In 1973 Hamilton introduced to very similar "self-winding"watches. Self-winding was the 1970's term for automatic. The Auto-Saratoga was offered in 14K yellow gold electroplate and the Yorktowne came in a stainless steel case.
In 1975 Hamilton dropped the Yorktowne moniker and named both versions Saratoga - although perhaps it's best named Auto Saratoga (stainless steel)
I recently purchased a Yorktowne / Saratoga and it arrived in better than average condition. I don't know when it was last serviced so, like all projects, it's first stop after arrival was a trip to the spa.
The outside of the casebook is very plain and just says stainless steel - water resistant and the model number 815001-3. The "-3" means the bezel is stainless steel. I suspect the yellow version would be the same numbers except have a "-4" at the end.
One way to tell a 1970's watch from a 1960's watch is the inside of the case back. A pre-1970 watch will have "Hamilton Watch Co - Lancaster PA" inside the case back. Post-1970 watches tend to be more plain on the inside.
There are no ETA markings on the 818 but you can tell it's an ETA grade based on the classic ETA-shape of the oscillating weight.
One of the subtle changes to movements starting in the 1970's is the set lever screw isn't a screw - it's a detent that you push in with a screw driver to get the stem out. You have to be careful not to push it too far though - or you may need to remove the dial to get it back into position.
The dial is held in position with two levers that press against the dial feet. You need to swing the levers out to free the dial feet so the dial can be removed.
Here you can see one of the levers is released. The other one is under the balance cock and a little harder to access (and photograph).
With the dial removed you can see the dial-side of the main plate looks very familiar to other ETA grades from the 1960's.
The rotor assembly is held on with two blue-colored screws. Once it's lifted off the movement will look more like a manual winding movement.
This sort of reversing wheel setup looks like what you might see on a 1950's ETA movement like the 672 - except the oscillating weight is held on differently.
Unlike the 672, the 818 has a much better design for attaching the oscillating weight.
It seems to me like the balance wheel is much larger than on earlier grades - which is funny since it swings considerably faster.
The first thing to come out is the barrel bridge and mainspring barrel - once the spring tension is relieved, of course. Then the train bridge can come out next - allowing access to all four wheels in the gear train.
The next to last thing to take out is the balance wheel itself. This could really come out anytime but I tend to work my way from the mainspring to the balance.
The last thing off is the pallet fork - only one screw holds it's bridge in place. Now everything can go into the ultrasonic cleaner.
All the parts are nice and shiny now and ready to go back together with fresh lubrication. Several different oils are used in ETA movement like this. The escape wheel, pallet fork and balance get a lighter weight oil than the rest of the train. Then the setting parts, mainspring and rotor assembly are oiled too.
The first things back in are the gear train. Everything will spin nicely when the train bridge is properly in place. Getting all four wheels to line up can be a finicky proposition but with patience the train bridge will drop right into place. No force is required (nor will the parts tolerate it).
Now that the train bridge is on, the pallet fork can be reinstalled. One movements with only a wheel or two under the train bridge I will often put the pallet fork in first. However on movements like this it's best to put the pallet fork in after the train - as the pallet jewels could make adjusting the escape wheel harder if the pallet fork was already in place.
Now the mainspring barrel goes in and I'll put a dab of microgliss lubricant on the clutch and winding pinion.
The barrel bridge and ratchet wheel are back in place so the watch can be wound up. With energy stored in the mainspring, the balance should start moving once it's reinstalled in the right place.
Success - the watch is ticking away. The 21,600 BPH rate is noticeably faster than an 18,000 grade.
According to the timer, everything is spot-on... no tweaking necessary.
The setting parts, cannon pinion, etc. get reinstalled an a little more microgliss lubricates the set bridge. Now the hour wheel can go on top of the cannon pinion and the dial can be reinstalled.
The dial is re-secured and the hands are pressed back on at 12:00 so I know they're in sync.
You need to check the alignment of the hands from this angle too - to make sure they won't run into each other.
Now the oscillating weight can go back on. At this point the movement is ready to go back into the case.
Two case screws secure the movement inside the case and the movement ring locks it all inside. Now I just need to screw the case back on and it's off to the light tent for it's "pillow shot".
Voila - the watch turned out great and it runs as good as it looks. I really like the red second hand. I may look for a new strap with a red accent to complement it. The brown strap that came with the watch is decent enough but it's a little on the boring side. I think this watch deserves a strap that will make a more bold statement.
UPDATE: Here's another shot of the watch with a new strap. It's a carbon-fiber strap with red stitching. I think it make a big difference... don't you?