In the early 1950’s Tudor introduced their first automatic watch. To save on the cost of developing a completely new movement; parent company Rolex modified the calibre 380 from FEF to be fitted with an autowinder mechanism, and the Tudor calibre 390 was born. Rolex also made a date mechanism that was named Tudor calibre 395. The movement stayed in production until being phased out by more robust ETA based automatics. All models came with Kif shock protection.
Tudor/Rolex calibre 390-395
- Made approximately ca: 1950-1965
- Made in Switzerland
- Power reserve 38h
- 17 Jewels
- 18000 B/A
- DM 28.2mm
- H XXmm
Surface finish on calibre 390 has Rhodium plating or gilt copper finish. Gear train bridge has nice design with beveled edges and a fine finishing. Screws are polished to a high standard.
Surface finish on top side of the plate and bridges: 7 Points
Surface finish on screws: 9 Points
Surface finish on crown and ratchet wheel: 6
Movement Jeweling: 5 points
Movement design innovation (for ca 1950): 6 points
The Tudor base plate on the calibre 390 is very clean and nice, Winding/setting mechanism is decent.
Base plate finish: 7 Points
Setting and winding mechanism: 7 Points
Gear-train finish: 7 Points
Date change snappiness: 6 Points*
Movement durability is a issue on the calibre 390 due to the poor design o the the autowinder mechanism. The main issue is the way the ratchet and crown wheel is held in place by a metal plate creating a large friction surface. This friction surface has a tendency to grind creating shavings and dust that enters the rest of the movement causing more wear. This movement literally eats itself when being wound.
Movement durability: 2 Points
Calibre 390 utilises a flat hairspring and accurate when in good condition.
Accuracy: 8 points
Power reserve of 38 hours is okay.
Power reserve: 7 Points
Tudor calibre 390/395 points summary:
Surface finish on bridges and top side of base plate: 7
Surface finish top screws: 9
Surface finish on ratchet and ratchet wheel: 6
Movement Jeweling: 5
Movement innovative design for ca 1950: 6
Base plate finish: 7
Setting and winding mechanism: 7
Gear-train finish: 7
Date change snappiness: 6*
Movement durability: 2
Autowinder mechanism: 2
Power reserve: 7
Grand total: 72-78*