How long does a XO last?  Would you buy them surplus 20+ years old?   - Page 1
Forum section: electronics / projects

author: alank2
author_rank: Super Contributor
timestamp: June 18, 2015, 08:37:22 pm
content: How long does a XO last? Would you buy them surplus 20+ years old? Epson branded ones. If you wouldn't go this old, how old would you go. For a product you have to support and warranty.

author: tggzzz
author_rank: Super Contributor
timestamp: June 18, 2015, 08:42:50 pm
content: I didn't realise you could buy executive officers (XOs). I presumed you had to train them.

author: lincoln
author_rank: Regular Contributor
timestamp: June 18, 2015, 08:47:46 pm
content: Just a plain crystal? If the specs fit your need there is nothing really to go wrong with them (unlike caps ect.) Newer parts tend to have better stability & accuracy specs per a given form factor.what are you planning on doing with them?OCXO tend to get more stable as they age but that assumes they have been powered the entire time.

author: Gyro
author_rank: Super Contributor
timestamp: June 18, 2015, 08:49:55 pm
content: It depends on the XOs and how they've been stored. If they're the standard hermetic metal cans then there shouldn't be any internal degradation.Storage issues depend on packaging, original manufacturers packaging, ESD protection etc.One thing that is a problem is if they've been stored together in a bin or a bag. That clinking sound is multiple 100G shocks. It's been know to cause big problems on production lines and something that crystal manufacturers warn against.If you're looking at individual surplus units then they should have very long life, in fact getting more stable as they age (certainly powered). No problem with 50 year old XOs in vintage instruments.

author: alank2
author_rank: Super Contributor
timestamp: June 18, 2015, 08:58:39 pm
content: Crystal oscillators, like this:http://www.digikey.com/product-detail/en/SG-615P%2016.0000MC0:ROHS/SER2212TR-ND/1022021

author: Gyro
author_rank: Super Contributor
timestamp: June 18, 2015, 09:05:12 pm
content: Wow, did they make those 20+ years ago? I guess they must have (sign of getting old).In that case it really comes down to storage. If they're still reeled and you're confident that they've been stored properly then they should be fine.Oh, they're smd - you should follow Epson's recommended pre-bake for moisture if they're not still sealed, even if they are the desiccant may have gone off by now.

author: alank2
author_rank: Super Contributor
timestamp: June 18, 2015, 09:08:08 pm
content: They are still reeled. So no worries then if stored correctly to use in a new product?

author: Gyro
author_rank: Super Contributor
timestamp: June 18, 2015, 09:53:20 pm
content: Of course it's your warranty, so your risk. But if you're confident in the packaging and storage then I don't believe there's any specific aging issue. Just be sure they're properly dried before you mount them.You might just want to hold on for a few more replies just in case.Oh, they probably aren't ROHS if that's an issue for you.

author: macboy
author_rank: Super Contributor
timestamp: June 19, 2015, 01:37:39 pm
content: Quote from: Gyro on June 18, 2015, 09:53:20 pmThis afterthought might be the single biggest consideration. 20 years ago is definitely pre-ROHS. They might be OK but I would not take that bet.

author: IconicPCB
author_rank: Super Contributor
timestamp: June 19, 2015, 10:45:00 pm
content: Napoleon XO only gets better with age.