Gruen 306
Mechanical
c. 1934
No photos yet
Notes
1934-
*) Flume lists the frequencies 18000 and 20160 A/h, but in Gruen catalogs an according remark is missing.
bimetallic screw balance, Breguet hairspring
signature often or always Gruen 106
differences not known between 1067, 1077
probably designations for different base-plate shapes, round corners (Fig.1, 2) or octogonal
Dimensions
| Width | 12.85 lignes (28.99 mm) |
|---|---|
| Height | 3.4 mm |
| Stem height | 0.3 mm |
| Hands (H × M × S) | 1.5 × 0.9 × 0.2 mm |
Technical data
| Beat rate | — |
|---|---|
| Lift angle | — |
| Power reserve | 40 h |
| Jewels | — |
| Shock protection | — |
| Mobile stud carrier | No |
Complications
| Self winding | No |
|---|---|
| Date | No |
| Day | No |
| Hacking | No |
| Chronograph | No |
Mainspring
| GR code | GR2591 |
|---|---|
| Height | 1.1 mm |
| Thickness | 0.09 mm |
| Length | 220 mm |
| Barrel diameter | 7 mm |
Overview
| Type | Mechanical |
|---|---|
| Manufacturer | Gruen |
| Year | c. 1934 |
| Family | — |
| Clone of | — |
Related calibers
Documents
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Updated 7 days ago · 0 revisions