Amplitude seems low on a serviced watch.

impalla62ss · Dec 23, 2023

I just got a watch back from service. IWC cal. 401 from the '50s. It is within spec on timekeeping, but the Amplitude seems low at 220. Should I be concerned?

Fallout Boy · Dec 23, 2023

As I learned: depends on rate of winding (full - low), position of the watch....

https://omegaforums.net/threads/tim...n-open-for-all-inquiries.167077/#post-2276777

impalla62ss · Dec 23, 2023

Face up, full wind

Fallout Boy
As I learned: depends on rate of winding (full - low), position of the watch....

https://omegaforums.net/threads/tim...n-open-for-all-inquiries.167077/#post-2276777

Face up, Full wind. Amplitude is consistently low in other positions. I'll check out the link.

Fallout Boy · Dec 23, 2023

We better wait for the pro´s 😀

Are there reference-values ?

impalla62ss · Dec 23, 2023

Found this thread. https://omegaforums.net/threads/amplitude-debate.78234/ good info.
I am unable to find reference values on the web.

lejaune · Dec 23, 2023

The lift angle of cal. 401 is 56 degrees, so the actual amplitude is 7.7% higher than you measured.

Canuck · Dec 23, 2023

I get the feeling most collectors would enjoy their watches more if they didn’t have a timing machine! 😉

p4ul · Dec 23, 2023

or mowing machines.

Dan S · Dec 23, 2023

impalla62ss
I just got a watch back from service. IWC cal. 401 from the '50s. It is within spec on timekeeping, but the Amplitude seems low at 220. Should I be concerned?

The amplitude seems to say 212, not 220. But you should probably check the lift angle since you apparently have it set to the default.

impalla62ss · Dec 23, 2023

Thanks for all the help. I’ll reset the lift angle.

impalla62ss · Dec 23, 2023

Here it is with the correct lift angle. Amplitude seems pretty low for a serviced watch.

Canuck · Dec 23, 2023

With a pattern as scattered as that one is, you might consider checking with who it was that did the job, and asking them why it shows rather poorly. The watch could be 65 years old, and perhaps it has been over the road, and you may have to keep your expectations in check.

impalla62ss · Dec 23, 2023

Canuck
With a pattern as scattered as that one is, you might consider checking with who it was that did the job, and asking them why it shows rather poorly. The watch could be 65 years old, and perhaps it has been over the road, and you may have to keep your expectations in check.

Thanks Canuck, I'll keep you posted.

ansoa-66 · Dec 23, 2023

I don't consider the amplitude to be low for a 50's watch that had no parts swapped.
What I find interesting is the pattern of the reading. That doesn't look like the watch was particularly good serviced or some parts have defects.

khangct · Dec 23, 2023

To me, that amplitude is acceptable for 50s watch.

impalla62ss · Dec 23, 2023

A ansoa-66
I don't consider the amplitude to be low for a 50's watch that had no parts swapped.
What I find interesting is the pattern of the reading. That doesn't look like the watch was particularly good serviced or some parts have defects.

The watch got a new mainspring. For a $800 service I expect new parts if needed for cost, I could of had a clean for $300. I'll hear back from them after the holiday. I know it is an old watch but the IWC Cal. 401 is a good movement, and should perform better than this.

lejaune · Dec 23, 2023

If things remain the same, increasing the lift angle setting should increase the amplitude as a result, and should not affect the rate. Something else is in play here, it seems.

kaplan · Dec 31, 2023

For $800 it is very low

Kwijibo · Jan 9, 2024

it could be many things but with a new mainspring ... rather low. how is the +/- delta?

Dan S · Jan 9, 2024

Weird how the timekeeping is wandering around so much. I don’t usually see that on a watch that has been serviced unless maybe you changes the position.