TAG Heuer Calibre 16

The TAG Heuer Calibre 16 is a Swiss made automatic chronograph watch movement with 25 jewels and a frequency of 28,800 bph. This caliber is basically either an ETA 7750 or Sellita SW500 with a custom branded rotor.

When did TAG switch from ETA 7750 to Sellita SW500?

Early models using the Cal. 16 will be powered by the ETA 7750. Later, when ETA movements became unavailable to watch brands outside of the Swatch Group, companies like TAG Heuer started using the next best Swiss made alternative: the Sellita SW500 (ETA 7750 clone movement).

TAG documentation started showing the Calibre 16 being based on ETA 7750 or SW500 a least as far back as 2014.

However, the exact date or serial numbers when this switch happened is unknown, therefore you will simply need to check your watch to figure out which one you have.

How to know if a Calibre 16 is ETA or Sellita based?

The easiest way to tell which base caliber your Calibre 16 is using, is to check the engraving located on the mainplate under the balance wheel. The example pictured on this page is an ETA 7750 base.

Setting the Time:

To set the time on your Calibre 16 powered TAG Heuer watch, pull the crown out two clicks to time-setting mode. If your watch is equipped with a screw-down crown, be sure to unscrew it first. With the crown in time-setting mode, turn it clockwise or counterclockwise to the desired time.

Setting the Calendar:

Extremely Important Note: Do not attempt to set the day or date on your watch while the hands are set between the hours of 7pm and 3am. You may see other sites say 10pm and 2am, but ETA officially states:

“Rapid date and day correction is not possible between 8 p.m. and 2 a.m.” -Source ETA 7750 Technical Communication

Just to be on the safe side, be as far out of that range as possible (just in case the hands weren’t installed exactly at 12am). If you set the day and day within those hours, the automatic calendar system is engaged to advance the datewheels to the next day and there is a chance to break something – even if nothing breaks, you may still cause the date to switch over at something like 6am rather than 12am.

To set the day/date on your caliber 16 watch read the extremely important note above first. Pull the crown out one click to calendar setting mode. Turn the crown clockwise (away from you) to set the date and counterclockwise (towards you) to set the day of the week.

Chronograph start/stop/reset:

Button sequence: Top, top, bottom.

• Top button: Start/Stop
• Bottom button: Reset

Chronograph Hand Lining Up:

Unlike quartz powered chronograph movements, mechanical watches do not have the luxury of using a reset sequence to get the chronograph hand to line up to 12:00. If the chronograph hand on your caliber 16 powered watch is not lining up, it could be a mechanical problem and should be inspected by a professional watchmaker. Your watch may need serviced or the hand might need to be reinstalled.

Is it OK to Leave the Chronograph Seconds Constantly Running?

It is not recommended to leave the central chronograph sweeping second hand in a constantly running or engaged state. With the way the gear train is set up on the cal. 16, this could add extra and unnecessary wear and tear. Additionally, by doing so your watch will experience a change in amplitude, leading to a loss of power reserve and accuracy.

Pros and Cons:

Pros:

• Based on 7750/SW500 makes it serviceable without having to send your watch to the manufacturer
• Solid, reliable workhorse movement

Cons:

• Service costs can be expensive for automatic chronograph movements
• 7750’s finicky day/date setting (you must remember to move the hands into the safe zone first)

Additional Resources:

• Other mentions of caliber 7750