# Sticky  The history of the "The Citizen"



## ppaulusz

Citizen introduced the "The Citizen" in 1995 and it is still in production as the company's flagship quartz watch. We, in this forum, all know that. We're also aware that the "The Citizen" models were always specified by the manufacturer to perform within +/-5 seconds/year. Though the design of the dials has changed over the years, the classic "The Citizen"-look remained the same. 
The model represents a kind of consistency in the ever changing world of watches.

We (myself included) always refer to the Citizen Caliber A660 as the movement of the "The Citizen" ever since 1995. 
But why we do that? Did Citizen mention it anywhere that the "The Citizen" was always fitted with the A660? No, Citizen never mentioned that! Rightly or wrongly, we (including myself) just assumed it. Why? It seemed only logical, beside there was never a case of "information overflood" from Japan about technological issues. Does "logic" always prevail? Not always, but most of the time yes, it does! What about this case? Well, our logic has failed!

Here comes the shocking news: the "The Citizen" is fitted with the A660 only since the year 2000!!!

Between 1995 and 2000 there were 1 or 2 other movements inside the mighty "The Citizen". As far as I know, it all started with Cal.0350 in 1995. In around 1997-1998 the Cal.0350 might have been replaced with another movement. I will reveal the caliber number of that "second generation" movement (if it ever existed at all) in the near future but right now let's go back to the "first generation" movement of the "The Citizen"!

What should we know about Cal.0350? It's accuracy performance naturally is identical to the current Cal.A660 but some useful features are missing from the "first generation" movement. Cal.0350 does not have perpetual calendar (that - by the way - makes the ETA 252.611, released also in 1995, the indisputed first thermocompensated quartz movement with perpetual calendar!) and it does not offer battery end-of-life indication either. It might lack other features as well but I do not have info about that.

Here comes 1997-98 and that questionable "second generation" movement... but I won't go into details about it - not right now - but as promised, I'll do that in the near future!

Let's move to the "current generation" movement of the "The Citizen", the A660! It was released in the year 2000 but not exclusively for the "The Citizen" as it was fitted (in limited number) in the Citizen Campanola as well! Actually, that fact that the movement was available in the Campanola in the year 2000 should have made us aware that it might have been a new movement then or at least made us careful about the way we thought about the partnership of the "The Citizen" and Cal.A660.

So far so good, but where is the proof for the above? Well, one picture can say more than thousand words, so at the end of my post I attached 2 pictures of the "The Citizen" of 1995 (dial and caseback) and 2 pictures of the "The Citizen" of 2000 (dial and caseback).

... to be continued...;-)

(pictures from the net)


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## Beau8

Very informative~Cheers! ;-)


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## Catalin

Interesting, but not quite what Citizen seems to say at:
http://citizen.jp/discovery/model/1990lt/the_citizen_men.html
However what the (bad) automatic translation (see http://translate.google.com/translate?prev=hp&hl=en&js=y&u=http%3A%2F%2Fcitizen.jp%2Fdiscovery%2Fmodel%2F1990lt%2Fthe_citizen_men.html&sl=ja&tl=en&history_state0= ) is saying might not totally exclude your story - but for the moment I would expect more first-hand information ...

I also have a strong feeling that somebody on this forum has a Chronomaster from 1998 or 1999 - which (in case it has A660) would make the entire story you have built kind of silly :-d


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## ppaulusz

Catalin said:


> ...I also have a strong feeling that somebody on this forum has a Chronomaster from 1998 or 1999 - which (in case it has A660) would make the entire story you have built kind of silly :-d


A Chronomaster from 1998 or 1999?! The unofficial name of "Chronomaster" did not appear on the dial of the "The Citizen" till 2005-ish...

Did you check the photos of the casebacks I included in the opening post?


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## Catalin

ppaulusz said:


> A Chronomaster from 1998 or 1999?! The unofficial name of "Chronomaster" did not appear on the dial of the "The Citizen" till 2005-ish...
> 
> Did you check the photos of the casebacks I included in the opening post?


Yes, but the fact that there are some models with some caliber does not guarantee that ALL models were ONLY with that caliber - I don't believe all Exceed models have the same caliber ;-)

That being said - there IS a second generation listed in 1998:

http://translate.googleusercontent....le.com&usg=ALkJrhjEYARcZITZbUwdgjKd0ZDAxwSXFQ


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## ppaulusz

Catalin said:


> ...That being said - there IS a second generation listed in 1998...


So after all I might not be in the process of building a "silly story"...;-)

Translate this Japanese sentence to English and see what you get out of it (it's about the 1998 "second generation"):

1998モデルです。つまり、オートカレンダー電池切れ表示機能がついており、2000モデル以降のボタン穴がない最終モデルとなっております


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## ppaulusz

Catalin said:


> Yes, but the fact that there are some models with some caliber does not guarantee that ALL models were ONLY with that caliber - I don't believe all Exceed models have the same caliber ;-)


Your argument is wrong here as: There are a number of Exceed models in productions at any given time but there is only one "The Citizen" model in production at any given time! ;-)


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## South Pender

Interesting, but is your evidence of this more-recent introduction of the A660 movement in The Citizen based entirely on the watch specimen or specimens you have seen, or have you communicated directly with Citizen about this? I'm not suggesting that your assertion is wrong, but it would be more convincing if we knew its source and underlying evidence.


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## ppaulusz

South Pender said:


> Interesting, but is your evidence of this more-recent introduction of the A660 movement in The Citizen based entirely on the watch specimen or specimens you have seen, or have you communicated directly with Citizen about this? I'm not suggesting that your assertion is wrong, but it would be more convincing if we knew its source and underlying evidence.


I did not modify the pictures that I included. What do you see on the caseback of the 1995 model? Forget my "story" and pay attention to the pictures! Can you see any mentioning of Cal.A660 on the caseback of the 1995 model or you - just like me - see 0350 written on the caseback (meaning Cal.0350)?


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## South Pender

ppaulusz said:


> I did not modified the pictures that I included. What do you see on the caseback of the 1995 model? Forget my "story" and pay attention to the pictures! Can you see any mentioning of Cal.A660 on the caseback of the 1995 model or you - just like me - see 0350 written on the caseback (meaning Cal.0350)?


I think that answers my question. Suggestive, but not dispositive.


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## ppaulusz

ppaulusz said:


> So after all I might not be in the process of building a "silly story"...;-)
> 
> Translate this Japanese sentence to English and see what you get out of it (it's about the 1998 "second generation"):
> 
> 1998モデルです。つまり、オートカレンダー電池切れ表示機能がついており、2000モデル以降のボタン穴がない最終モデルとなっております


OK, let's do an update:

We know that after the "first generation" (1995) Citizen released a "second generation" of the "The Citizen" in 1998.
There are "movement specific" differences of the features between these generations so they can't be using identical movements!

According to the Japanese script in the quote there has to be a "third generation" of the "The Citizen" as from 2000 onwards there is "button hole" on the case (for adjustment of the perpetual calendar) next to the crown. That means a new movement again!
So there are 3 generations so far - based on movement differences alone!

The only part I might have gotten wrong in my opening post is that I might had the wrong conclusion about the perpetual calendar. Just because there were no "button hole" on generation 1 and 2 that cannot exclude the possibility of the perpetual calendar on those generations (adjustable perhaps via the crown similarly to the ETA 252.611).
Right now I have a feeling that
- "generation 1" might not had perpetual calendar at all
- "generation 2" might had perpetual calendar without the "button hole"


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## Eeeb

Well, I have not yet found a Citizen that violated the protocol of displaying the calibre on the case back... but I'm not much of a Citizen collector.

Good detective work George! Now we need to find some movement pics!!!


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## ppaulusz

Eeeb said:


> Well, I have not yet found a Citizen that violated the protocol of displaying the calibre on the case back... but I'm not much of a Citizen collector.
> 
> Good detective work George! Now we need to find some movement pics!!!


I will provide movement picture of the "second generation" (1998 model) "The Citizen" in a couple of weeks time if everything goes by my plan. The weird thing is that I don't even know the caliber ID of the movement fitted in the 1998 model "The Citizen". Anyhow, I'm doing this in the name of science... though I wish I had a sponsor to pay the bill of the experiment.;-)


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## dwjquest

Quite interesting as usual!

I have a 2004 The Citizen with an A660 movement.


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## ppaulusz

dwjquest said:


> ...I have a 2004 The Citizen with an A660 movement.


Thanks, Dave! The question is this: Does anyone among our forum members have a pre-2000 The Citizen? If yes, please come forward with the movement details (caliber ID, year of production and features)!
We have a very slim chance to find one in our forum members' collections as most members bought their The Citizens new from Japan - not least because they read about the watch in this very forum(!)... but this forum did not exist back in 1999(!) ... anyhow, I might have "something" to show you in the not too distant future.;-)


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## ronalddheld

All archivable information, as well as the Longines VHP post.


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## ppaulusz

ronalddheld said:


> All archivable information, as well as the Longines VHP post.


The Longines VHP post is complete as is so that one is archivable. 
This "The Citizen"-story, on the other hand, is not complete, it needs more info and it might need correction as well. It might take a joint effort from the forum members to present the full and factual history of the "The Citizen". It would be nice to get some help from the _Land of the Rising Sun..._


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## ronalddheld

Sure it would, but detailed technical data is not forthcoming from them.


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## ppaulusz

ronalddheld said:


> Sure it would, but detailed technical data is not forthcoming from them.


OK, then we will do it without their help!;-)


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## Eeeb

ppaulusz said:


> OK, then we will do it without their help!;-)


I think we have done amazing things piecing things together as much as we have. The CIA should hire us all as analysts of the <insert current bogyman> watches of mass destruction industry! :-d


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## Dr. Robert

the A660 in my Campanola is very precise............I use the watch to set all my others, quartz & mechanical.


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## ronalddheld

Considering what scraps of information we were not given, I would say so.
Too bad someone from ETA, Seiko or Citizen would not acknowledge our efforts. Maybe even provide us with complete technical data on those modules? NOT!


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## rex

*What I'm confused about is the A660 supposedly doesn't use thermocompensation>>>*

as written by Carlos Perez almost 10 years ago...

http://www.timezone.com/library/cjrml/cjrml0001

The present pinnacle of Japanese quartz horology hearkens back to the standard set by the Seiko Twin Quartz in 1978. As part of the Historical collection of 2000, Seiko released a limited edition reissue of the groundbreaking Astron, this time featuring a special version of the Grand Seiko 9F61 calibre, accurate to ± 5 seconds per year. Perhaps more significant to the present market is Citizen's limited production line of perpetual calendar quartz wristwatches also accurate to ± 5 seconds/year, simply named "*The Citizen*." Citizen is well known for the high accuracy of its quartz watches, though little is known about their technology as they claim to not use thermocompensation but a proprietary method of accuracy improvement. The Citizen's handmade module A660 is thus an enigma, though a welcome one.

In addition, in regard to my Grand Seiko 9F61 caliber the owner's manual instructions state in order to obtain the best accuracy the watch must be worn for at least 8 hours a day. Nothing is ever metioned in my Chronomaster manual about best accuracy is obtained when the watch is worn.

Any thoughts to share on this ppaulsz? Thanks Bud!


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## South Pender

Hey Rex, in the manual that came with my Citizen Chronomaster, the following appears on p. 82, Section K Specifications:

"Time Accuracy: Approx. ± 5 seconds per year
(when worn for 12 hours per day at +5 to +35°C)"


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## ppaulusz

*Re: What I'm confused about is the A660 supposedly doesn't use thermocompensation>>>*



rex said:


> ...Nothing is ever metioned in my Chronomaster manual about best accuracy is obtained when the watch is worn.
> 
> Any thoughts to share on this ppaulsz? Thanks Bud!


Rex, I do have a copy of the Cal.A660 manual and it is clearly stated on page 60 (section F) that: 
"_Your watch will keep time accurately when used at normal temperatures__ (5-35°C_)_ and worn for approximately 12 hours per day_."

and on page 76 (section M) that:
"_Time Accuracy: Approx. ± 5 seconds per year
__(when worn for 12 hours per day at +5 to +35__°C)_"

About Carlos Perez's article: it is a good read but it needs an "update" (adding new infos and corrections) as it was written about 10 years ago...


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## Catalin

*Re: What I'm confused about is the A660 supposedly doesn't use thermocompensation>>>*



rex said:


> as written by Carlos Perez almost 10 years ago...
> 
> http://www.timezone.com/library/cjrml/cjrml0001
> 
> The present pinnacle of Japanese quartz horology hearkens back to the standard set by the Seiko Twin Quartz in 1978. As part of the Historical collection of 2000, Seiko released a limited edition reissue of the groundbreaking Astron, this time featuring a special version of the Grand Seiko 9F61 calibre, accurate to ± 5 seconds per year. Perhaps more significant to the present market is Citizen's limited production line of perpetual calendar quartz wristwatches also accurate to ± 5 seconds/year, simply named "*The Citizen*." Citizen is well known for the high accuracy of its quartz watches, though little is known about their technology as they claim to not use thermocompensation but a proprietary method of accuracy improvement. The Citizen's handmade module A660 is thus an enigma, though a welcome one.
> ...


He probably meant to say it is not using TC by the traditional INHIBITION COUNT ... but anyway the article is kind of old and by today standards is lacking a little in references ...


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## South Pender

*Re: What I'm confused about is the A660 supposedly doesn't use thermocompensation>>>*



Catalin said:


> He probably meant to say it is not using TC by the traditional INHIBITION COUNT ... but anyway the article is kind of old and by today standards is lacking a little in references ...


I found that assertion (that Citizen did not use thermocompensation) interesting and confusing too. That does seem impossible given The Citizen's performance. Perhaps, though, he meant, as you suggest, that a digital-count adjustment process was not used. I had thought all along that Citizen almost certainly _did_ use this method of TC, as it seems to be the most widely- and successfully-used procedure in recent HEQ watches. Nonetheless, whatever Citizen does use (and we have to assume that it's some form of TC) is arguably the most precise method, and if it's not some form of digital-count method, it would sure be interesting to find out just what it is, as we do know that the A660 movement uses a 32K Hz single-quartz oscillator so that dual-quartz and high-frequency technologies are out.


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## ppaulusz

*Re: What I'm confused about is the A660 supposedly doesn't use thermocompensation>>>*



South Pender said:


> ...Perhaps, though, he meant, as you suggest, that a digital-count adjustment process was not used...


He (Carlos Perez) meant nothing at all! He simply wrote down what Citizen claimed: "..._they claim to not use thermocompensation but a proprietary method of accuracy improvement_."


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## South Pender

*Re: What I'm confused about is the A660 supposedly doesn't use thermocompensation>>>*



ppaulusz said:


> He (Carlos Perez) meant nothing at all! He simply wrote down what Citizen claimed: "..._they claim to not use thermocompensation but a proprietary method of accuracy improvement_."


That's one possibility.


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## ppaulusz

*Re: What I'm confused about is the A660 supposedly doesn't use thermocompensation>>>*



South Pender said:


> That's one possibility.


The only one according to Mr Perez's article. It would not be fair to "put words into his mouth", would it?


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## South Pender

*Re: What I'm confused about is the A660 supposedly doesn't use thermocompensation>>>*



ppaulusz said:


> The only one according to Mr Perez's article. It would not be fair to "put words into his mouth", would it?


I think this is a trivial issue, but let me just say that, rather than putting words in Carlos Perez's mouth, Catalin (not I) was suggesting that, when he wrote "...they claim to not use thermocompensation but a proprietary method of accuracy improvement," we don't know what information he actually had from Citizen and may have actually meant what Catalin noted. Mr. Perez's statement is not a verbatim quote from Citizen. In any case, it really hardly matters. The point is that any conjecture that the Citizen A660 movement is not TC is almost certainly incorrect ;-)


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## Bruce Reding

An excellent puzzle piece, George! (And a great example of the cumulative sleuthing that I mentioned in my other post.) :-!:-!:-!

Where did you get these pics? (I have to say, btw, that I have always loved the quirky "Close to the Hearts of People Everywhere" on the back of older models of this watch. I'm glad I got mine before they switched it out for the eagle.)


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## ppaulusz

*Re: What I'm confused about is the A660 supposedly doesn't use thermocompensation>>>*



South Pender said:


> ...The point is that any conjecture that the Citizen A660 movement is not TC is almost certainly incorrect ;-)


Exactly! ;-)


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## ppaulusz

Bruce Reding said:


> ...Where did you get these pics? (I have to say, btw, that I have always loved the quirky "Close to the Hears of People Everywhere" on the back of older models of this watch. I'm glad I got mine before they switched it out for the eagle.)


Bruce, I got the pictures from a sales ad. I do prefer pre-2005 The Citizen models for their clean-cut dials: no "Chronomaster" on the dial, only "Citizen"! The look of "_understated elegance_" as you used to put it! Your The Citizen is one of the finest examples of that pre-2005 design.:-!

(picture from the net: The Citizen 1995)


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## ronalddheld

It seems hard to believe.


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## ppaulusz

ppaulusz said:


> ... to be continued...;-)...


... right now with details and pictures of the second generation of the "The Citizen"!

First of all the main news: the The Citizen was released with three different movements over the years!
Here is the list of them:
- Cal.0350 (1995-1997)
- Cal.A610H (1998-1999)
- Cal.A660H (since 2000)

I don't know much of Cal.0350: it might have perpetual calendar, it did not have battery end-of-life indication.

I had the opportunity to briefly visit my watchmaker with my second generation The Citizen (Cal.A610H). I wanted to find out two things:
- whether the movement has a calibration terminal
and
- how the perpetual calendar is adjusted (year and month)

I did not have my camera with me so no photos of the movement right now... but I saw the movement and found it to be very much like the current Cal.A660H. How could that be when the current models (since 2000) have a "button hole" for adjusting the perpetual calendar and the earlier models don't have "button hole"? Should not that difference indicate a difference in the movement design as well? Perhaps it should but to my surprise it did not! Both the A610H and the A660H have the same design for the adjustment of the perpetual calendar! While the movements do have the same design, the cases do have different designs. If the watchcase of the 1998 model had a hole - where the model 2000 has - the adjustment of the perpetual calendar would be possible with a pin or with a ballpen. Citizen thought in 1998 that it was better for the users as well as for Citizen Services that the users did not have direct access to the setting of the perpetual calendar. A few years later (in 2000) Citizen changed its mind and provided direct access to the setting of the perpetual calendar. Indirectly (by taking of the caseback) anyone could have adjusted the perpetual calendar of the 1998 model if one knew the steps of the procedure (it was not detailed in the users' manual of the 1998 model). Most probably the steps are identical to the one described in the users' manual of Cal.A660H.

I was in a hurry and I forgot to check the number of jewels in the A610H. I bet it's 17 jewels just like in the A660H (and A690G).

My watchmaker could not find any sign of a calibration terminal on the A610H... unfortunately.:-( He believes that Citizen simply replace the electronic modules of the movements that perform out of specifications (accuracy-wise).

The users' manuals of the A610H and A660H are identical to the letter (except in the description of the adjustment of the perpetual calendar). The 1998 model The Citizen might not have Duratech coating as there is no mentioning of that in the users' manual.
Also, pre-2000 models of the The Citizen had snap-on caseback instead of screwed-on caseback. The WR rating is 100m (10 bar) in case of the 1998 model.

One day with the right tool I will remove the caseback of my 1998 model The Citizen and make some high-resolution pictures of the movement. The trick is that one needs to remove the bracelet first as the sweet spot of the caseback for removal is at the 12 hour mark - impossible to reach it without first removing the bracelet.

What do I think about my 1998 The Citizen? It's a very nice watch. Elegant design with quality materials and workmanship. I love its dial and bracelet! Will I keep it for good? :think: I don't think so... Why? Because, it does not have digital calibration terminal...:-(

Strange that these days only the 18ct gold version of the The Citizen comes with luxury wooden box... back in 1998 even the SS version had that luxury.:-!

According to its users' manual only 1000 were made in each year!


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## Eeeb

Great contribution to the forum! Thanks George :-!


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## Bruce Reding

Yes indeed. Great stuff, George! :-!


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## reverendkb

Dr. Robert said:


> the A660 in my Campanola is very precise............I use the watch to set all my others, quartz & mechanical.


That is a gorgeous timepiece, my friend. 
Heavens, I've missed this forum. Haven't been on site for awhile. 
Kudo's, George, as usual.


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## ppaulusz

ppaulusz said:


> ..,I did not have my camera with me so no photos of the movement right now... but I saw the movement and found it to be very much like the current Cal.A660H...
> 
> ...I was in a hurry and I forgot to check the number of jewels in the A610H. I bet it's 17 jewels just like in the A660H (and A690G)...
> 
> ...The users' manuals of the A610H and A660H are identical to the letter (except in the description of the adjustment of the perpetual calendar)...


OK, here is the photo of the A610H!;-) It proves that I was right: it's indeed identical to the A660H and to the A690G!


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## ppaulusz

ppaulusz said:


> ... According to its users' manual only 1000 were made in each year!...


I do have a copy of the current The Citizen and that one has no section about "Limited Production".

On the other hand the 1998 model The Citizen is a limited edition:


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## rex

*Kudo's to Ppaulsz for all your hard work in the making of this thread!>>*

In addition, I look forward to seeing some updated hi-resolution pics of your movement w/out the backplate attached...Quite possibly it will reveal where the 17 jewels are located and why they have to use so many for a simple quartz movement!

Take care Bud.:thanks


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## ppaulusz

*Re: Kudo's to Ppaulsz for all your hard work in the making of this thread!>>*



rex said:


> In addition, I look forward to seeing some updated hi-resolution pics of your movement w/out the backplate attached...Quite possibly it will reveal where the 17 jewels are located and why they have to use so many for a simple quartz movement!...


:thanks, Rex!
I bought the watch "_in the name of science_" as I wrote 3 weeks ago.
_Mission accomplished..._! It was fun but it is over: I sold the watch.


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## rex

*OMG!!! Why in the world did you let that happen?>>*

That's heartbreaking news! Oh well...It was fun while it lasted. :-s

Take care Pal.


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## Swengen

What a fine discussion! Thanks for the education guys. :-!


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## South Pender

I'd like to echo the above post. Just great research, ppaulusz. Many thanks for your conscientious efforts.


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## ppaulusz

:thanks, Gents!

Though I sold my The Citizen it should not automatically mean the end of this thread. There is still a lot about the The Citizen that we do not know. I'd like to have a look of that very first generation movement (Cal.0350 - in production from 1995 till 1997) of the The Citizen. I think, that movement is quite different to the later movements.
Could that movement be similar to the Cal.0330G (found in my Citizen Exceed Gold)?:think:
My Exceed Gold is rated for +/-10 seconds/year (it seems to perform well within that specification - kept in its box!). It does not have date function nor time zone function.

Here are the pictures of the Cal.0330G (found in some dress watch designs of the Exceed-line):


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## Eeeb

Very interesting shock protection... Looks very rugged.


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## ppaulusz

ppaulusz said:


> ...Though I sold my The Citizen it should not automatically mean the end of this thread. There is still a lot about the The Citizen that we do not know...


Here comes the long awaited info from Citizen about the secret of the accuracy of their flagship model - THE CITIZEN (A660H)!!!

In short: the secret is THERMOCOMPENSATION - well, that should not surprise the ones who know that a single 32kHz oscillator does need electronic thermocompensation to achieve better than COSC performance. Still every now and then the rumors came back that Citizen uses proprietory method that is not thermocompensation. Now we know, that is absolutely WRONG!

All 3 manufacturers (Citizen, ETA, Seiko) have proprietory methods - based on thermocompensation!

We have plenty official info about the thermocompensation scheme of the thermocompensated ETA movement. We also have just enough official info about the thermocompensation scheme of the Seiko 9F movements. Until now we did not have official info from Citizen about the thermocompensation scheme of the A660H. Now we got it!

Here are the details:
- the A660H features a built-in thermosensor/thermister
- the temperature is measured with an accuracy of 0.1℃
- the temperature is measured in every 60 seconds („inhibition period") in other words 1440 times a day
- using the results of these temperature measurements the system automatically adjusts the frequency of the crystal to achieve high-accuracy

Important note: the system automatically „adjusts the frequency of the crystal" to achieve high-accuracy - I used 3 different on-line translators and they all tranlated it similarly: „adjusts the frequency of the crystal". I do have a problem with that, I must admit. As far as I know, so far Rolex was the only one (back in 1977) that used a thermocompensation method (with the OysterQuartz movements) that directly altered the frequency of the quartz crystal and the resulted accuracy was the worst compared with other (later) thermocompensation schemes. It's an expensive technology and pretty much unnecessary as better result can be achieved by relatively cheap „digital count adjustment" method. Not that I want to alter the meaning of Citizen's description of the scheme of the A660H but I felt the need to add my opinion to the above: I do believe that Citizen do indeed uses digital count adjustment instead of directly altering the frequency of the crystal.

One other thing I'd like to add: although officially the above description of the scheme is about caliber A660H, I'm pretty sure that caliber A610 and caliber A690 also use this scheme - and most probably all modern high-accuracy Citizen movements (eg: E510, 0330, G530 etc.) works by the same principles.

Finally here is the official Citizen link (in Japanese): 
The_Citizen's_thermocompensation_scheme


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## Catalin

ppaulusz said:


> ...
> Important note: the system automatically „adjusts the frequency of the crystal" to achieve high-accuracy - I used 3 different on-line translators and they all tranlated it similarly: „adjusts the frequency of the crystal". I do have a problem with that, I must admit. As far as I know, so far Rolex was the only one (back in 1977) that used a thermocompensation method (with the OysterQuartz movements) that directly altered the frequency of the quartz crystal and the resulted accuracy was the worst compared with other (later) thermocompensation schemes. It's an expensive technology and pretty much unnecessary as better result can be achieved by relatively cheap „digital count adjustment" method. Not that I want to alter the meaning of Citizen's description of the scheme of the A660H but I felt the need to add my opinion to the above: I do believe that Citizen do indeed uses digital count adjustment instead of directly altering the frequency of the crystal.
> ...


I don't think any knowledgeable people ever doubted that A660 is using TC.

The way how 'altering the frequency' is done is probably some way that has evolved from the method described in:

http://www.citizenwatch.com/downloads/techguides/2730.pdf

(there is even a reference in the PDF to 0.1 C difference in temperature which is also present on the JP page).

Right now I am not 100% convinced that A660 and E510 use the same implementation but it is possible that the generic method is the same ...


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## Eeeb

Oooh! Nicely detailed description. As one of our other posts shows, you can effectively alter the frequency of the oscillator circuit by varying capacitance.


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## South Pender

Great stuff, ppaulusz and Catalin!  Ppaulusz, this TC method of altering the frequency of the crystal (if true) would help explain, I guess, the absence of a digital calibration terminal in Citizen's HEQ movements. Still, given Rolex's results, and Citizen's success with the A660 in getting down to well below 5 sec./year, it does seem hard to believe that the digital count method isn't used.


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## Catalin

South Pender said:


> Great stuff, ppaulusz and Catalin!  Ppaulusz, this TC method of altering the frequency of the crystal (if true) would help explain, I guess, the absence of a digital calibration terminal in Citizen's HEQ movements. Still, given Rolex's results, and Citizen's success with the A660 in getting down to well below 5 sec./year, it does seem hard to believe that the digital count method isn't used.


The method could still allow for digital calibration, Citizen is just not offering it outside factory - I suspect that was a result of initially using it (which they call DFA) from non-volatile memory - and in the original design there was a -40V tension needed for erasing a cell, and +40V to program a cell - there is a description for that stuff inside http://www.citizenwatch.com/downloads/techguides/2200.pdf ... of course that in the meantime the technology has evolved, but once such a management decision is taken most likely a company will stick to it ...


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## ppaulusz

South Pender said:


> Great stuff, ppaulusz and Catalin!  Ppaulusz, this TC method of altering the frequency of the crystal (if true) would help explain, I guess, the absence of a digital calibration terminal in Citizen's HEQ movements...


My problem is the lack of any (digital or analog) calibration terminal. The Rolex OysterQuartz had a trimmer capacitor so did Citizen Cal.2730.
My Attesa (Cal.E510) had its electronic module replaced by Citizen (Japan). One would think that Citizen rather would have calibrated it if it would have been possible but that movement (like any late design Citizen movement) has no calibration terminal. I can accept Catalin's argument that these Citizen movement cannot be calibrated outside factory (meaning that they can be calibrated only in the factory) but I can't see the logic of that corporate decision. Let's not forget that Citizen used to mark on its movements (like any other manufacturer) the calibration terminal (trimmer capacitor) when they had one.

The original (non-ETA) Longines VHP (Cal.L276 from 1984) and the Seiko 8J movements are thermocompensated ones but like the late design thermocompensated Citizen movements they do not have calibration terminal and could not be calibrated as far as I know.


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## ppaulusz

ppaulusz said:


> ...I can accept Catalin's argument that these Citizen movement cannot be calibrated outside factory (meaning that they can be calibrated only in the factory) but I can't see the logic of that corporate decision...


However the above is not proved with evidence though I've already suggested in an earlier post in this forum that there was a fairly simple way to find out what the thruth is. Next time when someone from this forum sends his The Citizen back to Japan for calibration, the person should "prepare" the movement of his watch by secretly marking the electronic module of the movement. When the watch returns from Japan with improved accuracy then the owner should look for that secret marking on the electronic module. If the marking is still there then the watch got calibrated in the factory. However if the marking is not there any more that would indicate that the electronic module was simply replaced not calibrated.


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## Hans Moleman

Good find!

The article clearly mentions correcting for the effects of temperature.
Hence TC.

It is a bit vague on how this is achieved. That could be the translation.

Is it done by changing the frequency?
'Changing frequency' could easily refer to the manufacturing process, or the calibration.


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## South Pender

Hans Moleman said:


> Good find!
> 
> The article clearly mentions correcting for the effects of temperature.
> Hence TC.
> 
> It is a bit vague on how this is achieved. That could be the translation.
> 
> Is it done by changing the frequency?
> 'Changing frequency' could easily refer to the manufacturing process, or the calibration.


Yes, I think there's something to that. Although to us, changing the frequency would mean one specific thing (making the crystal oscillate at a slightly different frequency--a la Rolex Oysterquartz), to the flacks and manual-writers at Citizen, this may just be their way of saying, in a very generic way, that an adjustment is made on the basis of the temperature data received from the thermistor. It may even be a deliberate evasion of a more specifically-detailed explanation. It's too bad we have to guess at these things, but I guess that competitive advantage and closely-guarded proprietary technology are the causes.


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## Hans Moleman

And right they are!
No need to disclose anything. 

On the frequency changing topic I am a bit hesitant anyway.
Didn't it take very long for a crystal oscillator to settle down?
Days even?

How would it cope with a change every few minutes?
It would never have time to settle down.
That can't be helpful.


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## Catalin

ppaulusz said:


> However the above is not proved with evidence though I've already suggested in an earlier post in this forum that there was a fairly simple way to find out what the thruth is. Next time when someone from this forum sends his The Citizen back to Japan for calibration, the person should "prepare" the movement of his watch by secretly marking the electronic module of the movement. When the watch returns from Japan with improved accuracy then the owner should look for that secret marking on the electronic module. If the marking is still there then the watch got calibrated in the factory. However if the marking is not there any more that would indicate that the electronic module was simply replaced not calibrated.


I was thinking precisely about that on my titanium E510 (which will be back in a few days), but that one was 'under (late) warranty' (which I believe does not cover opened cases) so the idea might be left for the next 'opportunity' :-d ... on the other hand even if the module is replaced we will not know if the replacement was a brand-new module or another module that was left from a previous warranty calibration - normally not the normal procedure on high-end watches but the absolute 'standard' on warranty fixes for high-end electronics ...


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## ronalddheld

Not too certain about the translation. Is the temperature interval .1F or .1K?
Also, what could be the timescale for the transients to die down every frequency shift, and how does it affect the long term accuracy?


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## rex

*Re: What I'm confused about is the A660 supposedly doesn't use thermocompensation>>>*

Obviously, in OCT/09 I wasn't aware of page 60 of my Chronomaster owner's manual!
http://www.fototime.com/{FC1E2E85-583F-4803-A9E3-98681F0D6A1F}/origpict/DSC04026.JPG


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## ZAR

I think ''The Citizen'' always had the same cal. - A660. ;-)


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## ppaulusz

ZAR said:


> I think ''The Citizen'' always had the same cal. - A660. ;-)


You might _think_ so but we _know_ that there were 3 different calibers over the years:
- Cal.0350 (1995 - 1997)
- Cal.A610 (1998 - 1999)
- Cal.A660 (since 2000)

The latter two are virtually identical but due to different casing designs (that led to different methods to adjust the perpetual calendar) they were given different caliber IDs.


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## ronalddheld

Are we due for a new caliber? I suppose that is in the "wishful thinking" catagory?


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## Catalin

ppaulusz said:


> You might _think_ so but we _know_ that there were 3 different calibers over the years:
> - Cal.0350 (1995 - 1997)
> - Cal.A610 (1998 - 1999)
> - Cal.A660 (since 2000)
> 
> The latter two are virtually identical but due to different casing designs (that led to different methods to adjust the perpetual calendar) they were given different caliber IDs.


Yes, A610 and A660 are practically identical ...

I still wonder what is known about 0350 ...


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## ppaulusz

ppaulusz said:


> ...I'd like to have a look of that very first generation movement (Cal.0350 - in production from 1995 till 1997) of the The Citizen. I think, that movement is quite different to the later movements.
> Could that movement be similar to the Cal.0330G (found in my Citizen Exceed Gold)?:think:
> My Exceed Gold is rated for +/-10 seconds/year (it seems to perform well within that specification - kept in its box!). It does not have date function nor time zone function...


Just an update: I am aware of 3 thermocompensated Citizen movements from the Cal.03xx family:
- Cal.0330 (without calendar)
- Cal.0310 (with calendar)
- Cal.0350 (with perpetual calendar)
I've seen photos of Citizen Exceed models fitted with Cal.0310, I own a Citizen Exceed Gold watch fitted with Cal.0330 and I've seen photo of a 1995 model The Citizen fitted with Cal.0350.
I have not yet seen movement picture of Cal.0310 and Cal.0350 but I'm pretty sure that they do look fairly similar to Cal.0330 (see photos of it in post #47 of this thread). 
In other words Cal.0350 (fitted in the first The Citizen models) must look quite different to Cal.A660 (fitted in current The Citizen models).


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## ppaulusz

ppaulusz said:


> ...Here are the details:
> - the A660H features a built-in thermosensor/thermister
> - the temperature is measured with an accuracy of 0.1℃
> - the temperature is measured in every 60 seconds („inhibition period") in other words 1440 times a day
> - using the results of these temperature measurements the system automatically adjusts the frequency of the crystal to achieve high-accuracy
> 
> ...
> 
> One other thing I'd like to add: although officially the above description of the scheme is about caliber A660H, I'm pretty sure that caliber A610 and caliber A690 also use this scheme - and most probably all modern high-accuracy Citizen movements (eg: E510, 0330, G530 etc.) works by the same principles.
> 
> Finally here is the official Citizen link (in Japanese):
> The_Citizen's_thermocompensation_scheme


The above is confirmed by the "Witschi test":
https://www.watchuseek.com/f9/therm...g-cal-e510g-tested-witschi-qt6000-470618.html


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## South Pender

Not to be too thick about this, but let me see whether I fully understand this. You have established that the Citizen A660 movement (and other HEQ Citizen movements) use information gathered from a thermistor to actually change the frequency of the oscillator. In some ways this is similar to the way Rolex (with the Oysterquartz) did it, isn't it, except for the method of making the adjustment to the frequency (the latter being the TCVCXO method, or varying the voltage)?

The ETA thermoline movements, on the other hand, use similar thermistor-obtained information to change the signal to the stepper motor as to the count it should consider before advancing the seconds hand by one second--the digital-count adjustment method. It would seem, on the surface anyway, that this method would lead more directly to external adjustment via a digital calibration terminal than would Citizen's method.

This leaves me with two questions:

(a) Would it be possible for Citizen to incorporate an external adjustment component given the way the thermocompensation is accomplished--i.e., an external adjustment that would directly affect the frequency of the oscillator?

(b) Do we know how Seiko accomplish their thermocompensation with their TC modules, particularly the 9FXX series with the digital calibration capability? Does the latter capability pretty much point to the digital-count method, or could Seiko too make the adjustment directly to the quartz crystal?


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## ppaulusz

South Pender said:


> Not to be too thick about this, but let me see whether I fully understand this. You have established that the Citizen A660 movement (and other HEQ Citizen movements) use information gathered from a thermistor to actually change the frequency of the oscillator. In some ways this is similar to the way Rolex (with the Oysterquartz) did it, isn't it, except for the method of making the adjustment to the frequency (the latter being the TCVCXO method, or varying the voltage)?...


No, according to my tests on the Witschi, the thermocompensation technology of the modern high-accuracy Citizen quartz movements works like this: 
_Continuous inhibition (digital count suppression) combined with the continuous adjustment of the frequency of the quartz oscillator(!) - based on the temperature information received by the built-in thermistor_.
In other words, that scheme uses inhibition and frequency adjustment as well.


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## ppaulusz

South Pender said:


> ...The ETA thermoline movements, on the other hand, use similar thermistor-obtained information to change the signal to the stepper motor as to the count it should consider before advancing the seconds hand by one second--the digital-count adjustment method. It would seem, on the surface anyway, that this method would lead more directly to external adjustment via a digital calibration terminal than would Citizen's method...


No, because Citizen too uses digital count adjustment (inhibition) as part of its thermocompensation scheme.
In other words, Citizen too could have included digital calibration terminals on its movements.
Actually, there is at least one movement (ETA's first perpetual calendar movement that was introduced in the 1992 model Longines Conquest Perpetual Calendar watch) that has no thermocompensation but does have digital calibration terminal that allows adjustments in steps of 0.66 s/month (or 8 s/year).
Conclusion: digital calibration and thermocompensation are two different things - one can exists without the other. When both are included then we have a winner, in my opinion.


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## ppaulusz

South Pender said:


> ...This leaves me with two questions:
> 
> (a) Would it be possible for Citizen to incorporate an external adjustment component given the way the thermocompensation is accomplished--i.e., an external adjustment that would directly affect the frequency of the oscillator?
> 
> (b) Do we know how Seiko accomplish their thermocompensation with their TC modules, particularly the 9FXX series with the digital calibration capability? Does the latter capability pretty much point to the digital-count method, or could Seiko too make the adjustment directly to the quartz crystal?


a) See my earlier posts.

b) I have not been testing any Seiko 9F on my Witschi so far so I only can speculate here: I'm pretty sure that the Seiko 9F movements use Citizen-like thermocompensation scheme that includes inhibition and frequency adjustment as well. Seiko was wise/smart enough to include the digital calibration terminal as well - therefore we are offered the full package - as far as accuracy concerned - compared to Citizen's offerings.


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## Catalin

ppaulusz said:


> a) See my earlier posts.
> 
> b) I have not been testing any Seiko 9F on my Witschi so far so I only can speculate here: I'm pretty sure that the Seiko 9F movements use Citizen-like thermocompensation scheme that includes inhibition and frequency adjustment as well. Seiko was wise/smart enough to include the digital calibration terminal as well - therefore we are offered the full package - as far as accuracy concerned - compared to Citizen's offerings.


My own guess would be that Seiko 9F (and some 8J) most likely use a TC approach closer to the ETA variant (but maybe without running the quartz so 'high' and instead with a better 'compensation table').


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## Catalin

South Pender said:


> ...
> (a) Would it be possible for Citizen to incorporate an external adjustment component given the way the thermocompensation is accomplished--i.e., an external adjustment that would directly affect the frequency of the oscillator?
> ...


I believe that could be perfectly 'doable' (at the inhibition level) but so far Citizen is not very interested in that :-(

What I find FAR more interesting is that IMHO the Citizen approach is the only one where the TC part (here including the actual quartz) might be a 'plug-in module' - which Citizen could very easily add to almost any modern caliber (without changing the rest of the electronics of that caliber) - for instance to the radio models now being 'the rage' in the Exceed line :think:


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## South Pender

Many thanks, ppaulusz and Catalin. Just when you think you get it...there's more....!:-d


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## ppaulusz

Catalin said:


> ... I still wonder what is known about 0350 ...


Hi Gents, I'm sorry to bother you with the revisiting of this 6 years old post/topic but the time finally has arrived to conclude it and answer the only remaining question about the The Citizen: Does the first generation The Citizen (marketed between 1995-1997) with the Cal.0350 feature perpetual calendar? (Now, you might want to re-read this thread to update yourself on the subject and better understand what follows.)
The short answer: No, it does not feature perpetual calendar!!!

There is a (much) longer answer as well so if you're interested here are the details:
First of all, in the official Citizen site (it's in Japanese) it is incorrectly claimed that the first generation The Citizen (Cal.0350) is fitted with a perpetual calendar and time-zone setting function: http://citizen.jp/discovery/model/1990lt/the_citizen_men.html
However, in the following link we can see the quick instruction guide of the Cal.0350 that shows a non-perpetual calendar: http://citizen.jp/cs/guide-pdf/0350.pdf
Well the two info (both from the official Citizen site!) contradict each other and there is not much info elsewhere so I ended up purchasing a watch (again, in the name of science) just to solve this mystery. The watch I've just got delivered is a limited edition Citizen Exceed (released in October of 1997 for the 20[SUP]th[/SUP] Anniversary of the Exceed line of watches and only 1977 pieces were made for the occasion - 1977 indicating the year of the introduction of the Exceed-line) that featured the high-accuracy (±5 sec./year) Cal.0350 movement, the very same movement that was fitted in the first generation of The Citizen watches! Here is the link to this Exceed: http://citizen.jp/discovery/model/1990lt/eba74-1061.html (while the link is right, it references the eba74-1061 model wrongly as that one is a different model!)

Now, I can testify that this movement (Cal.0350) is not fitted with a perpetual calendar, no time-zone function either and of course no digital calibration terminal can be detected but it is very accurate! According to my Rubidium-based watch timer, it runs +0.03 sec/day - measured at room temperature of 23.4 degree of Celsius - so there is a very high probability that it would perform within ±5 sec./year if worn for at least 12 hours/day&#8230; Not bad! I'm impressed! By the way that movement looks identical to the other movements in the Citizen Cal. 03*0 family (0310 and 0330) in a similar way as all the Citizen Cal.A6*0 movements look identical (A660 and A610 and A690 and A670).

Honestly, I bought this rare limited edition watch in the name of science (learning the mystery of the original The Citizen movement then sell the watch) but now I might just keep it!

I included some photo of the watch and the movement at the end of this post.

Thanks for reading and have a nice day!

(Note: This was just a one-off post by me - admittedly long overdue - after so many years to conclude an old thread that was started by me about the history of the The Citizen. I'm glad that finally it is complete and useful as reference.)


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## ronalddheld

Good to see you posting.. I presume from your post that you would want this thread closed and archived?


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## ppaulusz

ronalddheld said:


> Good to see you posting.. I presume from your post that you would want this thread closed and archived?


Thanks, Ron! Yes, I think that would be the best: this thread now can be closed and archived!

Take care! Cheers!


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## jvspin

Just received a 1998 The Citizen with the A610 movement.

I can confirm that the perpetual calendar on the A610 is set exactly the same as the A660. The tool used to remove a link pin worked fine for pressing against the same place the button on the A660 pushes.

One thing that doesn't show up in photos is that the sapphire crystal on the 1998 model is slightly curved.

Below are a couple of photos. One on my 7" wrist.














First time buying a watch from yahoo auctions in Japan. Used the zenmarket proxy service and must say it was dangerously easy .


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