ETA/Valjoux Caliber 7751 Watch Movement

Ela Valjoux Caliber 7751

Brand	ETA / Valjoux
Caliber Number	7751
Base Caliber	ETA 7750
Movement Type	Automatic
Diameter	13 1/4”’ (30.00mm)
Thickness	7.90mm
Jewels	25
Power Reserve	~48 hours
Vibrations Per Hour	28,800 BPH
Lift Angle	49 degrees
Shock System	Incabloc
Functions	Central hours, central minutes, central chronograph seconds, central date hand, small running seconds at 9:00, day of the week at 12:00 (left side), month at 12:00 (right side), 30 minutes chronograph counter at 12:00, 12 hours chronograph counter at 6:00, moonphase indicator at 6:00, 24 hour time at 9:00
Country of Manufacture	Switzerland
Known Models	Zahnd & Kormann Triple Date Moonphase Chrono, Dubey & Schaldenbrand Gran Chrono Astro, Compass Titan 2 (Too many to list, please add your watch in the comments below…)

The ETA/Valjoux caliber 7751 is a 25 jewels Swiss made self-winding automatic movement. This extremely multi-functional caliber is based on the legendary ETA/Valjoux caliber 7750 chronograph, but with additional complications including a full moon phase indicator at 6:00, a central date hand pointing to the date in the outer perimeter of the dial, day of the week and month windows at 12:00, and a 24 hour hand at 9:00.

ETA 7751

Some of the topics covered in this caliber listing:

Setting the time

When setting the date on your caliber 7751 watch, do not attempt to do so while the hands on the watch are displaying between 8:00PM and 2:00AM. Before adjusting anything, be sure to move the hands to a time outside of this zone – this is to make sure the date flipping sequence at midnight has occurred. For the moonphase, do not make adjustments between 8:00PM and 6:00AM. Doing so can cause serious damage to the calendar gears in the movement.

Winding – Neutral (position) 1 is hand-winding position. If your watch is equipped with a screw down crown, unscrew it and you will be in position 1.
Time – Pull the crown out 2 clicks (position 3). Turn the crown clockwise or counterclockwise to set the time.
Day of the week – Use the pusher on the side of the watch near the 10:00 position
Date – Pull the crown out one click (position 2) and turn it counterclockwise
Month – While in date setting mode (position 2 and turning counterclockwise) continue to change the date until it passes the 31st of the month. This will advance the month indicator to the next month. Keep doing this until your current month is selected, stopping on the day.
Moonphase – Pull the crown out one click and turn clockwise until your desired moonphase setting is reached.

Chronograph Sequence

The chrono sequence on the VD51B is the same as most chronograph watches:

Start – top button
Stop – top button
Reset – bottom button

Note: If your chronograph isn’t running, it’s most likely due to your watch not having enough power reserve. Simply wind the watch fully before engaging the chronograph function. Also be aware that running the chronograph makes use of additional gears in the movement and will cause your overall power reserve to run out faster. This should not be an issue as long as you are wearing the watch.

Dial Side View of the Complications

Triple calendar (Day/month windows at 12:00, date hand), 30 minute chronograph totalizer:

24 hour subdial at 9:00, small running seconds:

Moonphase indicator at 6:00, 12 hour chronograph totalizer:

Watches with this caliber

The pictured example of the ETA caliber 7751 was found in a Dubey & Schaldenbrand Gran Chrono Astro.

This movement has been custom decorated by the manufacturer. The movement has a hand-engraved decorated gold finish. The rotor is skeletonized and blued steel screws can be spotted throughout. Dubey & Schaldenbrand proudly states that their use of this caliber has a chronometer-quality escapement.