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Longines VHP accuracy

40104 Views 122 Replies 14 Participants Last post by  ronalddheld
Fellow watch nerds!

I have a Longines Conquest VHP watch that runs too fast. Faster than the 10 seconds per year that Longines advertises with. My watch gains 5 seconds per month. Almost a minute per year.
I have been keeping an eye on it, for a few months now, and it is very consistent at gaining one second every 6.5 days.

It might be due for a new battery since it is almost 8 years old. The second sweep still moves every second though.

It has been quite good so far, although I have not paid it as much attention before. I think it used to be one or two seconds out per month.

Anyone else has experiences with a VHP? I read that the rate can be adjusted when serviced. Is that a good idea? Who could do that?

It is a 1999 Conquest Perpetual Calendar Calibre 546. It has 'L1.632.4' inscribed on the back. Not too sure what that stands for.

Cheers
Hans.
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Hans, your theory about step 3B makes sense. It might be the missing link. Yes, it can happen that the watch has an "on switch" (crown position 0) for safety reason and for avoiding draining of the battery in the shop (as you mentioned)...
Hans, I just had a chat with my Brother who knows a great deal more about electronics than me. He helped me with the calibration or rather I helped him as he is the handyman in the family. The bottom line is: in his opinion, you are right, that extra step is needed!!! He even added that he should have known better and should have realised the importance of the 0 position of the crown straight away.
Take it as a compliment, Hans!:-!
So the 11-steps guide becomes the 12-steps guide:
1. Remove the battery (leave the crown at position 1 - neutral).
2. Connect needles to the '+' and '-' terminals. (See in diagram on page 19.)
3. Connect the 3V external power supply to the wires that are soldered to these needles.
4. Push the crown to position 0 then release it back to position 1 - that action is needed to switch the watch on - then wait for the date ring to complete its turn.
5. Pull the crown to position 3.
6. With one more needle connected to the '+' of the external power supply; tap the 'C-' or 'C+'terminal X times. (The direction and the number of pulses depend on the current rate of the watch. See the manual for more info.)
7. Push the crown into position 1.
8. Wait 5 seconds.
9. Disconnect power (remove the needles).
10. Insert the battery and close the watch.
11. Push the crown to position 0 to switch the watch on. (The seconds-hand will start to run.)
12. Set time as you would normally do.

Well, looks like our group effort finally got this thing right.

I look forward to your result, Hans, using the latest formula.

Our friend, David, might want to use the latest guide too for his attempt to calibrate his Longines. I'm sure he too will post his findings for this forum.
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Once we get confirmation that this works, this is definitely going in one of the stickies! (Probably references makes sense.)
7-steps instruction guide for calibration of the non-perpetual VHP:

1. Open your watch.
2. Pull the crown to position 3.
3. Connect a wire (or needle on the wire) to the '+' of the battery; tap the 'C-' or 'C+' terminal X times.
4. Disconnect wire/needle.
5. Push the crown into position 1.
6. Close the watch.
7. Set the time as you would normally do.
Thank you for this summary. I will use it as soon as I re-establish the running rate of my watch. (I have been neglecting it since I purchased The Citizen). One small point of clarification; I assume you regard the crown as being in position 1 when it is pressed fully home into the body, as opposed to the perpetual models which apparently have a further spring-loaded crown position referred to as position 0?
Thank you for this summary. I will use it as soon as I re-establish the running rate of my watch. (I have been neglecting it since I purchased The Citizen). One small point of clarification; I assume you regard the crown as being in position 1 when it is pressed fully home into the body, as opposed to the perpetual models which apparently have a further spring-loaded crown position referred to as position 0?
You are welcome, mspil!
That is right: position 1 is the normal position of the crown ("pressed fully home").
Well, I just delivered 5 retard pulses to my Perpetual VHP... but, I confess, in the confusion of making sure the wife didn't short the leads I am not sure if I pushed to position 0. Oh well, we'll all blunder through this somehow! :-d

I'm looking forward to getting my 'new' VHP dual xtal back from the jeweler (he is trying to get new links for the bracelet from Longines... I got it from Asia and it is missing a number of links.) That watch should be easier as it doesn't need battery removal.

One point for the other Perpetual owners, did you have a plastic insulator under the battery?

If so, I'll have to fabricate one for the eTime 1.01 (my build from scratch VHP... yes, I'm still working on it... I'll post all the problems when it is done or given up on!). The bare Longines movement I got didn't have an insulator. (At least I'm finding this out before assembly!)
Well, I just delivered 5 retard pulses to my Perpetual VHP... but, I confess, in the confusion of making sure the wife didn't short the leads I am not sure if I pushed to position 0. Oh well, we'll all blunder through this somehow! :-d

I'm looking forward to getting my 'new' VHP dual xtal back from the jeweler (he is trying to get new links for the bracelet from Longines... I got it from Asia and it is missing a number of links.) That watch should be easier as it doesn't need battery removal.

One point for the other Perpetual owners, did you have a plastic insulator under the battery?

If so, I'll have to fabricate one for the eTime 1.01 (my build from scratch VHP... yes, I'm still working on it... I'll post all the problems when it is done or given up on!). The bare Longines movement I got didn't have an insulator. (At least I'm finding this out before assembly!)
Yes, Jim, my Longines has a plastic insulator under that large lithium battery.
I wonder if your calibration attempt was a success. The jinx is there for anyone who tries to calibrate that beast...:-d
I've had another go at the correction. This time with the 'on switch'. Good name that!

Got caught out with one minor thing: Pushing this 'on switch' makes the date ring spin one complete turn. This seems to be quite a drain on the battery.
After the correction I put the battery back in and pushed this 'on switch' again. The date ring advanced only one number, then stopped.
A fresh battery made the date ring do its proper trick. The battery was 8 years old anyway; it did not seem to have the strength left for moving dates along.
The second arm was still moving every second with that old battery.

I'll keep an eye on the rate.
There will be more adjustments to come. I want it perfect.
Psychiatrists probably have a name for that.
There will be more adjustments to come. I want it perfect.
Psychiatrists probably have a name for that.
Yes -- two that I'm aware of:

1. heqphoria -- a state of kharmic bliss one enters when one's watch attains 1 second per year, and

2. heqphilia -- we won't go there. :-d
Oh, and by the way, as long as we're on the topic of proper HEQ terminology ...

Fellow watch nerds!
We HEQers much prefer the term "we-who-think-detailed-descriptions-of-our-watch-accuracy-tests-make-ideal-cocktail-party-topics". :-d
That would make for how many of us throughout the world?
:-!
One step closer to heqphoria!
My watch has stopped ignoring me.

It looks like I have over-corrected it, but at least it proves it responds to the correction.

Now I'll have to wait a few weeks to get some good numbers.

Thanks guys!
:-!
One step closer to heqphoria!
My watch has stopped ignoring me.

It looks like I have over-corrected it, but at least it proves it responds to the correction.

Now I'll have to wait a few weeks to get some good numbers.

Thanks guys!
Cool Hans! I look forward to the report.
:-!
One step closer to heqphoria!
My watch has stopped ignoring me.

It looks like I have over-corrected it, but at least it proves it responds to the correction.

Now I'll have to wait a few weeks to get some good numbers.

Thanks guys!
Good on you, Hans!:-!
Now, it's official: we have the right formula!:thanks
Once we get confirmation that this works, this is definitely going in one of the stickies! (Probably references makes sense.)
Bruce, Hans just confirmed that the 12-steps guide is the right one for the ETA 252.611 (perpetual calendar with 3V lithium battery). For the rest of the Thermolines (including the perpetual calendar with normal 1.55V battery) and the earlier dual-oscillator ETA movements, the 7-steps guide is the right formula.
For the stickies you will find the 7-steps guide in post #30 and the 12-steps guide is listed in post #41 in this thread.
Thanks.
It was real teamwork, thanks to everyone who got involved! We've done it!:-!
OUTSTANDING!!! |>|>|>

Posted in the Reference sticky.
Looks like this story has a wee tail.

A few observations over two days all points to the fact that I've overshot my mark.
Instead of applying 14 pulses to go slower I must have administered 7 too many.
The watch went from 1 second gain per week to 0.5 second loss per week.
That is still an improvement but hardly an accurate adjustment.

Did I lose count?
Hardly.

It must have been the way I applied these 'impulses'.
I applied them as one would push a button. Holding it down a second or so.
That seems to be too long and is interpreted as several impulses.

Next time I'll try a quick tap method.

Cheers
Hans.
See less See more
Looks like this story has a wee tail.

A few observations over two days all points to the fact that I've overshot my mark.
Instead of applying 14 pulses to go slower I must have administered 7 too many.
The watch went from 1 second gain per week to 0.5 second loss per week.
That is still an improvement but hardly an accurate adjustment.

Did I lose count?
Hardly.

It must have been the way I applied these 'impulses'.
I applied them as one would push a button. Holding it down a second or so.
That seems to be too long and is interpreted as several impulses.

Next time I'll try a quick tap method.

Cheers
Hans.
It is an interesting and very important observation, Hans.
You must be correct: the quick tap method is the way to go!|>
Looks like this story has a wee tail.

A few observations over two days all points to the fact that I've overshot my mark.
Instead of applying 14 pulses to go slower I must have administered 7 too many.
The watch went from 1 second gain per week to 0.5 second loss per week.
That is still an improvement but hardly an accurate adjustment.

Did I lose count?
Hardly.

It must have been the way I applied these 'impulses'.
I applied them as one would push a button. Holding it down a second or so.
That seems to be too long and is interpreted as several impulses.

Next time I'll try a quick tap method.

Cheers
Hans.
Don't feel bad... It looks like I did exactly the same thing. I'm running slow now. We'll get this right eventually :-d:-d
I am impressed you've managed to make a correction with the borrowed hands!
There doesn't seem to be enough space, even for my own two hands.

Thanks for catching a few of those arrows!
Don't feel bad... It looks like I did exactly the same thing. I'm running slow now. We'll get this right eventually :-d:-d
Gentlemen, I had a second thought about the "duration of the impulse" dilemma. Now, I am not that certain that it does matter at all. Isn't the impulse an "open or close" situation when the duration of the action does not really matter only the action itself? I am very much a layperson in these matters so I would welcome feedbacks from the experts.
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