Having featured hand winders, automatics and electro-mechanical examples, I thought I’d kick off 2012’s Featured Watches with the other type of movement I cover in the time frame of my collection – the electronic ‘tuning fork’ watch. Although made as a Citizen watch with its own ‘Hisonic’ name, the movement is in fact the Bulova Accutron which was licensed to a range of other manufacturers. Through this arrangement Citizen was able to bring this technology to the Japanese market for the first time, in 1971, using the 218 and 219 Bulova versions. Citizen manufactured the movements themselves, giving them their own movement numbers, and later supplied parts to Bulova. I understand American made Bulova parts and Japanese made ones are inter-changeable. Citizen’s version of the 218 Accutron was used in the Hisonics whilst the 219 was used in a Cosmotron model – more of that when I do the Cosmotron article.
The tuning fork movement significantly raised the bar in terms of watch performance – Bulova gave written guarantees that the watch would lose or gain no more than one minute per month. Here’s a really excellent article which gives lots of historical and technical information: http://members.iinet.net.au/~fotoplot/acc.htm
The advent of quartz technology killed off tuning fork watches, with production ending around 1977, so the Hisonics were produced for only a short while. They are high end time pieces – in Citizen’s 1973 catalog the cheapest retailed at JPY35,000, rising to JPY60,000.
My example is from September 1973, and would have cost JPY38,000 at the time:
The dial is marked ‘tuning fork’ and ‘hisonic’ along with the applied tuning fork logo – here you can see how the second hand has a solid centre, combined with a black and steel hand set:
Running at 360Hz, i.e. 360 steps per second, the sweep of the second hand is exceptionally smooth – here’s a one second exposure of the ‘beat’:
The movement in this is the 3701A – the date and day version, shown on the back. Some models had a gold medallion on the back rather than an engraved centre as here (the scratches are actually in the plastic film still on the watch a the time). The back is held by screw-in ring, and has a location tab so it only fits at this position:
The crown is signed – in normal position the date can be quickset, at one click out the watch is hacked and time can be set, at second click (fully out) the battery is fully disconnected when the watch is not in use:
Here’s the movement, with a nicely finished top plate – important to note that the battery is placed positive side down:
Here’s the license acknowledgement stamped at the top of the movement:
An original leather strap, with signed buckle:
The case measures about 38mm across, and about 41mm lug to lug:
I acquired this one in non-working condition, so it was not expensive despite its very nice condition. Luckily it was brought to life by Paul at ‘Electric Watches’, who is the go-to guy in my opinion for servicing and repair of electric / electronic vintage watches. I’ve added a link to his site in my Blogroll.
The watch is running very well, and is very accurate – I wore it over New Year and could see no discernible deviation over about 5 days 🙂
Sweephand's Vintage Citizen Watch Blog 
So glad to see the HiSonic covered here Sweephand. What an excellent website, with such nicely developed and fascinating coverage of Citizen watches.
Hi Eric, thanks for visiting my blog and for your kind comments. Here are a couple more hummers if you haven’t found them already:
https://sweep-hand.org/2012/05/21/this-weeks-featured-watch-33-the-cosmotron-gx/
https://sweep-hand.org/2014/03/19/this-weeks-featured-watch-57-cosmotron-gx-green-dial/
Stephen
What a brilliant website and just what I need now that I’ve become very interested in tuning fork watches.
However, I feel I may have just bought a “pup”.
The wording on the dial is the same as the one featured (but Stardust effect) with 3701 under the 6. But on the back cover it reads 3702 and on the movement 3702A.
Would this be a re-dial?
Any help/advice will be greatly appreciated.
Regards Rob….
Hi Rob, thanks for visiting and for your very kind comments 🙂 I would normally expect the dial code to match the movement in the watch, i.e. 3702. You’ll know I guess that Citizen produced 3700, 3701, and 3702 movements with day and date complications, so dials from each will fit, so I don’t think we can rule out for sure that the dial is an original. Can you please let me know what the case number is, presumably it’s in the form of 3702-xxxxxx.
Thanks, Stephen
Hello Stephen.
Thanks for your reply. The case number on the back reads: 3702-370287Y. I’ve included a photo of the dial. Regards Rob….
On 16 March 2017 at 19:36, Sweephand’s Vintage Citizen Watch Blog wrote:
> sweephand commented: “Hi Rob, thanks for visiting and for your very kind > comments 🙂 I would normally expect the dial code to match the movement in > the watch, i.e. 3702. You’ll know I guess that Citizen produced 3700, 3701, > and 3702 movements with day and date complications, s” >
Hi Rob – thanks for the info (although I’m afraid visitors can’t post pics here directly). Here’s an original 1974 catalog pic of this model, is this the same as yours?:
Stephen. Looks the same to me apart from the colour. My one is white.
Rob….
Sorry, I meant to add the serial number which is: 312308-44. Rob….
Ok, although I haven’t got a catalog pic, other colours were made. Here’s a white one for sale on Yahoo Japan. Hard to see the dial code but it looks like it might be 3701:
Stephen
Serial number gives December 1973 production. Looks like yours is all ok 🙂 Stephen
That’s good to know Stephen:-) I have a GX, now all I need is a diver. Thanks very much for all your help.
Regards, Rob….
You’re welcome Rob, good luck on your search for a diver. Stephen