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The Encyclopedia of Horology

Wristwatch · Automatic wristwatch

Ulysse Nardin Chronometer Co. automatic wristwatch, caliber Felsa Bidynator 690

Partially verified

This vintage Ulysse Nardin automatic wristwatch is dated by the seller to circa the 1940s. It features a self-winding movement signed by Ulysse Nardin Chronometer Co., identified as caliber Felsa Bidynator 690 series with 17 jewels and adjusted temperature. The movement serial is 6503325. Housed in a 33 mm round case with decorative lugs, the seller reports the metal lacks hallmarks but tested as 14K solid yellow gold. The missing original back has been replaced with a custom transparent exhibition back attached using ultraviolet adhesive. The watch is mounted on an 18 mm brown crocodile-grain leather strap.

Case back view displaying the Ulysse Nardin signed Felsa Bidynator 690 automatic movement through a custom transparent case back
Case back view displaying the Ulysse Nardin signed Felsa Bidynator 690 automatic movement through a custom transparent case back — Secondhand Horology. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
secondhandhorology.com
Category
Wristwatch · Automatic wristwatch
Maker / attribution
Ulysse Nardin
Reference
Not recorded
Catalogue / lot identifier
WA-1116
Source-reported date
circa 1940's
Country
Switzerland
Source-reported serial
6503325

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Identity and Movement

The seller dates this vintage wristwatch to circa the 1940s and identifies the self-winding mechanical movement as an original Ulysse Nardin Chronometer Co. caliber Felsa Bidynator 690 series. Movement specifications reported by the vendor include 17 jewels, adjusted temperature, sweep seconds, 18,000 A/h, and a 44-hour power reserve.

Direct visual inspection of the movement confirms the automatic rotor is engraved 'ULYSSE NARDIN CHRONOMETER Co.', 'ADJUSTED TEMPERATURE', 'SEVENTEEN 17 JEWELS', 'SWISS', and serial '6503325'. The balance cock is stamped with the export/import code 'BXP'.

Evidence for this section
  • “This unique timepiece is a vintage Ulysse Nardin automatic wristwatch dated from the circa 1940's. It is a self-winding watch with an original Ulysse Nardin Chronometer Co. movement, caliber Felsa Bidynator 690 series, 17 jewels, adjusted temperature, sweep second, 18,000 A/h, 44 hours power reserve, Swiss made.”
  • “Automatic winding rotor engraved 'ULYSSE NARDIN CHRONOMETER Co.', 'ADJUSTED TEMPERATURE', 'SEVENTEEN 17 JEWELS', 'SWISS', and serial '6503325'”
  • “Balance cock stamped with export/import code 'BXP'”

Case Construction and Alterations

The watch is housed in a 33 mm round case featuring a fancy lug design, measuring 39.8 mm lug-to-lug and 12 mm in thickness. The seller notes that the case and lugs do not have any marks, but reports that the metal tested as 14K solid yellow gold.

The original case back is missing. It has been replaced with a custom transparent exhibition back attached using ultraviolet adhesive to show the movement beneath.

Evidence for this section
  • “Cased in a 33mm round case and fancy lug design.”
  • “Case Lug to Lug 39.8”
  • “Case Thickness 12”
  • “The original case back was missing, the case and lugs do not have any marks, but it tested as 14K yellow solid gold.”
  • “Custom display back attached with high grade ultra violet adhesive and should be considered to be extremely safe to wear.”

Dial and Exterior Accessories

The dial is not visible in the provided image record, which depicts only the exhibition case back view. The seller describes it as an original champagne textured dial featuring applied gold hour markers, matching gold hands, and signatures for 'Ulysse Nardin' and 'Automatic'.

Visual observation shows a fluted winding crown at the case rim and a brown textured leather strap. The listing records the strap as an 18 mm new-old-stock brown crocodile-grain two-piece leather band.

Evidence for this section
  • “The original champagne textured dial with gold applied hour markers and gold matching hands. The dial is also signed with the Ulysse Nardin name and Automatic.”
  • “It comes with a new-old-stock brown Crocodile Grain two-piece leather strap.”
  • “Lug Width 18”
  • “Fluted winding crown visible at the bottom edge of the case rim in the image orientation, paired with a brown textured leather strap”

Open research questions

  • What specific testing method was used to determine the unhallmarked case metal is 14K solid gold?
  • Can the ultraviolet adhesive holding the custom display back be safely dissolved or removed during future movement servicing without affecting the case?
  • Are there visual records of the dial to confirm its textured champagne finish and original state?

Source evidence

Recorded claims and source quotations for Ulysse Nardin Chronometer Co. automatic wristwatch, caliber Felsa Bidynator 690
FieldSource-reported valueSource quotation
Movement caliberFelsa Bidynator 690 series“caliber Felsa Bidynator 690 series”
Jewel count17 Jewels“Seventeen 17 Jewels”
Movement serial number6503325“6503325”
Case diameter33 mm“Case Diameter 33”
Case material14K yellow solid gold“tested as 14K yellow solid gold”
Case diameter with crown35.3 mm“Case Diameter w/Crown 35.3”
Service historyReported serviced June 2023“Just serviced – June 2023.”
Power reserve44 hours (seller reported)“44 hours power reserve”
Frequency18,000 A/h (seller reported)“18,000 A/h”

Visible details

  • Automatic winding rotor engraved 'ULYSSE NARDIN CHRONOMETER Co.', 'ADJUSTED TEMPERATURE', 'SEVENTEEN 17 JEWELS', 'SWISS', and serial '6503325'
  • Balance cock stamped with export/import code 'BXP'
  • Transparent exhibition display back fitted to the yellow-gold-tone case
  • Fluted winding crown visible at the bottom edge of the case rim in the image orientation, paired with a brown textured leather strap

Research qualifications

  • The original case back is missing and was replaced with an aftermarket clear display back attached with ultraviolet adhesive
  • Case metal lacks hallmarks and relies entirely on seller testing as 14K solid yellow gold
  • Dial view is not visible in the provided image

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

ULYSSE NARDIN CHRONOMETER Automatic Watch Cal. Felsa Bidynator 690 17 – SECOND HAND HOROLOGY

Reviewed 2026-10-21 · Record b13ebb491e

Terms in this record

Glossary explanations for terms named in this object’s record.

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