Help! cant find a Component in Uk.. a crystal!

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iainjh

iainjh

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hi, help!

"indiana jones and the search for the NTSC Crystal for apple" or similar here.

my apple ii needs a new crystal, but I cannot for the life of me find a supplier in uk or in europe for the right part. Anyone who knows where to find this particular component, please could they help! Its NTSC hence needs to be the right freq. 14.31818 MHZ and has to be a series resonant part.

its a particular part apparently - some crystals work but the apple only then outputs monochrome. I have bought some off ebay and the apple works perfectly, the display is rock solid but dammit, no color, just B&W. I need the right type and part.

14.31818 MHZ
series resonant
2 pin/ through hole type

i quote from an apple ii site:

"
It is 14.31818 MHZ. However not all 14.31818 MHZ crystals are the same. You need a series resonant crystal. Even then, not all series resonant crystals will generate the correct frequency in an Apple II circuit. For an Apple II to generate correct color burst, the only part that I have found that consistently works is Vishay/Dale part number XT9UNLANA14M31818. This is available from Mouser (part number 73-XT49U1431-S)."

Mouser list the 73-XT49U1431-S as obselete and its out of stock. ebay wont turn it up and i may be searching element14 wrongly..

apparently CMAC HC49 part works, but I cant find that either.

please help!

cheers all, iain

 
Oh boy, have I not searched forever for this too, to convert my Europlus to color.. For the risk of discouraging you, I gave up in the end, sold my Eurplus and bought an NTSC IIe with the crystal (and color) included.. ;-)
 
ill have a look in my parts box

EDIT: i have one you can have for postage i think,just send me a pm with your address and ill pop it in the mail when youve paid the postage bud
 
Last edited:
Thank you! It's a very specific " series resonant" is that correct?

ill pm you in the am:)

thanks!!!
 
How many would you guys want of these? They're like a dime a dozen around here...
 
i think I'm now set! But thank you v much for the offer. I can buy loads of parts but finding those particular parts THAT WORK.. nightmare in pal-land :)

cheers!

mods the thread can close I think
 
Please don't close.

I would like to try to find an equivalent which is not discontinued to help others.

The important factor when trying to find an equivalent in this particular case is the ESR or equivalent series resistance.

When searching on Digikey, I have found various crystals of 14.31818 MHz with ESR varying from 25 Ohms to 60 Ohms. Can you tell me the ESR of the original Vishay/Dale component?

ADDED EDIT:
the information on Mouser.com says the ESR of your original crystal is 25 Ohms.

Therefore this component available from Digikey should perform the job adequately (this is from ECS series HC-49UX):
http://www.digikey.ca/product-detail/en/ecs-inc/ECS-143-S-1X/X1021-ND/827513

I have located other crystals of 14.31818 MHz on Mouser.com and they are also from Vishay but the ESR is 40 Ohms and that's probably why they don't work properly with your specific application.

ADDED EDIT 2:
This other component from a different manufacturer is also series resonant with an ESR of 25 Ohms (this is from CTS-Frequency controls series MP):
http://www.digikey.ca/product-detail/en/cts-frequency-controls/MP143/CTX088-ND/67739

I hope having 2 gives more options.
 
Last edited by a moderator:
Although the ESR will decide whether it's suitable for Series oscillators, I doubt you'll find many Crystal datasheets that quote the ESR. Most parts will already tell you this in the part number. The datasheet will normally just list the load capacity value (Zero or S if series). Vishay for example use the following format:

Example: XT49U-16
A-RR-14M31

XT49U = Model Number (usually specifies the housing type)
16 = This is the coupling capacitor to be used. If this is missing or an S then they are usually series crystals.
A = Bulk packaging type.
RR = Further features such as working temperature range
14M31 = The frequency (May also be written in full ie: 14.31Mhz)

Bryce.
 
Ok, haven't noticed that before, but it's also not something that's really needed for most situations (including this one). In this case: http://www.ecsxtal.com/store/pdf/hc49ux.pdf all that you need to know is at the bottom of the page ie: Is there a load capacitance mentioned in the part number or is there an "S". Bringing ESR into it is complicating things more than you need to.

Bryce.
 
Hi I've not forgotten this thread, thanks all for help!

roy bates is very kindly posting me one.. I will also order a couple from digikey or if I find a supplier without a £12 shipping fee for a 50p part... Just to check and let everyone know if it works! There's bound to be a few Europeans who'd like to get color from their Apple ii's

ta for now
 
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Roy bates crystal arrived

still got a black and white display

i have a known good crystal coming from the USA, but in meantime I'll Nick the one out of my iie and try that. Perhaps I've not cut/ made the right traces on the motherboard and don't know that's it..

so thanks to Roy... More in a few days!
 
Can you describe how you modded the board or send a picture of it. It should be easy to see if you've done something that wouldn't work.

Bryce.
 
hi

right heres some info

first, I have now managed to get a crystal from an apple ii forum in the usa. and my apple outputs proper NTSC 3.58 in color. yay!

for the record, pal apple ii's (europlus at least) need several pads cut and made, pads 12,13,14,15,16. see the pic. These work.

FullSizeRender.jpgand evidence on CRT and LCD:

FullSizeRender (1).jpgIMG_2449.JPG

the crystal i got is exactly the one described above, supplied by mouser.
 
iainjh said:
the crystal i got is exactly the one described above, supplied by mouser.
Click to expand...
I assume you mean the one in the original post ( 73-XT49U1431-S ), correct ?

If that is so, since those from Digikey have identical properties, we can assume these will work too assuming you also cut the mentioned pads, correct ?

I don't have an Apple II, I'm just trying to document in case other people come up with a similar problem in the future.
 
Last edited by a moderator:
so,did the crystal i sent work or not,im not sure now?

as later on you was talking about getting another crystal but then talked about cutting traces?

so,im not sure if it would of worked or not
 
there are traces to make and cut on the board; I'd already done those, but it was still in black and white with a crystal I bought.

then your crystal didnt work either.

the one I got from the us, did.

so all happy! finally it works! I need send you postage dont i.

- - - Updated - - -

yes correct!

eslapion said:
iainjh said:
the crystal i got is exactly the one described above, supplied by mouser.
Click to expand...
I assume you mean the one in the original post ( 73-XT49U1431-S ), correct ?

If that is so, since those from Digikey have identical properties, we can assume these will work too assuming you also cut the mentioned pads, correct ?

I don't have an Apple II, I'm just trying to document in case other people come up with a similar problem in the future.
Click to expand...
 
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