Re: Why are consumer-grade quartz watches (deliberately set?) fast?

Generally speaking, it is considered better for a watch to run fast than slow - fast won't make you miss any trains. So mfrs (and watchmakers when they service) shoot for slightly fast, never slow. A lot of mechanical watches (cheap ones) leave the factory as much as 20-30 secs/ day fast .

Unless the movement is thermo-compensated (very few are) then the rate of the crystal will vary with temperature. The crystal is cut in a way that it runs at peak speed at 25C (77F - slightly warmer than room temp because watches are worn on the body) and runs slightly slow if the temperature is either hotter or colder - a 10C change either way will slow the crystal down by about 2 secs/ week, which would have put your watches about even. Someone who spends a lot of time outdoors might easily experience swings of 10C or even more - currently the temp in the NE US is below 0C or more than 25 degrees below 25C. The mfrs take this into account and set the crystal slightly fast.

Actually the way modern watch circuits work is that every crystal is cut to run slightly fast and then the circuit skips a designated # of beats every so often to make up for the overspeed (the crystal can be slowed down in this way but not speeded up) . The # of skips is set usually one time at the factory either thru burning lines on the circuit or thru eeprom (the latter might be re-programmable but in practice hardly anyone outside the factory has the machine to do it).

Modern quartz watches no longer have a "trimmer" but your desire for accuracy could be filled by a radio controlled watch and also there are some super-accurate movements on the market - IIRC the Seiko perpetuals (not very expensive - start at around $100 - sometimes even lower on ebay ) are good for 20 seconds/ year or less than 1/2 second per week.

Here is the bargain of the moment:

http://cgi.ebay.com/NEW-SEIKO-MENS-PERPETUAL-CALENDAR-WATCH-SNQ067_W0QQitemZ270500653197QQcmdZViewItemQQptZWristwatches?hash=item3efb18688d

$49 delivered - I'm almost tempted but Seiko "Speed Racer" styling does nothing for me and I could care less about whether my watch gains 2 secs/ week, .2 or 20 (which is about where my mechanicals are and I won't give them up). Perpetual means that the calendar is always right - it knows which months have 30 or 31 days and even about leap years (though the year 2100 will throw them off). Lithium battery good for 4 years or more. An insanely good deal. Too bad I don't like the watch.

"NadCixelsyd" <nadcixelsyd@xxxxxxx> wrote in message news:31830820-74ab-44f0-bbd7-847be742a6f2@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Let me digress: When I was a child some 60 years ago, consumer-grade
watches were accurate to about twenty seconds per day. Then, Bulova
invented the Accutron with a tuning fork, which was accurate to two
seconds per day. Thirty (+/-) years ago, quartz watches typically had
an accuracy of better than one second per day.

If they're tuned as precisely as pollible, some quartz watches should
be a tad fast, some should be a tad slow. However, I've noticed that
every quartz watch that I've ever owned runs a bit fast. So I tried
an experiment with two inexpensive quartz watches. Measured weekly
(using eyeballs and www.time.gov) over a period of four months
(without resetting), one watch consistently gained 3.5 seconds per
week. The other watch gained 2.5 seconds per week. In other words,
if I could adjust these watches to slow down by 22 and 15 milliseconds
per hour, respectively, they would have been accurate to within one
half second at all times for the past four months.

As a secondary question, are any consumer-grade quartz watches time-
adjustable? I realize that most consumers only need the time to
within a minute or two, but I'm finiky.

.

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