Citizen Hisonic

August 28, 2020

So where to start with this one. Well it was given to me by a friend, He had bought it in a job lot and figured it was not one he could ever fix.

The Citizen Hisonic uses the Bulova Accutron tuning fork 218 movement that Citizen could use under licence. You don’t see many of these for sale here in the UK. Japan is where you will find the most of them.

On inspection I did not think this one would run again either as all I could see was battery leak everywhere ruining all the parts. This was a good thing however. If you have read my Accutron 218 post you will know I was worried to service these as it was something I had never worked on before. So to have a seemingly un-repairable one gave me the perfect opportunity to learn this movement without any fear of breaking a working watch.

As you can see here the dial and watch look quite nice but that movement looks very poor.

I removed the watch from the case to get a better look at the dial in preparation for disassembly.

The dial has some nice patina possibly caused by the battery leakage evaporation. The hands have some tarnish but its not permanent.

I started to disassemble, I knew the dial side from doing my Bulova so started with that first. In a mater of only a few minutes it was all stripped down.

It was very apparent that the leakage from the battery was considerable, What is hard to know if if this was from an original 1.35v mercury battery that they would have been originally been running on, or a 1.5v silver oxide battery added later. To run a 1.5V some adjustment to the phasing / regulation of the watch is required or its possible the watch will not run at all on 1.5v.

Either way things appear to be pretty bad. Oh well onto the movement side, Up until now I had never taken the drive side of the 218 apart so I was vert careful as I undone every screw and removed each part.

I actually found this quite a simple process, nothing too scary other than the index wheel that has 300 teeth and is only 2.4mm diameter. I had been told to handle these very carefully as thy are delicate and hard to replace without buying a whole movement. Rodico was my best friend for this.

Again as you can see on these photos that there is considerable corrosion. At this point though I pleased just to accomplish the disassembly.

The next question was how to clean this mainplate. I decided that I would first off all wash it in my ultrasonic in warm soapy water. After drying I then dipped it into silver dip solution as this usually removes tarnish from brass. It worked well and improved the colour considerably.

After this I then ran all parts and main plate through the watch cleaning machine for good measure.

Now for the rebuild. Despite is fairly straightforward disassembly I knew the assembly would be a bit trickier being my first time. I had the manual so knew what went where and some of the tricks to fitting so started on the movement side, you first have t fit the hacking leaver and other small parts before presenting the tuning fork up and whilst resting in position then fit both coils into the fork before screwing everything down.

Once at this position its time to locate the train wheels in place. There is a sequence and the tricky index wheel is the third one to fit. After fiddling and using rodico to get the wheel in position you can then put the train bridge on and use an oiler or tool to coax the pinions into their jewels to then screw the bridge on without the fear of breaking a pinion. At first this is a really tricky procedure but for me now I have done it quite a few times its allot simpler. This watch though probably took a good 15 minutes to get everything lined up!

I then fitted the keyless works so I could install a battery and take the watch out of hack. Doing this meant I would then be able to phase the fingers on the index for it to run. Problem was it would not run! I was not really that surprised and after testing I found that a coil had to be dead .

I stripped it all back again to get at the coils and found that the one nearest the battery was at fault. On the microscope I could see that the tiny copper wire was missing from the contact. A copper coil is just that one long coil of wire so if there is a break it wont work. I had no spare coil. Again after some time I found a tiny trace of the wire and decided to try to bridge the connection. So i added a load of solder to the joint and then used conductive paint to run from the solder to the copper wire .

I had no idea if this would work but hey I had nothing to loose. The paint takes around 2 days to cure so I just left it on my bench.

Once all back together I installed the battery and again nothing. I had read that sometimes an Accurtron needs a bit of a whack at 3 or 9 to kickstart the fork vibration. I did this and to my surprise I heard the hum. I engaged the pawl lever finger and that tiny index wheel went spinning like crazy.

Brilliant. I was so surprised but also a big sense of achievement came over me. Given the state of this watch the possibility that now it would work was such a great feeling.
Once the dial and hands were back on I found that it just would not run right which eventually lead me back to the index finger. This little part is fitted to a post on the fork with a collet and transfers the vibrations of the fork to motion on the wheel. I could see there was a crack in this collet and then adjusting the index in the collet slot the collet broke in two…
Basically the collet was not being held rigid enough for the vibrations to transfer. A replacement was needed…

One was found though some weeks later but fitting would mean a full strip down yet again. No choice I had to do it but then its also gaining experience all the time.

After another rebuild the watch finally worked as it should. I had to phase for a 1.5V battery but this is not too difficult to do

So here it is the finished watch! I wear this both on a bracelet or a leather strap depending on how I feel. Great bit of learning on this watch and another one saved.

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