| Manufacturer | ETA/Unitas |
| Caliber Number | 6503 |
| Base Caliber |
ETA/Unitas 6497 |
| Movement Type | Manual wind |
| Size (lignes) |
16.5”’ |
| Diameter |
36.6mm |
| Height |
5.0mm thick |
| Jewels | 15 or 17 |
| Vibrations Per Hour |
18,800 bph |
| Shock System | Incabloc |
| Winding Direction | Uni-directional |
| Hacking? |
No |
| Functions | Hours, minutes, small seconds at 9:00, date |
| Country of Manufacture | Switzerland |
| Known Brands |
Add your watch in the comments below… |
ETA/Unitas caliber 6503 is the rarely seen version of the manual wind ETA 6497 with a date complication.
The 6503 was produced in the 1960s and is currently discontinued. It is hard to find watches powered by this movement, if you have a timepiece with the 6503, please share it in the comments below.
Modern Usage:
There is a German watch company called Guinand which still produces a manual wind pocket watch featuring a calendar window at 3:00 (Model G-1996S). Guinand’s caliber HS81 is based on the ETA/Unitas 6503, but with modifications created by Helmut Sinn, including a central sweeping seconds hand (instead of the standard 6497 small seconds at 9:00), as well as a hacking mechanism. It is likely that they had access to new old stock 6503 movements for this model.
Additional Resources:
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