Hi Folks

I have a 1914 7j version of the above pw. It runs fast, gaining 1 minute a day, and I am working on the theory that the mainspring is too strong.

Brian C. kindly gave me the original specs of the mainspring for this watch #2227 (length, width, thickness) = (635mm, 2.8mm, 0.18mm).

However this seems too wide for the barrel that I have. Perhaps mine is a non standard barrel that has been changed at some time. The spring in the barrel is (520mm, 2.62mm, 0.19mm).

Also the fact that the mainspring is shorter means there is an increase in strength as well as the fact that it is thicker. It also only runs for a bare 24 hours whereas other standard US pws I have tend to run for >=30 hours.

Also other US pws mainsprings I have tend to be around the 480-500mm length and they run for ~30hours. Hence Waltham's use a different gearing?

If someone has this model, I would appreciate some feedback on it's timekeeping and if possible the spring and mainspring barrel dimensions.

Gordon