Bulova 9AB movement 17j L0/1950 – Felsa Bidynator?
If collecting mechanical watches and movements is your thing, then being involved in the jewelry biz for over 4 decades has its perks. Acquiring these two identical NOS factory replacement Bulova 9AB automatic movements is one of those. While chatting with another jeweler, he mentioned that he had traded a third jeweler some sizing work for a dozen or so factory watch movements from the 50-60’s. Of course I immediately barter a trade for some melee diamonds for these two, and some of the other movements he had. I have been considering making a custom 14k-18K case and bracelet, but it got put on the back burner, as I have just so many projects going.
Then a week ago I was trying to identify a project Bulova that I had just bought, and enthusiastically got involved with MyBulova. I just noticed yesterday that there is a movement section, so I thought I would share these with the community. One starts with a turn of the crown. The twin of that one takes a little shot of air from my camera sensor cleaning bulb to fire up, then runs a bit then stops until encouraged again. Likely 69 years without new oil has made it balky.
While photographing them it dawned on me that these really looked like Felsa Bidynator rotors. So the investigation ensued. I did not find any specific attribution of Felsa manufacturing the Bulova 9AB, but a version of the Bidynator 695 was the certainly the basis for the similar Wittnauer 11AFG, which also has a sub-second sweep. The Bulova 9AB was only offered for a single year, three years after Felsa had introduced the Bidynator 690 in 1947. The Felsa 690 was a sensation in the Swiss industry, and most of the ebauche manufacturers in Switzerland had Felsa make a version of the 69X series for their watches. It would seem unlikely that Bulova could have designed and brought into production a unique bi-directional [Duo Wind] automatic in such a short time. I would suggest that at the very least Bulova did what the other manufacturers did and turned to Felsa. At a minimum it would seem that the Bidynator self-winding mechanism may have been adapted to a proposed or future Bulova stem-wind movement. The rotor itself is the most compelling argument for Felsa having a hand in bringing this movement into the world for a single year.