This watchs history: Ok, I admit, I have a weak spot for japanese watches. I have a Seiko 5 and a Citizen eco-dive World Timer in my collection, and lately I started to gain interest in vintage chronographs.What vintage chronograph should I get? I've chased some Zenith El Primero's (automatic chronograph), Omega Speedmasters, Vintage Angelus Chronodato's,Sinn 903's (the one with the Lemania inside) and Heuer Carrera's the latter four all handwinded chronographs. Major downer was the price-tag of all these (Swiss Made) watches.
On the Seiko&Citizen forum I learned about the Seiko chronographs 6139 and 6138. I liked them a lot. They came in many many dial and case variations. And the prices were much friendlier than their Swiss counterparts. On an auction site I spotted a model I was particular interested in. It featured a slide rule bezel, as was on the Sinn 903 and on the Breitling Navitimers. On a last second bid I was highest and got it at a fair price. The watch seemed in perfect condition, still had the box and warranty card, and it even came with a 6 months warranty from the seller.
The watch still has it's original Seiko "Certificate of origin and guarantee." This little 18 pages booklet shows some nice pictures taken on the production floor of what must have been a Seiko factory. The watch was bought in Tehran, Iran. It also came in an old Seiko watch presentation box, but this one could not be the original box, for the box does not close fully with the watch in it.
Brand and Reference:
Seiko in europe is synonymous for mass produced quartz watches. Most of the companies marketing effort in Europe is for their high tech kinetic watches. Their automatic watches are difficult to get. I think that's a pity, for in early days and now Seiko manufactures fantastic mechanical movements.
The 6138 was one of these fantastic movements.
Before getting into detail on the 1638 movement, lets have a closer look on the year 1969, a very important year for the watch industry, especially in relation to the chronograph watches.
Automatic wristwatches were already well-known before 1969, but strangely enough there was still no mass produced automatic chronograph movement on the market. Sure, Lemania did make a small serie of automatic chronographic movements back in 1947, but they were never serie-produced, and never were for sale to the public. In the same year Omegas Speedmaster made history for being the first watch (and chronograph) on the moon, but it was not an automatic movement.
The very first chronograph was born in the year 1862. The first chronograph in wrist-watch format was available around 1910, and the world had to wait for another 60 years before the first automatic chronographs. The automatic chronograph is still regarded as one of the last great achievements of mechanical horology.
No less than three automatic movements were released in 1969 for the public.
First there was the Cal.11 , made by a consortium of Buren, Heuer, Breitling, Hamilton and |Dubois Depraz. The Cal.11 was first shown at the Basel fair in march 69. The Cal. 11 was a automatic movement with a micro-rotor and with the chronograph module placed on top of it.
Almost exactly at the same time Zenith/Movado came with the (still present, though revised a few times) famous El Primero. Zenith claims that the Primero is the first integrated automatic chronograph movement.
And then there was a contender from the other side of the world who also introduced an automatic chronograph movement in 69. The Seiko 6139. The 6139 was a 1 register chrono, with a 30 minute totalisor, it was patended early 69.
Its successor the 6138 came out a year later in 1970. While the Cal.11 and the El Primero were revised a few times, the 6138 remained unchanged untill 1979, it last year of production. The Caliber 11 was replaced by the Cal.12 three years later.
So, while the watch industry gaining momentum, the automatic chronograph movement was considered the peak of what was technically possible, it was even more tragical that also in 1969 a new phenomeon was on the brink of a breakthrough that re-shuffled the watch industry completely: The Quartz-watch. Seiko, of all manufacturers, was first to introduce the quartz.. So timing was bad for the introduction of the automatic chronos. However technical astonishing, they were soon out-performed both in accuracy and price by the quartz models. We all know what happened. Many traditional companies didnt survive the quarz revolution. Only those who did ride along with the quartz-mania did survive.
The 6138 was the successor of the 6139 automatic chronograph movement. The 6138 was technical at least equal to his Swiss counterparts. There were two versions of the 6138: The 6138A introduced in 1970 had 21 jewels, and the 6138B introduced in the same year with 23 jewels.
Both got a column wheel that regulates the chrono functions, and a vertical clutch mechanism for the engagement. Its measures are a diameter of 27,4mm and a height of 7,9mm. The "speed" is 21.600 a/H.
The 1638 is a 2 register chrono. One counting up to 30 minutes, the other counting up to 12 hours. The chrono second-hand measures up to 1/5th of a second.
It further features a quick-set!! dual !! day/date indicator. Another goodie is that the movement can be handwound, something that I really miss on most other Seiko automatic movements.
Something that is lacking, and something that I had to get used to, is the fact that there is no moving second-hand indicating normal time. The only second-hand is that of the chrono. So with the chrono functions disabled there is nothing moving on the dial .
A common symptom for these watches is that the 12 hour register hand keeps on moving, even without the chrono function engaged. That is because normally there is a brake mechanism that prevents the 12 hour counter from moving, but because of neglected maintenance, or over oiling this brake does not work properly, and the 12 hour counter starts moving even in normal mode. This watch does not have this malfunction.
The Case: This one fits perfect in todays Big Bigger Biggest fad. The 6138 was put in large cases. The diameter op the dial itself is 30mm, including the slide rule bezel the diameter increases to 42mm, and including the case the diameter is a proud 48mm.
Besides the "normal" configuration, with crown and chrono-pushers at 3 oclock, there were also 6138-versions that have the crown and pushers at the 12 oclock position. The so-called " Bull-Heads". There are also models with a smaller 12 hour counter and a larger 30 minute counter.
This particular model has got the more traditional 3 oclock configuration, It features something else what makes the model 7000 one of the most sought after in the Seiko 6138 series: The Slide Rule Bezel.
The Slide Rule Bezel:
The 7000 features the slide rule bezel, made famous by Breitling on their Navitimer series. With the circular slide rule calculations can be made. On a Breiltling watch the following functions can be calculated:
Multiplying two numbers
Dividing two numbers
Converting miles into kilometers or nautical miles
Rate of descent calculation
I still have to figure out what calculations can be made on the 6138-7000 model's slide rule. The lay-out of the figures and marks on the slide rule are different compared to a Breitling.If you are interested in slide rule watches I can recommend this site. If you're looking for a manual on a Breitling style slide-rule check this site
The Back:On the back the serial number can be found. This watchs serial number is 461234 The production date can be retrieved from the serial number. The first digit tells the year (after 1970) of production. The second digit the month. So this particular watch was produced in june 1974 The Bracelet:
This watch came with an all original Seiko ss bracelet. It's got a signed ss clasp. The bracelet was a bit tight when I received it. I contacted the seller, he had some spare parts left, and was kindly enough to send them to me. Now the bracelet fits perfect. Nothing beats an all original bracelet on vintage watches. The bracelet is in top-condition.
The Dial: A wonderful dial in matte black combined with large hour markers and the white hour/minute sticks gives this watch an european look and feel. All chrono hands are in red. The word SEIKO is applied on the dial.
The crystal is acrylic.
Functions:Hour, minute, NO small or sweeping seconds. Day indicator in two languages: Arabic and English. The sunday in english is in the colour red, other days are white. In Arabic the friday is in red.
Date indicator.Chrono functions: central 60 seconds hand, measuring up to 1/5th of a second. 30 minute counter, and a 12 hours counter. Slide rule bezel to perform several calculations.
Conclusion:Seikos 6138 chronos are still relatively easy to get. You'll be amazed at the variety of designs/dial colours they were made. Some models are very rare, including this 7000 model, featuring the slide rule bezel. The fact that this watch still has got it's original bracelet (in excellent condition) is a big bonus, as is the original warranty booklet that came with the watch.
You really cant go wrong with one of these. You get one of the worlds first automatic intergrated chronograph movements, featuring a column wheel, quick-set dual language day/date, at a fraction of the price of a comparable Swiss automatic chrono. Like all watches of this age, parts are more difficult to get as years go by. If you have one, check it regulary. Youll have a fantastic watch for many many years to come.
Unless stated differently, All of the pictures are of the actual watch, and the pictures are taken by myself, (I'm not a great photographer)
If you have any questions or remarks, feel free to e-mail me.This watch is
I have more watches for sale, to see the actual inventory of my watches for sale, see my little web-shop Horlogerie Nivelacuso at http://shop.kapaza.nl/nivelacuso/