zahc:
The tuning fork ends surround the coils. It does not look much like a musical tuning fork:
The tuning fork was actuated by a one transistor oscillator which was regulated by feedback from one coil of the tuning fork. The coils are inside the ends of each tine of the tuning fork, as you can see in the original photograph.
On one of the tines of the tuning fork (see inset in photo) there was a little tiny pawl which engaged a little tiny ratchet (the drive wheel or main wheel). As the pawl wiggled back and forth from the tuning fork, it turned the ratchet, and this ratchet was geared to the hands. I would bet that the problem with TommyGunn's watch is that the pawl or main wheel is worn out --these, besides the rest of the gearing, are the only wearing parts. However, the pawl ends were jeweled to minimize friction and wear.
Rebuilt Accutrons are available for as little as $700 if I recall correctly.
Really, for the age, it was a very advanced timekeeping system, especially since the components were all so tiny. The main wheel, that is, the ratchet, had hundreds of almost-microscopic teeth around its edge for the pawl to engage.
The watch, when running, emitted a 360Hz hum, which was annoying to some folks.
There are various repair services around for these watches, and you can google Bulova Accutron to see closeups of the drive and transistor and wiring. Some of the photographs on one of the sites are pretty crappy, but keep googling until you find nice, sharp macro photographs of the details, such as the one above.
One of the amazing things about it was that most of the connections were hand-soldered. (One of the wiring diagrams has an error, in that they show a direct connection from the collector to the emitter inside the transistor, which is impossible.)
The two green plastic parts in the previous photograph were known as the "kidneys." The left kidney housed the battery. The right kidney housed the circuitry. You can see a resistor in that one, and I'm not sure if the cylindrical metal object underneath it which looks like the crystal in a modern watch is the transistor or the capacitor --I just forget which. (There
was no quartz crystal in this watch. The time base was the tuning fork.)
This watch was obsoleted by the first successful quartz crystal-regulated oscillator watch by Texas Instruments, one of which I bought right away. The tremendous technological advance in the TI watch was the miniaturization possible because of the then-still-new Large Scale Integrated Circuits --which was TI's business in the first place. The dial was a tiny red LED display and remained off to save battery power. You pushed a button to activate the dial LEDs and show the time. Unlike the Accutron, there were no moving parts inside the TI watch. (Except, of course for the very tiny mechanical vibration of the quartz crystal itself --a forgiveable exception.)
The major problem with my TI watch was the plastic wrist band, which broke right where the tongue of the buckle went into the holes of the band.
Mine looked just like this, except it was plain black, with no Star Wars stuff on it --an intriguing all-black hunk of plastic on my wrist:
Terry, 230RN
(All photo credits in properties.)
