treadmark501 Posted August 30, 2011 Report Posted August 30, 2011 does anyone know the reliability of these "modified" Asian 7750 Chrono movements with seconds @ 9 but minutes @ 3??? I remember reading a movement review a long time ago but can't remember which "modified" A7750 has potential problems. these are in the new PAM 288:
FxrAndy Posted August 30, 2011 Report Posted August 30, 2011 that should be a nice stable movement, there is also a swiss 7750 with this modification, the reason it is good is because the modification is only in use when the chrono is running and then for only a second or so a min. unlike the seconds at 6 that is running all the time
RWG Technical Posted August 30, 2011 Report Posted August 30, 2011 Agree with the above. This version heen around for a long time, 6 years or more... Transfer gears are not an issue since they only come into play for 2 seconds each minute while the chrono is running. As with any A7750, if the watch is a keeper, you should have it serviced and cleaned and oiled and adjusted.
treadmark501 Posted August 31, 2011 Author Report Posted August 31, 2011 thanks Andy & The Zigmeister it seems like this particular A7750 movement in the PAM 288K does NOT have a "working regulator"??? so, does that mean the accuracy cannot be adjusted if it's running fast/slow??? seems like there are a few different version of this "modified" A7750 movement???
treadmark501 Posted August 31, 2011 Author Report Posted August 31, 2011 look at this pic, taken from puretime, of the "modified" A7750 in PAM 288... it doesn't have the +/- sign on top of the main spring... so does that mean this movement can not have the time accuracy adjusted to faster/slower by nudging that little bar on top of the main spring? this seems like a "cheap" A7750 movement?
Bike Mike Posted September 2, 2011 Report Posted September 2, 2011 See the 2 "arms" off the balance bridge...the one with the 2 "spots" of brass...that is your regulating arm. On the underside there is a "fork" that adjusts the length of the hair spring. Move that lever clockwise and you basically shorten the length of the hair spring decreasing the balance swing, causing a increase in the rate. Works just the opposite way moving the arm the CCW. What you are looking for is typically used for micro adjustments.
treadmark501 Posted September 4, 2011 Author Report Posted September 4, 2011 Mike, so if I move that regulator arm "clockwise" to shorten the length of the hair spring, which will increase the rate, that will make the seconds faster a bit? & what is "micro adjustments"? thanks.
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now