7750 versions balance differences and etachron tool questions

[GenTLe]

Hi All,
as I'm quite new to this world, I'm not really aware of the various evolutions of the movements.

One of the things I noticed, because I received a partial 7750 from MBK on RWG (thanks again!) to use for spare parts, is that there are different balance co:ks and hairspring studs & regulator systems around.

 

a. Can someone tell me something about them?

 

Second shot of questions: after I've read this: http://www.timekeeperforum.com/forum/threads/adjustment-and-regulation.21105/I discovered the "EtaChron" system and that these things needs adjustments.
b. Do the bergeoun etachron tools fit the various eta Movements like the 2836?
c. Do they work in the same way?
d. And how to handle these regulation with the a7750 that have only the etachron stud (if it has it at all!)?

 

 

For example this is like the one I received, no etachron at all and different co:k shape:

 

 

Then there is this (etachron stud, not etachron regulator):

 

 

 

 

And finally the supposedly gen eta (is this a gen? It's on wiki, but those blue screws...) completely etachron.

 

 

 

Thanks!!

[ceejay]

First up the Blue screws...

 

The top grade COSC ETA movements have the blue screws, that's why the Chinese copy the blue screws to mimic the top grade movements.

 

Next have a look at this http://people.timezone.com/library/horologium/horologium631674031715938957

 

Hope this helps?

[GenTLe]

Hi CJ: not really (I have already seen that site months ago).

Mainly I am interested to get how to adjust Asian 7750 without the etachron (if possible at all), to get if the bergeon etachron tool fits the Asian movement where that system it is used (like 2836) and, finally, if there is around a not-crazy-priced bergeon compatible tool or if Bergeon are the only one producing this thing.

Thanks for the reply in any case!