Citizen 8203A

 
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Citizen 8203A

Description

1977 Citizen launched their most successful series of 11 12 ligne movements, the caliber series 8200. The maximum version with selfwinding mechanism, day and weekday display was the caliber Citizen 8203A. It was later replaced by the virtually identical Miyota 8205.

base plate

base plate

The base plate already shows, that this movement is build to last: Each and every bearing, with the exception of the mainspring barrel, has got a bearing ruby, and there are no cap jewels, except of the balance bearing.

gear train

gear train

The whole gear train, including the selfwindig and the click mechanism is housed below one large bridge. Only the minute wheel has got an own bridge, since there’s the indirectly center second train going through it.

side view of the gear train

side view of the gear train

Of course, this amount of wheels under one single bridge is not very much service friendly, but it practially isn’t that hard to get all the gears in place.

The click mechanism is  widely distributed unter the bridge, left, at 10 o’clock, there’s the sliding exchange wheel, which is located in an ellipse shaped bearing and can slip in the non-winding direction. This allows the removal of the breguet  coupling in the yoke winding mechanism.

engaged change wheel

engaged change wheel

The pawl is more a part of the selfwindig mechanism, since it’s located there, on the right side, and impinges the last reduction wheel of the selfwinding mechanism. In connection with the following clutch, which only transports power in one direction, it is responsible, that the oscillating weight only winds in one direction, which is spins freely in the other one.

detail: pawl

detail: pawl

The ball beared oscillating weight of the caliber 8203A is different from the otherwise almost identical caliber 8205A only in the fact, that the oscillating weight consists of two, riveted parts. And although, you can read “8200A” on it, it is the caliber 8203A, on which the hairspring stud is differently shaped.

Citizen 8203A without oscillating weight and escapement

Citizen 8203A without oscillating weight and escapement

On this movement, the dial is secured by two screws on the side, which don’t fix the dial feet orthogonally, but fix them sideways:

detail: dial foot and securing screw

detail: dial foot and securing screw

As long as the dial side is empty, you can spot the three-stage yoke winding system, of which the setting lever spring is a true spring and not fixed by a setting lever screw.

In the second position of the crown, you can correct day and weekday.

yet empty dial side

yet empty dial side

The date mechanism is, although the date only changes slowly, rather complex and contains plastic parts.

The plastic wheel at 9 o’clock advances the date ring once a day and drives the wheel at 10 o’clock which advances the weekday disc by two positions (equals one day).

visible date mechanism

visible date mechanism

An important detail is the kangaraoo-shaped spring at 3 o’clock, which is the fast correcting mechanism for day and weekday. In the second crown position, it is either moved to the top or to the bottom and with its levers, advances either the weekday one(!) position or the plastic date wheel one position.

closed date mechanism

closed date mechanism

When the deck plate of the date mechanism is mounted, the whole construction looks more robust.

Citizen 8203A dial side

Citizen 8203A dial side

The weekday disc, with red sunday, is secured with a snap ring on the hour cannon pinion.

In the lab

On the specimen shown here, the friction of the cannon pinion was too low and had to be corrected. There was also a full service made, but unfortunately, the gunked mainspring still sticks together, so that the rates are terrible and later re-servicing is required.

Because of that, there are no timegrapher measurings.

Technical data

Manufacturer:Citizen
Caliber:8203A
Number of jewels:21
Escapement:Pallet lever
Balance types: Glucydur anular balance
Shock protection(s): Parashock 1 (Citizen)
Balance bearing / direction hairspring:Clockwise
Moveable stud:yes
Adjust mechanism:Hairspring key
Construction type:solid construction
Winding mechanism:yoke winding system
Setting lever spring:3 hole(s)
Functions:hour, minute, second, day, week day, selfwinding
A/h:21600
Size:11 1/2''' (measured: 25,6mm)
Production period:1977-

Usage gallery

Citizen mens' watch Modell GN-4W-S

Citizen mens' watch Modell GN-4W-S