Seiko 7A38 - by the numbers

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Forum Home > In the beginning there was Seiko Quartz - the World's First .... > Seiko 0800 Series Quartz (Daini)

selfdater
Member
Posts: 59

The (Daini) 0800 series was first seen in the 1975 JDM catalogues alongside the 0900 and 4800 series (both from Suwa). This is Daini's first quartz movement after the exotic (and expensive) 3922/3923 so is really the start of mainstream Daini quartz. However, it's still a high-end machine and (along with the 4800) marks the appearance of the "King Quartz" branding. 


As usual, there are a few flavours:

Calibre             Accuracy    Branding
0822, 0823             15s/m        QT
0841, 0842, 0843       15s/m        QZ but not marked on the dial (I think). Also seen in "3003" models.
0852, 0853             10s/m        King Quartz 


Calibers ending in "1" are time only, "2" have date and "3" have day/date. Unlike the 4800 series (Suwa), there are no "Grand Quartz" models. 


Poring over the catalogues leads to general confusion about the relative levels of the brandings (QT, QZ, QR, King, Grand etc). For example from the 1975H2 catalogue we can see the following (similar) examples: 

Model       Branding     Price (Yen)
3803-7110     QT             82000
4843-7000     Grand Quartz   80000
4823-8010     King Quartz    58000
0853-8020     King Quartz    57000
0823-8000     QT             50000 


So a "QT" (if it's a 3803) can cost more than even a Grand Quartz. On the other hand an 0823 "QT" moves towards affordable territory. 


My lonely 0800 series watch is a 0852-8020 King Quartz from 1975. Nice batons :).


May 14, 2016 at 1:16 PM Flag Quote & Reply

donwatch
Member
Posts: 568

Seiko 0843-8041 with original band--Keeping almost perfect time  ( a few seconds in months )   This is a Daini from November 1975  :D      

May 15, 2016 at 1:10 PM Flag Quote & Reply

donwatch
Member
Posts: 568

Seiko 0843-8079   "3003" SQ   May 1975  / Daini Factory   Grand Quartz quality mvt.  8)     

December 31, 2016 at 3:31 PM Flag Quote & Reply

donwatch
Member
Posts: 568

Another 0843 !  Found on Ebay for $30.00 missing stem and crown.  I have a parts watch :P or two.   I installed the stem and new battery and it lives :D   Now I need to take it back apart and shorten the stem so that the crown rests closer to the case :|   I nice high end Seiko from the mid-1970's   

January 8, 2017 at 2:54 PM Flag Quote & Reply

ReggieH
Member
Posts: 13

Hi, All--I've wondered about the place of the 084x movement in the scheme of things myself. The 1975 Seiko catalog, vol. 2, pp. 9-10, 28-32 seems to show all three 08xx-series movements, though not together. I think 0843 _replaces_ 0823 because:--

      1. In a cursory eBay search, I didn't see an 0823 later than early 1975, nor an 0843 earlier than mid-1975.

      2. The tech sheet I have for 0843 claims a +-10 s/m accuracy--better than the 0823. And the 0843 has a trimmer condenser                that the 0823 seems to lack.

      3. A Seiko Quartz Power Consumption & Battery Guide indicates that the 0843 draws only about half the current of the 0823--           an improvement in battery life, I suppose.

I'll try to attach a not-very-good photo of my 1976 0843 on original bracelet.

Best, ReggieH

June 28, 2017 at 1:39 PM Flag Quote & Reply

selfdater
Member
Posts: 59

Your post seems to be well observed ReggieH. I tend to agree that the 082x was first and that the 084x and 085x represented subsequent improvements - the improvement in power consumption is fairly significant.


If this is right - and if 10s/m is right for the 084x - I wonder what is the difference between 084x and 085x?


July 2, 2017 at 6:39 AM Flag Quote & Reply

ReggieH
Member
Posts: 13

Hi, selfdater--Good question! I hadn't thought of that. There are differences in the circuit boards visible on Akiyose. The circuitry seems to obscure the movements. I haven't found much technical literature. The Seiko Battery Guide claims a 1-year life for the 0843 and a 2-year life for the 0853...some refinement in the step-motor operation? (I saw a post by the knowledgable Archer a while back on WUS on quartz operation, but now I can't find it.) Prices in the catalog I mentioned above don't really seem to clearly establish brand levels of quality.

I regret to think that the history of quartz may be slipping away from us in our own lifetimes.

Best, ReggieH

July 10, 2017 at 1:00 PM Flag Quote & Reply

selfdater
Member
Posts: 59

Any fans of this one? It's a JDM 0842-5010 from 1976 in brown with Roman numerals. The case and bracelet have an interesting finish and it has a matching "Hammerite" dial.



August 28, 2017 at 8:03 AM Flag Quote & Reply

John_D
Member
Posts: 5

Hi, I'm a bit late to this discussion but I have a King Quartz 0852-8000 that has sudenly decided to stop working. I've stripped it down, removed the circuit and checked the coil, which seems to be correct with a resistance of around 4K ohms. There is no obvious physical damage to the circuit board but appears to be just not running. I have a Seiko QT-99 quartztester and it shows no impulse activity, though if I use my demag unit on the watch I can spin up the hands which confirms that the 'motor' and coil are functioning correctly.  I cannot find a technical manual for the 0852/3, to get a part number for the circuit block, only the 0843 one which initially I thought was the same (pt.no. 4001-025)


but there appears to be an extra complexity on the 0852 one with two small adjustable fingers that go either side of a fine wire that is attached to the watch chassis...


Has anyone on here got any more information on this, especially the part number of the 0852/3 circuit block, and what do the adjustable fingers do?

April 12, 2020 at 5:50 PM Flag Quote & Reply

Rob A
Member
Posts: 1

John_D at April 12, 2020 at 5:50 PM

Hi, I'm a bit late to this discussion but I have a King Quartz 0852-8000 that has sudenly decided to stop working. I've stripped it down, removed the circuit and checked the coil, which seems to be correct with a resistance of around 4K ohms. There is no obvious physical damage to the circuit board but appears to be just not running. I have a Seiko QT-99 quartztester and it shows no impulse activity, though if I use my demag unit on the watch I can spin up the hands which confirms that the 'motor' and coil are functioning correctly.  I cannot find a technical manual for the 0852/3, to get a part number for the circuit block, only the 0843 one which initially I thought was the same (pt.no. 4001-025)


but there appears to be an extra complexity on the 0852 one with two small adjustable fingers that go either side of a fine wire that is attached to the watch chassis...


Has anyone on here got any more information on this, especially the part number of the 0852/3 circuit block, and what do the adjustable fingers do?

Part number for 0852 circuit board is 4001-032, unsure if 0853 is the same. The fingers are for the second hand quick adjust, for when the watch is running a little bit behind or ahead. Turn crown one way and second hand stops for a couple of seconds. Turn the other way it advances a couple.
October 3, 2020 at 5:49 AM Flag Quote & Reply

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