A few weeks ago I saw a sale posting here on WUS for this watch, and I contacted the seller, who happens to live 20 minutes away. We got together today and had a great afternoon geeking out about watches. (He has some beauties.)
I don't understand my own mind, because I think this Hamilton Electronic is totally cool with it's transistors and mechanical balance; yet one could argue that quartz watches are better in every way. Something interests me philosophically and poetically about our intermediate steps in the evolution of technology.
My friend discovered this in a watchmaker's desk removed from an old department store that went out of business. He found this in the drawer (along with some REAL gems.) He had it refurbished, then scrounged two additional movements with the same dial. Now I have this beauty and two backups for spares.
For those who don't waste all their time researching obsolete movements like I have started doing, here's some info: 1975 vintage Hamilton Electronic, using the Dynotron ESA 9158 movement (Hamilton Caliber 702). Slightly less accurate than a well-calibrated tuning fork movement, but much cheaper to manufacture. Quartz hadn't quite decimated the field yet, and all the good timekeepers were still expensive to build. There's actually a mechanical balance and mainspring with traditional lever adjustment which interacts with the transistor oscillator. I still need to research the electro-mechanical driving principle, information is a bit scarce. The seconds hand ticks 3 times per second, and listening to the movement up to my ear tells me there's a "back-tick" so it sounds like 6/sec. Physically, this watch is 38mm wide, 41mm lug-lug, with surprisingly wide 22mm lugs. The brown/gold sunburst dial is so 'Seventies, and the precise pale blue seconds marks give it a clean sense of detail. I am smitten.
These are the back-ups - two spare movements and a full spare case (purchased originally for the crystal)
Here's a close-up of the spare movement, but the "Hamilton 702" label is missing from the exposed spare.
And the fully functional watch: