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Some Bulova Help Please


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Hello Louis,

Sorry I did not pick up on this thread earlier but have been on a few days break, there was a watch fair in Solihull and I paid a visit.

I must say that the watches you have found are treasures and the prices leave me in awe.

The Accutrons are a tad testing but you seem to be going about things the right way. You do not have to pay for the PDF sheets they are all on line as they are now in the public domain.

You may have found this link already but in case you have not

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

You will definitely need a stereo microscope that will allow depth perception and gives about 70X mag. As the index wheel is a piece of work about 2 mm wide with 320 teeth. Also a meter to test the coils etc.

Also be careful not to touch the index wheel with anything metal on the edge, plastic tweezers are needed.

Must go for now but look forward to more on my return home.

Cheers and welcome from an extremely jealous Vic

 

Howzit Vic ,  Look at what I picked up today...I'm also looking at the holder with the plug port .

The only thing is , I don't yet know how to use the meter . Any ideas ?

 I've looked at a few Stereo microscopes also.....those are neat , but a little bit of an investment . I've been looking a some that are 90X mag with an LED light ring ......Yikes , where am I going with all this ?

I forgot to mention that the meter is a working model .

 

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Edited by ricardopalamino
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Hello Louis,

 

The instructions are usually in the PDF Service Manuals.  I have the same sort of meter but found that It needed to use a power supply as described on the iinet link.  It is quite simple and runs off a 9V battery and is used in conjunction with a voltage meter.

 

post-197-0-96614800-1437469014_thumb.jpg

 

The meter you have also uses the movement holders that come with it but I can't see them in the pic you posted.

 

 

post-197-0-99163900-1437470456_thumb.jpg

 

The iinet link also has instructions on the use of the meter you have bought, you will find some of the features are now redundant in modern terms but it is still of value.  I recommend you soak yourself in the info off that link as many questions are answered along with instructions on phasing.  I found it of tremendous value.

 

here is something that you may not have come across yet, these specs give an idea of the complexity of the watches and the sheer achievement in their production so many years ago.

 

Accutron_Specs.doc

 

 

Cheers,

 

Vic

 

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Sorry Louis,

 

The link is the one we discussed in in the early postings ie the Accutron Watch Page.

 

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

 

You need to go through this site with a fine tooth comb because there is a wealth of info there for the taking including the circuit diagram for the power supply I made.

 

Good luck with the auction and make sure the holders are the correct ones.  I only mess with 214 and 218x models but there may be holders relevant to other movements - I am not sure.

 

Cheers,

 

Vic

 

 

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I repair the Accutron in the U.S. and on the 218s 99% of the time the cell coil is what is bad. If you do not hear a hum after replacing the battery tap the watch at the 9 marker and still no hum then you can bet the cell coil is bad. They are not cheap but you can find some on ebay once in a while. Remember the battery goes in upside down. If I can assist just let me know.

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Thanks once again Vic for the great info and material . The movement holder I am going to bid on is the same as the one in your pics .

 

Aloha lowcountry , I do appreciate you adding your experience to the conversation . If I may ask , What part is the cell coil you are referring to ?  One of the coils on either side of the tuning forlk? I do know that one of the coils serves 2 purposes...the left one I think . As I said any info is appreciated . 

 I have just recently become a fan of these interesting watches . The way that they work is intriguing to me ,.....definitely a challenge to work on .

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Hello Louis,

 

There is an extract below from that site I keep referring to, I know I keep going on about it but you need to read through it to get a good idea about phasing and generally working on the Accutrons.  It is possible to forge ahead and look things up as you go but you run the risk of getting into bother and knacking something up - slow down and read a little (I suppose you may expect this advice from a Senior Citizen :D) . 

 

I agree with lowcountry on that particular fix but there are two cell coils (one of which is a doubler that triggers the transistor) so it is good practise to test each coil to ascertain which of them is fouled up. The test is simple enough and all you need is a resistance test on your meter. On a 218 remove the screw at the top middle that joins the two coils together as you can not test individually when the circuit is through both.

 

The Right side coil or single coil has two contacts and if you are getting a circuit there it is usually ok - infinite resistance it is knackered.

 

The Left side or double coil has three contacts loosely shaped like a triangle - top(T), lower left (LL) and lower right (LR).  You should get circuits between T and LR, T and LL, LL and LR - any infinite resistance and it is knacked.  There is a possibility if the coils are working but the watch is not that some part of the little circuit board has failed but personally I would check for other things like indexing or perhaps has the tuning fork become demagnetised - if yes you need a new one - if anyone can advise me an easy way of remagnetising a tuning fork I would be grateful but I think it was set up at the factory for each fork so it may not be possible for a tinkerer.

 

Also if the coil does not move freely on the magnet due to accumulations of dirt that screws things up.

 

"Power from the battery flows through the transistor, and then through both of the driving coils. One of the coils (the one which is attached to the plate holding the transistor and its components) also has a secondary coil built into it. When the fork springs one way, this secondary coil provides a feedback voltage which causes the transistor to almost stop the flow of current in the driving coils, and stop driving the fork. When the fork springs back the other way, this feedback coil generates a "reverse" voltage, which causes the transistor to allow current to flow in the driving coils again. The fluctuating current in the driving coils produces a varying magnetic field, which alternately attracts and repels the tuning fork magnets. Thus it keeps on vibrating. The system is self-regulating. If the watch receives a jolt which adds to the fork vibration, the circuit automatically reduces power to the fork until it reaches the normal amplitude of vibration. The reverse is also true. While I said it is simple, it took quite a lot of work to develop the electronics to vibrate the tuning fork at the right amplitude, and yet work at such a low current that a battery would last at least a year."  - Not my words, thanks to R. Berkavicius for educating me with this info.

 

Hope this helps and as usual if anyone sees that I have got something wrong please post a correction I make mistakes sometimes ! - I will not be upset - quite the contrary, I will learn.

 

Cheers,

 

Vic

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Vic provided a very good description on how it works. What I learned is the coil on the left in a 218 with the transitor is called the component coil and the one on the right is the cell coil. In my experience I replace more cell coils than component coils. But you need to test both as Vic stated. Good luck and if you need any assistance let me know.

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Howzit Vic ,


 


  I have a NOS Cosmotron with tags , and I just acquired an original condition Hisonic last night .


  I also have a Seiko Elnix , Seiko EL-370 , Hamilton Electric , Elgin Electronic 105 , Gruen Precision Electronic and several Timex Electrics and Electronics .

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Vic provided a very good description on how it works. What I learned is the coil on the left in a 218 with the transitor is called the component coil and the one on the right is the cell coil. In my experience I replace more cell coils than component coils. But you need to test both as Vic stated. Good luck and if you need any assistance let me know.

I got this drawing on the points to test the coils from the net...

 

post-808-0-36040300-1438009580_thumb.png

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Aloha lowcountry and Vic ,...Help ....

I removed the plate for the date mechanism on an Accutron 2180 and the date trip spring flew out . I never worked on this model and don't know how to fit it . I have been trying to get a pic off of the internet to see the placement in the movement including the service manual with no luck yet . Do either of you gentlemen have a pic or drawing ? Even a hand drawing would help ...........Thanks , Louis

 

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Thanks Vick , but that's not the same spring as the one in my post . I had come across that blog in my search  , but that spring has a little hook that goes into a hole on the date plate . I've so far done a few of those . The one in my post does not have the hook , just straight ends . I'm sure it goes in the same place on the watch but I don't know how it's secured without the little hook .

 

  FYI , I received the Accutron 700 test meter and the movement holder with the jack in it...neat . The power supply you built that's connected to your meter is for what ? To supply power for testing instead of using a button cell ?

 

I appreciate your help and Info Amigo ,....Laters , Louis

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