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How to distinguish Asian 21,6 7750 from 28,8 7750???

jj69

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1/12/06
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What is the easiest way to distinguish between different versions of the Asian 7750? How can I identify the latest 28,800 version of the 7750 as opposed to the older 21,600 versions?

Is there an easy way to tell once the case back is removed?
 

jj69

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1/12/06
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Just to follow-up with some more info, I'm trying to figure out if the IWC 3717 I just purchased has the new or old 7750 in it. As we all know, dealers have the 3717 available with both movements.

I read in an old post that if a 7750 has the little non-working fork-shaped regulator on the back, then it's the old version. Is this true? Do all high-beat 7750s have no regulator?

This one does have the fork-shaped regulator on the movement, so I think it's probably be the old 21,6 version.

The reason I doubted the movement in the first place is because the chrono seconds hand does not seem very smooth when the chrono is running. It's almost like watching the seconds hand on a quartz watch.

Anyone?


jj69 said:
What is the easiest way to distinguish between different versions of the Asian 7750? How can I identify the latest 28,800 version of the 7750 as opposed to the older 21,600 versions?

Is there an easy way to tell once the case back is removed?
 

jj69

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One last follow-up. Here's a pic of the movement in question:


 

trekracer20

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29/12/06
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Were you supposed to get one with a 28k movement in it? I'm not an expert, but I can't say that I've seen any 28k 7750s with that adjustment piece attached...
 

jj69

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trekracer20 said:
Were you supposed to get one with a 28k movement in it? I'm not an expert, but I can't say that I've seen any 28k 7750s with that adjustment piece attached...

It was supposed to be a 28k movement. I've never seen a 28k with the regulator either, but I wanted to make sure.
 

alligoat

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If I were to bet, I'd bet it's 21600 bph because of the arrow thing on the regulator- which Ziggy says doesn't even work when regulating the watch! The new ones don't have that thing. But the only real way to find out is to take it to a watchmaker and have him check it out on his machine- he can tell you for sure and it's simple to do.
 

digi

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2/9/07
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no one mentioned the obvious. Put it in your ear. You cannot mistake a 28.8 ticking.
 

merlin699

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18/8/07
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I'm pretty sure it's a 21.6
I changed mine with a swiss one and it looks the same (the asian one). To the adjustment piece I must say: it actually works - not in the quality of a swiss movement and you have to move the outer part of the mechanism and not the lever - but it works.
To the beatrate I have to agree to digi - 28.8 is a totally diferent sound :wink:
 

Krieg

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12/12/06
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digi said:
no one mentioned the obvious. Put it in your ear. You cannot mistake a 28.8 ticking.

I do agree. A 28.8 sounds very quicky to the ear.
 

robmpulse

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6/1/07
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damn, my beginmariner really does have the 28.8.

I was expecting it to be a lot smoother than it is visually......
 

Camris

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Well, just to clear a little bit up, The new 7750 with whats called a "free sprung" balance dose not have a regulator, it uses weighted screws on the balance to adjust the arc of the balance wheel, turn the screws out, it slows the watch down, turn them in to speed the watch up.

When adjusting a watch like this one ( with a regulator) you can do it two ways, make the adjust mements at the gate ( the part you referred to as the "fork) or at the regualtor lever which if for a much finer adjustment then moving the gate.

When you adjust this what you are doing is shortening or leangthening the hair spring so that it's rotation is faster or slower thus making the watch gain time or lose it.
making big adjustments to get it into the ball park then you can fine tune it.

After you have worked with watches for a while you can do all the adjustments at the gate and not have to adjust it further.

Timing is a huge subject and this is the bearest of an exspanation.

Calix
 

guru

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use the search option in this forum, you will find a lot of info