Seiko 7A38 - by the numbers



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Forum Home > Bend it, Mend it - Mods & Wreckers > Registration of the sweep-second hand against dial (not hitting the marks).

Rob Benham
Posts: 277

When finally I got the first few of my watches back from the US, the Yves Saint Laurent was one of them.  Despite being NOS, it was not functioning correctly.  Being based on a 7A28 it was easy to remove the dial to lube both ends.  I played for the first time with lubing and vaccing out, lubing and vaccing out until I felt the 30+ year old oil was purged.  Okay so far, but then I got a surprise - to say the least.

This supurb case does not have the tachy ring.  Oh well, it is for the type of chap that won't want to know his ground speed to the last knot.  But then I noticed the needle was not falling on the marks - getting worse the further it was from the top.  I was at a loss.  Then after some days I had a thought. (It takes me that long now)

I got out several samples of my English collection and looked at the hand registration on them.  They all wandered in and out of phase!  I then looked at the watch that started it all, the one I bought new in 85, and it does the same.  I just couldn't believe it. 

Now, am I A/going mad.  B/buying batteries that have fluctuating power output.  C/ Owning watches that have the dials printed incorrectly  . . . ?

At worst it's about .2 of a second - worst reading seems to vary from watch to watch.  Of course, they're all okay at the top.

could other members report their experience and indeed if there is a fault causing this that I don't know about.  i.e., over/under oiling so that the load takes up differing slack on the wheel teeth. 

Photos to follow.  

August 6, 2017 at 9:42 PM Flag Quote & Reply

Rob Benham
Posts: 277

August 6, 2017 at 9:53 PM Flag Quote & Reply

Site Owner
Posts: 13312

Sorry, Rob. This mildly infuriating problem is not news. There might not be any prior mention of it on this forum, but ....

If you Google: Quartz not hitting the marks (or markers), you'll find plenty of topics posted about it on other watch fora:

It afflicts many brands, not just Seiko / C.G.H. - even supposedly 'high-end' Swiss quartz watches.

I can't say I've read any of the threads on WatchuSeek, but I did read that one on TZ-UK.  Indeed I posted in it back in July 2012:

It really is worth watching the last 10 seconds of that video:

Truly appalling mis-aligment. Hard to believe they put it out as a TV advert. :roll:

PS - What the heck are you doing posting at 2:50am in the morning ?? Are you still on Texas time ? :lol:

August 7, 2017 at 2:06 PM Flag Quote & Reply

Rob Benham
Posts: 277

No, still in UK.  Many, many hours on science forums trying to get to grips with the substance of Spacetime.  Often the sun is rising before I admit failure. 

What's so odd about someone like me not noticing the registration of the hand is that we were expected to take aircraft Tech Log readings down to a fraction of the thickness of the needle.  It seems it helped the senior tecs to monitor tiny trends.  I wonder what else I've missed. :/

August 16, 2017 at 12:38 PM Flag Quote & Reply

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