Fancy Cased Automatic measures 40mm lug to lug x 33mm non inclusive of the Crown using Calipers. Original Butler finish Dial shows a combination of applied Gilt hashmarks and Arabic numerals. Hour and Minute hands are Gilt Alpha style, Sweep center seconds hand is Gilt Modern style. Bulova logo is applied Gilt, Duo Wind insignia is printed Black, Black printed track is numerically calibrated at 5 Second intervals. Crown is original. Snap fit Caseback is Stainless Steel and stamped as shown. 1950 was the first Year an Automatic movement in a Bulova.
Movement has the L0 date code or is it L8?, what about the case?? The 11 series movement starts to show up about 1955 in the movement database, the rest of the Duo-winds use a 10 series movement.
It sure matches the Thayer ad better than the Duo-wind ad...2 Stars on the Duo-wind ID.
Very interesting, as the Bulova 11 AAC is based on the Swiss Felsa 415 Bidynator.
http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&&2uswk&Felsa_410
Circa 1946.
* edit: 1942, according to Dr Ranffts site.
My bad.
Remarks
1942
first calibre with bidirectional rotor winding, pilot series for the family 690...699 with almost the same base-plate, even samples with caledar corresponding the 693 are known.
The Bulova 9 AB and 10 AU are also Felsa based Swiss automatics.
In reply to Very interesting, as the by FifthAvenueRes…
Mark...it's more difficult to do our homework now because we have so much more information available. But with Ranfft's site, this site, and NOVA's site -plus the new ads we have- our homework can be more productive once done. I think it's great we have all these resources available. We can not only say so much more now vs a year ago, but we can also cite the reasons we are saying these things.
Your link to Ranfft above does not address the years when the 11 series is introduced (nor the 10 series) but only referrers to the Felsa bidiator technology. This wasn't clear to me from your post without going to the link you provided. Thanks for posting the link.
In reply to 1950 1950 - Note the solid by FifthAvenueRes…
So? We have an early example of an 11 series movement.
No one ever disputed that the watch is a duo-wind, just what it should be called, since we have ads naming the duo-wind the Thayer.
The closest matching ad names this watch the Thayer, and nothing presented to date has shown that the new ad is not the best available evidence of what this watch should be called.
"Duo-Wind" may have only ever been a generic descriptive name used in third-party ads for this duo-wind and self-winding model. The only Bulova-produced ad we have for this watch names it the Thayer and includes Duo-Wind on the dial, just like the subject watch. Nothing about that fact has changed.