NOS small value capacitors, worth it?

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wahee
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NOS small value capacitors, worth it?

Post by wahee » Thu Feb 06, 2020 6:12 am

I was able to get a large quantity of capacitors with a seeming date code of 1982.
I don't recognise the symbol on the case to get a manufacturer ref

Small value 1uf 35v polarised electrolytic capacitors

I measured a few and capacitance was around 1.1 to 1.2uf
Slightly higher than a modern equivalent

ESR and resistance same as a new quality capacitor

I suppose it's a matter of trying them and seeing if they are any good.

I just wondered if this is a false economy or OK for low voltage applications (repair of old drum machines etc)
Last edited by wahee on Thu Feb 06, 2020 8:50 am, edited 1 time in total.
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Re: NOS small value capacitors, worth it?

Post by KSS » Thu Feb 06, 2020 6:38 am

wahee wrote:
Thu Feb 06, 2020 6:12 am
I was able to get a large quantity of capacitors with a seeming date code of 1982.
I just wondered if this is a false economy or OK for low voltage applications (repair of old drum machines etc)
ok
Really tough call. For your own use? Sure. For paid work? No.

So much depends on things not shared, and maybe unknown to you. How were they stored? Was it hot, wet, dry, light, dark? Varying between all of these? Well cared for during part of their past, and left to whatever another part of their past?

*Some* early 80's electrolytics were really badly manufactured. But not all. Some so bad that computer motherboards were blowing up and the whole "must recap" movement got a push. Largely over-hyped push IMO.

Also depends on your own level of building experience and how prolific you are. New caps o fthat size aren't real expensive, but these you already have.

As said, it's a tough call.

I'd put a few -one at a time- across a typical power rail to ground, and scope the line to see how they're doing a real world use. Have in the past carefully re-formed much larger caps and had good results. Have used smaller older caps like what you've got in personal builds with no problems to date.

It's a crapshoot, really. So "you gotta ask yourself, Do I feel lucky?"

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wahee
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Re: NOS small value capacitors, worth it?

Post by wahee » Thu Feb 06, 2020 8:16 pm

hi thanks for the reply. Yes mostly for my own kit and to repair old gear I have. Not sure on storage, as they were from an electronics surplus supplier.

I was repairing an old Soundmaster STIX ST-305 drum machine and it has quite a few in the audio section. I removed them and found they were actually pretty much in spec so replacing these Rubicon 80's caps with unknown 80's caps seemed a bit pointless.

I'll do a bit of a voltage test as you suggest and see how they cope.
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oudplayer
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Re: NOS small value capacitors, worth it?

Post by oudplayer » Thu Feb 06, 2020 11:20 pm

aluminum or tantalum?

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Re: NOS small value capacitors, worth it?

Post by KSS » Fri Feb 07, 2020 12:00 am

oudplayer wrote:
Thu Feb 06, 2020 11:20 pm
aluminum or tantalum?
Aluminum and tantalum are *not* mutually exclusive. Tantalum caps with axial aluminum body, hermetically sealed cases were common before the epoxy dipped 'blob' types appeared.

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wahee
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Re: NOS small value capacitors, worth it?

Post by wahee » Mon Feb 10, 2020 4:36 am

canister style radial aluminum jobs.

I knew the caps were NOS, I was just a bit surprised to find out how old they were
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