When I first bought my copy of Pieter Doensen’s excellent book, “Watch. History of the Modern Wrist Watch”, I was amazed by that movement photograph on the back cover. What on earth was it? It looked so complicated but I decided that I just had to find out more and, hopefully, eventually own one. It is, of course, the Longines calibre 6512 from a Longines Ultra-Quartz — the World’s First Cybernetic Watch,
As it turned out, this was the only cybernetic watch ever produced. I guess the thing that makes this watch so unique is the presence of the large number of discrete electronic components (resistors, capacitors, transistors) rather than a single integrated circuit (IC), and all of them appearing to be haphazardly soldered together! It is truly the Bird’s Nest of movements.
So what is a “Cybernetic” watch? Rather than me get it wrong, it is all explained in the Tech Bulletin scans below
This is a rare watch; I’m not sure how many were made but very few survive and even fewer are running. Over the last 4-5 years, I’ve obtained a couple of working examples but even more broken ones,
It’s the movement that makes the Longines Ultra-Quartz so special; known as the Cal. 6512, no other manufacturer used it or the principles implemented in it. Longines described three Modules in this movement. These are each described fully in the Tech Bulletin scans above, but briefly they are Electronic Module, Conventional Module and Motor Module. Some of the text below refers to these Modules.
First is a photograph of the complete movement. The battery would occupy the space in the top right.
The next photograph shows another movement with the Motor Module removed; the second photograph shows the Motor Module outside the movement. This module does exactly what it says: from the vibrating coil, it generates an impulse to drive the hands. The impulse is created through an indexing system that is identical in nature to the one used on Bulova Acutrons and ESA 9162/9164s.
The picture of the movement below also shows some sort of repair to the cannon pinion top pivot which is part of the plate with the writing on. This seems to be a common problem with this movement; I have several busted 6512 movements and others show repairs/alterations to this area. Compare this with the same area on the good movement above.
The next two photographs show the silver coloured torsion bar, counter weight and coil from the Motor Module. You can also see the indexing pawl + jewel that engages with the Index Wheel, also part of the Motor Module. In this example, the torsion bar is slightly bent which has resulted in the coil touching the sides of the permanent magnets (see photo of the complete Motor Module above)…and the coil is now open circuit and useless.
Although the Electronics Module is complicated with all that soldering and all those components, it is this delicate coil that fails on these watches…and, I suspect, usually due to careless handling and / or adjustment.
Literature on the Ultra-Quartz is scarce, so I’ve never seen a Longines Sales Brochure that might highlight the various Ultra-Quartz models. Having said that, after researching various Internet sources, there seems to be only two case styles: one is a square style while the other is a traditional shape for a round faced dial. Both appear to be available in either a heavy gold plate or stainless steel and various dial colours were available.
The dials on the round faced models are superb. The way the second hand passes underneath the hour markers is very striking.
This last watch appears to be a factory conversion: the Ultra-Quartz movement has been replaced with a quartz movement. The rear crown has been removed and replaced with a conventional side crown.