1977 Citizen launched their most successful series of 11 1⁄2 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.
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.
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.
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.
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.
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.
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:
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.
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).
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.
When the deck plate of the date mechanism is mounted, the whole construction looks more robust.
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.
|Number of jewels:||21|
Glucydur anular balance|
Parashock 1 (Citizen)|
|Balance bearing / direction hairspring:||Clockwise|
|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|
|Size:||11 1/2''' (measured: 25,6mm)|