Ronda Caliber 6203.B Watch Movement

Brand	Ronda
Caliber Number	Ronda 6203.B
Type	Quartz
Lignes	11.5”’
Diameter	26mm
Thickness	3.3mm
Jewels	1 or 5 (see blow)
Battery Cell Number	373 (1.5 V)
Claimed Battery Life	40 months
Accuracy Rating	-10 ~ +20 seconds/month
Hand Count	5
Hand Sizes	Main time: 1.2mm / 0.7mm / 0.2mm, dual time: 0.8mm / 0.4mm
Functions	Central hours, central minutes; central seconds; double digit big-date at 12:00; dual time subdial at 6:00 (with crown at 4:00 for setting independently)
Hacking Seconds?	Yes
Quickset Date?	Yes
Country	Switzerland (Swiss parts version also available)
Known Models	Junkers 1st Atlantic Flight (add your watch in the comments)

The Ronda caliber 6203.B is a quartz dual time movement from Ronda’s xtratech (previously normtech) line of watch movements. Technical documentation for this caliber was found dated as far back as September 6, 2012, with updates on March 17, 2017 and June 2023. Ronda calls this a repairable watch movement.

Although they are not the same, it is interesting to note that cal. 6203.B shares an official instruction manual with Ronda calibers 7003.L, 7003.N, 7004.N, and 7004.P.

Some of the topics covered in this caliber listing:

Swiss Made VS Swiss Parts:

According to the Ronda website, there are two versions of this movement: a gold plated Swiss Made version with 5 jewels and a nickel plated (silver color) Swiss parts version (made in China?) with 1 jewel. Only the Swiss made version is listed as having an EOL (end of life) low battery indicator.

Power Saving Feature

The battery is claimed to last about 40 months in normal conditions, but if you are not going to wear your watch for a while, the 6203.B has a power saving mechanism when the stem is pulled out stem (aka hacking function). Reduction of battery consumption approximately 70%. It is not advisable to leave the chronograph second hand running because it will drain the battery faster and put more wear and tear on the gears. As mentioned above, the Swiss made version has a low battery indicator which will cause the seconds hand to skip at 2 second intervals.

Accuracy:

According to Ronda, the caliber 6203.B should keep time within -10/+20 seconds per month with an operating temperature of 0 to 50 degrees Celsius.

How to change the battery:

The battery is held in with friction prongs. There are no screws. Insert the battery at an angle towards the prong arms and press down to “friction” in place.

Ronda Caliber 6203 B Battery Replacement

Ronda Caliber 6203 B Battery Replacement Service

The correct replacement battery is a 373 cell.

Make sure the orange insulator tab is in place.

Stem Removal

Since there are two crowns on the calibre 6203.B, there are two stem detent buttons…

To remove the crown/stem, find the nearest hole with the arrow. While the crown is in position 0, pressing this with your tweezers or other tool will allow the stem be unlocked so you can pull it out. Do not press too hard.