# Spring Drive Issues?



## KrazyK

I know I am about to grab the SBGH037 Hi-Beat, but you never know what might happen when a Snowflake might be sitting in the same case when picking it up. So I'm trying to prepare myself. I was recently told by a Seiko enthusiast and watch builder to not get a Spring Drive cause he sees more of them taking shop time than autos. I need to know if anyone has had issues yet and how long they had theirs. I keep reading how they are the best with the least amount of problems. So I'm all confused now. Please advise. 


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## ronr9286t

I've had 7 spring drive watches over the years, 3 purchased new and 4 purchased pre-owned. I currently have a GS SBGE033 and a Prospex SBDB011. I've never had as much as a hiccup from any of them. To be fair, of all of them, the one that was the oldest was less than 4 years old, so I cannot comment on long-term reliability. All of mine were accurate to spec (< 1 sec/day), and never failed to re-start with winding after running down completely and sitting for weeks (large rotation).

Ron


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## KrazyK

ronr9286t said:


> I've had 7 spring drive watches over the years, 3 purchased new and 4 purchased pre-owned. I currently have a GS SBGE033 and a Prospex SBDB011. I've never had as much as a hiccup from any of them. To be fair, of all of them, the one that was the oldest was less than 4 years old, so I cannot comment on long-term reliability. All of mine were accurate to spec (< 1 sec/day), and never failed to re-start with winding after running down completely and sitting for weeks (large rotation).
> 
> Ron


I like what I'm hearing. But yes the long term is what concerns me most but considering it being Seiko and the spring drive being perfected with R&D since the 80's, I can o my assume they'll never release something with hesitation on issues. Seiko is just that way. Every Seiko I've owned since I was a young teen is still running to this day with no issues. I could only assume the Spring Drive is as solid as the rest. Relatively speaking in mechanical terms.

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## liwang22

Check out Timeless Luxury. They are now a designated Seiko boutique and can handle any issues on your behalf with Seiko Japan 


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## PJ S

Ten years old (International model) Seiko Spring Drive, almost 4 years since originally purchased — never deviated more than a second within a few days, and 99.5% of the time, it's less than ½ a second adrift.


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## Alex_TA

Get another friend.


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## conquistadore

I have four Spring Drive models, including one of the first Seikos with that movement, from 1999. It keeps very accurate time, very well within manufacturer's specs. I haven't had ANY issues with any of them!


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## KrazyK

Thanks everyone for your input! Not sure why this individually said that about spring drives. Maybe has had one bad experience. 


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## Alysandir

I would also like to add that, rather than ship all Grand Seikos to Japan for servicing, the US now has its own service center in New Jersey. I know that's been a concern of a lot of prospective GS purchasers.

And, if I may, I believe starting shortly, all GS boutiques now provide a "first service is free" deal on all new GS watches. Meaning, you pay nothing your first service. I'm not sure Seiko would offer that if they thought the Spring Drive was a beast to keep running.

Regards,
Alysandir


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## skyWalker

In my opinion, if you want to get a Grand Seiko, you should go for the Spring Drive. Their automatic is not up to mark, unless you're fine with +10sec per day.

But if you want a Spring Drive, you don't need a Grand Seiko. I understand their Prospex range also has Spring Drive.


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## v1vne

I own a Seiko: Grand Seiko SDGJ001 Hi-Beat GMT White Dial. 
It is very accurate.
I also own a Seiko: Grand Seiko SBGV007, with a 9F82 Quartz movement. 
Whatever Seiko, Grand Seiko model you buy will probably be a fine watch.
There are many models that appeal to me, I would just purchase the model 
that appeals to you most. If you want the model with the least maintenance,
and is the most accurate, I would consider the 9f Quartz. 
I do not own a spring drive model.
I have not had any problems with my Grand Seiko's.


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## samanator

I've had SD watches both Seiko and GS since 2008, six in total. Mine have been flawless even including two going through routine service. I've never heard of SD reliability issues and I know of at least 35 people outside the forum that have had them long term with no issues.


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## MLJinAK

Have had my SD for 8 months now - no issues.


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## Laso1

I have 2 from 2005, 1 - 2006, 1 - 2007, 1 - 2008, a snow flake, a diver, and a land master. None have been serviced and all of them keep impeccable time. I would not hesitate to buy a Spring Drive.


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## videogameland

RaptorAddict said:


> I know I am about to grab the SBGH037 Hi-Beat, but you never know what might happen when a Snowflake might be sitting in the same case when picking it up. So I'm trying to prepare myself. I was recently told by a Seiko enthusiast and watch builder to not get a Spring Drive cause he sees more of them taking shop time than autos. I need to know if anyone has had issues yet and how long they had theirs. I keep reading how they are the best with the least amount of problems. So I'm all confused now. Please advise.
> 
> Sent from my iPhone using Tapatalk


I still have my GS spring drive snowflake and I have never serviced it, still works perfectly. Bought it in 2011 so its been about 5 years so far.. If it aint broke, dont fix it.


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## larthurl

I am about to buy my first GS. I've asked the AD about servicing and they couldn't provide any info b/c they have not been carrying the line that long.
What is recommended service interval and what to GS owners actually do?
Thanks


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## larthurl

That's the SD model I'm looking to get.
I can't get over how beautiful it is.


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## PJ S

larthurl said:


> What is recommended service interval and what to GS owners actually do?


Regularly used, just like a full mechanical, every 5-7 years on average.
As time goes on, just monitor it - and if you find it's not as accurate or does something erratic, then it may be needing serviced.
If you're wearing it in water, then have it pressure tested at 2-3 year intervals, just to make sure it's still water resistant to its specified rating.


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## Alex_TA

larthurl said:


> What is recommended service interval and what to GS owners actually do?


Eternity 

If you still insist on a maintenance your AD will send your future watch to NJ SC (if you're in USA) or straight to Japan.


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## T1meout

PJ S said:


> Regularly used, just like a full mechanical, every 5-7 years on average.
> As time goes on, just monitor it - and if you find it's not as accurate or does something erratic, then it may be needing serviced.
> If you're wearing it in water, then have it pressure tested at 2-3 year intervals, just to make sure it's still water resistant to its specified rating.


Don't know exactly, but I'm quite certain that official Seiko recommended service intervals is less than 5 years.


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## 124Spider

I have had an SPS003 since early 2009, and an SBGE001 since late 2010. Both have been running substantially all the time since I got them, and both continue to tell essentially perfect time. I have never heard from any credible source that there is any issue with Spring Drive.

Mark


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## Kcnwea

I'm glad to hear all the positive reviews of the spring drive. Hopefully I'll be picking one up soon. 


V/r - Noel


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## cb1111

Slightly dissenting opinion. I have a SD from the early 2000's (about 2004 or so) that recently started stopping (if that makes sense) after it has been running for about a half hour. I'll be sending it off to NJ shortly and will reply back one it comes back.


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## cb1111

cb1111 said:


> Slightly dissenting opinion. I have a SD from the early 2000's (about 2004 or so) that recently started stopping (if that makes sense) after it has been running for about a half hour. I'll be sending it off to NJ shortly and will reply back one it comes back.


 What was I thinking? It was the release model from 2005 - the SN005 (black dial that actually looks brown).

We'll see what Seiko has to say.


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## 124Spider

cb1111 said:


> Slightly dissenting opinion. I have a SD from the early 2000's (about 2004 or so) that recently started stopping (if that makes sense) after it has been running for about a half hour. I'll be sending it off to NJ shortly and will reply back one it comes back.


I infer that this watch has never seen any maintenance; is this correct?


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## PJ S

cb1111 said:


> What was I thinking? It was the release model from 2005 - the SN005 (black dial that actually looks brown).


You mean the SNR005 - this one?


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## cb1111

PJ S said:


> You mean the SNR005 - this one?


That's the one. Great watch.


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## J-Rock121

cb1111 said:


> Slightly dissenting opinion. I have a SD from the early 2000's (about 2004 or so) that recently started stopping (if that makes sense) after it has been running for about a half hour. I'll be sending it off to NJ shortly and will reply back one it comes back.





124Spider said:


> I infer that this watch has never seen any maintenance; is this correct?


Inquiring minds want to know since this will be a big factor. FWIW, my local GS boutique said it should be serviced once every 3 - 5 years (forgot how many years specifically). If you've been following this guideline & you're still having issues then I'm curious how much Seiko will charge. However, if you haven't then it wouldn't surprise me if it broke down as with any watch.


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## PJ S

cb1111 said:


> That's the one. Great watch.


It sure is - mine's the white version.
That image is the first I've seen the brown effect you mentioned.
Mine has a pearlescent iridescence, which shows very subtle shades of pink and violet/blue as you angle it in sunlight.
Hmm&#8230;I'm now somewhat intrigued, even though I really don't want two of the same watch.


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## 124Spider

J-Rock121 said:


> Inquiring minds want to know since this will be a big factor. FWIW, my local GS boutique said it should be serviced once every 3 - 5 years (forgot how many years specifically). If you've been following this guideline & you're still having issues then I'm curious how much Seiko will charge. However, if you haven't then it wouldn't surprise me if it broke down as with any watch.


He's not answering so far, but almost certainly, he didn't get it the recommended routine maintenance.

But I can understand why, and I'm now doing the same thing. I had my SPS003 serviced at 4 years (clean & oil; nothing was wrong), but it took a long time and cost a lot of money. This is pretty much the ultimate in 
"in-house" movement, and cannot be serviced anywhere but Japan. So I'm going to significantly spread the maintenance out. Also, I know what routinely goes wrong with clocks, and I doubt very much getting his watch fixed like new will cost him much (if any) more than a routine service, or take any longer.

Mark


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## Laso1

Like this one?


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## PJ S

^
Have you been helping yourself to my watch box? ;-)


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## J-Rock121

124Spider said:


> He's not answering so far, but almost certainly, he didn't get it the recommended routine maintenance.
> 
> But I can understand why, and I'm now doing the same thing. I had my SPS003 serviced at 4 years (clean & oil; nothing was wrong), but it took a long time and cost a lot of money. This is pretty much the ultimate in
> "in-house" movement, and cannot be serviced anywhere but Japan. So I'm going to significantly spread the maintenance out. Also, I know what routinely goes wrong with clocks, and I doubt very much getting his watch fixed like new will cost him much (if any) more than a routine service, or take any longer.
> 
> Mark


Ya, hope it won't cost too much for his sake. FWIW, there's going to be a new GS service center in New Jersey soon so shouldn't cost as much & take as long. And if you buy from either a GS boutique and/or AD (I think only the former but someone correct me if I'm wrong) then you'll get your first service performed for free as long as you bring it in before the first three years (starting 5-16). And you'll get an Astron to use/borrow the whole time it's in-service.


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## greent54

Laso1 said:


> Like this one?
> 
> View attachment 9158346


Wow never seen that one before

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## greent54

RaptorAddict said:


> Thanks everyone for your input! Not sure why this individually said that about spring drives. Maybe has had one bad experience.
> 
> Sent from my iPhone using Tapatalk


Probably ain't got one

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## [email protected]

Well, my experience with SD was not so good. I purchased a new Marinemaster SBDB009 “Spring Drive Tuna” in May 2017 and it kept great time and appeared to function perfectly up until last week when it stopped self winding. I can still wind it by hand but I expected to get more then 3 years out of it before I see issues. I guess I'll send it to Seiko NJ to get it fixed. Maybe I got a lemon as I can't find any info online of similar problems with SD.


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## peterbright

Was your "friend" wearing a Rolex?


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## koolpep

[email protected] said:


> Well, my experience with SD was not so good. I purchased a new Marinemaster SBDB009 "Spring Drive Tuna" in May 2017 and it kept great time and appeared to function perfectly up until last week when it stopped self winding. I can still wind it by hand but I expected to get more then 3 years out of it before I see issues. I guess I'll send it to Seiko NJ to get it fixed. Maybe I got a lemon as I can't find any info online of similar problems with SD.


Happens to the best of them. Rotor issue.

Side story: 
My wife's Rolex had that, after 4.5 years. At that time the warranty was 3 years, the watch was 1.5 years out of warranty but the AD said: let me see what we can do for you. And voila the Rolex service center fixed it free of charge. Even though the watch wasn't purchased with this AD. I liked that a lot.


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## kritameth

I'm personally going to go at least 10 years before servicing my SBGA211. I am not advocating others to do this, my thoughts just happened to be aligned with Craig on this topic.


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## Biginboca

kritameth said:


> I'm personally going to go at least 10 years before servicing my SBGA211. I am not advocating others to do this, my thoughts just happened to be aligned with Craig on this topic.


I agree with this. Having sent a spring drive in for service in the past and being without it for months my current one will not go in before 10 years, and maybe longer. When you get it serviced the charge is the same no matter what they do so why send in a perfectly working watch more frequently.

In my experience the weaknesses of the spring drive is the mainspring/barrel and the winding rotor. All the issues you read about and that I have experienced have centered around these components which are easy and cheap to replace.


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## krayzie

I like how this video is mainly trying to point out that people nowadays don't have any common sense lol!


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## koolpep

Yeah, indeed. Rolex advises “around every 10 years” and the ADs usually tell you just to hand it in if something is wrong, like it doesn’t keep time anymore or other issues, like power reserve.

GS advises to service “ideally every 3-4 years” but I am with everyone here....use common sense.

Cheers.


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## Mark Hans

RaptorAddict said:


> I know I am about to grab the SBGH037 Hi-Beat, but you never know what might happen when a Snowflake might be sitting in the same case when picking it up. So I'm trying to prepare myself. I was recently told by a Seiko enthusiast and watch builder to not get a Spring Drive cause he sees more of them taking shop time than autos. I need to know if anyone has had issues yet and how long they had theirs. I keep reading how they are the best with the least amount of problems. So I'm all confused now. Please advise.
> 
> Sent from my iPhone using Tapatalk


I have had two Spring Drives, one I still own..... A beautiful blue dial Date version 72 hours and now sold, GMT, also spring drive. After a few weeks, I see that both watches start to react to the wearer in a much as that quartz brake the keeps the watch to ⅔ seconds a MONTH only works in the watch winder. In there, it is perfect. On the wrist, how about 8 minutes in a month!.... that is NOT right. Gave me partner the same watch, he gets more or less the same probems. Neither of us work in any special conditions, it has to be something to to with the control' I love the watch, but no longer trust the timekeeping. Maybe the Hi--Beat is better, but Spring Drive?, I have my doubts now.


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## JLittle

I've only had my Snowflake (spring drive) for a little bit but it's spot on accurate, hasn't lost or gained even one second yet.


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## Mark Hans

All I ask is the community of Spring Drive Enthusiasts to actually set their watches to the beep at the 1st day of the month (or any other time, but set correctly) and report back here in all honesty, having worn them for most of those 30 days the variance. If it is 2-5 second, then GS claims are correct and I have unfortunately have a bad SD watche to send to Japan. I've done the test, it's horrible compared to Rolex (which I hate) or the Seiko Hi Beat 3600, but accuracy is accuracy when sold as such!. Anyone willing to take on the challenge?............ You'll need a Frankfurt radio controlled watch or clock to do this trick. Those are 100% accurate, irrespective of anything. I will start my fresh test on January 1st for one month and report the results here!..................


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## BrianBinFL

Very few people here wear the same watch for 30 days straight. That said, if your watch is off 8 minutes in a month it needs to be serviced. Though the spec is 15 seconds per month most of them will come in closer to 6 to 8 seconds in a month.


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## Ginseng108

Well, I have two SD that I've owned and worn for the majority of my wrist time since the summer and one is less than a second per month and the other is about 2-3 seconds per month.


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## kritameth

Mark Hans said:


> All I ask is the community of Spring Drive Enthusiasts to actually set their watches to the beep at the 1st day of the month (or any other time, but set correctly) and report back here in all honesty, having worn them for most of those 30 days the variance. If it is 2-5 second, then GS claims are correct and I have unfortunately have a bad SD watche to send to Japan. I've done the test, it's horrible compared to Rolex (which I hate) or the Seiko Hi Beat 3600, but accuracy is accuracy when sold as such!. Anyone willing to take on the challenge?............ You'll need a Frankfurt radio controlled watch or clock to do this trick. Those are 100% accurate, irrespective of anything. I will start my fresh test on January 1st for one month and report the results here!..................


Echoing @BrianBinFL and @Ginseng108, though I'll be more direct and say I think you're trolling, that's not the norm for SD. And if we're talking anomaly, I've seen a Rolex run over 5 minutes slow per day, so that's over 2 and a half hours slow per month. No, I don't think Rolex is horrible, and neither should you think SD is horrible based on a deviation from normalcy. It may be magnetized, either way I'd suggest sending her in to a service center.


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## JLittle

BrianBinFL said:


> Very few people here wear the same watch for 30 days straight. That said, if your watch is off 8 minutes in a month it needs to be serviced. Though the spec is 15 seconds per month most of them will come in closer to 6 to 8 seconds in a month.


All of this.


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## watchmandragon

Mark Hans said:


> All I ask is the community of Spring Drive Enthusiasts to actually set their watches to the beep at the 1st day of the month (or any other time, but set correctly) and report back here in all honesty, having worn them for most of those 30 days the variance. If it is 2-5 second, then GS claims are correct and I have unfortunately have a bad SD watche to send to Japan. I've done the test, it's horrible compared to Rolex (which I hate) or the Seiko Hi Beat 3600, but accuracy is accuracy when sold as such!. Anyone willing to take on the challenge?............ You'll need a Frankfurt radio controlled watch or clock to do this trick. Those are 100% accurate, irrespective of anything. I will start my fresh test on January 1st for one month and report the results here!..................


A friend of mine had the same problem with his Grand Seiko, it was fast by about 6 minutes per month. He sent it in for servicing and when it came back it had the same problem with keeping correct time, this time it ran slow by about 4 minutes per month. It kept great time on the winder and terrible time on the wrist. He sent it back again for servicing and it still had the problem of keeping accurate time on the wrist.

He gave up getting it fixed as and ended up selling the watch at a loss.


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## Tanker G1

watchmandragon said:


> A friend of mine had the same problem with his Grand Seiko, it was fast by about 6 minutes per month. He sent it in for servicing and when it came back it had the same problem with keeping correct time, this time it ran slow by about 4 minutes per month. It kept great time on the winder and terrible time on the wrist. He sent it back again for servicing and it still had the problem of keeping accurate time on the wrist.
> 
> He gave up getting it fixed as and ended up selling the watch at a loss.


I call in to question the truth of this post given your history.


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## kritameth

Tanker G1 said:


> I call in to question the truth of this post given your history.


+1. Presumably it's the same friend of his with trembling hands, apparently setting the time on GS, but not any other watch, is so difficult he had to sell the watch at a loss. I believe 99% of the things he says is made up.


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## matthew P

I’ve worn my spring drive as a daily in heat and snow, at home at at work in a physical environment and it keeps a consistent plus two seconds per week...... it was doing that when I got it 5 years ago used and it’s been doing it consistently since I got it back from its 10 year service. 


•• sent by two turn tables and a microphone ••


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## GSNewbie

Mark Hans said:


> All I ask is the community of Spring Drive Enthusiasts to actually set their watches to the beep at the 1st day of the month (or any other time, but set correctly) and report back here in all honesty, having worn them for most of those 30 days the variance. If it is 2-5 second, then GS claims are correct and I have unfortunately have a bad SD watche to send to Japan. I've done the test, it's horrible compared to Rolex (which I hate) or the Seiko Hi Beat 3600, but accuracy is accuracy when sold as such!. Anyone willing to take on the challenge?............ You'll need a Frankfurt radio controlled watch or clock to do this trick. Those are 100% accurate, irrespective of anything. I will start my fresh test on January 1st for one month and report the results here!..................


To be honest, unfortunately, I can't believe in this story either. If it is true, then you should return the watch to the dealer and get a refund.
I have two GS, a Hi-Beat SBGJ 237and a Spring Drive, SBGA407, which I purchased in the beginning of this month.
I count myself as a seconds counter and extremely accurate customer, regardless of brand. I set my watch for the first time on 04.12.2020 and today, 27.12.2020 it runs 3 seconds ahead!
The caliber pulls up very well on the wrist. On the watch winder she comes of course not yet, would also be the question of what rotation speed I should set it😉.
Of course, there are also automatic watches that go similarly accurate. Few, however, do not care how they are put down and also to temperature fluctuations, some models are more sensitive.
However, I must say that my most accurate watch I own is just a Rolex DJ 41 with caliber 3235, certainly a nice coincidence. This runs in 8 weeks, no matter in what position filed with 0 seconds deviation...
Nevertheless, I love my new acquisition and the gear is currently loosely within the specifications of GS!
Chapeau GS!


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## Ginseng108

Tanker G1 said:


> I call in to question the truth of this post given your history.


It certainly is an unusual and exceptional claim. Equally exceptional evidence would be required before anyone could make a reasonable assessment of the veracity of the claim. Until then, I don't consider it a reliable data point.


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## Mark Hans

watchmandragon said:


> A friend of mine had the same problem with his Grand Seiko, it was fast by about 6 minutes per month. He sent it in for servicing and when it came back it had the same problem with keeping correct time, this time it ran slow by about 4 minutes per month. It kept great time on the winder and terrible time on the wrist. He sent it back again for servicing and it still had the problem of keeping accurate time on the wrist.
> 
> He gave up getting it fixed as and ended up selling the watch at a loss.


This is my fear. It keeps within 2+ seconds a month on the watch winder, so I know the theory and mechanics work, but on my wrist (I'm your average no big deal man), it's 4-8 minutes a month is nearly doubled!. If I send it back; GS will laugh and say, it's fine!..... because it is, until someone (not only me) wears it. The Quartz that controls the 'brake' on the movement is susceptible to the tiny differences in each of our body energies, rather like our temperature. The average is 36.6, but some of us are at 36, some at 37. The energy levels in the body are the same, up and down a touch. If GS SD did not work this out, then there is a fault in the design. Clearly I am reading all over the web that SD has this problem when worn by those who actually bought the watch for it's claimed accuracy. This is NOT TRUE and few actually test watches like the Swiss do!.....!. GS, when are you going to contact us with a solution? This is giving you a terrible reputation, I do NOT joke....... I LOVE GS, but I don't trust the time keeping against such watches as the GS 36000 Hi Beat or Rolex 72 hour reserve, all who prove to be more reliable without any electronic interference. it doesn't' exactly give you confidence in this Fusian!.......... Grand Seiko, if you want me to shut up about my brand new GS -SD,contact me on [email protected] and fix my problem. I am NOT HAPPY and deeply disappointed at my purchase of a €5000 G-Seiko that is unreliable in telling the precise time. Spring Drive.. Isn't this what we used to know as the Rolex Killer?............ I think not, It's a Lexus pretending to be a Mercedes Benz. I ask you PLEASE, to contact me, sort out my brand new SD GS and give me what you promised, a watch that would be accurate to within 5 seconds a month, not 8 minutes!............. Back to you. Someone forward this to GS, they are arrogant, obstinate and not listening to their customers. Don't buy a Spring Drive! It's flawed and what hurts the most is, I have a deep blue dial version 41mm, and sold my Rolex because I thought this was going to be better. I was wrong. The Spring Drive is totally unreliable in keeping time and the Rolex is 98% correct. You can not imagine how embarrassing this is and to top it off, I'm a fully trained Senior Zen Master, from Kyoto. Quality and Finish are totally Japanese, technology sounds impressive, but Timex can do the same! 8 minutes wrong in a month, you can change the world!............... For the last time, GS, please contact me for a solution! or this blog will go viral I promice you. [email protected]. 







ow flakes melt!.


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## watchmandragon

Mark Hans said:


> This is my fear. It keeps within 2+ seconds a month on the watch winder, so I know the theory and mechanics work, but on my wrist (I'm your average no big deal man), it's 4-8 minutes a month is nearly doubled!. If I send it back; GS will laugh and say, it's fine!..... because it is, until someone (not only me) wears it. The Quartz that controls the 'brake' on the movement is susceptible to the tiny differences in each of our body energies, rather like our temperature. The average is 36.6, but some of us are at 36, some at 37. The energy levels in the body are the same, up and down a touch. If GS SD did not work this out, then there is a fault in the design. Clearly I am reading all over the web that SD has this problem when worn by those who actually bought the watch for it's claimed accuracy. This is NOT TRUE and few actually test watches like the Swiss do!.....!. GS, when are you going to contact us with a solution? This is giving you a terrible reputation, I do NOT joke....... I LOVE GS, but I don't trust the time keeping against such watches as the GS 36000 Hi Beat or Rolex 72 hour reserve, all who prove to be more reliable without any electronic interference. it doesn't' exactly give you confidence in this Fusian!.......... Grand Seiko, if you want me to shut up about my brand new GS -SD,contact me on [email protected] and fix my problem. I am NOT HAPPY and deeply disappointed at my purchase of a €5000 G-Seiko that is unreliable in telling the precise time. Spring Drive.. Isn't this what we used to know as the Rolex Killer?............ I think not, It's a Lexus pretending to be a Mercedes Benz. I ask you PLEASE, to contact me, sort out my brand new SD GS and give me what you promised, a watch that would be accurate to within 5 seconds a month, not 8 minutes!............. Back to you. Someone forward this to GS, they are arrogant, obstinate and not listening to their customers. Don't buy a Spring Drive! It's flawed and what hurts the most is, I have a deep blue dial version 41mm, and sold my Rolex because I thought this was going to be better. I was wrong. The Spring Drive is totally unreliable in keeping time and the Rolex is 98% correct. You can not imagine how embarrassing this is and to top it off, I'm a fully trained Senior Zen Master, from Kyoto. Quality and Finish are totally Japanese, technology sounds impressive, but Timex can do the same! 8 minutes wrong in a month, you can change the world!............... For the last time, GS, please contact me for a solution! or this blog will go viral I promice you. [email protected].
> View attachment 15618371
> ow flakes melt!.


If it is of any consolation. One of my Rolex's would run fast by about 50 seconds a day. When it was on the winder it ran fine. When I took it to the AD it was within Rolex COSC when tested. The AD regulated the watch and he decided to wear it for a week to see how it kept time. Too much to his surprise it was still running fast by about 60 seconds per day. Lucky for me the watch was still under warranty and instead of servicing it, the AD replaced the movement.

Hopefully, Grand Seiko will address the issue and either replace the movement, service the movement to get it properly regulated. Grand Seiko is known for their service and hopefully they will make the situation right for you.


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## Mark Hans

watchmandragon said:


> If it is of any consolation. One of my Rolex's would run fast by about 50 seconds a day. When it was on the winder it ran fine. When I took it to the AD it was within Rolex COSC when tested. The AD regulated the watch and he decided to wear it for a week to see how it kept time. Too much to his surprise it was still running fast by about 60 seconds per day. Lucky for me the watch was still under warranty and instead of servicing it, the AD replaced the movement.
> 
> Hopefully, Grand Seiko will address the issue and either replace the movement, service the movement to get it properly regulated. Grand Seiko is known for their service and hopefully they will make the situation right for you.


So I have to send my brand new SD to Japan?, my local dealer looks very blankly at me!........ looks OK on his machine............. No, I want my watch replaced! 
My complaints are genuine and backed up by a Junghans Mega Wrist Watch (which I never wear) but I set all watches and clocks by. THe Mega is ALWAYS 100% accurate unless I live a million years. Sure it's quartz, regulated by some sort of time signal from Frankfurt, but it is always right, ALWAYS. I chose GS Spring Drive for the same reason, 2 -3 seconds a month was fantastic, so I spent my €5K on this watch. Not 3 months of average wearing, including a bike ride or two, nothing special and it is waterproof for a Covid Hand Wash!......), the time starts to go haywire, so badly, it's alarming. I put it in my winder, the time returns to perfect. I give it to my partner, he wears it and has an equally but different result, still very inaccurate. On him it is even more wild!...... yes, give him my ex Rolex, time keeping was within the 1 second a day, on me too!........ Conclusion, body interfierrance with quartz controller!. How simple, it isn't shielded, so is susceptible to individual body energy. We are all unique, as is our energy. Mine is moderate, my partner is clearly stronger, the watch can not cope with either of us, but in the winder, he is accurate to the second!. What to do? €5000 of wasted money, sure snowflake, moon dust or in my case a deep blue all have the same engine and it doesn't work properly. No wonder it didn't get a certificate of accuracy....... it doesn't' deserve one!...... I am waiting for GS to contact me and offer me a replacement or a refund, but I'd rather have a replacement which has been fixed!. This is a design problem, nothing to do with me!...... If it works in the winder perfectly, then the problem lies in the magnetic energy the body gives off, which includes all of us!............. GS missed this point! and need to fix it. The quartz controller needs to be shielded!, then it really will work......... Please GS, just send me a revised and updated copy of exaclty the same watch as I have. I Love it, it's beautiful in every detail, but it keeps bloody awful time!. That's not the Zen I trained for for 10 years in Kyoto!............. far from it.


----------



## Mark Hans

JLittle said:


> I've only had my Snowflake (spring drive) for a little bit but it's spot on accurate, hasn't lost or gained even one second yet.


Lucky You. And the Snowflake has a classic dial I am told and very beuatiful if you like white dials! What are you checking the accuracy by? I'd like to know what it really does in say 30 days, constant wearing, so in bed, shower and sport!. (if you are lucky sex too! ), ....... please report to the second!........... nice test. Maybe I'm NOT alone!. Even with a hot lover, a hot shower and a bit of a work out, it should be within 3 seconds in a month. Did you now Seiko produced the twin Quartz in the 80's that kept to the same accuracy. Can't remember the model but it was truly within specs. I loved it and owned it for years until I foolishly swapped it over for an IWC....... Oooops.


----------



## JLittle

Mark Hans said:


> Lucky You. And the Snowflake has a classic dial I am told and very beuatiful if you like white dials! What are you checking the accuracy by? I'd like to know what it really does in say 30 days, constant wearing, so in bed, shower and sport!. (if you are lucky sex too! ), ....... please report to the second!........... nice test. Maybe I'm NOT alone!. Even with a hot lover, a hot shower and a bit of a work out, it should be within 3 seconds in a month. Did you now Seiko produced the twin Quartz in the 80's that kept to the same accuracy. Can't remember the model but it was truly within specs. I loved it and owned it for years until I foolishly swapped it over for an IWC....... Oooops.


Well, I don't wear in constantly. I have other watches that need love too. Especially my favorite, my Omega. So I'm not the guy to ask to do the test. Sorry watch brother.


----------



## Seikorookie

This is my Seiko Prospex LX SNR033 over the last month. It gets worn at some point almost every day. I am NOT easy on a watch. Lots of activities and it's even worn to bed. My watch graph results:










This is my Grand Seiko SBGA231. This is the watch graph for it:










Both of these watches are incredible. When they just sit on my dresser they stay at +.2secs/day.


----------



## kritameth

Seikorookie said:


> This is my Seiko Prospex LX SNR033 over the last month. It gets worn at some point almost every day. I am NOT easy on a watch. Lots of activities and it's even worn to bed. My watch graph results:
> 
> View attachment 15618482
> 
> 
> This is my Grand Seiko SBGA231. This is the watch graph for it:
> 
> View attachment 15618486
> 
> 
> Both of these watches are incredible. When they just sit on my dresser they stay at +.2secs/day.


Simply amazing. Wow! ??


----------



## watchmandragon

Mark Hans said:


> So I have to send my brand new SD to Japan?, my local dealer looks very blankly at me!........ looks OK on his machine............. No, I want my watch replaced!
> My complaints are genuine and backed up by a Junghans Mega Wrist Watch (which I never wear) but I set all watches and clocks by. THe Mega is ALWAYS 100% accurate unless I live a million years. Sure it's quartz, regulated by some sort of time signal from Frankfurt, but it is always right, ALWAYS. I chose GS Spring Drive for the same reason, 2 -3 seconds a month was fantastic, so I spent my €5K on this watch. Not 3 months of average wearing, including a bike ride or two, nothing special and it is waterproof for a Covid Hand Wash!......), the time starts to go haywire, so badly, it's alarming. I put it in my winder, the time returns to perfect. I give it to my partner, he wears it and has an equally but different result, still very inaccurate. On him it is even more wild!...... yes, give him my ex Rolex, time keeping was within the 1 second a day, on me too!........ Conclusion, body interfierrance with quartz controller!. How simple, it isn't shielded, so is susceptible to individual body energy. We are all unique, as is our energy. Mine is moderate, my partner is clearly stronger, the watch can not cope with either of us, but in the winder, he is accurate to the second!. What to do? €5000 of wasted money, sure snowflake, moon dust or in my case a deep blue all have the same engine and it doesn't work properly. No wonder it didn't get a certificate of accuracy....... it doesn't' deserve one!...... I am waiting for GS to contact me and offer me a replacement or a refund, but I'd rather have a replacement which has been fixed!. This is a design problem, nothing to do with me!...... If it works in the winder perfectly, then the problem lies in the magnetic energy the body gives off, which includes all of us!............. GS missed this point! and need to fix it. The quartz controller needs to be shielded!, then it really will work......... Please GS, just send me a revised and updated copy of exaclty the same watch as I have. I Love it, it's beautiful in every detail, but it keeps bloody awful time!. That's not the Zen I trained for for 10 years in Kyoto!............. far from it.


My friend had the same problem you had and when I posted it to this thread, I was crucified by the Grand Seiko lovers and accused of making it up my friend's watch had the same problem as you when I responded to your post.

Grand Seiko checked my friends watch out and said it kept time within Grand Seiko tolerance level. When he got it back from Grand Seiko and wore it the watch had the same problem. He asked for a refund or a replacement model and Grand Seiko told him no. The Grand Seiko saga lasted for over 10 months before he gave up and decided to ditch the time bomb.

He sold the Grand Seiko watch on Redditt for a massive loss as he had to be honest in his sales posting that his Grand Seiko watch ran fast by about 10 minutes a month and Grand Seiko could not fix the problem..

Bug the heck out of Seiko that they replace your watch free of charge. If I were you and they replace it, don't wear it and sell it as new and move on and sell the Grand Seiko time bomb ASAP.

If it were me I would go to the AD you purchased it from and be persistent like ants on sugar.

Ignore the folks who respond that you and me are the same person. I am willing to bet my 401k account that you and me are not the same poster.


----------



## kritameth

It looks to me like it's one person trying to legitimize his outrageous claims by talking to himself through 2 different accounts. Another member popping up specifically just to trash on GS, similar M.O. of equating GS to buying a Japanese car to a German car and using logics lacking substance and reason, the chance of that can't be high.


----------



## Seikorookie

kritameth said:


> It looks to me like it's one person trying to legitimize his outrageous claims by talking to himself through 2 different accounts. Another member popping up specifically just to trash on GS, similar M.O. of equating GS to buying a Japanese car to a German car and using logics lacking substance and reason, the chance of that can't be high.


I see neither were interested in my graphs......


----------



## kritameth

Seikorookie said:


> I see neither were interested in my graphs......


Threads on this forum are slowly being trashed, one by one. I hope mods take action before this gets much worse.


----------



## watchmandragon

Seikorookie said:


> I see neither were interested in my graphs......


Your graph is meaningless to me. You had a good experience with your Grand Seiko, my friend did not. Grand Seiko does not have 100% customer satisfaction nor does Rolex have 100% customer satisfaction nor do the top 10 Swiss luxury watch brands have 100% customer satisfaction.

As I stated above I had a problem with accuracy with my Rolex which perplexed the Rolex AD watch smith and Rolex RSC. Lucky for me Rolex replaced the movement for free.

Grand Seiko should have done the same for my friend and the same for the poster Mark Hans.

Not every watch that is made by Grand Seiko and Rolex is 100% in terms of quality control. Grand Seiko and the top Swiss luxury watch makers do not have 100% quality control in terms of all the watches they make not having a timing accuracy issue within COSC standards after the watch is sold and purchased.

Just because the time graph for someone's else Grand Seiko shows great accuracy for their Grand Seiko does not apply to somebody's else Grand Seiko that the accuracy will be the same.


----------



## kritameth

watchmandragon said:


> Your graph is meaningless to me. You had a good experience with your Grand Seiko, my friend did not. Grand Seiko does not have 100% customer satisfaction nor does Rolex have 100% customer satisfaction nor do the top 10 Swiss luxury watch brands have 100% customer satisfaction.
> 
> As I stated above I had a problem with accuracy with my Rolex which perplexed the Rolex AD watch smith and Rolex RSC. Lucky for me Rolex replaced the movement for free.
> 
> Grand Seiko should have done the same for my friend and the same for the poster Mark Hans.
> 
> Not every watch that is made by Grand Seiko and Rolex is 100% in terms of quality control. Grand Seiko and the top Swiss luxury watch makers do not have 100% quality control in terms of all the watches they make not having a timing accuracy issue within COSC standards.


And that story of your "friend" is meaningless to us. There are hundreds of variables that can be at play, one of which, and perhaps most crucially, is the legitimacy of your story that needs to be called into question based on all your previous posts. At the most basic of levels, it's illogical to expect us to take your story at the same face value as @Seikorookie's, when his empirical evidence is shown for all of us to verify right here and right now.


----------



## watchmandragon

Seikorookie said:


> I see neither were interested in my graphs......


Your graph is meaningless as it only applies to your watch.

Let me educate you with the following example.

5 people have high blood pressure. All 5 go to the same doctor who prescribes all 5 patients the same blood pressure medication. The blood pressure medication reduces the blood pressure to normal levels for 4 of the 5 patients. Patient 5 after taking the blood pressure medication does not have his blood pressure lowered.

Patient 5 routinely takes his blood pressure and notes no change after taking the blood pressure medication. He goes to his doctor and says the blood pressure medication is not working. His doctor tells him this is impossible and shows the patient 5 the blood pressure charts for the empirical evidence blood pressure readings for the 4 patients whose blood pressure is lowered to normal levels from taking the same blood pressure medication as patient 5 and says it is impossible for patient 5 blood pressure to not go down because the blood pressure medication worked for patients 1, 2, 3, and 4.


----------



## watchmandragon

Seikorookie said:


> This is my Seiko Prospex LX SNR033 over the last month. It gets worn at some point almost every day. I am NOT easy on a watch. Lots of activities and it's even worn to bed. My watch graph results:
> 
> View attachment 15618482
> 
> 
> This is my Grand Seiko SBGA231. This is the watch graph for it:
> 
> View attachment 15618486
> 
> 
> Both of these watches are incredible. When they just sit on my dresser they stay at +.2secs/day.


Congratulation, drink some White Coconut milk the next time you put your watch on a time graph,


----------



## Tanker G1

In case anyone is wondering, it's right here under the three dots:


----------



## kritameth

Tanker G1 said:


> In case anyone is wondering, it's right here under the three dots:
> 
> View attachment 15618664


This post alone is worth more than all his posts combined. 😂


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## Seikorookie

Tanker G1 said:


> In case anyone is wondering, it's right here under the three dots:
> 
> View attachment 15618664


Thank-you.


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## kritameth

Tanker G1 said:


> In case anyone is wondering, it's right here under the three dots:
> 
> View attachment 15618664


Had no idea it'd be this nice. Literally wiped his existence off my screen. Back to normal again. Thank you.


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## matthew P

Tanker G1 said:


> In case anyone is wondering, it's right here under the three dots:
> 
> View attachment 15618664


Welcome to my happy place, I've been here for days but I'm glad you've chosen to join me.... please invite your friends

•• sent by two turn tables and a microphone ••


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## SolarPower

Assuming @Mark Hans is not trolling, there is no reason to believe that a SD watch on a human wrist would be doing any different from being on a winder or elsewhere away from the wrist due to any other reason than the mechanical movement of the said wrist. We will get back to that later too.

Coming from physics and biomedical science I can assure you that although our bodies emit physical fields and radiations in a wide range of electromagnetic spectrum (from radio waves at about decimeter wavelength to Infrared and all the way to visible light - yes, we emit visible light, albeit so weak you need special conditions and equipment to see those photons), these fields are very weak.

For example, the intensity of magnetic field generated by currents in our hearts and brains (with the heart being more intense, obviously) is 3 orders of magnitude less than just a fluctuation of the Earth magnetic field. To measure this signal one would need to have a special magnetically isolated room with a human and equipment inside it (to get rid of the Earth field) and a superconducting SQUID magnetometer with the sensor located in liquid Helium. And BTW in simple practical terms the strength of the magnetic field falls as inverse cube of distance, so the sensor has to be as close to the heart, as possible. Now with the watch on a wrist and exposed to Earth magnetic field the effect of human body magnetism or electrical potentials to that matter etc, is negligible.

As for the temperature, we, thanks to the publications and multiple in-depth posts by BrianBinFl, all are well aware how SD electronics and the quartz is sensitive to temperature fluctuations. There too is no effect of being on a human wrist at 36.6 Celsius or thereabouts vs sitting on a winder or whatever, assuming the winder is at room temperature.

So it all boils down to mechanical movements of a wrist vs winder, which affects mechanical watches, but luckily has virtually no affect on the Spring Drive,
EDIT: As I think about it a bit more, and assuming the story is true, the simplest explanation would be that the watch on his wrist does not see enough motion to wind-up properly and comes to zero power and therefore [now and then] he would need to wind it up from zero power reserve, which, as we know, would cause the time go fast for short while.

With all of the above explanations, we can put all the theories of a watch behaving differently while on a wrist vs winder to the a well deserved rest. That is assuming we are talking our physical World.
I am sure there could be other theories aiming to explain the "observed" differences with all kind of "otherworldly" effects, however, yours truly isn't interested in those.


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## dealta66

I wore my sbga415 everyday since oct when I got it. October 25-Dec 27, it gained 3 seconds. 


Sent from my iPhone using Tapatalk


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## dealta66

I work in retail for 48hrs a week. I don’t baby my gs


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## GMT-man

SolarPower said:


> There too is no effect of being on a human wrist at 36.6 Celsius or thereabouts


The actual watch temperature seems to be around 30-32C, not the body temperature, because the watch is not inside one's body (like in some movies  ). This is easy to find out by wearing a sports watch with thermocompensated barometer, the thermometer in those shows the barometer sensor temperature = internal temperature of the watch.

This is my experience with sports watches.

What comes to SD experience my Spring Drive GMT has been running solidly at +0.2 SPD for 3 years now. And I am not pampering it. I might take it off when laying bricks or pouring concrete to save it from scratches, but it stays on my wrist when chopping wood, playing tennis and operating a chain saw.


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## J-Rock121

GMT-man said:


> ...What comes to SD experience my Spring Drive GMT has been running solidly at +0.2 SPD for 3 years now. And I am not pampering it. I might take it off when laying bricks or pouring concrete to save it from scratches, but it stays on my wrist when chopping wood, playing tennis and operating a chain saw.


You sir, are awesome! I'm sure I'm being paranoid but just not comfortable wearing mechanical watches with any strenuous activities. I'll just rock my smartwatch (gasp!) or VSA INOX quartz for those times.


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## GSNewbie

@SD Owners.
When putting the SD on a Watch winder, which speed do set up?
Since the watch winds on both sides, this should of course be preset.


----------



## Mark Hans

watchmandragon said:


> My friend had the same problem you had and when I posted it to this thread, I was crucified by the Grand Seiko lovers and accused of making it up my friend's watch had the same problem as you when I responded to your post.
> 
> Grand Seiko checked my friends watch out and said it kept time within Grand Seiko tolerance level. When he got it back from Grand Seiko and wore it the watch had the same problem. He asked for a refund or a replacement model and Grand Seiko told him no. The Grand Seiko saga lasted for over 10 months before he gave up and decided to ditch the time bomb.
> 
> He sold the Grand Seiko watch on Redditt for a massive loss as he had to be honest in his sales posting that his Grand Seiko watch ran fast by about 10 minutes a month and Grand Seiko could not fix the problem..
> 
> Bug the heck out of Seiko that they replace your watch free of charge. If I were you and they replace it, don't wear it and sell it as new and move on and sell the Grand Seiko time bomb ASAP.
> 
> If it were me I would go to the AD you purchased it from and be persistent like ants on sugar.
> 
> Ignore the folks who respond that you and me are the same person. I am willing to bet my 401k account that you and me are not the same poster.


I can assure all readers that we are NOT the same person, nor do I have 401K?....., but the problems are indeed identical. I'm really pissed off, as I love the watch, but as I said, I no longer trust it!. Our local Seiko dealer is NOT going to help out on this one because according to him, it runs perfectly. He is NOT going to wear it for a week to test it either, so I am about to send an E mail to Tokyo ask them to replace it. Good idea, and when it comes back, if it still does the same, it's going on Chrono as brand new!. I'm disappointed truly and a serious watch collector. I refuse to pay Rolex Premium Prices (sold mine for the GS SD and had 20K left over to spend on better things. €5K is the max on my wrist, any more is an over proliferation of showing off wealth that few would even notice! (unless it's a flashy Rolex or IWC). The G Seiko looks beautiful I have to say, but a watch is meant to tell the time...... very accurately in this case...... As said, I would hold back on the Spring Drive and stick with the Hi-Beat Versions which I am told are tremendous!.... Mark, Amsterdam with very little in the Bank!!!. Cheers......


----------



## TheGreenGrape

🤷‍♂️just sell it and get a non SD watch. maybe you did get a dud. mine works just fine with whatever im doing.


----------



## kritameth

Mark Hans said:


> I can assure all readers that we are NOT the same person, nor do I have 401K?....., but the problems are indeed identical. I'm really pissed off, as I love the watch, but as I said, I no longer trust it!. Our local Seiko dealer is NOT going to help out on this one because according to him, it runs perfectly. He is NOT going to wear it for a week to test it either, so I am about to send an E mail to Tokyo ask them to replace it. Good idea, and when it comes back, if it still does the same, it's going on Chrono as brand new!. I'm disappointed truly and a serious watch collector. I refuse to pay Rolex Premium Prices (sold mine for the GS SD and had 20K left over to spend on better things. €5K is the max on my wrist, any more is an over proliferation of showing off wealth that few would even notice! (unless it's a flashy Rolex or IWC). The G Seiko looks beautiful I have to say, but a watch is meant to tell the time...... very accurately in this case...... As said, I would hold back on the Spring Drive and stick with the Hi-Beat Versions which I am told are tremendous!.... Mark, Amsterdam with very little in the Bank!!!. Cheers......


Mark, is it still under warranty? Please share with us some pictures of the watch and part of the warranty paper work with the date of purchase. I have a line of contact and will do my best to help if you are forthcoming and willing to work with me. Even if it's out of warranty let's get you back on track. Rest assured, and hence why I still have my suspicions you are trolling, the problem you are experiencing is a highly isolated one. Assuming you're not "Watchmandragon" - and if you're not please don't associate yourself with him, because the problem you're having is not identical since he made up that story - please refrain from a similar M.O, i.e. stop using lackluster logics. You can't expect a watch manufacturer to simply replace it just because you say there's something wrong, no matter how entitled you feel, when they've performed their standards of tests and it reads fine. Since you also like using car analogies like WMD, it's as if you were to bring your car to a dealership demanding a new one claiming there's something wrong, even after the technicians have carried out tests and shows it's all fine. It doesn't matter if you paid $10M for a Pagani, that won't happen. Now I'm not saying yours might not have a one-in-a-million problem, I'm only saying look at it from their logical POV, and curb your disappointment when they refuse to replace it based on the fact that you say your SD runs perfect on a winder but is almost 10 minutes fast on wrist. Simple reasoning would dictate that no amount of temperature deviation or activity could cause that, just take a minute to think about it, unless you're working in a highly magnetized environment, and even then it's questionable it'd continue to run normal on a winder after that much effect. And I won't even touch on a myriad of other things you brought up with questionable logics and morals, such as you willing to pass off a clearly used watch as new on Chrono24, but provide those pictures and additional supporting evidence and I will get you in touch with my contacts to resolve this.


----------



## Ginseng108

@Seikorookie, thanks for sharing the graphs. It very much reflects the majority experience with Spring Drive.

The two provocateurs have made a miss-mash of this thread and I see that one got banned. No big loss.

A watch, any watch, can experience common or unusual issues. Any watch with or without an underlying issue can interact in some way with the motion-states it experiences. We conceptualize it as on-wrist and off-wrist, but a movement inside any watch is blind to the source of the movement. To a winding weight, it's all just motion. And insofar as winding, the motion is either effective or it isn't. I can tell you that sitting at a desk for 9 hours, getting up occasionally to get coffee, taking the occasional break and lunch, this is entirely sufficient to keep my SNR029 and SNR033 pinned to full PR throughout the entire day. It's bloody efficient!

If your Spring Drive isn't behaving substantially the same, then perhaps you have an issue. Go get it taken care of, or not. You don't need us to agree that you have an issue. There's nothing you can gain from us that you can't get more authoritatively from Seiko GS Service.


----------



## SolarPower

GMT-man said:


> The actual watch temperature seems to be around 30-32C, not the body temperature, because the watch is not inside one's body (like in some movies  ). This is easy to find out by wearing a sports watch with thermocompensated barometer, the thermometer in those shows the barometer sensor temperature = internal temperature of the watch.
> 
> This is my experience with sports watches.
> 
> What comes to SD experience my Spring Drive GMT has been running solidly at +0.2 SPD for 3 years now. And I am not pampering it. I might take it off when laying bricks or pouring concrete to save it from scratches, but it stays on my wrist when chopping wood, playing tennis and operating a chain saw.


Yes Sir, this is correct. Obviously skin temperature is lower than internal one and the watch temperature is even lower yet. This only adds to the fact that there is minimal temperature delta between the watch on a wrist and on a winder. Both are at or very close to room temperature. And real life room temperatures are all different in different rooms anyway. 

Also the quartz PPM (Pulse per million) frequency changes are minimal with few degree temperature change around the target temperature point.

In this great thread, for those who did not see it, BrianBinFl posted lots of data which should satisfy anybody's curiosity about how SD operates, it's accuracy, etc.
Accuracy of Grand Seiko Spring Drive | WatchUSeek Watch Forums

Here is his specific post on the quartz frequency as a function of temperature with the calculations on how it affects the accuracy at 37 degrees :


BrianBinFL said:


> So I accidentally made an interesting discovery today that seems relevant to this discussion of Spring Drive accuracy.
> 
> This will be a long and boring read except for those who enjoy technical minutia.
> 
> So I started out with a point of curiosity about how the frequency of a quartz crystal varies with changes in temperature. I assumed that as the temperature rose from room temp the frequency would change in one direction (slower or faster) and as the temperature fell from room temperature the frequency would change in the other direction. That was incorrect.
> 
> Apparently the frequency fluctuation relative to temperature is parabolic. The crystal is designed such that at room temperature (assumed to be 25° C) the crystal is at its maximum accuracy (closest to the intended frequency of 32768 Hz in the case of Spring Drive) and as the temperature rises or falls from 25° C the frequency of the crystal slows down by a coefficient as specified for the crystal. The amount it slows down is measured in parts per million (PPM).
> 
> The parabola looks like this:
> 
> View attachment 14645713
> 
> 
> When discussing Spring Drive accuracy the result of around +0.2 SPD (a fifth of a second per day) comes up a lot. The number comes up often enough that I have speculated that GS deliberately calibrates them to run around 0.2 SPD fast. Of course there are also some people who report significantly better accuracy than that, and occasionally worse.
> 
> When assessing both of my Spring Drive watches I am comparing to a live-GPS-readout clock that is specified accurate to 100 microseconds, with readout in tenths of a second. I photograph the watch in front of the clock, taking care to observe the watch at the same angle and with the seconds hand in roughly the same position (to minimize parallax), for the starting and ending measurements (with a couple weeks or more elapsed between start and end). Since the seconds sweep is perfectly continuous and never at rest you can get a pretty darn good sync check with a single photograph, no video needed.
> 
> Both of my Spring Drives are right in the +0.18 to +0.19 SPD range, with my new SBGA373 coming in at +0.1856 SPD after very careful analysis with the watch staying in the watch box 100% of the time except for winding.
> 
> No offense to anybody but to this point I have assumed that whenever I see someone say they are getting accuracy in the 1 second per month range I have assumed that their time reference or methodology was lacking. While that may be the case in some instances, for others it may be a 100% legit observation. Read on.
> 
> So once I found out that the temperature/frequency response curve was parabolic (a surprise) then I wondered how much deviation wearing the watch for 9 hours or so would cause. It would be expected to cause some variation because most crystal manufacturers set the "turnover point" (the peak of the parabola) at 25° C and body temperature is about 37° C (12° C warmer). For this analysis I assumed that the crystal would eventually get to full body temperature given direct contact of the watch case with the skin.
> 
> The temperature coefficient I see used most often for the type of crystals used in watches is -0.04 ppm/°C[SUP]2[/SUP]. I have no idea if the GS-made crystals have that coefficient or not, but absent better information that's the coefficient I used.
> 
> The formula to calculate the PPM is pretty simple:
> 
> PPM = -0.04 * (T-T[SUB]0[/SUB])[SUP]2[/SUP]
> 
> So:
> 
> PPM = -0.04 * (37-25)[SUP]2[/SUP]
> 
> PPM = -0.04 * (12)[SUP]2[/SUP]
> 
> PPM = -0.04 * 144
> 
> PPM = -5.76
> 
> So now we know our frequency deviation in parts per million.
> 
> Our crystal is supposed to vibrate at 32768 Hz (32,768 vibrations per second). 32,768 Hz is 0.032768 MHz. 0.032768 times -5.76 = -0.18874368. So our error for 9 hours at 37° C is -0.18874368 * 60 * 60 * 9 = -6115.295232 cycles. We need to divide -6115.295232 by 32768 to turn that error back into seconds and we get -0.186624.
> 
> Hey, that number looks really familiar. Those of you with really good memories may remember from above that my SBGA373 came in at +0.1856 SPD after very careful analysis. The absolute value of that number is only around a thousandth of a second different than the "9 hours at 37° C" error we just calculated.
> 
> Is it possible that GS actually calibrates the Spring Drive so that at room temperature it is just fast enough to offset the loss the watch will experience from a typical day on the wrist? Honestly I wouldn't be surprised if that were the case.
> 
> Of course all of this makes a lot of assumptions about the characteristics of GS quartz crystals, and there are probably things that I haven't accounted for, or have perhaps accounted for incorrectly, but I have to say that when I was working out how to do the math and finally calculated my "9 hours" error and saw that number come up, I immediately recognized it and got the biggest grin.
> 
> So back to Spring Drive accuracy, given the above it seems completely reasonable that if you wear your Spring Drive for the right number of hours per day, and the rest of the time it is resting at a temperature close to the turnover point in the parabola, you could very well end up getting accuracy of around +1 second in a month.
> 
> Anyway, I hope someone gives a darn about all this. I sure had fun working it out.


----------



## SolarPower

kritameth said:


> Mark, is it still under warranty? Please share with us some pictures of the watch and part of the warranty paper work with the date of purchase. I have a line of contact and will do my best to help if you are forthcoming and willing to work with me. Even if it's out of warranty let's get you back on track. Rest assured, and hence why I still have my suspicions you are trolling, the problem you are experiencing is a highly isolated one. Assuming you're not "Watchmandragon" - and if you're not please don't associate yourself with him, because the problem you're having is not identical since he made up that story - please refrain from a similar M.O, i.e. stop using lackluster logics. You can't expect a watch manufacturer to simply replace it just because you say there's something wrong, no matter how entitled you feel, when they've performed their standards of tests and it reads fine. Since you also like using car analogies like WMD, it's as if you were to bring your car to a dealership demanding a new one claiming there's something wrong, even after the technicians have carried out tests and shows it's all fine. It doesn't matter if you paid $10M for a Pagani, that won't happen. Now I'm not saying yours might not have a one-in-a-million problem, I'm only saying look at it from their logical POV, and curb your disappointment when they refuse to replace it based on the fact that you say your SD runs perfect on a winder but is almost 10 minutes fast on wrist. Simple reasoning would dictate that no amount of temperature deviation or activity could cause that, just take a minute to think about it, unless you're working in a highly magnetized environment, and even then it's questionable it'd continue to run normal on a winder after that much effect. And I won't even touch on a myriad of other things you brought up with questionable logics and morals, such as you willing to pass off a clearly used watch as new on Chrono24, but provide those pictures and additional supporting evidence and I will get you in touch with my contacts to resolve this.


Nice of you to offer a hand!
As for Pagani, it is less than you quoted and 2020 Huayra starts at $3,400,000


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## Mark Hans

kritameth said:


> Mark, is it still under warranty? Please share with us some pictures of the watch and part of the warranty paper work with the date of purchase. I have a line of contact and will do my best to help if you are forthcoming and willing to work with me. Even if it's out of warranty let's get you back on track. Rest assured, and hence why I still have my suspicions you are trolling, the problem you are experiencing is a highly isolated one. Assuming you're not "Watchmandragon" - and if you're not please don't associate yourself with him, because the problem you're having is not identical since he made up that story - please refrain from a similar M.O, i.e. stop using lackluster logics. You can't expect a watch manufacturer to simply replace it just because you say there's something wrong, no matter how entitled you feel, when they've performed their standards of tests and it reads fine. Since you also like using car analogies like WMD, it's as if you were to bring your car to a dealership demanding a new one claiming there's something wrong, even after the technicians have carried out tests and shows it's all fine. It doesn't matter if you paid $10M for a Pagani, that won't happen. Now I'm not saying yours might not have a one-in-a-million problem, I'm only saying look at it from their logical POV, and curb your disappointment when they refuse to replace it based on the fact that you say your SD runs perfect on a winder but is almost 10 minutes fast on wrist. Simple reasoning would dictate that no amount of temperature deviation or activity could cause that, just take a minute to think about it, unless you're working in a highly magnetized environment, and even then it's questionable it'd continue to run normal on a winder after that much effect. And I won't even touch on a myriad of other things you brought up with questionable logics and morals, such as you willing to pass off a clearly used watch as new on Chrono24, but provide those pictures and additional supporting evidence and I will get you in touch with my contacts to resolve this.


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## Mark Hans

Dear Said Dritameth. (I hope I got that right). The watch comes from 6th August 2019, SBTA375. Serial number 9r65-DC**. I bought it from from a dealer in Crupa, Poland. It was absolutely brand new, boxes, stickers, labels, I have them all........ so he's not even 18 months old. I removed (Seiko in Amsterdam where I live) removed the metal band and gave me a blue leather band which I prefer. I don't know what trolling means, but I understand you've had a very angry customer on here before!. I'm not angry I am very disappointed. I've only worn this watch for three months and now it sits stationary in my box, because of the embarrassing mistrust I have. You can not imagine what it is like to spend SO much money on a watch that claims to be THIS accurate & then find yourself 5 minutes early or late. How can this be?...... but it's a fact, so I am not pretending to be anyone other than who I am and the person named on the guarantee.


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## Mark Hans

This is my Grand Seiko Watch.......... Can't be more honest than this!


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## Mark Hans

But I actually LOVE this watch. It is simply gorgeous, it tells time perpectually which is amazing. It's also completely and utterly silent, save the winding. Put it under your pillow, nothing, Not even a nice hum!. Thats a pity. So you see, I am a true LOVER of Grand Seiko, I just wish mine worked on my wrist.


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## kritameth

Mark Hans said:


> Dear Said Dritameth. (I hope I got that right). The watch comes from 6th August 2019, SBTA375. Serial number 9r65-DC**. I bought it from from a dealer in Crupa, Poland. It was absolutely brand new, boxes, stickers, labels, I have them all........ so he's not even 18 months old. I removed (Seiko in Amsterdam where I live) removed the metal band and gave me a blue leather band which I prefer. I don't know what trolling means, but I understand you've had a very angry customer on here before!. I'm not angry I am very disappointed. I've only worn this watch for three months and now it sits stationary in my box, because of the embarrassing mistrust I have. You can not imagine what it is like to spend SO much money on a watch that claims to be THIS accurate & then find yourself 5 minutes early or late. How can this be?...... but it's a fact, so I am not pretending to be anyone other than who I am and the person named on the guarantee.
> View attachment 15619806


Thank you for providing this Mark, the SBGA375 is a lovely piece! I give you my word I will do my best to help. Since you were planning to monitor it for a month starting Jan 1 I'd like to please ask you use an app, e.g. WatchCheck, at least once a day (the more often the better) to track the accuracy and share the result here. This is so we can better assess the situation and better assist you, e.g. perhaps it's accurate all days except one, where it ran 8 minutes fast, we would deduce it was something in your surroundings that day.


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## whineboy

dealta66 said:


> I wore my sbga415 everyday since oct when I got it. October 25-Dec 27, it gained 3 seconds.
> 
> Sent from my iPhone using Tapatalk


Not to go off-topic from trashing dragontrollwatchsquid, but, dayummmm, that's impressive.

Having a great time.
whineboy


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## Mark Hans

Whineboy, I'm happy for you, that's exactly what I expected. I actually LOVE this watch. It is simply gorgeous, it tells time perpetually which is amazing. It's also completely and utterly silent, save the winding. Put it under your pillow, nothing, Not even a nice hum!. Thats a pity. So you see, I am a true LOVER of Grand Seiko, I just wish mine worked on my wrist. Anyway, as Said has now identified me as who I am, he's offered an olive branch. I knew if I could find this forum (Grand Seiko), someone out there would take my complaint seriously. The SD is running on my wrist, set to +1 hr GMT via my Junhans Mega 43mm. This watch sits on my bench and just ticks away the time, already for 15 years. Takes one new battery every two years and keeps 100% time. So, I'm two hours down the line, I have made coffee in one of those old fashioned machines, washed up, cleaned the kitchen and not a lot more. No big magnets. My Spring Drive has gained 'one' full second in just under two hours!........ Yes, I will record it for one calendar month and do it in detail, so it will appear here. This is day one............ and we are one hour in!........ Have a great 28th December. Mark, Amsterdam.


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## SolarPower

Good job Mark. Please keep doing it. Watch your GS power reserve and don't touch time settings on the watch. Your error is well within inaccuracy of your time setting and picture taking. 
Allow it a day, then it will be clear. Keep posting pics.


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## Mark Hans

Mark Hans said:


> Whineboy, I'm happy for you, that's exactly what I expected. I actually LOVE this watch. It is simply gorgeous, it tells time perpetually which is amazing. It's also completely and utterly silent, save the winding. Put it under your pillow, nothing, Not even a nice hum!. Thats a pity. So you see, I am a true LOVER of Grand Seiko, I just wish mine worked on my wrist. Anyway, as Said has now identified me as who I am, he's offered an olive branch. I knew if I could find this forum (Grand Seiko), someone out there would take my complaint seriously. The SD is running on my wrist, set to +1 hr GMT via my Junhans Mega 43mm. This watch sits on my bench and just ticks away the time, already for 15 years. Takes one new battery every two years and keeps 100% time. So, I'm two hours down the line, I have made coffee in one of those old fashioned machines, washed up, cleaned the kitchen and not a lot more. No big magnets. My Spring Drive has gained 'one' full second in just under two hours!........ Yes, I will record it for one calendar month and do it in detail, so it will appear here. This is day one............ and we are one hour in!........ Have a great 28th December. Mark, Amsterdam.
> View attachment 15620640


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## Mark Hans

So here's my day. We started this exercise at around 9am, by 11, my GS SD had gained almost a full second. I did coffee, a bit of husband duty, nothing special, but really nice, made breakfast, went for a drive in a 1985 VW van, did a few E mails........ no power stations or big magnets, really boring life (under Covid Rules). So he's been on my wrist since around 9am, it's now 11.20pm. He is a good 2 seconds advanced from my Junghans Mega or my one month, regulator who argues over 3 seconds, (it's the weather granted). He i regulate by the careful placement of feather light pure silver weights, a gram or so each. He's on time........... not notable today anyway, but doing rather better than the Spring Drive. Let's see what the morning brings. I sleep in a rather good bed, double spring and supportive, well ventilated (Covid) and a very handsome partner who DOESN'T wear this watch because he says it doesnt' tell the right time. OK, an addition to this story, I bought it for him!...................... Because the Junhans jumps the second and the SD perpetually sweeps it's way around the dial, a 10th of a second photo can distort the truth. Anyway, we are 14 hours into this one month trial and my SD is 'almost' two second ahead of itself, in 14 hours. Lets see what happens by the morning. Truly, if you are considering buying a Spring Drive, this should be a serious warning. €5000 is NOT cheap. My Seiko Sports Model 7n0287 (without hacking devises is actually runing about the same gane pace, only difference is I paid over €4500 less for the Sport 5so he is forgiven for his 20 seconds a day variance, at that money , it just looks super cool in his deep blue dial and enamel bezel!. It never failed me, ever!.......... It's not a cronomteter, its a Seiko Sports 5 with a rather lovely blue dial set. Truly a nice watch!.


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## Mark Hans

OK, we up the odds. We v The Junhands Mega against the Grand Seiko Spring Drive and finally the Seiko 5 Sports which is the blue version taken from a classic Swiss watch, the 5 Fathoms. A beautiful piece of Seiko Art. Wonderful water proof & vastly underpriced..... . Let's see who does best in a true 'one month test'. If you want me to wear all three, i will, but the Junghans Mega will NEVER be wrong, never! so he's the 'regulator against the two beautiful Seiko's.....
Now the fight is between a difference of €4000 Spring Drive v Sports 5 day date, both with the name Seiko. I am a Zen Master trained in Kyoto, so please, don't tell me how to arrange the stones!............ They have to be right. Grand Seiko, I hope you are watching this blog, because it could absolutely ruin your reputation against your 'junior' company Seiko. Today, Seiko rings better in my ears the GRAND SEIKO, a watch that doesn't keep time............. I'm not fooling, you might be fooling us!...... let's see who it telling the real truth. Sleep well, my GS SD will be on my wrist all night! I can play watches all my life because I love them and Seiko or GS have been deep in my heart until I finally (it took 5 years) decided to buy a Spring Drive. The worst decision I have made!, well accept a gold diamond Rolex, but I was 30 years younger and a stupid child........, OK, Grand Seiko, let's get serious. Either my watch is a Dud or there is a serious design flaw. I doubt few if any understand the essence of total accuracy but when my Grand Seiko tells me it is twelve O clock precisely, that is the true time................ or is it? More tomorrow. Mark, Amsterdam.


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## Alex_TA

GSNewbie said:


> @SD Owners.
> When putting the SD on a Watch winder, which speed do set up?
> Since the watch winds on both sides, this should of course be preset.


300 2 sides


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## Mark Hans

He's on my wrist for a full month... We are edging 3 second fast in the same days. PS Does anyone remember the Seiko Twin Quarz, I think in the 80'. Pure quartz, it was accurate to within 5 second a months guaranteed, Never saw it again. Plain Day Date, but TQ!


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## kritameth

Mark Hans said:


> He's on my wrist for a full month... We are edging 3 second fast in the same days. PS Does anyone remember the Seiko Twin Quarz, I think in the 80'. Pure quartz, it was accurate to within 5 second a months guaranteed, Never saw it again. Plain Day Date, but TQ!


TQ was discontinued a while ago, but if you're after HAQ check out models like the SBGV238 with the 9F82, accurate to 5 seconds per year. In regards to the SD, please keep going, though I'd ask to please refrain from going on a tangential mission to bash GS, I think that's been well established now and it makes it more difficult for people to engage. And in regards to the reference time - absolutely no offense to the Junghans, but it is, inevitably, another variable in the equation - would you be able to use a dedicated accuracy tracking app, if nothing but so you can post a screenshot showing the variations over time here.


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## GMT-man

To check the watch against a time standard you should get one of these. Not the watches (mostly), but the GPS clock accurate to within some 60 nanoseconds internally. Costs only about 100 bucks.


















GPS Clock by Geppetto Electronics on Tindie


An LED desk clock that gets time from GPS




www.tindie.com


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## Mark Hans

I absolutely do not WISH to knock hell out of Spring Drive, Why? I've stated I am merely disappointed. The Junhands Maga is famous, world famous, clocks or watches, because it is not a watch that tells the time from itself, it is controlled some 24 times a day via Frankfurt. It's so accurate, it hurts. It is NEVER wrong. Never! I have to say that my SD knows it is under pressure and today is settling at a cool 3 second fast in three days, so NOT too bad, but we are only on day 3. It hasn't done it's famous 8 second gain in a one day yet, but it's been still for 4 months and we have 28 days to go. Today he got a mix of light work, a shower and not a lot else. He gained nearly 1 second today. If he behaves like this over the next month, we are going to be talking 45 second over that period which in my mind would be fine............. but this would be the first time!..... we see, I'm recording it all with a graph and figures. I will use the Junghans Mega as my guide line, because I have two in the house, one watch, one clock and both are always identical............., they are radio controlled, so how ever bad they are, some big bastard master cracks the whip every hour and corrects them. If you listen to the beeps (of the hour, 6 of them), the Mega is exactly on time. I just hate Quartz watches that chonk the seconds. The Spring Drive Glides through life perpetually, which is much closer to pure time than a quartz radio controlled watch or clock. All that I am doing is showing the potential Spring Drive Purchasers a warning!.........Lets see how this turns out and see what we think by the end of January. I will accurately and honestly report my findings. I wish I had NEVER had to do this!................ I have better things to do, but this is important for sure. We go into day 4. Mark, Amsterdam.


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## BrianBinFL

GMT-man said:


> To check the watch against a time standard you should get one of these. Not the watches (mostly), but the GPS clock accurate to within some 60 nanoseconds internally. Costs only about 100 bucks.
> 
> 
> 
> 
> 
> 
> 
> 
> GPS Clock by Geppetto Electronics on Tindie
> 
> 
> An LED desk clock that gets time from GPS
> 
> 
> 
> 
> www.tindie.com


As expounded upon previously, I second this recommendation. The actual accuracy of the clock is 200 microseconds or 100 microseconds depending upon the version of the hardware you get. Of course the display resolution is a tenth of a second, which is coarse compared to the actual accuracy of the clock, but you know for certain the thing is right and "drift" is basically impossible.

This is a fantastic clock no matter how you slice it. I have given them as gifts to other accuracy nuts, and have a couple of them as well. I have a newer one with the 3D printed case on my dresser where the watches live, and an older one with the laser cut wood case on my watchmaker's bench.



















For those of you with eagle eyes, yes, the Certina is a fast by around 5 seconds. It hasn't been synchronized since March 20th and I'm letting it go a full year without a sync to see if the accuracy lives up to the spec of 10 seconds per year. So far it's performing better than spec by quite a bit.

When sync checking a Spring Drive or a traditional mechanical watch you just need a single photograph to check the sync. When checking a 1 beat per second quartz you need to use the video method to get the best accuracy.


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## GMT-man

BrianBinFL said:


> As expounded upon previously, I second this recommendation. The actual accuracy of the clock is 200 microseconds or 100 microseconds depending upon the version of the hardware you get. Of course the display resolution is a tenth of a second, which is coarse compared to the actual accuracy of the clock, but you know for certain the thing is right and "drift" is basically impossible.


It is a bit complicated to describe the accuracy of this clock. First there is the "first level" accuracy from GPS satellites. Then comes the somewhat diminished accuracy after the internal data processing (100 or 200 microseconds), and finally the refresh rate of the display, which is 600 Hz. While the display resolution is 0.1 seconds, each change of the decimal digit is never too soon, and at worst 1/600 of a second late, or 1.6 milliseconds (granularity). Plus the before mentioned insignificant amounts of inaccuracies baked in. In any case it is more accurate than anything at that price by big margin, and more than accurate enough for eyeballing or even high speed video.


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## BrianBinFL

GMT-man said:


> It is a bit complicated to describe the accuracy of this clock. First there is the "first level" accuracy from GPS satellites. Then comes the somewhat diminished accuracy after the internal data processing (100 or 200 microseconds), and finally the refresh rate of the display, which is 600 Hz. While the display resolution is 0.1 seconds, each change of the decimal digit is never too soon, and at worst 1/600 of a second late, or 1.6 milliseconds (granularity). Plus the before mentioned insignificant amounts of inaccuracies baked in. In any case it is more accurate than anything at that price by big margin, and more than accurate enough for eyeballing or even high speed video.


I agree wholeheartedly. I've communicated a bit with Nathan (the maker of the clock) about various things and he's a really sharp guy. He's gone very far out of is way to account for all sorts of things that I'd never thought of.

On his page Nathan says "This is absolutely the most accurate human-readable clock for the price that I know how to make." I think that's the best possible description of the clock. If someone wants to have a supremely accurate and precise clock by which to measure the true gain or loss of their timepiece then I do not think you can do better than this clock. If someone knows of something better please share it as I'm always looking for new toys to buy.


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## Mark Hans

Greetings. Yes very impressive clocks. My Junhans is accurate enough, unless we now being told that the beeps before the hour are wrong too. The Junhands does it's job & my Wall Regulator is also on time...... So, as promised I started on December 28th to record the apparent erratic behaviour of my Spring Drive. We start at 0. Over 6 days it did rather well, it settled down after a few hours and I would say on average kept perfect time. It's initial gaining of 3 seconds reduced to 2, then stabilized out to 0 gain or loss per day! Checked it at 10.00am today, he was still on his +2, so no change. Great! I went to work in a very normal old petrol car, I was in my office for an hour typing on the computer (been doing that since the 28th), washed up, went to the Super-Market, washed the sink and went home. Happened to check my SD, what? he was (is) 12 second fast since I last checked. So within 7 hours he gained 9 seconds... how?, why?. Now what have I done!..... The crown is nicely home, he's full of power, I can not imagine in a million years what I have done to upset my watch in such a short amount of time. As though I walked through some sort of magnetic time machine.

Seriously, this is NO JOKE.......... Perhaps a few of you in Spring Drive Land can give me 'any' sort of clue as to what I might have done today that was SO odd, or at least to upset my watch. I was not exaggerating about the 8 minutes in a month, this is just half a day, yet for 5 days, he is perfect?...... I really don't understand. Honestly, nothing I did today was off, in any sort of highly magnetic fields, I wear pretty normal clothes (I'm, 62) and didn't spend the day running either. I took a nice long lazy first day back at work................ I will continue...... I'm baffled and annoyed!......... Here we go again. Do I reset or leave it alone?....I am now working for the Forum because I think there is a fundamental design problem here, & I would like it resolved. Everything I have written since we started is backed up here by today!......... someone, please give me a clue! otherwise I am tempted to throw this GS straight into the River, which is running by my house!...............
The SD is an expensive watch in it's class!.........this shouldn't happen. *Mark, Amsterdam.*


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## SolarPower

To GMT-man and Brian,
I sure appreciate the accuracy of a GPS clock. Assuming that GPS Satellite to clock transmission delay is constant and does not change day to day (not sure if this is true though), with the processing of say 200 us (worse case scenario) + 1.6 ms displaying delay we are at 1.8 ms accuracy for time tracking. So the question is without an interface to set a watch automatically and relying on human reaction to set the time, time setting would be only *0.15 s* accurate, as the fastest possible conscious human reactions are around 0.15 s. So why do I need a clock which is 100 times more accurate than that? Any radio synced watch as a reference master time would do, wouldn't it?

If we are to measure a watch accuracy, isn't the best bet to let it run for 100s days? Then all the inaccuracy of setting the time and capturing the resulting deviation would be much less significant.


----------



## BrianBinFL

Mark Hans said:


> Greetings. Yes very impressive clocks. My Junhans is accurate enough, unless we now being told that the beeps before the hour are wrong too. The Junhands does it's job & my Wall Regulator is also on time......


I don't completely trust anything other than my GPS clock, but I have checked the correctness of time.is several times and its delta from correct time is very consistent, so it's a close second.



Mark Hans said:


> So, as promised I started on December 28th to record the apparent erratic behaviour of my Spring Drive. We start at 0. Over 6 days it did rather well, it settled down after a few hours and I would say on average kept perfect time. It's initial gaining of 3 seconds reduced to 2, then stabilized out to 0 gain or loss per day! Checked it at 10.00am today, he was still on his +2, so no change. Great! I went to work in a very normal old petrol car, I was in my office for an hour typing on the computer (been doing that since the 28th), washed up, went to the Super-Market, washed the sink and went home. Happened to check my SD, what? he was (is) 12 second fast since I last checked. So within 7 hours he gained 9 seconds... how?, why?. Now what have I done!..... The crown is nicely home, he's full of power, I can not imagine in a million years what I have done to upset my watch in such a short amount of time. As though I walked through some sort of magnetic time machine.
> 
> Seriously, this is NO JOKE.......... Perhaps a few of you in Spring Drive Land can give me 'any' sort of clue as to what I might have done today that was SO odd, or at least to upset my watch. I was not exaggerating about the 8 minutes in a month, this is just half a day, yet for 5 days, he is perfect?...... I really don't understand. Honestly, nothing I did today was off, in any sort of highly magnetic fields, I wear pretty normal clothes (I'm, 62) and didn't spend the day running either. I took a nice long lazy first day back at work................ I will continue...... I'm baffled and annoyed!......... Here we go again. Do I reset or leave it alone?....I am now working for the Forum because I think there is a fundamental design problem here, & I would like it resolved. Everything I have written since we started is backed up here by today!......... someone, please give me a clue! otherwise I am tempted to throw this GS straight into the River, which is running by my house!...............
> The SD is an expensive watch in it's class!.........this shouldn't happen. *Mark, Amsterdam.*


If your Spring Drive is varying by more than 1 second per day it is broken. You have two choices: a) send it to Grand Seiko for service, b) mail it to me and I will give it a good home. No sense throwing it in the river.


----------



## BrianBinFL

SolarPower said:


> To GMT-man and Brian,
> I sure appreciate the accuracy of a GPS clock. Assuming that GPS Satellite to clock transmission delay is constant and does not change day to day (not sure if this is true though), with the processing of say 200 us (worse case scenario) + 1.6 ms displaying delay we are at 1.8 ms accuracy for time tracking.


The transmission delay is a factor of the distance from the GPS satellite to you. The radio signal itself moves at the speed of light which is of course fixed (to our understanding of physics anyway). The satellites are at an elevation of about 20,200 km - a distance that light takes about 0.067 seconds to traverse. Yes, some satellites are a little closer or a little further, but not by enough to matter for our purposes here.



SolarPower said:


> So the question is without an interface to set a watch automatically and relying on human reaction to set the time, time setting would be only *0.15 s* accurate, as the fastest possible conscious human reactions are around 0.15 s. So why do I need a clock which is 100 times more accurate than that? Any radio synced watch as a reference master time would do, wouldn't it?


Good questions. I'm going to answer the last question first because it's the simplest to answer. Radio synced watches suck compared to a GPS clock as a reference time source if you have the option to have a GPS clock. Why? Because they generally only sync once a day and then they drift for the next 24 hours running only on their internal oscillator.

Now if the radio sync'd watch was an HAQ this might be fine. But most radio sync'd watches are not HAQ, they are what I would call "garbage quartz" - because they can be. If the time is going to get synchronized every 24 hours it's not super critical that the oscillators be great. My Seiko Coutura Radio Sync Solar gains about 0.35 seconds (around a third of a second) between the time it gets a sync and a day later just before it gets its next sync. If it misses a sync that means it will be off 0.7 seconds by the time it gets the sync on the second day.

Now for a human who is simply reading the time a 0.7 second error is irrelevant. But if you're trying to precisely check the sync of an accurate timepiece a 0.7 second error in your reference is disastrous.

The beauty of the GPS clock is that it is decoding the time stream from the GPS satellite in real time. If the clock is showing the time then the time is correct to within the stated error of the machine (200 microseconds). The GPS satellites each have an atomic clock on them. When you are reading GPS time you are reading real atomic clock time *at the moment*. When you look at a radio sync time reference you're reading something that was synced with the atomic clock some random amount of time ago (maybe 23 hours ago) and has been running on a garbage oscillator since that sync.

OK. On to the question of human reaction time and the relevance of a hyper accurate time source.

Human reaction time doesn't have to be a factor here. If you're trying for a perfect sync you'd never wait for the clock to read :00.0 to push the crown in - you know your watch would be "behind" if you did that. That's the beauty of having the tenths of a second display. You can watch the tenths stream by and make the decision to press the crown in about the time it hits 59.8 (or whatever the right number is for you) and nail it pretty much spot on. Also you don't just get one bite at the apple. If I'm doing a "precise sync check" I will sync the watch to the GPS clock and then use either the photo method or the video method (depending upon the type of watch) to check the sync and see how good it is. If it's within a tenth that'll do. If not I redo it.

*Photo Method*
Spring Drives are the absolute easiest watches to check sync on because they display time with infinite resolution as their seconds hand is perfectly continuous and has no beats. A simple photograph of the watch in front of a time source with tenths of a second is all you need to check sync. Sort of.

I say "sort of" because the resolution of the time source actually is the limiting factor when checking sync on a Spring Drive. The watch has infinite resolution but the clock does not.

Anyway, what I do is wait until the seconds hand is in the portion of the dial that minimizes parallax (which seems to be somewhere in the 25 to 40 second range with the way I usually have the watch, clock, and camera arranged) and then take about 8 or so pictures in rapid succession. Then I look for one picture where the clock is showing exactly xx.0 seconds, or, lacking that, at least one where the tenths digit is nice and bright so I know it wasn't in the middle of a change.

Then I compare the time shown on the seconds hand to the time shown on the clock. I usually consider it to be OK if it's within a tenth of a second of correct. If it's more than that I redo the sync. Once I'm happy with it I record the beginning information like this:

GPS time: 2019-10-01 01:09:58.5
Watch time: 2019-10-01 01:09:58.4
Starting error: -0.1s

Then I let the watch run for some sampling period. For this particular test I let it run for a bit more than 4 days. Then I do the same photo check and record the results:

GPS time: 2019-10-05 20:33:56.7
Watch time: 2019-10-05 20:33:57.5
Ending error: +0.8s

Then subtract the initial error from the ending error to find out the actual accumulated error: 0.8 - (-0.1) = 0.9

If you want to know the seconds per day then you subtract the starting date/time from the ending date/time to find out the elapsed number of days and divide the accumulated error by the number of days.

Here is the result for my SBGA373 Spring Drive:










Amusingly this lines up really nicely with the +0.18 SPD that we see in the Grand Seiko factory video where they are performing "final inspection" on a Spring Drive movement.










The photo method also works very well with a 10 bps (high beat 36000) movement as those movements have the same resolution as the GPS clock - tenths of a second. With 8 bps and 6 bps movements each tick of the seconds hand is 0.125 and 0.166 seconds respectively so correlating that with the tenths on the GPS clock is a little trickier, though the photo method is still perfectly adequate for almost any purpose with these watches.

The photo method is useless with quartz watches unless it is something like a Bulova Precisionist (which is unusual in that it moves the seconds hand 16 beats per second).

*Video Method*
For lesser watches (anything that's not Spring Drive) the video method really is best. There are also advantages to using the video method for Spring Drive watches because, as mentioned previously, though the resolution of the Spring Drive is perfect and infinite, the resolution of the clock is not.

I think I did a post on the video method somewhere. I'll try to find it. If not I'll do one at some point.



SolarPower said:


> If we are to measure a watch accuracy, isn't the best bet to let it run for 100s days? Then all the inaccuracy of setting the time and capturing the resulting deviation would be much less significant.


With my HAQ watches I actually let them go a whole year without disturbing the sync to see how they do. I sample them along the way to see how it's going. This is somewhat fun because if the watch is brand new and the watch arrived "stopped" from the manufacturer, you can often see the result of the quartz crystal changing frequency as it ages under power. This should be less of an issue with the Grand Seiko 9F calibers because Grand Seiko keeps the crystals under power for 90 days before they ever go in a watch, choosing only the crystals that are still excellent after that "aging".

But for my mechanicals (I include Spring Drive in the category of "mechanicals") I'm not keeping them wound and running for 100 days to do a sync check. With the precise measurements available using the GPS clock and either the photo or video method I can get a perfectly adequate sync check in a week or less. This is much more in line with my patience level.


----------



## SolarPower

BrianBinFL said:


> The transmission delay is a factor of the distance from the GPS satellite to you. The radio signal itself moves at the speed of light which is of course fixed (to our understanding of physics anyway). The satellites are at an elevation of about 20,200 km - a distance that light takes about 0.067 seconds to traverse. Yes, some satellites are a little closer or a little further, but not by enough to matter for our purposes here.


Thank you Brian, I always enjoy reading your posts. Your posts are helpful and educational. I learn things from you which I did not know. As an example, I now learned certain things about GPS-based time synchronization, as before your posts I was not into watch accuracy much and was not interested enough to google things, and now I am.

Let me say that I have a Ph.D. in physics, so going forward we can safely assume we both understand the basics.

Now back to accuracy of time reception by a GPS clock. In theory, it depends on
1. Ground Control Network operations, which among other things also updates the satellite clock corrections,
2. Repeatability of the transmission delay

For #1 above, I do not know how often time adjustments have to be made or what is accuracy threshold used and what is an algorithm they use for time adjustment to be transmitted.
However, for the scope of this discussion, the worst case scenario for your watch accuracy test is if the Ground to satellite cloud adjustment happens while you doing your test. We then should assume that the GPS clock gets the new adjusted time as you are in your measurement interval and therefore it will affect the final GPS time reading. Let me say that I believe those time deltas most likely are small and I think we can safely assume that they will be less than 1.6 ms of GPS clock's display time delay.

For #2 above, there is small delta in the distance to satellites given the particular time and position when you start to use your GPS clock as the satellites are not on geo-stationary orbit. However, since the receiving GPS clock supposed to see 6 or more satellites at any given time, the time delta caused by the distance deviation should be not that big. However, let us assume it is say 1% of the signal travel time, i.e. 0.67 ms. It is not insignificant, is it? However, perhaps this 1% assumption was too much.

However, what I truly meant questioning repeatability was not the distance delta, but rather occasional RF interference. We all know that this is something which happens to any radio signals no matter what frequency band is used. I am sure they optimized for this though, and now, as I think more of it, I believe that the GPS clock software sure has a provision for lost or incomplete data (ignoring it is first which comes to mind) and it does proper corrections as good data shows up. So this most likely would not be a concern.



BrianBinFL said:


> Good questions. I'm going to answer the last question first because it's the simplest to answer. Radio synced watches suck compared to a GPS clock as a reference time source if you have the option to have a GPS clock. Why? Because they generally only sync once a day and then they drift for the next 24 hours running only on their internal oscillator.
> 
> Now if the radio sync'd watch was an HAQ this might be fine. But most radio sync'd watches are not HAQ, they are what I would call "garbage quartz" - because they can be. If the time is going to get synchronized every 24 hours it's not super critical that the oscillators be great. My Seiko Coutura Radio Sync Solar gains about 0.35 seconds (around a third of a second) between the time it gets a sync and a day later just before it gets its next sync. If it misses a sync that means it will be off 0.7 seconds by the time it gets the sync on the second day.
> 
> Now for a human who is simply reading the time a 0.7 second error is irrelevant. But if you're trying to precisely check the sync of an accurate timepiece a 0.7 second error in your reference is disastrous.
> 
> The beauty of the GPS clock is that it is decoding the time stream from the GPS satellite in real time. If the clock is showing the time then the time is correct to within the stated error of the machine (200 microseconds). The GPS satellites each have an atomic clock on them. When you are reading GPS time you are reading real atomic clock time *at the moment*. When you look at a radio sync time reference you're reading something that was synced with the atomic clock some random amount of time ago (maybe 23 hours ago) and has been running on a garbage oscillator since that sync.


No argument here. GPS clock is way to go for absolute accuracy. Although I can sync my Radio controlled watch to an atomic clock on demand, it is still less reliable to use. My point was more about the human reaction delay, which we will discuss below.



BrianBinFL said:


> OK. On to the question of human reaction time and the relevance of a hyper accurate time source.
> 
> Human reaction time doesn't have to be a factor here. If you're trying for a perfect sync you'd never wait for the clock to read :00.0 to push the crown in - you know your watch would be "behind" if you did that. That's the beauty of having the tenths of a second display. You can watch the tenths stream by and make the decision to press the crown in about the time it hits 59.8 (or whatever the right number is for you) and nail it pretty much spot on. Also you don't just get one bite at the apple. If I'm doing a "precise sync check" I will sync the watch to the GPS clock and then use either the photo method or the video method (depending upon the type of watch) to check the sync and see how good it is. If it's within a tenth that'll do. If not I redo it.


I agree that with the photo method or video method you described below the human reaction is almost irrelevant. Let me say that you could even not touch your watch while doing the measurements. It is irrelevant what time your watch is set to, as the only thing which matters is the delta relative to GPS clock. Also, if you capture the pictures same time of the day, it would ease your parallax concerns even further.



BrianBinFL said:


> *Photo Method*
> Spring Drives are the absolute easiest watches to check sync on because they display time with infinite resolution as their seconds hand is perfectly continuous and has no beats. A simple photograph of the watch in front of a time source with tenths of a second is all you need to check sync. Sort of.
> 
> I say "sort of" because the resolution of the time source actually is the limiting factor when checking sync on a Spring Drive. The watch has infinite resolution but the clock does not.
> 
> Anyway, what I do is wait until the seconds hand is in the portion of the dial that minimizes parallax (which seems to be somewhere in the 25 to 40 second range with the way I usually have the watch, clock, and camera arranged) and then take about 8 or so pictures in rapid succession. Then I look for one picture where the clock is showing exactly xx.0 seconds, or, lacking that, at least one where the tenths digit is nice and bright so I know it wasn't in the middle of a change.
> 
> Then I compare the time shown on the seconds hand to the time shown on the clock. I usually consider it to be OK if it's within a tenth of a second of correct. If it's more than that I redo the sync. Once I'm happy with it I record the beginning information like this:
> 
> GPS time: 2019-10-01 01:09:58.5
> Watch time: 2019-10-01 01:09:58.4
> Starting error: -0.1s
> 
> Then I let the watch run for some sampling period. For this particular test I let it run for a bit more than 4 days. Then I do the same photo check and record the results:
> 
> GPS time: 2019-10-05 20:33:56.7
> Watch time: 2019-10-05 20:33:57.5
> Ending error: +0.8s
> 
> Then subtract the initial error from the ending error to find out the actual accumulated error: 0.8 - (-0.1) = 0.9
> 
> If you want to know the seconds per day then you subtract the starting date/time from the ending date/time to find out the elapsed number of days and divide the accumulated error by the number of days.
> 
> Here is the result for my SBGA373 Spring Drive:
> 
> View attachment 15630904
> 
> 
> Amusingly this lines up really nicely with the +0.18 SPD that we see in the Grand Seiko factory video where they are performing "final inspection" on a Spring Drive movement.
> 
> View attachment 15630919
> 
> 
> The photo method also works very well with a 10 bps (high beat 36000) movement as those movements have the same resolution as the GPS clock - tenths of a second. With 8 bps and 6 bps movements each tick of the seconds hand is 0.125 and 0.166 seconds respectively so correlating that with the tenths on the GPS clock is a little trickier, though the photo method is still perfectly adequate for almost any purpose with these watches.
> 
> The photo method is useless with quartz watches unless it is something like a Bulova Precisionist (which is unusual in that it moves the seconds hand 16 beats per second).
> 
> *Video Method*
> For lesser watches (anything that's not Spring Drive) the video method really is best. There are also advantages to using the video method for Spring Drive watches because, as mentioned previously, though the resolution of the Spring Drive is perfect and infinite, the resolution of the clock is not.
> 
> I think I did a post on the video method somewhere. I'll try to find it. If not I'll do one at some point.
> 
> With my HAQ watches I actually let them go a whole year without disturbing the sync to see how they do. I sample them along the way to see how it's going. This is somewhat fun because if the watch is brand new and the watch arrived "stopped" from the manufacturer, you can often see the result of the quartz crystal changing frequency as it ages under power. This should be less of an issue with the Grand Seiko 9F calibers because Grand Seiko keeps the crystals under power for 90 days before they ever go in a watch, choosing only the crystals that are still excellent after that "aging".
> 
> But for my mechanicals (I include Spring Drive in the category of "mechanicals") I'm not keeping them wound and running for 100 days to do a sync check. With the precise measurements available using the GPS clock and either the photo or video method I can get a perfectly adequate sync check in a week or less. This is much more in line with my patience level.


Nice! But, if duration of watch accuracy test is months, all the little precautions would be less important


----------



## BrianBinFL

SolarPower said:


> Now back to accuracy of time reception by a GPS clock. In theory, it depends on
> 1. Ground Control Network operations, which among other things also updates the satellite clock corrections,
> 2. Repeatability of the transmission delay
> 
> For #1 above, I do not know how often time adjustments have to be made or what is accuracy threshold used and what is an algorithm they use for time adjustment to be transmitted.
> However, for the scope of this discussion, the worst case scenario for your watch accuracy test is if the Ground to satellite cloud adjustment happens while you doing your test. We then should assume that the GPS clock gets the new adjusted time as you are in your measurement interval and therefore it will affect the final GPS time reading. Let me say that I believe those time deltas most likely are small and I think we can safely assume that they will be less than 1.6 ms of GPS clock's display time delay.


It has been a while since I read the actual numbers so I'll confess I had to look it up. The atomic clocks onboard the GPS satellites would lose about 7 microseconds per day due to the time dilation effect of their relative motion (relative to us), causing them to run slower than the ones on Earth. But they would gain about 45 microseconds a day due to the time dilation effect of being further from Earth's gravity than those on the surface, which causes them to run fast. Those two competing effects net out to a gain of about 38 microseconds per day.

Supposedly the clocks are kept synchronized such that their difference from UTC is never more than 1 microsecond. Interestingly the principal method of adjustment is not to adjust the clock itself, but to adjust the UTC correction data that is also included in the signal. So the signal tells the GPS time and also the amount of time to adjust that by to arrive at UTC.

Since the data is updated frequently enough such that the UTC time in the signal is never wrong by more than 1 microsecond this should be completely invisible to us.



SolarPower said:


> However, what I truly meant questioning repeatability was not the distance delta, but rather occasional RF interference. We all know that this is something which happens to any radio signals no matter what frequency band is used. I am sure they optimized for this though, and now, as I think more of it, I believe that the GPS clock software sure has a provision for lost or incomplete data (ignoring it is first which comes to mind) and it does proper corrections as good data shows up. So this most likely would not be a concern.


The way the GPS clocks deal with this is that the only actual timekeeping they do internally is the division of the seconds into tenths. The main time display is 100% from decoded GPS data. So if the GPS clock loses GPS lock (due to RF interference or any other reason) the clock will cease to display the time and will instead say "no GPS". So essentially, if the GPS clock is showing you the time, then you know it's right.



SolarPower said:


> No argument here. GPS clock is way to go for absolute accuracy. *Although I can sync my Radio controlled watch to an atomic clock on demand*, it is still less reliable to use. My point was more about the human reaction delay, which we will discuss below.


You are lucky in the bolded. I'm in Central Florida and WWVB is marginal here. I can only reliably get a sync at night and some of my devices won't even get a sync then. I have one wall clock that seems to always get a sync, and one that nearly never gets a sync. My Seiko Radio Sync Solar gets a sync almost every night (it will miss a night here and there) but my G-Shock has *never* gotten a sync here. My G-Shock has only ever gotten a sync when we were in Palatka (further north in Florida) once staying overnight for a class.

For my stubborn devices that don't like to get a sync from WWVB directly I use a WWVB emulator to sync them periodically. But of course they drift quite a bit between syncs so I don't rely upon them for any degree of accuracy.



SolarPower said:


> Nice! But, if duration of watch accuracy test is months, all the little precautions would be less important


This would be fine for my HAQ watches that stay running all the time. But my mechanicals are never wound for more than a week - and rarely even that long.


----------



## analog_watch

koolpep said:


> Yeah, indeed. Rolex advises "around every 10 years" and the ADs usually tell you just to hand it in if something is wrong, like it doesn't keep time anymore or other issues, like power reserve.
> 
> GS advises to service "ideally every 3-4 years" but I am with everyone here....use common sense.
> 
> Cheers.


I just visited the GS boutique in LA today and purchased a spring drive watch. I was the only one in the shop. Both ADs working said I should not bother bringing it in for service for 8-10 years or if there are any signs of a problem.


----------



## koolpep

analog_watch said:


> I just visited the GS boutique in LA today and purchased a spring drive watch. I was the only one in the shop. Both ADs working said I should not bother bringing it in for service for 8-10 years or if there are any signs of a problem.


Yes indeed. I agree with them. And I wouldn't do otherwise myself. This is a bullet proof movement. However GS says officially what I quoted on their website.


----------



## SolarPower

BrianBinFL said:


> It has been a while since I read the actual numbers so I'll confess I had to look it up. The atomic clocks onboard the GPS satellites would lose about 7 microseconds per day due to the time dilation effect of their relative motion (relative to us), causing them to run slower than the ones on Earth. But they would gain about 45 microseconds a day due to the time dilation effect of being further from Earth's gravity than those on the surface, which causes them to run fast. Those two competing effects net out to a gain of about 38 microseconds per day.
> 
> Supposedly the clocks are kept synchronized such that their difference from UTC is never more than 1 microsecond. Interestingly the principal method of adjustment is not to adjust the clock itself, but to adjust the UTC correction data that is also included in the signal. So the signal tells the GPS time and also the amount of time to adjust that by to arrive at UTC.
> 
> Since the data is updated frequently enough such that the UTC time in the signal is never wrong by more than 1 microsecond this should be completely invisible to us.
> 
> The way the GPS clocks deal with this is that the only actual timekeeping they do internally is the division of the seconds into tenths. The main time display is 100% from decoded GPS data. So if the GPS clock loses GPS lock (due to RF interference or any other reason) the clock will cease to display the time and will instead say "no GPS". So essentially, if the GPS clock is showing you the time, then you know it's right.
> 
> You are lucky in the bolded. I'm in Central Florida and WWVB is marginal here. I can only reliably get a sync at night and some of my devices won't even get a sync then. I have one wall clock that seems to always get a sync, and one that nearly never gets a sync. My Seiko Radio Sync Solar gets a sync almost every night (it will miss a night here and there) but my G-Shock has *never* gotten a sync here. My G-Shock has only ever gotten a sync when we were in Palatka (further north in Florida) once staying overnight for a class.
> 
> For my stubborn devices that don't like to get a sync from WWVB directly I use a WWVB emulator to sync them periodically. But of course they drift quite a bit between syncs so I don't rely upon them for any degree of accuracy.
> 
> This would be fine for my HAQ watches that stay running all the time. But my mechanicals are never wound for more than a week - and rarely even that long.


Very interesting Brian, thank you for your very informative post, as usual. You saved me and all us readers of this thread lot's of time doing our own research.

So, yes, as expected, the satellite time is very accurate and 1us is invisible to us, like you said.

Interesting how GPS clock is designed to work. I guess they are proud of 100us accuracy and do not want to have their built-in quartz to be the main clock and being displayed when there is no satellite update available, That is fine and I actually like their design for the reason you mentioned.

As for Radio sync, I have a clock which, like yours, would never (or almost never) sync. It has external antenna but it does not help. Also, like your watches, my Seiko is syncing with no problems, while my G-shock is more of a hit or miss. My Casio Lineage is better than G-shock, but not as good as my Seiko. However, all of them, except my clock, can sync on-demand most of the time, if you know how to place them properly on the window. Night time they do not require any special effort.

You have too many watches, from what I gather, Brian  At least too many to be accuracy tested and time adjusted all the time. Isn't it tiresome? Just kidding, as I know it is a pleasure


----------



## GMT-man

Few comments about the posts above by SolarPower and BrianBinFL (too lazy to quote and pick just the relevant point)

There is no 1.6 ms delay in the GPS clock display, the granularity (how well the 600 Hz display frequency happens to match the "absolute" time at each change of digits) is at MAXIMUM 1.6 ms. But it can also be zero. Thus it varies pseudo randomly between 0 and 1.6 ms, being the interference result between the 600 Hz and whatever the output sample frequency happens to be from the GPS time processor.

As the GPS system now provides accuracy in the decimetre domain and the working of the whole contraption is based on signal time accuracy, the received compound accuracy (after processing several satellite signals) must also be something in the order of 300 000 000 000 mm / 100 mm = 0.3 ns (after all the internal processing). GPS clock maker talks about 20 ns or so (meaning about 6 m / 20 f location accuracy) as a starting point, which is fully believable in this context. Having 1% signal delays somewhere between the satellites and the receiver would mean the GPS location being off by some 3000 kilometres, when we know 3 meters is now easily possible, even 3 dm, 30 million times better than the speculated 1% deviation. Thus the pure time signal must be just as accurate.

What comes to radio sync it might be fine where available (good enough for all practical reasons, that is, but not for us...), but at least here in Finland I have managed to get my G-Shock Mudmaster to sync just once in 3 years to the nearest tower in Germany. I seldom wear it anyway, so not a big deal for me.


----------



## SolarPower

GMT-man said:


> Few comments about the posts above by SolarPower and BrianBinFL (too lazy to quote and pick just the relevant point)
> 
> There is no 1.6 ms delay in the GPS clock display, the granularity (how well the 600 Hz display frequency happens to match the "absolute" time at each change of digits) is at MAXIMUM 1.6 ms. But it can also be zero. Thus it varies pseudo randomly between 0 and 1.6 ms, being the interference result between the 600 Hz and whatever the output sample frequency happens to be from the GPS time processor.
> 
> As the GPS system now provides accuracy in the decimetre domain and the working of the whole contraption is based on signal time accuracy, the received compound accuracy (after processing several satellite signals) must also be something in the order of 300 000 000 000 mm / 100 mm = 0.3 ns (after all the internal processing). GPS clock maker talks about 20 ns or so (meaning about 6 m / 20 f location accuracy) as a starting point, which is fully believable in this context. Having 1% signal delays somewhere between the satellites and the receiver would mean the GPS location being off by some 3000 kilometres, when we know 3 meters is now easily possible, even 3 dm, 30 million times better than the speculated 1% deviation. Thus the pure time signal must be just as accurate.
> 
> What comes to radio sync it might be fine where available (good enough for all practical reasons, that is, but not for us...), but at least here in Finland I have managed to get my G-Shock Mudmaster to sync just once in 3 years to the nearest tower in Germany. I seldom wear it anyway, so not a big deal for me.


Thanks for your post GMT-man.

You confused me with mm divided by mm resulting in ns  I guess what you were trying to say is that time needed for the wave to travel 1dm is : 0.1m / (3*10^(8)) m/s = 0.3*10^(-9) s = 0.3 ns which is true. Location calculation is somewhat more complex as it involves the distance to 4 or more satellites (although 3 could do it) and some stereometrics, but nonetheless your estimate holds as an estimate.

Now to 1% accuracy. It was 1% delay of travel time from an actual satellite distance (which is, like Brian pointed out) 20,200 km. So 1% of that would be 202 km, not 3,000 km. but still a lot, so your point is taken. I think that 1% assumption was incorrect. And besides, by now we agreed that it is not much a delay, but rather interference resulting in lost or corrupted data, however, the GPS clock is dealing with it by not showing any time until the signal is received.


----------



## GMT-man

SolarPower said:


> Now to 1% accuracy. It was 1% delay of travel time from an actual satellite distance (which is, like Brian pointed out) 20,200 km. So 1% of that would be 202 km, not 3,000 km. but still a lot, so your point is taken.


Mea culpa, I was in some kind of dumb mode for a moment. Anyway you & Brian are correct.


----------



## Dunnej

You'll have no problems. The Spring Drive is one of the most robust movements I've ever come across


----------



## SolarPower

GMT-man said:


> To check the watch against a time standard you should get one of these. Not the watches (mostly), but the GPS clock accurate to within some 60 nanoseconds internally. Costs only about 100 bucks.
> 
> View attachment 15622428
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> GPS Clock by Geppetto Electronics on Tindie
> 
> 
> An LED desk clock that gets time from GPS
> 
> 
> 
> 
> www.tindie.com





BrianBinFL said:


> As expounded upon previously, I second this recommendation. The actual accuracy of the clock is 200 microseconds or 100 microseconds depending upon the version of the hardware you get. Of course the display resolution is a tenth of a second, which is coarse compared to the actual accuracy of the clock, but you know for certain the thing is right and "drift" is basically impossible.
> 
> This is a fantastic clock no matter how you slice it. I have given them as gifts to other accuracy nuts, and have a couple of them as well. I have a newer one with the 3D printed case on my dresser where the watches live, and an older one with the laser cut wood case on my watchmaker's bench.
> 
> View attachment 15623369
> 
> 
> View attachment 15623370
> 
> 
> For those of you with eagle eyes, yes, the Certina is a fast by around 5 seconds. It hasn't been synchronized since March 20th and I'm letting it go a full year without a sync to see if the accuracy lives up to the spec of 10 seconds per year. So far it's performing better than spec by quite a bit.
> 
> When sync checking a Spring Drive or a traditional mechanical watch you just need a single photograph to check the sync. When checking a 1 beat per second quartz you need to use the video method to get the best accuracy.


Just want to thank GMT-man and BrianBinFL for referring me to this GPS Clock. Order for v.6 placed and looking forward to getting it soon. Even looked briefly through the source code. The guy seems very solid. He has other interesting clock boards for astronomers and just for fun too. Thank you both again.


----------



## SolarPower

OK, the clock is here. Picked up GPS signal out of the box easily and started showing me where exactly on the time axis I am.  









BTW, have not seen any updates from Mark. How is it going Mark?


----------



## BrianBinFL

You got the blue. Interesting. All 3 that I have purchased so far have been red digits. I think I'll get a blue one next. Thanks for the picture.


----------



## SolarPower

BrianBinFL said:


> You got the blue. Interesting. All 3 that I have purchased so far have been red digits. I think I'll get a blue one next. Thanks for the picture.


Thank you Brian. I have gone to your other thread you posted the link to above, where you explained the clock and it's functionality and the specs in great details. Excellently done, as usual. 
This clock is indeed perhaps the best we can get at the moment. Blue is an option started with v.6.

I could not resist and opened the case to look inside. The PCB, components, switches, buttons, antenna plug, etc. done with great quality. Very happy and will play with it looking at my GS (as opposed to Seiko) accuracy. So far my measurements showed my GS running gaining about 0.2 s/day in full agreement with your theory of why and how


----------



## GMT-man

SolarPower said:


> OK, the clock is here. Picked up GPS signal out of the box easily and started showing me where exactly on the time axis I am.


Quite frankly I find the box ugly. That is why I ordered (also duty & tax & postage reasons) just the circuit board and GPS antenna. I made a frame for the circuit board from exactly same kind of bamboo board you have as a tabletop in the photo.


----------



## SolarPower

GMT-man said:


> Quite frankly I find the box ugly. That is why I ordered (also duty & tax & postage reasons) just the circuit board and GPS antenna. I made a frame for the circuit board from exactly same kind of bamboo board you have as a tabletop in the photo.


Yes, the box is nothing special, except being 3-d printed. The looks is not your hi gloss volume manufactured bed stand alarm clock, but this to me makes it more interesting.
I am sure your bamboo case is prettier. Post a pic! That "table" in my pic is actually my workbench top in my garage.









I am yet to try the GPS clock in my office. Was using my garage for easy satellite view w/o a need to go through the window. Not sure if the reception will be good enough for the antenna to stay inside..


----------



## BrianBinFL

SolarPower said:


> I am yet to try the GPS clock in my office. Was using my garage for easy satellite view w/o a need to go through the window. Not sure if the reception will be good enough for the antenna to stay inside..


I just stuck the antenna on top of the door jamb leading into the master bathroom which is right by the dresser where the watch box and one of my GPS clocks live. I did basically the same thing for the other GPS clock that lives on my watchmaker's bench.

Warning: the GPS puck antennas that come with the clocks have magnets in them, so don't get them near your watches.


----------



## SolarPower

BrianBinFL said:


> I just stuck the antenna on top of the door jamb leading into the master bathroom which is right by the dresser where the watch box and one of my GPS clocks live. I did basically the same thing for the other GPS clock that lives on my watchmaker's bench.
> 
> Warning: the GPS puck antennas that come with the clocks have magnets in them, so don't get them near your watches.
> View attachment 15644103


Thanks Brian. So the clock is in my office now with the antenna attached to the outer wall facing my front yard. It is picking the satellites most of the times with some intermittent "no GPS" now and then. Will try to find better place for the antenna another day. For now I'd say it works well enough.

With the larger antenna and I am sure good quality receiver this clock is using and yet not 100% working indoors makes me wonder how GPS watches (and esp. Astron) fare..


----------



## GMT-man

I have the GPS antenna outside stuck to the topside of roof edge coping, which must be just about the best place for it anywhere on the property. Inside I got too many "no GPS" messages. I am at 60 degrees North, maybe that has something to do with the not too good GPS reception.


----------



## GMT-man

Here is my bamboo frame for the GPS clock.


----------



## BrianBinFL

SolarPower said:


> With the larger antenna and I am sure good quality receiver this clock is using and yet not 100% working indoors makes me wonder how GPS watches (and esp. Astron) fare.


I don't have an Astron yet. I suspect I will buy one at some point. From the limited reading I've done they only even attempt a GPS sync when they detect that they are outdoors (in sunlight). I'm sure you can force a sync attempt any time, but I would suspect if you are indoors it would fail most of the time.


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## SolarPower

GMT-man said:


> Here is my bamboo frame for the GPS clock.
> 
> View attachment 15644361


That is one nice looking GPS / watch combo!


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## SolarPower

GMT-man said:


> I have the GPS antenna outside stuck to the topside of roof edge coping, which must be just about the best place for it anywhere on the property. Inside I got too many "no GPS" messages. I am at 60 degrees North, maybe that has something to do with the not too good GPS reception.


From what I understand your latitude should not make a difference in GPS reception. From the GPS government page below:

The satellites in the GPS constellation are arranged into six equally-spaced orbital planes surrounding the Earth. Each plane contains four "slots" occupied by baseline satellites. This 24-slot arrangement ensures users can view at least four satellites from virtually any point on the planet.


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## natanielbruto03

ronr9286t said:


> I've had 7 spring drive watches over the years, 3 purchased new and 4 purchased pre-owned. I currently have a GS SBGE033 and a Prospex SBDB011. I've never had as much as a hiccup from any of them. To be fair, of all of them, the one that was the oldest was less than 4 years old, so I cannot comment on long-term reliability. All of mine were accurate to spec (< 1 sec/day), and never failed to re-start with winding after running down completely and sitting for weeks (large rotation). Ron


 7 spring drive how i wish i could own 1 Grand Seiko spring drive here in Japan its a lot of money to get GS spring drive.. sell it to me your old 1 GS


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