Some other differences…
Forum: TimeZone – Advanced Forum
Re: Compare/contrast ETA 2824 and 2892-A2 movement (James Donabed)
Date: Fri, 12 Dec 1997 07:46:19 GMT
From: Walt Odets <email@example.com>
In addition to SJX’s comment on the thickness differences, other differences include the 2892 with 21 jewels, 42 hour power reserve, enlarged ball bearing rotor mount, Glucydur balance; the 2824 with 25 jewels, 38 hour PR, often used with a less expensive balance.
Beyond this, the 2824 is very similar in construction to most of the other ETA’s, including the 2688, 2671, 2688, 2685, etc., all of which are basically ETA (“in house”) developments beginning in 1949. The 2892 is the most recent ETA (basic automatic) caliber and, unlike most of the other ETA’s currently in production, the 2892 was derived from an outside design, the Eterna-matic 3000, Cal. 1466-U, first released in 1963 (by Eterna). When finally made available as an ETA movement in 1976, it was very flat for an automatic with center sweep and date, had a distinct developmental history outside ETA and had accumulated a very good record of reliability in the Eterna watches. It is quite different in construction from the other ETA’s and appears much more robust to the eye than most of the “in house” ETAmovements.
An historical note: ETA was the movement manufacturing division of Eterna until 1932 when it split off and joined Ebauches S.A. (which included other big manufacturers like A. Schild). Eterna continued independent development of movements (which is how it came up with the1466U/2892), although Eterna and ETA also worked jointly on some designs. Almost all (all?) ETA and Eterna automatics share the Eterna-designed automatic winding system: a ball bearing mounted rotor winding in two directions via springless twin click wheels and two reduction wheels on the locking wheel
A side note on the 2824: Introduced by ETA in 1972, the 2824 was used in a 36,000 beat chronometer form by Ulysse Nardin (though it was available as a 28,800). UN has apparently reintroduced this movement in some of the San Marcos “fast beat” chronometers.
A final word on the 2892: If you see an automatic advertised with 21 jewels it is almost surely this movement.
And a closing remark: I haven’t uttered a single peep about a watchmaker who shall be nameless, but whose initials are Franck Muller