The GUB 75, the so-called “Spezimatic” movement of the Glashütter Uhrenbetrieben, is one of the most successful and most popular selfwinding movements of german production.
It is constructed with a three-quarter main bridge, which is typical for Glashütte, but difficult to service, since that bridge houses all gears, those of the time system as well as those of the selfwinding system.
The time system is constructed in a quite modern manner, since it already uses an indirectly driven center minute hand and also an in directly driven center second hand. That construction allows more space for a larger balance (here a screwless, three-leg Glucydur balance) and a larger mainspring barrel.
The balance is secured in two inhouse (GUB) shock protection systems and beats slowly with 18000 A/h. The hairspring is fix connected to the balance cock and is regulated in its effective length by a fork-like regulator arm.
With a height of only 5.05mm, this movement is very flat. The mainspring barrel can be removed without disassembling of the movement by removing its axle from the dial side.
The oscillating weight is secured by a spring (which flies very well :-)) on its axle.
The caliber 75 (later called as 06-26) was produced between 1965 and 1980. Together with the caliber 74 (same movement, without date indication), almost 3 million movements were made.
The date mechanism is below a plastic bearing plate. This is an unfortunate solution, since the plastic ages and get loose, as you can see on the photos at the regions of the screws.
A pretty genious solution was made for the quickset mechanism: By turning back the time for three hours, the date wheel slips below the date ring and avoids turning it back. This is possible, since the date wheel can slip a bit down, since it has got a spring below, as you can see on the following picture:
Of course this movement has got a yoke winding system. On the lower left end of the setting lever bridge, you can see the bearing and securing of the mainspring axle. When you remove the bridge and axle, you can remove the mainspring barrel from the movement without dissecting it.
|Number of jewels:||26|
Glucydur anular balance|
GUB (Glashütter Uhrenbetrieb)|
|Balance bearing / direction hairspring:||Counterclockwise|
|Adjust mechanism:||Hairspring key|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||3 hole(s)|
|Functions:||hour, minute, second, day, selfwinding|
|Size:||12 1/2''' (measured: 28,0mm)|
|Production period:||1964 - 1980|
Flume: K3 -|