Is there an expiration date for Capacitors and Resistors?

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canidoit

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NOS Caps and Resistors, is there a use by date? I mean if you buy NOS caps and resistors from the 60's like people do with Tubes, would they still be great to use?

How about Ceramic caps, if you LIGHTLY use them for like a couple of years in the 60's and then pull them off out of a circuit and re-use them 40 years later, would they still be good? They measure on the Multimeter fine and they still looks new with no signs of external damage or burn smell.

I read somewhere that Ceramic Caps are more durable and acceptable for re-use and can stay in storage longer than other caps, is there any truth to this?

Which types of caps would you say can be re-used and less riskier to re-use?
 
Electrolytic caps have a limited shelf life as the dielectric material dries out over time. I believe high voltage electrolytics (for HT power supply filtering, etc.) last even less long than low voltage types. I think most off-the-shelf, high voltage electrolytics generally have an "intended" shelf life of around ten years or so. Of course, in practice, they'll often last much longer and the low voltage types even more so (just check out all the thirty plus year old electronic equipment still running on the original electros).

Tantalum caps these days I believe are better than those of the past in terms of failure rates. In any case, I'd avoid reusing tants as when they do fail, they tend to fail as a short rather than an open circuit like most other caps, so can take out other parts of the circuit when they do go. Best to use new parts here...

Carbon comp resistors are pretty notorious for drifting in value over time with use. Some capacitor types are also more prone to drifting but I don't know which are better or worse for this (could it be that paper in oil types tend to go bad over time?). No idea about ceramic caps, sorry. My *guess* would be if they measure ok, then they'll probably work ok too, but hey, that's not really saying much...
 
ritz said:
Electrolytic caps have a limited shelf life as the dielectric material dries out over time. I believe high voltage electrolytics (for HT power supply filtering, etc.) last even less long than low voltage types. I think most off-the-shelf, high voltage electrolytics generally have an "intended" shelf life of around ten years or so. Of course, in practice, they'll often last much longer and the low voltage types even more so (just check out all the thirty plus year old electronic equipment still running on the original electros).

Electrolytic caps: datasheets mention longer life when they're charged (at least the common Philips blue ones, but it's understandable, so it'll be a general mechanism I figure).
So that might explain that a cap in equipment that is often used keeps going on while a virgin cap on the shelf is no longer usable at a certain point in time. There'll be other mechanisms at work though that might cause failing of the active cap (on/off-cycles etc).

Bye,

  Peter
 
clintrubber said:
ritz said:
Electrolytic caps have a limited shelf life as the dielectric material dries out over time. I believe high voltage electrolytics (for HT power supply filtering, etc.) last even less long than low voltage types. I think most off-the-shelf, high voltage electrolytics generally have an "intended" shelf life of around ten years or so. Of course, in practice, they'll often last much longer and the low voltage types even more so (just check out all the thirty plus year old electronic equipment still running on the original electros).

Electrolytic caps: datasheets mention longer life when they're charged (at least the common Philips blue ones, but it's understandable, so it'll be a general mechanism I figure).
So that might explain that a cap in equipment that is often used keeps going on while a virgin cap on the shelf is no longer usable at a certain point in time. There'll be other mechanisms at work though that might cause failing of the active cap (on/off-cycles etc).

Bye,

  Peter
Thanks

Do you think that a person should regularly turn their equipment on if they do not plan to use it for a long period of time. I have pieces of gear that I may turn on once a year like certain pre-amps, compressors or fx, etc. I am wondering whether I should atleast turn it on for 15 minutes once a month to prolong the life of the components inside.
 
canidoit said:
Thanks

Do you think that a person should regularly turn their equipment on if they do not plan to use it for a long period of time. I have pieces of gear that I may turn on once a year like certain pre-amps, compressors or fx, etc. I am wondering whether I should atleast turn it on for 15 minutes once a month to prolong the life of the components inside.

It's a very valid question, but wonder if anyone has the definitive answer on this. We know that some people keep large desks powered 24/7 for various reasons. Not doing that but switching things on/off once in a while will sure freshen up dusty caps a bit, but causes also additional transients etc etc. A new Brewery #2 might not be enough to hold all ideas & opinions on this...

So: I dunno. I could add an opinion, but it'll be one of the many.

Bye,

  Peter
 
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