running rate cal.1570

[Larryscott]

I have an early 60s Oyster Perpetual Date. cal. 1570.

I recently sent it to NY service center. When I got it back, I noticed that the daily running rate was 6-8 sec/day fast, and inconsistent. However, now after more than a month, the rate has increased to an uncomfortable 12.6 sec/day fast. On the upside, however, that rate holds true for +/- 1.2 seconds RMS. So, I am confident that having it regulated, it can have a running rate of 1-2 seconds per day.

Question: over a 2-8 years period, does an older 1570 speed up? or slow down between major servicing?

I want my watch guy to trim the rate by 12 sec/day. But, if the tendency is for the rate to increase with age, do I have it adjusted slightly slow? Or, if they slow down, I should have it set to run slightly fast?

In the past, this watch has run spot on for years at time, but I wasn't tracking it very close. Since it's just been serviced, I'm trying to get a really low running rate with hope for a stable rate for several years.

I would be real happy if I only had to set it monthly just to correct the calendar.