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Mr. Ohms....

 

John,

Your response to this op is well reasoned and insightful, as usual. Real world experience has shown us that cross caliber comparisons based on amplitude alone are very difficult indeed. You and I have seen very stable modern movements with relatively low amplitude, ie 270' in 5 positions, and horribly unstable calibres with relatively high amplitudes in the 310 to 325 range. Immediately after servicing a movement, I like to see a small amplitude delta at 0 hour even more than a small rate delta. Large variations in rate are generally easier to sort out than large variations in amplitude. A large variation in amplitude at zero hour is likely to lead to isochronal problems, as overall amplitude drops over time. Or, put differently, large positional variations in amplitude are a bigger problem than large positional variations in rate for the watchmaker. At the risk of putting too fine of a point on the subject, large amplitude variations lead to large rate variations, but high overall amplitude does not neccessarily equal small rate variation.

 

  

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