Sweephand's Vintage Citizen Watch Blog

A change today from a watch feature to something that’s always been a bit of a mystery – the letter stamped at the end of Citizen’s case numbers. Although not needed as a part number since the case number alone, e.g. 4-123456 provides that, I have never pinned down just what the additional letter indicates. I wrote to Citizen Japan about it – didn’t get a reply! So I’m left to my own theory 🙂

Most vintage Citizens with the above case number format, typically from the late 1960s and on through the 1970s have ‘TA’, ‘K’ or ‘Y’ stamped alongside the case number:

My theory is that these letters are factory codes – relatively recently I got hold of a scanned catalogue from the early 1970s, and that includes a list of factories:

My best guess is that ‘TA’ is the Tanashi or Tama Seimitsu factory, ‘K’ is the Kawaguchiko factory (dials were made there and dial codes often include ‘KA’ too), and ‘Y’ is …… not so obvious! You can see as well the ‘Star’ Seimitsu Company – older watches have ‘STAR’ marked on them since they initially made cases for Citizen, but later produced smaller parts, particularly screws.

There’s a change today from my daily and weekend watch features, since a new video documentary has just been published about Citizen’s testing of their parawater automatics in the 1960s. And I want to leave this post at the top of the home page for a couple of days. You may know that Citizen put their parawater system to the test with a campaign of releasing Jet Automatic watches into the Sea of Japan and the Pacific Ocean, using special buoys to hold them. I was very happy to provide some of my reference material to help in the production of the video, so rather than my usual watch post, I would invite you to take a look at the Italian language video here: https://www.youtube.com/watch?v=keIC983zWzc

I am very impressed with the quality of the film – it’s a shame my Italian is very limited since I would love to follow the narration. It is a very professional piece of work.

I think we’ll have an electric week this week – starting with the last in the line of 7800 calibre Cosmotrons, the Special version. The Special, calibre number 7803, is immediately identifiable by the button at the 8 o’clock position, which enables accurate time setting of the seconds and minutes hands, i.e. it not only zeros the second hand (to 12 o’clock) but also the minute hand when it is within + or – 3 minutes of 12 o’clock. The quality of many of the Cosmotrons is high, and particularly so on the Special variants. This example is from August 1973, and is an all stainless steel model with a ‘tv’ style case. The white dial features smart polished steel markers and hands, highlighted with slender black centres. There is no ‘X8’ on these later models, with ‘electronic’ printed beneath the Citizen mark and an applied Cosmotron logo above the 6 o’clock marker. The second hand is characteristic of the Cosmotrons, with its coffin shaped tail. The solid link bracelet is a familiar design also seen on a number of the 8110A automatic chronograph models. The case and bezel are generally polished, but it has brushed lug ends to match the bracelet: