The 6497 and 6498 began as UNITAS calibers, but when UNITAS became a part of swatch group (through a series of acquisitions) it became an ETA caliber, like the Valjoux 7750 and many others. The 6497 is a 16 1/2 ligne pocket watch movement. It is manual wind and a lepine configuration. The 6498 is a hunter configuration. Unitas was founded by Auguste Reymond as a movement manufacturer. They developed the 6497/8 in the 1950s and it gained popularity rapidly as a robust and accurate pocket watch movement. For more on the history of Unitas visit The Unitas Reference Site.
The watch I was working on today was a Caravelle which had been mangled. The hairspring was totally destroyed and the watch movement was covered in a green slime. The watch required a complete restoration, but it wasn’t too costly because all the parts are readily available.
I first became acquainted with the 6497 in watchmaking school at the Lititz Watch Technicum. The 6497 is the movment we base our school watch project on. As a result of that project I feel like I know the 6497 inside and out.
So, Why do I like it? I like robust movments and this is certainly that. Everything in it is sturdily made. It is well designed, everything goes together well. It is very easy to make this movement chronometer grade, even with the most basic model. If you can find a higher grade balance and/or the higher beat train, it would be even easier. I guess, that as a watchmaker I appreciate watches that just do their job well. This one certainly does that.
Straight from ETA the 6497 and 6498 come pretty plain. I have seen them with a “fish-scale” finish, and flat, both nickel plated. I have seen some gold plated and it looks like you can get the 6497 with geneva stripes. Many manufacturers do a lot to dress up this movment. Panerai does a nice job with the traditional Unitas bridge shape (which differs from the geometric style later adopted). It has beautiful finish work, blued screws and even some minor complications added such as center sweep hand on some models. Hamilton uses this movement, as does Swiss Army. Basically when you need a large manual wind movment, this is the obvious choice.
For my school watch I made the bridges, click, and stem. I also formed the hairspring and modifed the balance. My school watch features a free-sprung balance with over-coil hairspring. I refinished the ratchet and crown wheels; and I refinished and blued the screws. I also made the dial and hands. It was a complicated project, and I learned an incredible amount about watch component manufacture throughout the process. It took me about 175 hours to complete.