cobrajet25
Needs a Life!
"Underweared curmudgeon!"
Posts: 3,357
|
Post by cobrajet25 on Sept 5, 2014 5:02:20 GMT -8
Turns out they all have the same part number for the balance assembly. That doesn't mean the balance wheels are the same although I would think a smaller wheel would require a different hairspring which would make a different assembly part number like the 7s26. All have the same casing diameter of 27.0mm(12'''). The 7s26 grew to 29.4mm(13'''). The order in which they were released is a bit confusing. First was the 7005(1969), then the 7006(1970), then 7019(1974), then 7025(1976) and finally the 7009(1980). It would seem that the 7009 was the culmination of the series and the first to have the 3:18 crown position with appropriate day/date wheels. The 7002 was developed separately from this series as it was made to take a 4 o'clock crown and fit in the 6309/7548 casing. I think your dates are off a bit on the 7009 series. I have a 7009, dated May 75'. It's actually my first Seiko before I could scrape up the bucks for a new 6139-6005 which I bought in 76' The 7009 I posted is from '78, and the caliber appears in my '76 Casing Guide. The 7009 was carried well into the 1980s, along with the 6309.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Sept 5, 2014 8:01:19 GMT -8
Turns out they all have the same part number for the balance assembly. That doesn't mean the balance wheels are the same although I would think a smaller wheel would require a different hairspring which would make a different assembly part number like the 7s26. All have the same casing diameter of 27.0mm(12'''). The 7s26 grew to 29.4mm(13'''). The order in which they were released is a bit confusing. First was the 7005(1969), then the 7006(1970), then 7019(1974), then 7025(1976) and finally the 7009(1980). It would seem that the 7009 was the culmination of the series and the first to have the 3:18 crown position with appropriate day/date wheels. The 7002 was developed separately from this series as it was made to take a 4 o'clock crown and fit in the 6309/7548 casing. I think your dates are off a bit on the 7009 series. I have a 7009, dated May 75'. It's actually my first Seiko before I could scrape up the bucks for a new 6139-6005 which I bought in 76' could be; I just used Adriano's chart from his 61xx-70xx blog.
|
|