ETA 7750 calibrating/adjusting/regulating

[samgher]

I bought a new ETA 7750 and replaced the asian of my SMP. The movement is loosing 4 minutes per day. I read other post about adjusting the asian 7750's but no information about original swiss ETA.

The movement has a calibrating lever (marked with + and -) and the pointer is near the "-" mark. I know that this lever could be used to correct small deviations (seconds), but what happen it gains or looses several minutes per day?

Edited June 16, 2009 by samgher

[RWG Technical]

Find a real watchsmith locally who has the skills and tooling to check beat and rate. Have both adjusted.

Most of these surplus movements are handled so much that the adjusting levers get moved and are out of adjustment.

I don't recommend you try adjusting the rate lever only, too risky and without knowing that the beat is correct you could end up damaging the movement.

[samgher]

You were wright. The adjusting levers were out of adjustment because of handling. I decided to adjust by myself turning one of the levers clockwise, by trial and error. The isochronism now is +5 seconds per 24h in different positions (was -4 minutes before). I will find a watchsmith to check if all is ok (is very difficult to find a watchsmith in Peru).

Edited June 25, 2009 by samgher

[a_iverson]

I will refresh the topic.

My pam 087 is beating little bit to fast and it's going to friendly watchmaker, however he never worked before with rep movements. 

Therefore I have a question. 

Does the standard calibrating lever (red circle) works in Asia rep movements or he has to use the one in blue circle? 

Picture borrowed from puretime, 

I have exactly the same movement. 

[a_iverson]

Pam is back :-) 

Movement is now with in 3 seconds. Calibrating lever (the one in the red circle) doesn't work, it can be moved back and forth without any sign on chronocomparator. 

It looks like the only way (without disassembling down entire movement) to slow the movement down or speed it up is the lever from the blue circle. However it is very, very sensitive. You can easily speed up or slow down the movement 10-15 second per day by moving it a quarter of millimeter sideways. So be careful ;-) 

Maybe it will be helpful for somebody. Cheers.:-)