====== ETA A05 ======
**Cal. A05** is an [[automatic chronograph]] movement produced by [[ETA]] for [[Rado]] and [[Tissot]] based on the popular [[Valjoux 7750]] design.

===== History =====
The 7750 is derived from the manually-wound [[Valjoux 7733]] chronograph movement, itself a descendent of the [[Venus 188]], a company Valjoux purchased in 1966. It was designed (partially on computer, an industry first) by [[Edmond Capt]] and introduced in [[1974]]. After the [[quartz crisis]], the 7750 was reissued in [[1985]] and became the most common Swiss automatic chronograph movement. In the 2010s, ETA began creating specialized versions for companies in the [[Swatch Group]], including the larger [[Valgranges A07]] line and this **ETA A05** line for [[Tissot]] and [[Rado]].

The A05 is similar to the 7750 in that it is a 13 1/4 [[ligne]], 30 mm diameter [[cam switching]] [[chronograph]] movement operating at 28,800 A/h. It has 25 or 27 [[jewels]], a ball bearing [[rotor]], unidirectional winding, and 60 hours of power reserve.

There are two known versions of Cal. A05 

  * Cal A05.H21 - 25 jewels, 60 hours power reserve, based on [[ETA 7750]]
  * Cal A05.H31 - 27 jewels, 60 hours power reserve, minutes at 3 00, small seconds at 9 00, based on [[ETA 7753]]

===== See Also =====
  * [[ETA C01.211]] - A [[Lemania 5100]] chronograph movement also used by [[Tissot]]


<WRAP ud ud_mov>

**Description:**
  * [[Automatic chronograph]], 28,800 A/h
  * [[Cam switching]]

**Functions:**
  * Hours, minutes
  * Central chronograph seconds hand
  * A05.H21
  * [[Date window]] and [[day window]] at 3 00
  * [[Chronograph hours]] 12-hour counter at 6 00
  * [[Small seconds]] at 9 00
  * [[Chronograph minutes]] 30-minute counter at 12 00
  * A05.H31
  * [[Chronograph minutes]] 30-minute counter at 3 00
  * [[Date window]] at 6 00
  * [[Small seconds]] at 9 00

**Data:**
  * 13¼ [[ligne]]s
  * D 30.0 mm
  * 25 or 27 [[jewels]]
  * 28,800 A/h
  * Power reserve 60 hours

**Production period:**
  * Since 2010s
</WRAP>

{{tag>Movements Automatic_movements Chronograph_movements Valjoux_calibres Automatic_chronograph_movements}}