====== Eterna 1247 ======
[[Eterna]] **Cal. 1247** was one of a family of [[automatic]] watch movements produced from [[1949]] to [[1954]]

===== Overview =====
[[ETA]] was one of the three firms "chosen" to develop advanced [[automatic]] watch movements by [[Ebauches SA]], thanks in part to their history with [[Eterna]]. The chief designer at ETA, [[Heinrich Stamm]], had created many of the company's important watch movements, and was famous for the [[Eterna-Matic]] line of watches.

When it was introduced, Cal. 1237T was the first full-size movement with a [[ball bearing rotor]]. This five-ball design would become the logo of the [[Eterna]] watch company. The family was also the first ETA/Eterna movement with a free-rotating [[central rotor]], unlike the [[bumper]] rotor in its predecessor, [[Eterna 1158|Cal. 1158/1159]].

===== Technical Details =====
Although thicker than preceding and succeeding movements, this family is still quite thin at 5.9 mm. Most models have 17 jewels, though later versions have a 21 jewel option. All operate at 18,000 A/h and have 42 hours of power reserve.

This movement family includes 11.5 [[ligne]], 12.5 ligne, and 13 ligne variants.

===== Variants =====
Cal. 1247 one of a family of automatic movements.

All movements use suffix "U" to signify Eterna-U shock protection or "T" to signify "Eterna-T". Movements with the suffix "C" indicate a modification to the design.

  * Eterna 1248 - (1949) 11.5 ligne
  * Eterna 1247 - (1949-1954) 12.5 ligne
    * Eterna 1237 - (1949-1954) date
  * Eterna 1254 - (1949-1954) 13.5 ligne
    * Eterna 1246 - (1949-1954) date
  * Eterna 1249 - (1949-1954) 13 ligne
    * Eterna 1239 - (1949-1954) date
  * Eterna 1253 - (1949-1954) 13 ligne
    * Eterna 1243 - (1949-1954) date

===== See Also =====
  * [[Eterna-Matic]]
  * [[Eterna 1158]], the predecessor movement
  * [[Eterna 1413]], the successor movement


{{tag>Movements Eterna_calibres Automatic_movements}}