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Grand Seiko 9F adjustment steps are 6SPY or 8SPY?

2K views 5 replies 4 participants last post by  ppaulusz 
#1 ·
I asked these questions on the "Grand Seiko" forum 2 days ago and received no replies so I thought I would ask here,... the present GS Japan site indicates the adjustment steps of the 9F series HAQ movements to be 6SPY. Several posts I have read on this site indicate the adjustment steps to be 8SPY. Quote from Seiko site (in blue text below):

What is a regulation switch?

There are several ways to adjust the precision rate of a mechanical watch and the most reliable is the regulator, which makes fine adjustments to the balance spring's range of motion. The Grand Seiko team recognized its value. Caliber 9F also has a regulation switch with plus to minus graduations marked on it. This mechanism adjusts precision by switching the circuit to make corrections after a designated span of time. Let's remember that Caliber 9F is, in all but the most extreme conditions, precise to ±10 seconds per year. The regulation switch allows adjustments within this range. If a comparison were to be made, you could say that it is somewhat like the designation of a leap year to adjust the calendar. One gradation in the regulation switch is equal to 0.0165 seconds in a day, or 0.5 seconds a month. Since the movement has a precision that is 100 times greater than that of a highly accurate mechanical movement, the sensitivity of this regulation device is beyond remarkable.


1. Does anyone have more history or technical information about 9F*** movement regulation?
2. Did the steps used to be 8SPY and now in 2018 they have been changed to 6SPY?
3. Have they always been 6SPY and mistakenly reported as 8SPY?
4. What is the source documentation for 8SPY steps?
I recently acquired a SBGT237 and may want to regulate it in the future. (Although for the month I have had it the gain-loss is very close to +- 0SPY.) So far, I am amazed by the accuracy!:-!
 
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#2 ·
To the best of my recollection, 8 SPY was an assumption made from fragments of information and mathematical plausibility (e.g. the number of temperature measurements taken each day, the frequency of the XO and the need to divide that XO down to 1 second ticks, plus the stated SPY).

I am pleasantly surprised to see official Seiko documentation stating 6 SPY (or, indeed, any SPY) as they have been so darned secretive about their approach in the past that it has been frustrating trying to piece together a picture of how it all works.
 
#3 ·
To the best of my recollection, 8 SPY was an assumption made from fragments of information and mathematical plausibility (e.g. the number of temperature measurements taken each day, the frequency of the XO and the need to divide that XO down to 1 second ticks, plus the stated SPY).

I am pleasantly surprised to see official Seiko documentation stating 6 SPY (or, indeed, any SPY) as they have been so darned secretive about their approach in the past that it has been frustrating trying to piece together a picture of how it all works.
I'd like to add to the above that I (and any properly equipped watchmaker or enthusiast like me) could answer the 6 or 8 spy question in a matter of minutes if I could measure an earlier model and a current model 9F fitted Seiko with my quartz analyzer. Unfortunately, I've never had a 9F fitted watch...
 
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#5 ·
Tom-HK, ppaulusz and webvan....Thank you for your replies. This is what I was looking for.

My interest in this subject is more of a personal curiosity than anything. My initial intention with this watch was to keep a reasonably accurate record of the gain-loss until the first battery change is required. Then, depending on my findings, I might try to regulate it. (I intend to change the battery myself.) At this point, I don't have enough information to determine anything. Now I need to understand the 9F adjuster better. I was hoping it at least had detents but from what I have read so far, I don't believe it does. With out detents, how does one know when you have completed a step? There are "alignment graduations" around the adjuster but what do they align with? There is no pointer on the adjuster knob.

I am not a watch maker or repairman but I do have a lot of tools. Several years ago I was looking to buy a watchmaker's lathe (to make small parts for custom knives). A friend of a friend's grandfather had recently died. He was a watchmaker. When I looked at the lathe, his family wanted to "get rid of" all the other items in his shop. So I bought his entire shop with all tools and supplies, including the lathe. I am still figuring out what some of these tools are for.

So, again Thanks for your replies. I believe I have between 2 and 3 years (the battery life) to figure it out. And I may just be safe and send it to Seiko in Manwah, NJ for service. I recently got back a watch with the 8F33 movement and they did a good job with it. I usually replace the battery and reset the perpetual calendar myself, but this one had a circuit board problem which they replaced as part of the normal service. Their website indicates they also work on most models of Grand Seiko now.
 
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