Seiko 7A38 - by the numbers

The 5800 series watches from the Daini factory appear in the JDM catalogues from 1977 to 1979. The 5855 (date) and 5856 (day/date) take over the King Quartz branding from the Daini 0852/0853 models. Obviously considered by Seiko to be high quality movements, they are pitched at slightly higher prices than the KQ models from Suwa (4822/4823 calibre).

Whereas the 4800 series feels (and looks) like an evolution of the early quartz movements (eg 3800 series), the 5800 seems like a new generation. The thinner movement allows slimmer case designs and the bracelets are slicker (flimsy?) and blingier. These are the last KQ level movements to be introduced before the development of the Twin Quartz movements of the late 1970s.

There is also a lesser-spotted 5854 calibre (time only) which does not appear in the JDM catalogues and does not seem to receive KQ branding. Speculation: export models only. All 3 calibres have a stated accuracy of 10s/month.

First up is a 5856-8030 from 1978:

...and a 5856-8090, also from 1978:

There is an unusual feature with these movements: when the crown is in, it can be turned to adjust the seconds. Turning anticlockwise makes the second jump an extra second and turning clockwise delays by one second.

A Seiko King Quartz   5856-8000  (JDM)  from June 1977       

Another textured dial on this Seiko King Quartz  (JDM)  5856-8070 from June 1978.     This has a temperary plastic crystal.