|Caliber Number||1128, 1128A|
|Base Caliber||Omega 1120 (ETA 2892-A2)|
|Movement Type||Automatic, self-winding mechanical, GMT|
|Beats Per Hour||28,800 vph, 4Hz|
|Lift Angle||51 degrees|
|Power Reserve||44 hours|
|Hand-Winding Direction||Clockwise (forward)|
|Time Setting Direction||Counterclockwise advances hands forward|
|Balance Spring||Nivarox 1|
|Rotor Type||Ball bearing system|
|Hand Sizes||1.8mm / 1.5mm / .9mm / .25mm|
|Functions||Central hours; central minutes; central sweeping seconds; central GMT hand; date at 3:00|
|Country of Manufacture||Switzerland, Swiss made|
|Known Models||Omega Seamaster GMT “50 Years” Ref: 2234.50.00 (newer Speedy bracelet/clasp), 2534.50.00 (old style bracelet/clasp), 2538.20.00 (white dial on newer Speedy bracelet), 2134.80.00 (gold on bracelet), 2634.80.93 (gold on a strap) (Add your watch in the comments below…)|
The Omega caliber 1128 is an automatic GMT watch movement with 23 jewels and a beat rate of 28,800bph (4Hz). This Swiss made movement is found in the Omega Seamaster GMT 50th Anniversary Edition, which was released in 1998 to commemorate 50 years of the Seamaster collection.
Omega 1128 VS 1120:
The cal. 1128 is based on the calibre 1120 with the addition of a GMT (second time zone) complication. Most of the parts are interchangeable between these two calibers, with exception to parts related to the GMT.
The 1128 is a “true” GMT with the ability to set the main hour hand independently when jumping time zones – crown pulled out one click. This allows for your home time to remain the same, without adjusting the minutes or hacking the seconds while moving the hour hand forwards or backwards in accordance to your new local time – this method is also used to set the date and can be done in either direction. The GMT hand is set by pulling the crown out two clicks to set the time.
The 1128 is not equipped with the robust anti-magnetic technology found in the newer Omega in-house calibers (such as the Omega 9920), but the movement does include an antimagnetic iron dust cover (it is NOT a faraday cage) that is positioned between the movement and the caseback. Although you may find different numbers (or no numbers) on these shields, the example pictured here is number 096 FE 0041 (096FE0041) is common in Seamaster models.