Accutron 700 meter

[ManSkirtBrew]

I finally feel like I have the confidence, tools, and fine motor control to tackle these tuning fork movements. I've got my 700 test meter here (in beautiful shape with the original box, I might add!) and it seems to work as it's supposed to, at least with one of those 1.35v diode batteries in it.

I'm planning to phase the watches for silver oxide cell voltage at 1.65v, so what I'd like to do is use my low voltage power supply to supply the test meter, and so I don't have to keep buying cells. I feel like I saw a thread where someone made a dummy 343/344 cell with power leads on it. Anyone have pictures or a link to that?

 

[JohnR725]

  On 5/29/2023 at 6:37 PM, ManSkirtBrew said:

1.65v,

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I think if you read carefully it's actually phased or verified the phase at several voltages not a fixed 1.65 volts.

then I assume you saw this page on the variable voltage power supply but if you scroll down they modify the meter which means you to just attach your leads they are in one about the back or someplace or put a plug on the front and bypass the battery input on the front

http://members.iinet.net.au/~fotoplot/accps.htm

or if you can find a sensitive enough microamp meter analogue preferred which gets to be really hard today. I'm basically using an entirely different meter so I never modified or changed my Bulova meter.

then I'll have to leave a note to myself and look for something later I don't have time. When you go to the website they talk about this new procedure to phase for silver cells but is it really new? I'd see an article in a magazine that I downloaded recently so I need to track it down from somebody who worked at Bulova and I've seen other references to this what the factory did is a little different than what we do for instance here's a specification sheet we know the watches designed to run specifically at 1.35 V or else but notice the high-voltage check? Notice the year it other words the factory was checking watches at a higher voltage long before we grasped that we would have to do it. this is also why the power supply that they used in the factory was variable so they could go to the higher voltage.

 

 

 

[ManSkirtBrew]

Thanks @JohnR725. I'm still absorbing information, but my thought was to use the 700 test set just for the ammeter, with the variable power supply providing the voltage.

I've been reading the procedure here, which seems to imply that's what they're doing. Emphasis mine:
 

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Phasing the 214, 218 and 2210

...index and pawl jewels set exactly as per the Bulova workshop manual for the movement in question. If you are using the Bulova 700 test set in conjunction with your variable power supply, make sure it is set to "Read Microamps".

...the pawl bridge performs two tasks: the first is to move the pawl jewel towards the index wheel to attain the correct finger tension, and the second is to move the pawl jewel along the index wheel periphery to adjust phase...set the pawl jewel so that it is less than 1/2 jewel away from the index wheel when the pawl bridge is set to its "furthest away" position...swing the index jewel away from the index wheel and see that the finger gage is set to minimum clearance to the index finger, but not touching (adjust as reqd.), then swing the index finger back into the index wheel until the clearance between the finger and gage is about 1 to 1 1/2 jewel thicknesses. Check the pawl bridge lock screw and make sure it is snugged up enough to provide slight resistance when turning the adjusting cam. Also, double-check the pawl bridge pivot screw to make sure it is tight.

1) Make sure that the index and pawl fingers are set to their correct pre-phase tensions and positions as above. With the movement in its holder, and the power feed clip applied, raise the voltage of the power supply to about 1.05v. Very slowly turn the adjusting cam until the index wheel begins to turn. This places the pawl jewel on the index wheel, but in a random location. This is the "first run phase"

2) Continue to turn the cam very slowly until the index wheel stops. The index jewel tip is then centered near to the root of a tooth relative to the fork's neutral point. Remember, we are running at low amplitude here, a bit over 1 tooth. Because of the "draw" of the pawl jewel pushing the wheel backwards, the result is no forward motion of the index wheel. It just vibrates back and forth. This gives us a known starting point of the index mechanism as a reference to establish pawl finger tension and also locate the phase position.

3) Continue to turn the cam very slowly until the index wheel starts again and begins to run smoothly. We have now reached a point where the index jewel at rest is situated approximately 1/2 way along a tooth, and thus accurately enough in phase for a 1.35v cell. Also, the correct pawl finger tension has been established. This the "second run phase". What is left to do is to take it one step further to achieve the most accurate phase adjustment possible, more accurate than the standard factory recommended procedure can achieve. This will allow us to take maximum advantage of the high volt overhead.

4) At this point, raise the power supply voltage to about 1.75v. See if the index wheel is running normally or fast. If fast, then very slowly adjust the cam a small amount either way to find a spot where the watch again runs at normal speed. Be very careful not to depart too far from the original position found in step 3, or you might end up in another "cycle" of phasing (ie. + or - 1 whole tooth) whereby the pawl finger tension would be wrong.

5) If step 4 went well, then again increase the voltage to, say, 1.80v and repeat the process. Keep increasing the voltage a small amount and keep readjusting until you reach a point where you no longer can stop the wheel double indexing. Then drop the voltage back to the last known level that worked reliably, and re-phase. You get the idea, we are trying to "creep up" to the absolute maximum voltage that we can with the index wheel running normally. If you are able to get the watch to run ok at 1.80 - 1.85v or more, the watch should run fine on a 387S cell.

6) If you can't get the watch to run normally at more than 1.75 - 1.80v, then you have another option: You have so far phased the watch using the run-stop-run technique for finding the "second run phase" and fine tuning it for the highest voltage. Now, you can continue turning the phasing cam past the recommended point and on to the next phasing cycle - the "third run phase". Repeat the process of homing in on the highest voltage as before. This has the effect of slightly increasing the pawl finger tension, and thus increasing the "draw" by a small amount. Often, this is all that is needed to get a satisfactory result.

7) If you still can't get the watch to run normally at more than 1.75 - 1.80v after completing the above steps, and double checking that the train is perfectly free and the fork is not obstructed in any way, then you have only a couple of options: a) changing to another index wheel, coil assembly or fork and re-try, or b) use an Accucell or c) expect that the watch may run ok on the nightstand or display case, and possibly gain a little during wearing.

 

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I'm left with two questions:

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See if the index wheel is running normally or fast

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1. Should we just be able to tell that by eye, or is there a measurement to be taken?

2. Am I understanding correctly that the uA reading is just to verify the electronics are working properly, and not used during the phasing procedure?

[HectorLooi]

Is that a 218 movement? 218s are a good starting point to learn Accutron repair. They are infinitely simpler than 214s.

The uA are an indication of the amount of current drawn. It should be within the current range for the movement. An abnormally high current could indicate a faulty circuit, a dirty gear train or a high amount of pressure of the pawl/index fingers on the index wheel.

A high current draw will result in short battery life.

The adjustments to the index finger that we are talking about here are incredibly small.

My 218 just died on me after two years. I found that it's due to an open cell coil. Looks like it's time to build a jig to do coil rewinding as working coils are getting really hard to find. 

[JohnR725]

  On 5/29/2023 at 10:58 PM, HectorLooi said:

Looks like it's time to build a jig to do coil rewinding as working coils are getting really hard to find. 

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There used to be somebody out there that didn't do this but I think he got overloaded and work and doesn't do it anymore. Then when you're making a machine for winding coils about a machine to make index wheel's.

 

Then I figured out where I put the information on phasing for silver cells. I'm attaching a PDF on that.

 

1996-08-web horological times Accutron silver cells phasing.pdfFetching info...

[ArtK]

Hello all. I am new to this group. I own two Accutron 700 test meters and one spare d’arsonval movement in its housing. Does anyone know someone experienced in evaluating the caps, etc., and tuning up or restoring these devices for a fee? I am most interested in. I am in New York State. Thank you

[JohnR725]

  On 4/15/2025 at 1:41 PM, ArtK said:

Does anyone know someone experienced in evaluating the caps, etc., and tuning up or restoring these devices for a fee?

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What makes you think that your meter needs to be restored does it have a problem?

Unfortunately I don't have time to do this but I'll have to come back to the discussion and restore the links because it looks like the links up above are broken and I think they do exist they are just not pointing to where they need to point

Then it's good that you gave the number there's actually two separate meters I believe is a 600 and a 700. The preferred approach today is not to restore but to modify with the simplest modification to change the meter to working with silver cell batteries which have a higher voltage than Mercury cell batteries. But a preferred approach would be to make use of the meter movements because that is a very nice analog meter which works really well for tuning fork watches and to produce a variable voltage power supply to use with your very sensitive microamp meter.

I did find the missing links from up above their down below and on one of the links if you poke around far enough you will find the schematic for your meter but just in case. Is

Then the link to how to properly phase with silver cells although what's interesting is that Bulova actually did check their watches at a much higher voltage. In a case here's one of the ways the phase at a higher voltage  Which is I believe one of the broken links up above

https://www.accutronwatchpage.com/accphs.htm

Here's a webpage where someone modifies their meter which is a wild guess is probably the same person who drew the schematic up above based on his name and the initials on the schematic

https://www.accutronwatchpage.com/700meter/700meter.html

I really hate websites that do not link to their home page but here's the homepage L notice that both links above are actually on this website

https://www.accutronwatchpage.com/