The Seiko 6139 and 6138 series - the Japanese Domestic Market (JDM)-only 1971 Seiko 6138-8000 "Baby Panda," with the less seen steel-grey dial, here counts itself among the latter - were the first fully integrated automatic chronograph in the world featuring column wheel and vertical coupling mechanism. A feature of these sporty 6138-8000’s is their unique "panda" dials, hence the moniker.
With the 6138 movement, Seiko - as usual - set the standard followed by the Swiss watch industry 20 years later. The same movement configuration was adopted by Rolex when it made its own in-house movement for the Daytona in 2000, 30 years after Seiko released its 6139 and 6138 calibres. Oddly, the 6138 was the successor of the 6139 automatic chronograph movement, and produced in parallel with it until 1979.
The 6138 was technically at least equal to its Swiss counterparts, as it featured a fully integrated chronograph vice stacked modules. There were two versions of the 6138, with the first, the 6138A, introduced in 1970 with 21 jewels. The 6138B – like the one for sale here – was introduced subsequent, and featured 23 jewels. Both had a column wheel that regulated chrono functions, and a vertical clutch mechanism for engagement.
The 6138A/B was a two register chronograph, counting up to 30 minutes on one subdial and another 12 hours on the second dial. All 6138 movements feature a quick-set day/date indicator and can be handwound (unlike the 6139 model), relatively unique for Seiko chronographs of this era.
This 6138 Baby Panda comes with leather rally strap, grey nylon strap, Pelican travel case, and springbar tool.
JDM 1971 Seiko 6138-8000 "Baby Panda" Automatic Chronograph
DIAL: Steel-grey Seiko-signed dial, with matching hour, minute, and chronograph hands; light patina on subdials. Day and date function - with Kanji Japanese/English numeral day variants - at the 3 o'clock position works as designed.
CASE: Stainless-steel case measures 40mm (w/o crown, 42mm with) x 43.5mm; matching caseback. Case lines are as they should be, with no evidence of machine polish
CRYSTAL: Slightly-domed Seiko 6138 crystal, no scratches or cracks.
BAND: This Baby Panda comes on a brown leather rally strap; it also comes with a grey nylon strap.
MOVEMENT: 6128B Seiko 21-jewel automatic movement, manufactured in October 1971, which beats at 21,600 beats per hour.
CROWN: Unsigned correct stainless-steel crown.
