Quartz crystal help

[glewis721]

hi everybody
i have some quartz crystals that i can't decypher. Google was not helpful for any of them.

#1 sayes on the side: 12.0000 B and a T inside a diamond, seems like a company logo.
#2 sayes on the side: 14.31818 MGP 95 19 44
#3 sayes on the top: A143K9E
#4 sayes on the top: 3579.545 KC
#4 sayes on the side: 103-89 then a logo or something of the like that i can't make out
#4 sayes on the bottom, stamped in red between the leads: 2-67

i am certain that they all are quartz crystals

all measurements are not counting the leads.
#1 measures 1.2 cm X 1 cm X 0.3cm
#2 measures the same as #1
#3 measures 0.3 cm X 1 cm X 0.3 cm
#4 measures 2 cm X 1.8 cm X 0.7 cm

QUESTION:
what are the # of hertz of each crystal?

P.S. What does "low profile" mean in terms is these crystals?

 

[KrisBlueNZ]

"12.0000B" is probably 12.0000 MHz
"14.31818" will be 14.31818 MHz. This frequency was used in old PCs and is a multiple of the NTSC colour subcarrier frequency, 3.579545 MHz.
"3579.545 KC" will be 3.579545 MHz, the NTSC subcarrier frequency
I can't suggest anything for the others.

Edit: Low Profile means low height. For through-hole obround-style metal can crystals mounted with their leads pointing downwards, the old style, HC49/U, stands about 14 mm high. The low profile type, HC49/US (S stands for short, I guess) stands about 3.7 mm high. The other dimensions are about the same.

 

[glewis721]

thanks! i need 1 w/ 16mhz

 

[duke37]

That would need a big, big, big crystal.
I suggest you make a 16MHz oscillator and divide by 10^9.

 

[glewis721]

really?! because what i need is a crystal, 16MHz, low-profile
dont know if that changes anything

 

[duke37]

The change from 16mHz to 16Mhz changes an awful lot !

I do not know suppliers in the US.

 

[KrisBlueNZ]

duke37 is making a joke. The unit that you used, mhz, means millihertz. (Actually it should be mHz.) You corrected it in your latest post.
16 MHz crystals are widely available. Maybe not from Radio Shack, but from many other sources. Digikey, Mouser, Fry's are ones I know of in America.

 

[glewis721]

sorry it is MHz

 

[glewis721]

well the unknown one, #3, came from an old computer (but not ancient) motherboard. the comps model is unknown

 

[glewis721]

what is the symbol for crystals, and are they polarized?

 

[(*steve*)]

There are two different things. Not sure which ones you have or which one you want.

The first is an actual crystal. This will have 2 connections and is non-polarised.

The second is a crystal oscillator module. These typically have 4 legs. Two are for power, one is for the signal output, and the other one may be unused or have a function. These are clearly polarised.

 

[glewis721]

I have the 2 pin ones

 

[(*steve*)]

They look like a capacitor with a box drawn between the plates.

See here.

or look at this

 

[KrisBlueNZ]

And no they're not polarised. You can tell this from the fact that the schematic symbol is not polarised, i.e. it looks the same either way round.

 

[glewis721]

Ok thanks!