidirectional and uses the click ball and spring like on the older diver models.  There's also a gasket inside the bezel to give that dampened feel that is typical of Seiko divers.  The edges of the bezel are nicely milled with clear definition of edges unlike the overpolished bezels used on the current line of SKX divers.  There's 3 pushers and one crown used for all the functions of timekeeping and chronograph use.  Caseback is a simple tsunami wave, but unfortunately I forgot to grab a picture.

The bracelet is composed of an interesting link that gives off a futuristic look.  The clasp on this model is the folded friction fit clasp that is common for the time.  Overall quite comfortable though.

My friend's watch was in overall good condition except that the bezel and pushers were completely stuck.  Removing and cleaning the bezel is easy enough and most people should be able to do this themselves.  The pushers are also something that most people should be able to do, however, are much more of a challenge than the bezel because the C-clip holding the entire assembly together is very, very small and must be assembled inside the case.  Removal of the clip is simply pushing it off the pusher post using a spring bar tool or a small screwdriver.  Everything was then cleaned in a jewelry ultrasonic cleaner.  Assembly is more of a challenge but made easier by a tip from a guy named Spencer who suggested to assemble everything in the pusher tube and then use a dab of silicone grease on the edge of the clip to stick it to the pusher stem and then push on the opposite edge to secure it to the pusher.  It does require more force than you would expect, but the silicone helps the clip from going flying off into the abyss, which is the greatest risk in this process.  I also assembled the pushers into the case inside a plastic bag to minimize the potential for a lost clip.  Took me about 15 minutes per pusher to get back assembled so fortunately there's only 3.  When complete, there's a great sense of satisfaction in having functional pushers again.

The dial is very well done and functional.  High contrast white text on a matte black dial.  Printing is crisp.  White hands are legible and jump off the dial.  Overall classic looks.

Removal and replacement of the movement from the case was straightforward.  Push where it says PUSH to slide the crown out and tip it upside down to drop the movement out.  When you remove the movement, the chapter ring remains behind as it is secured under the crystal.  Surprisingly, the chapter ring does rotate which can make reinstallation a headache, especially in this model where the chapter ring is actually a tachymeter.  Not that anyone actually uses the tachymeter on their chronograph, but it looks stupid if not oriented correctly.  Fortunately Seiko formed a key between the ring and the movement so if you spin the ring into the correct position, the movement will fit correctly and orient everything perfectly.

Overall I was impressed with the 7A28-7040.  Seiko made a ton of different models with the 7A28/38 caliber in all different styles and today they are quite collectible fetching prices of $250-$350 US in good condition.  I don't know that I like it enough to spend that kind of money, but if I happen to ever find one of these at a local garage sale, I'd be sure to pick it up and have fun restoring it.

No comments: