| Re: Electra [message #3192 is a reply to message #3168] |
Mon, 03 March 2014 03:59  |
C. Hurt
Messages: 243
Registered: May 2013
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Gruen Guildsman |
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MikeTheWatchGuy wrote on Fri, 28 February 2014 16:23...What tipped you off?
I wasn't tipped off. I knew that Gruen analog electronics all used either PUW, or ETA-ESA movements. Watches using either PUW or ESA movements use the same electronic logo on the dial.
As far as dating, the details of the watch are more telling than the numbers.
First, the only electric (not electronic) watches in 1957 were Hamilton 500 Electrics, Lip comes along a couple of years later, as does the Accutron. Then everybody else starts offering electric and electronic watches using movements made by one of a few makers.
The ESA 9150 was the first transistorized balance wheel movement, and it was introduced in 1967. Chances are about 80% that any Swiss movement marked electronic rather than electric, and with a balance rather than a tuning fork, will be some variant of the 9150. You will occasionally see balance wheel electronic movements from France (Lip), Germany (Junghans or PUW), USA (Timex) or Japan, (Citizen or Seiko) but if it's Swiss, it's pretty much limited to ESA or Bifora, and they look nothing alike.
The battery strap in your watch is pretty distinctive, narrowing it down to the 9150 or the 9154, which look very similar, but have some functional differences.
[Updated on: Mon, 03 March 2014 04:03] Report message to a moderator |
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