Brand | Eterna |
Caliber Number | 520U |
Base Caliber | Eterna 520 |
Movement Type | Manual wind, mechanical |
Diameter | 12”’ (26.5mm) |
Thickness | 4mm |
Jewels | 15 |
Lift Angle | 42 degrees (needs confirmed) |
Power Reserve | 42 hours |
Vibrations Per Hour | 18,000 bph |
Balance Staff | U620 |
Hairspring | Flat |
Hands | 1.38mm / 0.80mm / 0.13mm |
Anti-Shock | Eterna-U Device |
Features | Hours, minutes, small seconds |
Country of Manufacture | Switzerland |
Production Years | 1940s – 1950s |
Known Models | 1952 Eterna dress watch |
The Eterna caliber 520U is a vintage mechanical movement based on the Eterna caliber 520. These calibers were produced in the 1940s and 1950s.
Anti-Shock
The 520U movement seen here is equipped with an in-house anti-shock device called Eterna-U.
Other Variations
There are a few variations of the 520 movement with a letter designation based on the type of anti-shock device used. The ones we know about are:
- 520 – the base caliber (4mm height)
- 520H – Eterna-H shock absorber
- 520L – Eterna-L shock absorber
- 520S – central sweeping seconds (4.95mm height)
- 500U – shown here
If you know more about these variations of the caliber 520, or know of some not listed, please leave the information in the comments.
The movement pictured above was found in a vintage Eterna dress watch here.
https://www.youtube.com/watch?v=IKHPZq4zuL0
About Eterna
Eterna was founded in 1856 in Grenchen, a municipality of Solothurn, Switzerland. Despite many people thinking that Eterna is part of the Swatch Group, the watch brand is owned by a Hong Kong watch conglomerate known as Citychamp Watch & Jewelry Group. ETA, the movement branch of Eterna that was established in 1932, became part of the Swatch Group and still produce movements that we know today. Eterna also still produces movements and modules for modern timepieces.
Please share your experiences and thoughts about the Eterna caliber 520U in the comments section below…
Caliber submitted by wahawatches.com
Trending Comments
Longines Caliber L836.6
The differenece is the beat rate. 3Hz vs 5Hz. 6 beats/s vs 10 beats/s.
Orient Caliber F6922
I've had my Mako and Ray Orient watches with these calibers, I guess. Their performance…
Invicta Caliber JSD-006ZY
Apart from the fact, that there is no further information about this caliber anywhere, it…
Seiko Instruments (SII) Caliber VH31
the VH-31 movement coupled with solar or kinetic in a Seiko watch would sell like…
Miyota/Citizen Caliber 9051
I have the 9051 in my Fujitsubo, it appears to be within 3 seconds. I'll…
Active Caliber Listings
I have the 9051 in my Fujitsubo, it appears to be within 3 seconds. I'll…
It might be a Chinese Standart-movement aka Tong Ji aka 7120 / SS7 with an…
Thank you for sharing your experience with the community. If possible, please submit images of…
Apart from the fact, that there is no further information about this caliber anywhere, it…
This £80 lorus has the y676c with Japan on the rotor