HOWTO Determine Unknown XTAL Freq

[news.cogeco.ca]

Good day.

I recently removed some crystals from some old electronic devices but do not
know what frequency they are.

Is there an easy and accurate way to determine their freqs?

Thank you.

-Tim

 

[Phil Allison]

"news.cogeco.ca"

I recently removed some crystals from some old electronic devices but do
not know what frequency they are.

Is there an easy and accurate way to determine their freqs?

** Try reading the labelling.

Nearly all crystals are printed or stamped with their frequency in MHz.




........ Phil

 

[Radiosrfun]

Good day.

I recently removed some crystals from some old electronic devices but do
not know what frequency they are.

Is there an easy and accurate way to determine their freqs?

Thank you.

-Tim

What sort of equipment? That may tell us a lot. IF TVs for example, the
Color Burst Crystals are one frequency. If from say computers - there are
others used. Aside from that - they're usually stamped and if you can't make
them out - then a crystal tester with associated readout device would help.

 

[jcomeau_ictx]

I recently removed some crystals from some old electronic devices but do not
know what frequency they are.

Is there an easy and accurate way to determine their freqs?

I'm assuming you don't have an oscilloscope? You might be able to use
one at your local high school. If just hooking up the test leads
doesn't start it oscillating, get it going with a 9V battery through
some safe resistance, at least 10K probably.

I don't know anything about your electronics background, but if it's
an option, and you don't have access to a scope, you could build a
simple circuit with a PIC microcontroller and hook the crystal to it;
then program a delay loop and flash an LED with some fraction of the
crystal frequency. I don't know offhand what would happen if the
crystal frequency were too high for the uC though. Probably nothing
destructive, but you wouldn't get the correct reading. I'd get my
hands on a scope if I were going to do much messing with crystals
anyway. I've seen them pretty cheap on eBay but of course the shipping
charges will get you.

 

[John Fields]

 

[DaveM]

LMAO!!!!!!!!!!


--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)

Life is like a roll of toilet paper; the closer to the end, the faster it goes.

 

[jasen]

I'm assuming you don't have an oscilloscope? You might be able to use
one at your local high school. If just hooking up the test leads
doesn't start it oscillating, get it going with a 9V battery through
some safe resistance, at least 10K probably.

I don't know anything about your electronics background, but if it's
an option, and you don't have access to a scope, you could build a
simple circuit with a PIC microcontroller and hook the crystal to it;
then program a delay loop and flash an LED with some fraction of the
crystal frequency. I don't know offhand what would happen if the
crystal frequency were too high for the uC though. Probably nothing
destructive, but you wouldn't get the correct reading. I'd get my
hands on a scope if I were going to do much messing with crystals
anyway. I've seen them pretty cheap on eBay but of course the shipping
charges will get you.

a 4060 or two might be more convenient than a UC for this task.

Bye.
Jasen

 

[jcomeau_ictx]

a 4060 or two might be more convenient than a UC for this task.

It might, especially with a solderless breadboard. The basic idea is
to make the invisible visible, and how you do it depends mostly on
what you have available. My preference would be to use a
microcontroller, since I'm more familiar with them, and changing the
delay loop is just a matter of a few lines of assembly code rather
than changing wiring. The last time I used a counter chip (a 4040) was
13 years ago: http://www.jcomeau.com/hacks/?1994-01-01-01

What I don't know, not having a scope available, and never having
played much if at all with crystals, if a scope probe will start a
crystal oscillating by itself, or if a voltage needs to be applied
across it. I just bought one on eBay so I guess I'll find out in a few
days.

 

[Phil Allison]

"jcomeau_ictx" <[email protected]>


( snipe mindless drivel)


** **** OFF - Bloody Google IDIOT !!





........ Phil

 

[jcomeau_ictx]

"jcomeau_ictx" <[email protected]>

( snipe mindless drivel)

** **** OFF - Bloody Google IDIOT !!

....... Phil

Sounds like someone could use a beer.

 

[Phil Allison]

"jcomeau_ictx" <[email protected]



** **** OFF - Bloody Google IDIOT !!

You are a KNOW NOTHING ASS dishing out STUPID and WRONG advice.


CRAWL BACK UNDER YOUR ROCK


You pathetic, asinine Frog




......... Phil

 

[Chuck]

Good day.

I recently removed some crystals from some old electronic devices but do not
know what frequency they are.

Is there an easy and accurate way to determine their freqs?

Thank you.

-Tim

Yes. There are many easy and accurate
ways to determine the frequency of a
crystal. They require some test
equipment though. Rather than have the
group guess what you have and to what
lengths you might be willing to go to
determine the frequencies, why not give
us some more information?

I assume that if you had any of the
equipment that would be needed, you
would not be asking the question, and I
strongly suspect that your curiosity
about the crystal frequencies is not
commensurate with the expenditure of
time and money necessary to quench it.

Correct?

Chuck

 

[John Fields]

Sounds like someone could use a beer.

What he's trying to tell you, in a nice way, is that it seems that
you don't know what you're talking about.

You see, there are two things you could be referring to: a crystal
or a crystal oscillator.

If it's the former, then before it can be made to oscillate it must
be surrounded by circuitry which will force it to oscillate.
Neither putting a scope probes across it nor placing a DC voltage
across it will cause it to oscillate.

If it's the latter, then it's a "crystal oscillator" not a "crystal"
and it will contain the crystal and the circuitry needed to make the
crystal oscillate when it is supplied with the proper supply
voltage, not by putting a scope probe across it.

Go here for a clue:

http://www.ecsxtal.com/store/pdf/quar_des.pdf

 

[jcomeau_ictx]

Go here for a clue:

http://www.ecsxtal.com/store/pdf/quar_des.pdf

Thanks for the edification. I thought I made it clear that I was
guessing.

Different newsgroups have different cultures, and I'm not familiar
with this one yet. comp.lang.forth, for example, usually makes a
reasonable attempt to answer the OP's question before degenerating
into ad hominem attacks and other vicious sniping. Live and learn.

I still think the uC approach might work, but I have to dig up another
crystal to make a quantitative comparison. I'll post when I have
something concrete to offer.

 

[Phil Allison]

"jcomeau_ictx" <[email protected]

Thanks for the edification. I thought I made it clear that I was
guessing.

** Go shove your

FUCKWIT GUESSES UP YOUR ARSE !!


CRAWL BACK UNDER YOUR ROCK


You pathetic, asinine Frog Fuckhead



......... Phil

 

[Phil Allison]

"Chuck"

Yes. There are many easy and accurate ways to determine the frequency of a
crystal.

** Like reading the labelling on the damn things.

Wake up - the OP was some kid trolling.




........ Phil

 

[Michael A. Terrell]

Once again, Phyllis raises her ugly head and howls:

"Chuck"


** Like reading the labelling on the damn things.

Wake up - the OP was some kid trolling.

....... Phil

Ignorant little Aussie bitch. Some crystals are marked with channel
numbers, stock numbers, receive frequency where you don't know the
offset for the IF, or even unmarked after the PC board is unwashed.
Turn off the computer and take your hormones.



--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Phil Allison]

"Michael A. Terrell Psychotic Autistic FREAK"

Some crystals are marked with channel
numbers, stock numbers, receive frequency where you don't know the
offset for the IF, or even unmarked after the PC board is unwashed.

** Up to the OP to post that sort of info.

Since he has not come back, he is most likely a troll - or he read my
post, opened his eyes & realised the frequency WAS written on the damn
things.

Either way -

YOU can go a shove your pointy head up a dead donkey's backside where you
normally hide it.

**** BRAIN !!



........ Phil

 

[Peter A Forbes]

"Chuck"



** Like reading the labelling on the damn things.

Wake up - the OP was some kid trolling.




....... Phil

Thank Agent for killfiles....

***PLONK****

Peter

 

[Phil Allison]

"Peter A Fuckwit Forbes" <[email protected]>



** ROTFL !!

What a FUCKING MORON !!!


........ Phil