FHF 66-4

Manual · 11.5‴ · Switzerland · 1955

Dimensions
25.94 mm
Height
3.50mm
Jewels
21
Power reserve
Timegrapher
Beat rate
18,000bph
Frequency
2.5Hz

Reference: healthy amplitude ≈ 270–315° fully wound (>200° at 24 h); beat error ideally < 0.5 ms.

Movement
Movement type Manual
Winding type Stem Winding (Crown)
Setting type Stem Set (Crown Pull)
Escapement type Swiss Lever
Control type Balance Wheel
Regulator type Pinned Regulator (or Index Regulator)
Shock protection Incabloc
Specifications
Lignes 11.5‴
Shape Round
Complications Sweep Second , Date
Hand count 3
Hand sizes 1.30 x 0.90 x 0.21mm
Further measures
Mounting Diameter (Dm): 25.6mm
Origin & References
Manufacturer Fabrique d’Horlogerie de Fontainemelon
Country Switzerland
Launch year 1955
COSC certified No
Signature
ca. 1955: Swiss; Incabloc (FHF 66-4N)
Notes
Remarks: differences not known between 66-4, 665-4
Other data: balance staff: U2885 stem: W3239 mainspring / battery: 1.00 x 10.5 x 0.12mm balance staff ronda: 4839 (11,5) stem ronda: 1652 (11,5) Mainspring: 1.000 x 10.000 x 0.125 x 320.000 mm
Ranfft mentioned about this caliber: There are variants with this quantity of jewels 17, 21