SEIKO Watch Repair
Charlie Darwin
that was running fine until recently when it started losing about 5 minutes
a day. Battery is fresh and tests good and battery compartment contacts all
are clean.
Wonder is something like this is cost effective to fix?
Sjouke Burry
Only visible with a microscope.
N_Cook
news:gtns3i$fpr$1...@news.albasani.net...
Not a watch repairer so just a suggestion. If its been jarred or maybe just
old age the quartz crystal may have fractured or mounting shifted. If you
can see a 2 wired barrel about 1mm diameter and 3mm long then try replacing
that with one from any scrap board from anything that has a clock on board.
AFAIK they are all the same frequency.
--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
AZ Nomad
Look inside for a tiny screwdriver adjustment. Try turning it a bit
one way and then see if it loses less or more time. Once you know which way
is faster and which way is slower you can start making daily adjustments.
BTW: I looked up the watch; it's worth about $35.
The website had it out of stock, but there are plenty of other models
from the same era available.
AZ Nomad
>Charlie Darwin <ch...@beagleno.net> wrote in message
>news:gtns3i$fpr$1...@news.albasani.net...
>> Got a 1970's vintage men's metal bracelet Seiko quartz watch (0903
>movement)
>> that was running fine until recently when it started losing about 5
>minutes
>> a day. Battery is fresh and tests good and battery compartment contacts
>all
>> are clean.
>>
>> Wonder is something like this is cost effective to fix?
>>
>>
>Not a watch repairer so just a suggestion. If its been jarred or maybe just
>old age the quartz crystal may have fractured or mounting shifted. If you
>can see a 2 wired barrel about 1mm diameter and 3mm long then try replacing
>that with one from any scrap board from anything that has a clock on board.
>AFAIK they are all the same frequency.
Huh? all quartz crystals are the same frequency? Where'd you get
that notion? I doubt there are less than a half dozen
frequencies used commony by watchmakers alone.
Bob Larter
I thought that 32.768KHz was the common one?
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
msg
<snip>
> When a piece of quartz aka xtal is put under pressure it oscillates at
> 32,768hz. That's been the standard for time keeping until it was
> discovered that cesium atoms vibrate at a constant frequency now
> that's the standard.
>
> You can cut quartz crystals to oscillate at different frequencies
> obviously but an uncut xtal vibrates at 32,768.
There are many online references for xtal theory and specifications;
here is a short but useful doc: http://www.us-electronics.com/files/crystals.pdf
It contains links to authoritative papers on crystal theory and use in
timekeeping.
I have never seen reference (except in New Age tomes) to 'uncut' xtal
resonant frequencies; care to elaborate?
Michael
AZ Nomad
>On Thu, 07 May 2009 22:57:44 +1000, Bob Larter
><bobby...@gmail.com>wrote:
>>AZ Nomad wrote:
>>> On Tue, 5 May 2009 07:27:57 +0100, N_Cook <div...@tcp.co.uk> wrote:
>>>> Charlie Darwin <ch...@beagleno.net> wrote in message
>>>> news:gtns3i$fpr$1...@news.albasani.net...
>>>>> Got a 1970's vintage men's metal bracelet Seiko quartz watch (0903
>>>> movement)
>>>>> that was running fine until recently when it started losing about 5
>>>> minutes
>>>>> a day. Battery is fresh and tests good and battery compartment contacts
>>>> all
>>>>> are clean.
>>>>>
>>>>> Wonder is something like this is cost effective to fix?
>>>>>
>>>>>
>>>
>>>> Not a watch repairer so just a suggestion. If its been jarred or maybe just
>>>> old age the quartz crystal may have fractured or mounting shifted. If you
>>>> can see a 2 wired barrel about 1mm diameter and 3mm long then try replacing
>>>> that with one from any scrap board from anything that has a clock on board.
>>>> AFAIK they are all the same frequency.
>>>
>>> Huh? all quartz crystals are the same frequency? Where'd you get
>>> that notion? I doubt there are less than a half dozen
>>> frequencies used commony by watchmakers alone.
>>
>>I thought that 32.768KHz was the common one?
>When a piece of quartz aka xtal is put under pressure it oscillates at
>32,768hz. That's been the standard for time keeping until it was
>discovered that cesium atoms vibrate at a constant frequency now
>that's the standard.
>You can cut quartz crystals to oscillate at different frequencies
>obviously but an uncut xtal vibrates at 32,768.
bullshit.
It depends on the crystal's dimensions.
Michael A. Terrell
Bob Larter wrote:
>
> AZ Nomad wrote:
> >
> > Huh? all quartz crystals are the same frequency? Where'd you get
> > that notion? I doubt there are less than a half dozen
> > frequencies used commony by watchmakers alone.
>
> I thought that 32.768KHz was the common one?
There are different 32.768 KHz crystals. Variations in load
capacitance, tolerance and temperature range.
--
You can't have a sense of humor, if you have no sense!
William Sommerwerck
dimensions. The shape of the cut has an effect on the way the crystal's
frequency varies with temperature.
William Sommerwerck
news:2q3kdb....@news.alt.net...
> On Thu, 7 May 2009 14:24:28 -0700, "William Sommerwerck"
> <grizzle...@comcast.net>wrote:
>> The frequency at which a crystal oscillates is largely dependent
>> on its dimensions. The shape of the cut has an effect on the way
>> the crystal's frequency varies with temperature.
> So how is the crystal's dimension achived? Is it grown for a specific
> frequency? And what other factors are involved.
Generally by cutting, then grinding. The final trim is usually done
adjusting the capacitive loading.
I don't remember when Western Electric first started growing crystals (50
years ago?), but, yes, the growth size would be a factor, too.
bz
> When a piece of quartz aka xtal is put under pressure it oscillates at
> 32,768hz. That's been the standard for time keeping until it was
> discovered that cesium atoms vibrate at a constant frequency now
> that's the standard.
>
> You can cut quartz crystals to oscillate at different frequencies
> obviously but an uncut xtal vibrates at 32,768.
The size of an uncut quartz crystal varies from microscopic to many inches.
Some huge quartz crystals have been grown.
The frequency of resonance is inversely proportional to the size.
Slices are cut from the 'raw' quartz crystal, the orientation of the cut
determines the temperature coefficient of the crystal, the oscillation
modes, and the magnitude of the piezo electric effect.
As far as I know, no 'uncut' quartz crystals are used in any watches.
Where did you get the idea that they were?
--
bz 73 de N5BZ k
please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.
bz+...@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
William Sommerwerck
> how quartz timekeeping was achieved but made no specific
> specifications on how the crystals were made for watches.
> I thought it was a little odd myself being a amateur radio operator
> for 20 years having used gear controlled by crystals before PLL
> circuits.
Actually, PLL synthesizers /are/ quartz-controlled.
I believe watch crystals -- being so small /and/ having to work at very low
frequencies -- are cut quite differently from RF crystals. In fact, I think
some are cut like tuning forks. (Correct me if I'm wrong.)
Bob Larter
> On Sun, 10 May 2009 11:06:42 -0700, "William Sommerwerck"
> <grizzle...@comcast.net>wrote:
>
>> "Meat Plow" <me...@petitmorte.net> wrote in message
>> news:2q3kdb....@news.alt.net...
>>> On Thu, 7 May 2009 14:24:28 -0700, "William Sommerwerck"
>>> <grizzle...@comcast.net>wrote:
>>>> The frequency at which a crystal oscillates is largely dependent
>>>> on its dimensions. The shape of the cut has an effect on the way
>>>> the crystal's frequency varies with temperature.
>>> So how is the crystal's dimension achived? Is it grown for a specific
>>> frequency? And what other factors are involved.
>> Generally by cutting, then grinding. The final trim is usually done
>> adjusting the capacitive loading.
>>
>> I don't remember when Western Electric first started growing crystals (50
>> years ago?), but, yes, the growth size would be a factor, too.
>>
>
> frequency. I thought that's what i said in the first place.
Dude, they've caught your troll. Give up on it. ;^)
bz
news:guc2vs$cd0$1...@news.motzarella.org:
You seem to be right http://www.absoluteastronomy.com/topics/Quartz_clock