Seiko 7A38 - by the numbers

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Forum Home > Non-Seiko General Discussion Area - Contemporary Chrono's > ETA Cal. 251.252/262/272 - the SWISS answer to the 7Axx

Seiko7A38
Site Owner
Posts: 8892

I've mentioned this swiss quartz chronograph calibre a couple of times recently in the Citizen Cal. 35xx thread ....

So now's probably as good a time to start a separate topic on it. In the early 1990's, quartz was very much in vogue ....

The Swiss obviously needed to fight back against Seiko's take-over of the lower end of the lucrative chronograph market.

Their answer to Seiko's 7Axx family of 15J movements came in the form of ETA's Cal 251.252 / 262 / 272  27J and 22J calibers.



Full documentation - Parts Lists and Technical Manuals (in .pdf format) for the ETA Cal. 251.2x2 can be found on Cousins UK website:

http://www.cousinsuk.com/search-results?searchtext=251.252




Warning: these files are not exactly small and clicking on the individual links automatically starts a download.


Whereas their equi-distant sub-dial (and optional date) layout is very similar to the Citizen 35xx calibers, those had multiple pushers (and crowns); the actuator layout on watches using these ETA 251.2x2 calibers is simpler and more conventional, with two pusher buttons above and below the crown on the right hand side.


May 31, 2013 at 7:50 AM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 8892

My first sighting of a watch using one of these calibers was an early 1990's Tissot PR100 belonging to a work colleage, 3 years ago. 

Like myself, he used to replace his own batteries, and we joked about each others' watch's jewel content - 'only' 15J versus his 22J.


His was a stainless white-faced version like this (photo saved from an eBay auction listing in August 2010, which I bid on, but lost):



I think what I liked most about the dial layout was the 'correctly aligned' date window at 4 o'clock, which is due to the day wheel lettering being printed 'askew'. Most other watches you'll see using the same ETA Cal. 251.272 movement have an angled day window @ 4:30.


The original Tissot PR100 design came in a number of different dial colours: including black and blue and also in two-tone finishes.




Probably the one that almost caught my fancy was this 'Panda' which was listed on eBay in October 2010:



If you recognise the dingy style of photos, then you'll probably know which watch-botching Filipino eBay seller was offering it - and why I resisted the temptation. Sadly I've never seen another one like it with that 'Panda' dial. Probably the most common variant is the two-tone white-faced version. I've seen loads of these on eBay over the years. This decent-looking example was on eBay in July 2012:



I've even had a PR100 on my eBay watching page within the last week or so, but accidentally deleted it, making room for other stuff. :(

Found it again. It was this stainless / black dial in Germany. I'd actually bid it to 45 Euros, then either gave up or totally forgot about it.

http://www.ebay.co.uk/itm/Tissot-PR-100-Chronograph-/171041536872 .... It sold for 83 Euros.

May 31, 2013 at 11:09 AM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 8892

What re-kindled my interest in the ETA 251.2x2 movements - and unintentionally gave quite a few folks a good chuckle  into the bargain was Kevkojak's recent 'The TAG in a bag....' thread on RLT: http://www.thewatchforum.co.uk/index.php?showtopic=83479




Whereas that watch and its movement may now be well beyond economic redemption, the quality of the components is clearly evident.

If you zoom in on the backplate of the Cal. 251.262, you'll see it's stamped TAG Heuer. ETA are a movement supplier to other watch manufacturers. Like Citizen / Miyota, where the OEM requires it - and pays a premium, the movement will be re-branded accordingly.


Here's a super-detailed blog article on the complete strip and re-build of a similarly re-branded Cal. 251.262 in a Breitling Colt chrono':

http://raulhorology.com/tag/eta-251-262/




Well worth a read, or even just to scan through the photos ....



But before you boldly go where KevKojak's mate did (after a couple of beers ), I suggest you read the paragraph which states:


The trickiest part of the whole process was fitting the train wheel bridge, there are 7 wheel pivots to locate into jewel holes and also 3 rotors to locate into jewel holes. After several unsuccessful attempts to locate everything myself, I was helped out by one of the tutors. The size of the wheels and their close proximity to each other makes the task hard but the magnetic rotors make things even harder as they are prone to moving. Considering this is one of the more complex quartz movements and one of the trickiest to work on ....

May 31, 2013 at 11:51 AM Flag Quote & Reply

Sir Alan
Member
Posts: 451

That makes me feel a little better over my so far unsuccesful attempts to get the main bridge back on my 7A38.

I'm not easily beaten but I have learnt patience ............


May 31, 2013 at 3:05 PM Flag Quote & Reply

Konkordski
Member
Posts: 41

I saw this thread I thought hang on, they look very similar to my Swatch AquaChrono's... Sure enough, looking through the transparent case it's basically the same 22 jewel movement, at least in less dressed-up form with plain steel parts. With an eye-piece you can just about read the calibre of 251.282 in the same location. These offer timing to the second up to 12 hours.

Below is the first design I got in 1995 and wore almost exclusively for 8/9 years. I then got four more NOS/mint models off eBay in 2004/5. I'm far from a collector though as 90% of designs are far too jazzy and childish!

 

 

Sorry this is the best movement picture I can find online:



The plot thickens when I looked at my single late 90s model, it has a totally different 4 jewel ETA movement offering date and 1/10 sec timing but only up to 60 mins. The movement is shrouded in plastic and the click of the buttons is nasty in comparison. They seem to switch to this cheaper movement in 96/97 and use it to this day.

 

 

Regardless of the movement they all keep time as well as my 7A28, roughly a half-second fast per day.  These AquaChrono's are a bit chunky to wear with a shirt but the "metrosexual" stretchy bracelets are so comfortable :)  The small chrono hands can get stuck when not used for a few years but can be revived by holding down the button in alignment mode.  Movement of the hands (e.g. when resetting) is actually a lot quicker and crisper than Seiko. ;)

 

Swatch seems to be making fairly classy designs these days but far less distinctive and few are tempting enough for me to part with £100+ for one.


June 28, 2013 at 7:04 AM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 8892

Regardless of the movement they all keep time as well as my 7A28, roughly a half-second fast per day.


You could always tune that 7A28 to be more accurate, using the rotary step switch (increments of 0.26 secs / day). ;)

See: http://www.seiko7a38.com/apps/forums/topics/show/7777735-7a28-7a38-7a48-accuracy-rate-adjustment

June 28, 2013 at 8:50 AM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 8892

I haven't done any more research into them, but perhaps these ETA 251.262 movements are smarter than your average Seiko 7Axx. 

I was browsing TZ-UK yesterday and came across a thread where the OP was considering buying a 7A38. He's since joined the forum.

See: http://forum.tz-uk.com/showthread.php?277472

In his second paragraph he wrote:


.... the fantastic ETA 251.262 quartz chrono (another legendary milestone movement in my book) - proof in the pudding of how handy this movement is this morning, clocks went forward, pull out the crown one click, little twist and hey presto watch set for another 6 months.


So does this mean they have an in-built perpetual calender ? :/

October 7, 2013 at 5:31 AM Flag Quote & Reply

nickyboyo
Member
Posts: 7

Good day Paul,


Thank you very much for the welcome. Great site to you have here, some lovely watches on display.

As for the ETA, no there is no perpetual calendar, and as far as i am aware there is no quick set date. You do have a quick set hour, great for moving through time zones, and quite a quick way of changing the date when required.

I do like the ETA's central minute register and 12 hour timing ability. It certainly is a fine movement, but there is just something special about the 7A series.


Now to find myself a 7A38....

October 7, 2013 at 2:57 PM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 8892

O.K., thanks for clearing that up, Nick. ;)

It was your phrase: "hey presto watch set for another 6 months" that confused me. :/

I read that as your not needing to advance the date manually at the end of 28 day or 30 day months. :roll:

October 7, 2013 at 3:07 PM Flag Quote & Reply

Konkordski
Member
Posts: 41

Pulling the crown out one notch and turning moves just the hour hand in 1hr steps, so when daylight-saving time begins/ends you can jump forward/back 1hr while the watch is still running.  The downside is this is the main way of advancing the date :/


With my eagle eye I recently got hold of a 251.262 very cheaply but it has clearly been exposed to air/moisture for years thanks to a broken case-back, but despite the bent stem and rust-spotted backplate it fired up and runs 100%.  I think of these as an AK47 to Seiko's M16 ;)


EDIT: Was too slow writing my reply :)

October 7, 2013 at 3:09 PM Flag Quote & Reply

Seiko7A38
Site Owner
Posts: 8892

Just having a quick browse on eBay Italy, searching on Pryngeps Cronografo, to see if I could see any more 7Axx lookalikes, like these

..... and spotted this quite attractive, if a little over-ornate in typical Italian fashion, NOS Pryngeps chronograph powered by a 251.262:


http://www.ebay.it/itm/330861794481

Pryngeps cronografo mov. ETA 251262 nuovo inusato


January 18, 2014 at 8:39 AM Flag Quote & Reply

PHK
Member
Posts: 222

Here's my contribution; eta caliber 251-262 Hamilton LL Bean Chronograph.


February 20, 2014 at 7:01 PM Flag Quote & Reply

PHK
Member
Posts: 222

And here is the rest of the post:

I've been waiting for years to find one. Missed out in 1990-1991 when they were in the LL Bean catalog for about $399.

 

Finally found one on eBay last week. So far I love it. Date at 6 o'clock, 1/10 sec, a minute hand counter and 12 hour timing.

 

The only problem is that I can't find the product number for it. H-xxxxxxxx ? I'm buffing the slightly domed crystal slowly with Brasso.

 

Paul in LV 8)

(I must type too slow)


February 20, 2014 at 7:22 PM Flag Quote & Reply

mrwozza70
Member
Posts: 13

Just received a Precista PRS-17c with the 251.252 calibre. I'll enjoy the manual for this I think!


May 14, 2014 at 12:04 PM Flag Quote & Reply

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